SOCIALIST REPUBLIC OF VIET NAM

 

 

 

 

QCVN 123:2021/BTTTT

 

AMENDMENT 1:2025 QCVN 07:2023/BXD

ON SHORT-RANGE WIRELESS DEVICES WITH FREQUENCY RANGE FROM 40 GHz TO 246 GHz

 

National technical regulation

on Short Range Device (SRD) - Radio equipment to be used

in the 40 GHz to 246 GHz frequency range

 

 

                                          

 

 

 

 

                                    

 

 

 

 

 

 

 

 

 

 

 

 

HANOI - 2021

 

Table of Contents

 

1. GENERAL PROVISIONS... 5

1.1. Scope of Application... 5

1.2. Applicability... 5

1.3. Referenced Documents... 5

1.4. Definitions... 6

1.5. Symbols... 7

1.6. Abbreviations... 8

2. TECHNICAL REQUIREMENTS... 8

2.1. Requirements for the Transmitter Section... 9

2.1.1. Output RF Power... 9

2.1.2. Authorized Frequency Band... 9

2.1.3. Out-of-Band Emission... 10

2.1.4. Spurious Emission... 11

2.2. Requirements for the Receiver Section... 13

2.2.1. Unwanted Emission... 13

3. TESTING METHODS... 13

3.1. Testing Requirements... 13

3.1.1. Testing Environment Conditions... 13

3.1.2. Sample Selection for Testing... 14

3.1.3. Interpretation of Test Results... 14

3.1.4. Testing Above 110 GHz... 15

3.2. Testing for the Transmitter Section... 15

3.2.1. Output RF Power Measurement... 15

3.2.2. Authorized Frequency Band Measurement... 16

3.2.3. Out-of-Band Emission Measurement... 17

3.2.4. Spurious Emission Measurement... 18

3.3. Testing for the Receiver Section... 19

4. MANAGEMENT REQUIREMENTS... 20

5. RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS... 20

6. IMPLEMENTATION... 20

Appendix A (Requirements) Radiation Measurements... 21

Appendix B (Requirements) General Conditions... 24

Appendix C (Requirements) General Conditions... 33

Appendix D (Requirements) Harmonized System (HS) Code for Short-Range Wireless Devices with Frequency Range from 40 GHz to 246 GHz... 36

 

Appendix E (Reference) Technical Specifications and Testing Methods for Short-Range Wireless Devices Operating in the 57 GHz to 64 GHz Frequency Range... 37

 

Bibliography... 42

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AMENDMENT 1:2025 QCVN 07:2023/BXD

 

ON SHORT-RANGE WIRELESS DEVICES WITH FREQUENCY RANGE FROM 40 GHz TO 246 GHz

National technical regulation
on Short Range Device (SRD) – Radio Equipment to be Used
in the 40 GHz to 246 GHz frequency range

 

 

Chapter 1. GENERAL PROVISIONS

1.1. Scope of Application

This regulation applies to various types of short-range wireless transmitting and receiving devices (SRD), including: wireless alarm devices, wireless remote control devices, wireless remote measuring devices, general data transmission devices, operating within the frequency range from 40 GHz to 246 GHz as specified in Table 1 of this regulation for the following cases:

- With a wireless output connected to a separate antenna or integrated antenna;

- Using any type of modulation;

- Fixed, mobile, and handheld devices.

Table 1 - Frequency Bands for Short-Range Wireless Devices with Frequency Range from 40 GHz to 246 GHz

This regulation applies to products and goods that are short-range wireless devices with HS codes specified in Appendix D.

1.2. Applicability

This regulation applies to domestic and foreign organizations and individuals engaged in production and business activities involving devices within the scope of this regulation on the territory of Vietnam.

1.3. Referenced Documents

ETSI TR 100 028 (V1.4.1) (all parts): "Electromagnetic Compatibility and Radio Spectrum Matters (ERM); Uncertainties in the Measurement of Mobile Radio Equipment Characteristics".

CEPT/ERC Recommendation 74-01: "Unwanted Emissions in the Spurious Domain", Hradec Kralove, Cardiff 2011.

Recommendation ITU-R SM.329-12 (09/2012): "Unwanted Emissions in the Spurious Domain, SM Series, Spectrum Management".

CISPR 16 (2006) (parts 1-1, 1-4 and 1-5): "Specification for Radio Disturbance and Immunity Measuring Apparatus and Methods".

 

ETSI TR 102 273 (V1.2.1) (all parts): "Electromagnetic Compatibility and Radio Spectrum Matters (ERM); Improvement on Radiated Methods of Measurement (using test site) and Evaluation of the Corresponding Measurement Uncertainties".

Recommendation ITU-T O.153: "Basic Parameters for the Measurement of Error Performance at Bit Rates Below the Primary Rate".

ETSI TS 103 052: "Electromagnetic Compatibility and Radio Spectrum Matters (ERM); Radiated Measurement Methods and General Arrangements for Test Sites Up to 100 GHz".

1.4. Terms and Definitions

1.4.1. Alarm (alarm)

The use of radio signals to indicate an alarm condition at a remote location.

1.4.2. Artificial Antenna (artificial antenna)

A non-radiating load with an impedance equal to the high-frequency output impedance of the device being measured, as specified by the manufacturer.

1.4.3. Assigned Frequency Band (assigned frequency band)

The frequency band in which the device is permitted to operate to perform all functions as designed.

1.4.4. Dedicated Antenna (dedicated antenna)

Detachable antennas and those designed as an integral part of the device must be tested with radio equipment.

1.4.5. Direct Sequence Spread Spectrum (direct sequence spread spectrum)

The modulated product is obtained from the combination of data to be transmitted and a fixed code sequence used for direct modulation of the carrier wave, for example, by phase shifting.

NOTE: The coding rate determines the occupied bandwidth.

1.4.6. Environmental conditions (environmental profile)

The operational environmental conditions that devices within the scope of this standard must comply with.

1.4.7. Fixed Station (fixed station)

A device intended for stationary use at a single location.

1.4.8. Frequency Hopping Spread Spectrum (frequency hopping spread spectrum)

A spread spectrum technique where the transmitted signal sequentially occupies different frequencies over time, each frequency occupying a specific time interval according to a predetermined schedule.

NOTE: Both the transmitter and receiver use the same hopping pattern. The number of hop positions and the bandwidth for each hop position determine the occupied bandwidth.

1.4.9. Integral Antenna (integral antenna)

A fixed antenna attached to the device and designed as an integral part of it.

1.4.10. Mobile Station (mobile station)

A device mounted on mobile platforms or used as a mobile station.

Necessary Bandwidth (necessary bandwidth)

The width of the emission band sufficient to transmit information at the required speed and quality.

NOTE: The necessary bandwidth includes the frequency tolerance relative to the assigned band.

1.4.12. Occupied Bandwidth (occupied bandwidth)

The width of the band wherein the average power emitted at frequencies below the lower limit and above the upper limit of the band is 0.5% of the total average transmission power.

NOTE: The value corresponds to -23 dBc relative to the peak emission power.

1.4.13. Operating Frequency (operating frequency)

The nominal operating frequency of the device, considered as the central operating frequency.

NOTE: The device may operate across multiple bands.

1.4.14. Operating Frequency Range (operating frequency range)

The range of frequencies within which the device can be adjusted by tuning, switching, or reprogramming.

1.4.15. Portable Station (portable station)

A device that can be carried while moving.

1.4.16. Power Spectral Density (power spectral density)

The ratio of power to bandwidth measured in radio usage.

NOTE: The unit of power spectral density is dBm/Hz or dBm for the used bandwidth. In case of measurement using a spectrum analyzer, the measurement bandwidth equals RBW.

1.4.17. Radiated Measurements (radiated measurements)

Measurements related to the radiation field.

1.4.18. Spread Spectrum (spread spectrum)

A modulation technique in which the energy of the transmitted signal is spread over a wide frequency band.

1.4.19. Ultra-Low Power Equipment (ultralow power equipment) Equipment using a transmission power envelope below the threshold of the receiver and transmitter in idle mode as specified in Table 5 of the CEPT/ERC Recommendation 74-01.

1.4.20. Unwanted Emissions

(unwanted emissions) Emissions on a frequency or multiple frequencies outside the necessary bandwidth that can be reduced without affecting the transmission of information.

NOTE: Unwanted emissions include harmonic emissions, parasitic emissions, modulation components, and frequency conversion components.

1.5. Symbols

dBc

Bandwidth

Chapter 2. TECHNICAL PROVISIONS

Technical requirements of this standard apply in the operational environment published by the manufacturer. The device must comply with all technical requirements of this standard when operating within the limits of the published operational environmental conditions.

2.1. Provisions for the Transmission Section

2.1.1. RF Output Power

2.1.1.1. Definition

RF output power is the average isotropic equivalent radiated power (e.i.r.p.) during the transmission of a data packet. For devices implementing power control, the average e.i.r.p. is the highest power level in the power control sequence during the transmission cycle.

2.1.1.2. Limits

The maximum RF output power corresponds to the system operating at the highest published power level. For smart antennas and directional antennas, this limit corresponds to the configuration achieving the highest e.i.r.p.

The maximum RF output power limit in broadband operation shall not exceed the values specified in the table below.

Table 2 - Maximum RF Output Power Limit

2.1.1.3. Measurement Method

The measurement method is specified in 3.2.1.

2.1.2. Authorized Frequency Range

2.1.2.1. Definition

The authorized frequency range is the band within which the device operates. The manufacturer must publish the authorized frequency range.

Let f_{nh cơ} be the lowest operating frequency, let f_H is the highest operating frequency. If the device can operate in different modes and on different frequency bands, these frequencies must be recorded for each mode and each band.

2.1.2.2. Limits

The frequency range of the device is from the lowest frequency (f_{nh cơ}) to the highest frequency (f_H) limited by the power spectrum envelope. In devices that allow adjustment or selection of different operating frequencies, the power envelope occupies different positions within the allocated bandwidth. This frequency range is determined by the lowest value f_{nh cơ} and the highest value f_H, determined from the adjustment of the device from the lowest operating frequency to the highest operating frequency.

The occupied bandwidth (at 99% of the desired emission power) and the necessary bandwidth must be within the assigned bandwidth.

The permitted operating frequency range of the device must fall within the frequency bands specified in Table 1 of this Standard.

2.1.2.3. Measurement Method

The measurement method is specified at 3.2.2.

2.1.3. Out-of-Band Emission

According to the recommendation of CEPT/ERC 74-01 and ITU-R SM.329-12, the boundary between the out-of-band emission region and the spurious emission region is ±250% of the necessary bandwidth from the center emission frequency.

2.1.3.1. Definition

Out-of-band emission is emission on one or more frequencies outside the necessary bandwidth, resulting from modulation processes, but does not include spurious emissions.

Out-of-band emission is determined based on the measurement of the average spectral density (e.i.r.p.) under normal operating conditions.

The measurement results of f_H and f_{nh cơ} are used to determine the occupied bandwidth of the device.

The occupied bandwidth value (f_H - f_{nh cơ}) is used to determine the out-of-band emission region and the spurious emission region.

2.1.3.2. Limits

The edge values of the out-of-band emission region and the spurious emission region depend on the occupied bandwidth of the EUT.

The edge limits are determined as follows:

F₁ = center frequency of OBW [GHz] - (2.5 * (f_H - f_{nh cơ}))

F₂ = center frequency of OBW [GHz] + (2.5 * (f_H - f_{nh cơ}))

Where, the center frequency of OBW is the center frequency of the signal.

This calculation is used to determine the edges of the out-of-band emission and spurious emission regions, which will be greater/smaller than the maximum allowed value in the operational frequency range (see Figure 1).

 

 

Figure 1 - Overview of the dependence of OOB/spurious emission on OBW

Additionally, F₁/F₂ can be calculated as follows: If considering F₁/F₂ as the frequencies below or above theoretically, their values are calculated based on 250% of the maximum value of OBW (see Table 2). Therefore, the amplitude edge between OOB/spurious emission will be fixed at the frequency given in Table 3 below (typically F₁/F₂ is calculated as 250% of the signal center frequency).

Table 3 - Limit value tChapter number F₁ and F₂, based on the theoretical maximum OBW of EUT
center

≤ f < f₁ < f ≤ F_{nh cơ} and f_H ) shall not exceed the values specified in Tables 4 and 5 below.₂Table 4 - Out-of-Band Emission Region

Frequency [GHz]

 

OOB Limit

The measurement method is specified at 3.2.3

2.1.4. Spurious Emission

2.1.4.1. Definition

Spurious emission is emission on one or more frequencies outside the necessary bandwidth whose value can be reduced without affecting information transmission. Spurious emission includes harmonic emission, parasitic emission, modulated components, and frequency conversion components, but does not include out-of-band emission.

Spurious emission is measured as the power spectral density under normal operating conditions. According to the recommendation of CEPT/ERC 74-01 and ITU-R SM.329-12, the boundary between the spurious emission region and the out-of-band emission region is ±250% of the necessary bandwidth of the center frequency emission.

The frequency ranges evaluated in the spurious emission region are:

- Frequency f < F

[GHz]₁ - Frequency f > F

and

[GHz].₂ The determination of the values of these frequencies is described in 2.1.3.2, with the minimum and maximum values listed in Table 3 above.

2.1.4.2. Limits

The power of spurious emission shall not exceed the values specified in Table 6 below.

                                                      Table

Spurious Emission Limit 6 - Frequency Range (MHz)

 

The measurement bandwidth is defined as follows:

• 100 kHz between frequencies from 30 MHz to 1 GHz;

• 1 MHz for frequencies above 1 GHz.

2.1.4.3. Measurement Method

The measurement method is specified at 3.2.4.

2.2. Provisions for the Receiver Section

2.2.1. Unwanted Emission

2.2.1.1. Definition

Unwanted emission from the receiver is radiation at any frequency by the equipment and antenna. The value of unwanted emission must be measured by the effective radiated power level including: Enclosure radiation and integrated equipment or with dedicated antennas.

2.2.1.2. Limits

Unwanted emission power:

- Shall not exceed 2 nW (-57 dBm) in the frequency range 30 MHz to 1 GHz;

- Shall not exceed 20 nW (-47 dBm reference bandwidth 1 MHz) in the frequency range above 1 GHz.

- Shall not exceed 20 nW (-47 dBm reference bandwidth 1 MHz) in the frequency band above 1 GHz.

The upper frequency limit is the second harmonic of EUT or 300 GHz, whichever is lower.

Measured unwanted emissions must be recorded in the measurement results.

2.2.1.3. Measurement Method

The measurement method is specified at 3.3.

3. MEASUREMENT METHODS

 

3.1. Measurement Requirements

3.1.1. Environmental Measurement Conditions

Measurements prescribed in this standard must be carried out within the environmental measurement condition limits.

3.1.1.1. Normal Measurement Conditions

3.1.1.1.1. Temperature and Humidity

Normal temperature and humidity conditions for measurements must fall within the following range:

- Temperature: from +15°C to +35°C; ⁰- Humidity: from 20 % to 75 %. ⁰3.1.1.1.2. Normal Measurement Power Supply

a) Main Alternating Voltage

The voltage source connected to the test equipment must be the rated voltage. Within the scope of this standard, the rated voltage is the voltage published by the manufacturer, or the voltage for which the equipment is designed to operate.

The frequency of the alternating current power supply voltage must be within the range of 49 Hz to 51 Hz.

b) Other Power Supplies

In cases where the measuring device uses other power sources or batteries (primary or secondary), the test voltage supplied by the manufacturer must be accepted by the testing laboratories. These values must be recorded in the measurement results.

3.1.1.2. General Requirements for Measurement Power Supply

Equipment must be tested using appropriate measurement power supplies as specified in 3.1.1.2.1 or 3.1.1.2.2. If the equipment being tested can use both external and internal power sources, external power should be used for testing, followed by repeating the test using internal power.

3.1.1.2.1. External Measurement Power Supply

Throughout the testing process, the equipment's power supply must be replaced with an external measurement power supply capable of providing normal measurement voltage. The internal impedance of the external measurement power supply must be sufficiently low and controlled to not affect the measurement results. During this measurement, the external power supply voltage must be measured at the equipment inputs. External power supplies must be isolated appropriately and implemented as battery terminals within the equipment. For radiation measurements, external sources must be arranged to have minimal impact on the measurements.

Throughout the testing process, the power supply voltage tolerance must remain within ±1 % of the voltage at the start of each measurement. Reducing voltage tolerance will decrease measurement error.

3.1.1.2.2. Internal Measurement Power Supply

For radiation measurements on handheld devices with built-in antennas, the equipment must use fully charged batteries. Battery types must be provided according to the manufacturer's recommendations. If an internal power source is used, after testing, the power supply voltage tolerance must remain within ±5 % of the voltage at the start of each measurement. If these requirements are not met, this value must be recorded in the measurement results.

In fixed testing positions, an external power supply may replace the internal battery provided or recommended by the manufacturer. This information must be recorded in the measurement results.

3.1.2. Sample Selection for Testing

For individual devices, testing must include all auxiliary equipment. If the device has optional functions that do not affect high-frequency RF parameters, only testing with a configuration combining all complex features is required.

3.1.3. Interpretation of Measurement Results

The interpretation of results in the measurement report for measurements described in this standard is as follows:

1) Compare the measured value with the corresponding limit to determine if the equipment meets the requirements of the standard;

2) The uncertainty of measurement for each parameter measured must be shown in the measurement report;

3) The uncertainty of measurement recorded for each measurement must be equal to or less than the values specified in Table 7.

For the measurement methods in this standard, the uncertainty of measurement must be calculated according to the guidance in TR 100 028 and correspond to the expansion factor (coverage factor) k = 1.96 or k = 2 (for confidence levels of 95 % and 95.45 % respectively, assuming a Gaussian distribution of actual measurement errors).

The specific expansion factor used to calculate the uncertainty of measurement must be clearly stated.

Table 7 - Maximum Uncertainty of Measurement

Maximum Uncertainty of Measurement

RF Frequency

Currently available calibration capability is limited to the band around 110 GHz. Therefore, measurement results above 110 GHz from different laboratories may not be completely comparable due to the lack of calibration equipment for the necessary operating frequency bands.

3.2. Testing for Transmitter Section

3.2.1. RF Output Power Measurement

3.2. Measurement for the transmitter section

3.2.1. Measurement of RF output power

The RF output power, depending on the conditions as specified in 3.1.1, is measured using the test positions described in Section B.2 of Appendix B and recorded in the measurement method. All devices to be tested must be set with the central frequency within the defined bands.

Step 1:

a) Using appropriate attenuators, the measuring device must be connected to an appropriate diode splitter or equivalent equipment. The output of the diode splitter is connected to the Y channel of the signal generator or equivalent power measuring equipment.

b) The combination of the diode splitter and the oscilloscope must be capable of displaying the duty cycle of the transmitter's output signal.

c) The observed duty cycle (Tx_on/(Tx_on + Tx_off)) is denoted as x (0 < x ≤ 1) and must be recorded in the test results. For testing purposes, the device must operate with a duty cycle greater than or equal to 0.1.

Step 2:

a) The RF output power of the transmitter when operating at maximum power level must be measured using a spectrum analyzer with an integration factor greater than or equal to five times the transmitter's repetition period. Use the average RMS demodulation mode. The observed value is recorded as "A" (dBm).

b) The EIRP value is calculated from the measured power level A (dBm) and the observed duty cycle x, according to the following formula.

c) PD = A + 10 × log₁₀ (1/x).

3.2.2. Measurement of the permitted operating frequency band

3.2.2.1. Measurement Method

The measurement method must be recorded in the test results.

The measurement methods for devices using FHSS modulation are specified in 3.2.2.2.

Use the following measurements corresponding to the transmission frequency bands and record the measured values in the test results. In cases where applicable, when performing test data sequences as prescribed in B.1 and B.1.1 of Appendix B.

The transmitter power level must be set to the maximum power level.

The testing procedure is carried out as follows:

a) Set the spectrum analyzer to the average display mode with a minimum scan step of 50.

b) Select the lowest operating frequency of the device under test and activate the transmitter in the modulation mode. The RF emission of the device must be displayed on the spectrum analyzer.

c) Using the marker of the spectrum analyzer, find the frequency lower than the lowest operating frequency at which the power spectral density drops below the threshold value specified in 2.1.2. This frequency is recorded in the test results.

d) Choose the highest operating frequency of the device under test and determine the highest frequency at which the power spectral density drops below the threshold value specified in 2.1.2. This frequency is recorded in the test results.

e) The difference between the frequencies measured in steps c) and d) is the operating frequency band. This value must be recorded in the test results.

This measurement must be repeated for each frequency band as published by the manufacturer.

3.2.3.2. Measurement method for devices using FHSS modulation

Use the following measurements corresponding to the transmission frequency bands and record the measured values in the test results.

During the tests, test data sequences are performed as prescribed in B.1 of Appendix B. The transmitter power level must be set to the rated power level.

The testing procedure is carried out as follows:

a) Set the spectrum analyzer to the average display mode with a minimum scan step of 50.

b) Select the lowest hopping frequency of the device under test and activate the transmitter in the modulation mode.

c) Find the frequency lower than the lowest operating frequency at which the power spectral density drops below the threshold value specified in 2.1.2. This frequency is recorded in the test results.

d) Select the highest hopping frequency of the device under test and determine the highest frequency at which the power spectral density drops below the threshold value specified in 2.1.2. This frequency is recorded in the test results.

e) The difference between the frequencies measured in steps c) and d) is the operating frequency band of the device. This value must be recorded in the test results.

This measurement must be repeated for each frequency band as published by the manufacturer.

3.2.3. Out-of-band emission measurement

The receiving instrument is either a voltmeter or a spectrum analyzer. The receiver bandwidth is set according to CISPR 16. To achieve the required sensitivity, a narrower measurement bandwidth may be necessary, this value must be recorded in the test results.

The settings for the spectrum analyzer are as follows:

- Resolution Bandwidth (RBW): See Table 8.

- Video Bandwidth (VBW) ≥ 3 MHz.

- Detector Mode: RMS/Hz averaged over a minimum period of one signal cycle (maximum 100 ms)

The spectrum measured at the spectrum analyzer is recorded within a relative amplitude range of 35 dB. There is no requirement to perform the measurement when the average power spectral density is below -40 dBm/MHz (e.i.r.p.).

The receiver bandwidth must be less than the maximum value indicated in Table 8.

Table 8 - Measurement Bandwidth

 

The test position is selected as per Appendix A, this measurement uses the full frequency range to meet specific requirements. The measurement method is described in Appendix C. The receiver bandwidths must be set to appropriate values to accurately measure unwanted emissions. This bandwidth must be recorded in the test results.

For frequencies above 40 GHz, use a frequency divider as described in Figure 2. An internal oscillator is used to reduce the received signal frequency with phase noise better than -80 dBc/Hz at 100 kHz offset. The frequency of the internal oscillator is chosen so that the signal after the frequency divider falls within the operating band of the spectrum analyzer while maintaining the full IF bandwidth to capture the entire frequency spectrum of the signal. The EIRP value of the EUT must be measured and recorded.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Normal mode out-of-band emissions of the signal must be measured and recorded on adjacent frequency bands to the specified operating frequency band in Table 1, up to the frequency where the emission level is 50 dB below the maximum emission level.

3.2.4. Spurious Emission Measurement

This measurement method applies to transmitters with integral antennas.

a) This measurement requires the use of the full defined frequency range.

a) In this measurement, all specified frequency bands must be fully utilized.

The initial antenna is oriented vertically polarized and connected to the receiver through an appropriate filter to prevent overload of the receiver if necessary. The bandwidth of the receiver is adjusted to a level such that its reception sensitivity is 6 dB lower than the unwanted emission limit indicated in Table 3, Section 2.1.3.2. This bandwidth is recorded in the measurement results.

To measure spurious emissions below the second harmonic of the carrier frequency, a sharp filter ("Q" notch filter) centered at the carrier frequency with a minimum signal loss of approximately 30 dB must be used.

The transmitters for testing must be placed on stands in standard positions and will be set to unmodulated mode (see Appendix B, Part B.1). If modulation cannot be stopped and the measurement must be performed in modulated mode, this must be recorded in the measurement results.

b) The receiver must be calibrated from 30 MHz to 2.2 times the carrier frequency, except for channels designed for the transmitter's operation. The frequency of each detected unwanted emission is recorded. If the measurement positions are interfered with from outside, to obtain better values, the screen is expanded and the distance between the transmitter and the test antenna is reduced.

c) At each frequency where an emission appears, the receiver must be adjusted and the test antenna raised or lowered within the specified height range until the maximum signal level appears on the receiver.

d) The transmitters are rotated 360° around the vertical axis to maximize received signals.

e) The test antennas are raised or lowered again within the specified height range to the maximum received level. This level is recorded.

f) At each frequency where an emission appears, the signal generators, replacement antennas, and receiver must be adjusted. The test antenna is raised or lowered within the specified height range until the maximum signal level appears on the receiver. The level of the signal generator for the similar signal level on the receiver as in e) is recorded. After additional calibration of the gain of the replacement antenna and cable loss between the signal generator and the replacement antenna, this is the unwanted emission at this frequency.

g) The frequencies and levels of each detected emission and the receiver's bandwidth must be recorded in the measurement results.

h) Steps c) to g) must be repeated with the test antenna oriented horizontally polarized.

i) If power adjustment features are used, steps c) to h) of the measurement must be repeated at the lowest power level.

j) Steps c) to h) must be repeated with the transmitter in standby mode if this option is available.

The sensitivity of the spectrum analyzer is indicated with a minimum noise floor of 6 dB below the limit specified in Table 5. To improve the receiver's sensitivity, the measurement bandwidth may be reduced or the measurement distance may be decreased. If this is not feasible, the noise floor in the measurements will be recorded in the measurement results.

According to Recommendation 3 of CEPT/ERC 74-01, the limits for spurious emissions apply to the frequency range from 9 kHz to 300 GHz. However, depending on specific conditions, the frequency bands for spurious emission measurements may be limited while still ensuring compliance with the limits. Refer to Recommendation 3 of CEPT/ERC 74-01 for further guidance.

NOTE: High-frequency measurements may not have a way to determine measurement uncertainty due to the lack of primary reference materials. Additionally, simplifying the measurement technique further to save time/costs, while still ensuring compliance with requirements, may be considered.

3.3. Receiver Testing

a) This measurement requires the use of the full defined frequency range.

a) In this measurement, full use of the test positions for the determined frequency bands must be required.

The initial test antenna is oriented vertically polarized and connected to the receiver through an appropriate filter to prevent overload of the receiver if necessary. The receiver's bandwidth must be adjusted until its sensitivity is at least 6 dB below the unwanted emission limit specified in Clause 3.2.3. This bandwidth will be recorded in the measurement results.

The testing equipment must be placed on stands in standard positions.

 b) The receiver must be calibrated from 30 MHz to 2.2 times the carrier frequency. The frequency of each detected unwanted emission is recorded. If the measurement positions are interfered with from outside to obtain better values, the screen is expanded and the distance between the transmitter and the test antenna is reduced.

 c) At each frequency where a component appears, the receiver must be adjusted and the test antenna raised or lowered within the specified height range until the maximum signal level appears on the receiver.

d) The receivers are rotated 360° around the vertical axis to maximize received signals.

e) The test antennas are raised or lowered again within the specified height range to the maximum received level. This level is recorded.

f) At each frequency where a component is detected, the signal generators, replacement antennas, and receiver must be adjusted. The test antenna is raised or lowered within the specified height range until the maximum signal level appears on the receiver. The level of the signal generator for the similar signal level on the receiver as in e) is recorded. After additional calibration of the gain of the replacement antenna and cable loss between the signal generator and the replacement antenna, this value is the unwanted radiation component at this frequency.

g) The frequencies and levels of each detected emission and the receiver's bandwidth must be recorded in the measurement results.

h) Measurements from c) to g) must be repeated with the test antenna oriented horizontally polarized.

According to Recommendation 3 of CEPT/ERC 74-01, the limits for spurious emissions for the radio devices under consideration apply up to 300 GHz. However, for practical measurement purposes, the frequency bands for spurious emission measurements may be limited. For further guidance, refer to Recommendation 3 of CEPT/ERC 74-01.

5. RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS

4.1. Short-range common radio equipment within the scope regulated under Article 1.1 must comply with the provisions set forth in this standard.

4.2. The technical requirements measurement for conformity certification and declaration of conformity under this standard shall be carried out in accordance with current regulations. Organizations and individuals are permitted to use testing/calibration results from domestic laboratories designated, foreign laboratories recognized, or domestic and foreign laboratories certified in compliance with ISO/IEC 17025 standards, or manufacturer testing/calibration results.

 

5. RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS

Relevant organizations and individuals are responsible for implementing the provisions on conformity certification and declaration of conformity for equipment within the scope of application of this standard and are subject to inspection by state management agencies in accordance with current regulations.

6. IMPLEMENTATION ORGANIZATION

6.1. The Telecommunications Administration, the Radio Frequency Management Department, and Provincial Departments of Information and Communications are responsible for organizing the implementation, guidance, and management of equipment within the scope of application under this standard.

6.2. In case there are changes, additions, or replacements to the provisions stated in this standard, they shall be implemented according to the new document.

6.3. During the implementation of this Standard, if any issues arise or difficulties occur, relevant organizations and individuals should reflect them in writing to the Ministry of Information and Communications (Science and Technology Department) for guidance and resolution.

ANNEX A

Product Name, Goods According to QCVN

Radiation measurements

 

A.1. Substitution measurement

Substitution measurement can be used without ensuring the suitability of the test position because the error at certain frequencies will be constant and can be compensated through substitution measurement. The accuracy of the measurement mainly depends on the accuracy of the RF source parameters and the gain value of the substitution antenna.

A.1.1. Principle of substitution measurement

When evaluating radiated power using substitution measurement, the peak power value can be determined.

Using the "comparison test position" error evaluation method reduces the uncertainty of measurement. However, this method increases the measurement time due to the need to determine multiple parameters for each EUT.

Figure A.1 illustrates the "comparison test position" suitable method. Figure A.1 includes: an antenna without power absorption parameters (1) providing a wide enough angle, with a support allowing height adjustment (2), an antenna connection cable (3), and a display device such as a receiver meter or spectrum analyzer or power meter (4).
Figure A.1 - First step of substitution measurement

 

In the first step of substitution measurement, the maximum emission level of the EUT is determined. This level has no unit and does not represent the measured value. It provides a reference value.

 

The substitution measurement position in Zone 2 of Figure A.2 includes an unmodulated transmitter capable of frequency and power adjustment, with power values that can be evaluated through calibration or comparison with a calibrated meter (1), a 50 Ω cable with appropriate loss indices (2), a loss adapter (3) connecting to the antenna, including real resistances, an antenna support that does not affect the test results (4), and a dipole antenna up to 1 GHz or an antenna with calibrated gain, equivalent isotropic gain (5).

Figure A.2 - Second step of substitution measurement

 

 

 

For the measurement frequencies, in the second step, the transmitter emits power levels corresponding to the index values in the first step.

A.2. Pre-substitution measurement

 

Pre-substitution measurement is a simplified process that cannot change the substitution method. It is only feasible when the measurement position is proven suitable for the specific frequency range being tested between 30 MHz to 100 GHz. Correspondence verification can be performed using the NSA or VSWR method.

This verification is difficult to perform at measurement positions other than outdoor test sites (OATS) due to the combined effects of metal shielding resonance and radio wave absorbing materials, resulting in six reflective surfaces compared to one surface of OATS._{See Article 5 of TR 102 273-2.}Another common drawback is that even with sufficient frequency steps, it must be interpolated between these steps, leading to increased measurement uncertainty.

A.2.1. Principle of radiated power measurement based on measurement position loss

Pre-substitution measurement can evaluate peak radiated power and other types of radiated power.

Due to the influence of the measurement position and measuring equipment, this method increases measurement uncertainty, which is equivalent to field strength measurement in CISPR 16. To ensure measurement results are close to threshold values, re-evaluation and additional substitution measurement are required.

To determine the measurement position loss, a suitable measurement position meeting the requirements of CISPR 16-1-4 and an RF source are needed. This source includes a calibrated dipole antenna up to 1 GHz or an antenna with equivalent isotropic gain already calibrated (1), an antenna support that does not affect test results (2), a calibrated matching network (3) compatible with the antenna's adaptation coefficient, comprising positive resistors, a 50 Ω cable with appropriate loss indices (4) and an unmodulated transmitter capable of frequency and power adjustment, with power values that can be evaluated through calibration or comparison with a calibrated meter (5).

Additionally, power measurement devices are also required, including: an antenna with specified gain parameters (6), an adjustable height support (7), a 50 Ω cable with specified loss indices (8) and a calibrated receiver meter (9).

To determine the measurement point attenuation, a measurement setup that complies with the requirements of CISPR 16-1-4 and a radio frequency (RF) source are required. The source includes a standard dipole antenna up to 1 GHz or an antenna with equivalent isotropic radiated power (EIRP) calibration (1), an antenna mount that does not affect the test results (2), a calibrated attenuator (3) suitable for the antenna's matching coefficient, comprising active resistors, a 50 Ω cable with appropriate cable loss indicators (4), and an unmodulated signal generator capable of frequency and power adjustment, whose power value can be determined through calibration or comparison with a calibrated meter (5).

Additionally, power measuring equipment is required, including: An antenna with specified gain parameters (6), an adjustable height stand (7), a 50 Ω cable with specified loss indicators (8), and a calibrated receiver meter (9).

Antenna (1) must be placed at the greatest possible distance, at a height equivalent to the height of the Equipment Under Test (EUT) before replacement based on measurement parameters. It should be noted that the polarization of both antennas used must be identical. The known radiation power is generated at the RF source output. Measurement antennas will be adjusted to the height where the measured power index at the receiver is highest (9). This power will be recorded. The difference between transmission power and reception power in dB is the attenuation at the measurement location. The determination of the attenuation at the measurement location must be carried out with all frequency steps within the evaluation frequency band, and these values must be recorded.

 

 

 

 

 

 

 

 

 

 

 

 

Figure A.3 - Example of a measurement location based on measurement location attenuation

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure A.4 - Example of a measurement location based on measurement location attenuation

In practical measurements, the radiation power is determined by the measured value and the attenuation value at the measurement location according to the unit.

Provisions on the HS Code of Terrestrial Mobile Radio Equipment and Terrestrial Radio Relay Equipment

Product Name, Goods According to QCVN

General Conditions

B.1. Measured Signal and Modulation Process

The measured modulation signal is the signal used to modulate the carrier wave, depending on the type of equipment being tested and the required measurement. The measured modulation signal only applies to devices with external modulation connectors. For devices without external modulation connectors, internal modulation of the device is used for testing.

The measured signal has the following characteristics:

- Represents normal operation.

- Occupies the largest RF bandwidth.

For non-continuous transmitting devices, the measured signal must:

- Generate the same RF signal for each transmission path.

- Maintain stable transmission over time.

- Repeat the transmission sequence accurately.

Detailed information about the measured signal must be recorded in the test results.

If there is no regulation for external modulation testing, then internal modulation of the device is used for testing.

B.1.1. Measured Signal for Data Transmission

For devices with external data modulation connectors, the measured signal must be as follows:

D-M2: The test signal is a pseudo-random binary sequence consisting of at least 511 bits, continuously repeated, in accordance with ITU-T recommendation O.153. If the signal sequence is not continuously repeated, the actual method applied must be clearly stated in the test results.

D-M3: When selective signaling is used, accompanied by encoding/decoding units in the testing equipment, there must be agreement between the equipment supplier and the testing laboratory regarding the test signal. This test signal may be formatted and may contain error detection and correction coding.

B.1.2. Product Information

The following parameters must be published by the equipment manufacturer to perform measurements and declare compliance:

a) Operating frequency channels: These are the central frequencies that the EUT can adjust. If the device supports multiple sub-channels (for example, allowing operation with different channel widths), these frequency channels must be disclosed.

b) Types of modulation used by the EUT.

c) Access methods used by the EUT.

d) Description of integrated antennas used by the device and measures to prevent users from connecting to another antenna.

B.1.3. Testing for Frequency-Hopping Devices

Testing must be conducted at frequencies within ±20 ppm of the highest and lowest hopping frequencies. For special frequency-hopping devices, three separate tests must be performed under the above conditions, specifically as follows:

a) The hopping sequence is stopped, and the device is tested on two different channels as described above.

b) The hopping sequence is active, and the device is tested with two hopping channels as described above, accessed sequentially, with an equal number of accesses per measurement.

c) The hopping sequence operates normally, and the device is tested with all hopping channels as specified by the manufacturer.

B.2. Measurement Area and Radiation Measurements

B.2.1. Measurement Box

B.2.1.1. Requirements

The measurement box for radio equipment operating in the relevant frequency range allows the EUT to be supported fundamentally, together with a horn-type receiving antenna (Rx), used to measure transmitted energy, in a physical relationship with a fixed position relative to the EUT or to a calibrated transmitting antenna (Tx). The measurement box must be designed for use in both reflective-free environments and remote areas, i.e., distances greater than 2d/l, where d is the largest aperture size of the EUT's antenna.²The measurement box must incorporate at least one RF connector, a device with electromagnetic couplings to the EUT, and a device to locate the EUT's position. The stability of this equipment must be maintained throughout the entire testing process and will be suitable in reflective-free rooms, typically air-conditioned rooms. The circuits combined with RF coupling devices must not contain active electrical components or nonlinear elements.

Only after confirming that the measurement box does not affect the operation of the EUT can the EUT be fully prepared for testing.

During the preparation phase, the EUT must be connected to the measurement box so that the power at the output is maximized. The antenna orientation will be included in the EUT's polarization data.

Additionally, the measurement box must provide a connection to an external power supply.

The measurement box must be provided by the equipment manufacturer along with comprehensive documentation, which will be evaluated and selected by an accredited testing laboratory.

The operational characteristics of the measurement box must be measured and selected by an accredited testing laboratory. It has the following appropriate and basic parameters:

- The gain of the horn waveguide does not exceed 20 dB;

- The minimum distance between the transmitting antenna and the receiving antenna must ensure mutual interaction in real conditions (greater than 2d/l), where d is the largest aperture size of the EUT's antenna).

NOTE 1: Information on measurement uncertainty and verification procedures is detailed in Articles 5 and 6 of standard TR 102 273-6.²/l), where d is the largest aperture dimension of the EUT antenna).

NOTE 1: Information on measurement uncertainty and verification procedures is detailed in Articles 5 and 6 of the TR 102 273-6 standard.

NOTE 2: The remote field conditions for establishing measurement setups must be carefully considered within the frequency bands specified in this standard. The voltage standing wave ratio (VSWR) during measurement shall not exceed 1.5 at the waveguide flanges.

- The performance of the measurement set when placed in a fully reflective test chamber or in a temperature-controlled test chamber shall not be affected by human or object contact inside the test chamber. Measurement can be repeated after the EUT is replaced and removed;

- The performance of the measurement set shall remain within the limits indicated in the calibration report when measurement conditions change within the limits described in 3.1.1.2 and 3.1.1.3. The characteristics and calibration of the measurement set must be reflected in the calibration report.

B.2.1.2. Calibration

Calibration of the measurement set establishes the relationship between the output from the measurement set and the transmitted power (as sampled at an antenna position) from the EUT in the measurement set. This can be achieved using an antenna with gain equal to or less than 20 dB, provided by an external signal source, where the EUT will determine the power values changing with temperature and frequency.

Calibration of the measurement set must be performed by each EUT manufacturer or in an accredited test laboratory. These results must be accepted by accredited test laboratories.

Calibration must be carried out at operating frequency bands, at least three times, according to the polarization announcement of the EUT.

 

Figure B.1 - Example of a measurement set

For more detailed information on the usage, validity period, and performance limits of the measurement set up to 100 GHz, see TS 103 502.

B.2.2. Measurement positions and general layout

B.2.2.1. Outdoor measurement position (OATS)

The outdoor measurement position includes a turntable at one end and a height-adjustable antenna at the other, both positioned above a ground plane, ideally a good conductor and infinitely extended. In practice, a good conductive ground plane can be created, but an infinite ground plane cannot be created. Figure B.2 illustrates a typical outdoor measurement position.

 

 

 

         

Figure B.2 - Typical outdoor measurement position.

The ground plane generates desired reflections, thus the receiving antenna receives a signal that is the sum of the directly transmitted signal and the reflected signal. For each height of the transmitting antenna (or EUT) and the receiving antenna height relative to the ground plane, the phase difference between these two signals creates a unique received level.

In practice, the straight antennas have variable heights, so the measurement antenna height is optimized for maximum signal strength, combined with the turntable to create azimuth angles.

Both absolute and relative measurements can be conducted at the outdoor measurement position. In the case of absolute measurement, the measurement at the recognized position requires verification at the OATS position. Performance comparison is considered theoretical, acceptance based on a predetermined limit not being exceeded.

B.2.2.2. Other measurement positions

The measurement positions described below are equipped with absorber materials to reduce reflections. The absorber material capability provides upper and lower frequency thresholds. For high-frequency use appropriate to these test positions, reflection loss, and room resonance must be checked.

B.2.2.3. Fully reflective test chamber with ground plane.

A fully reflective test chamber with a ground plane is a shielded room, wherein the inner walls and ceiling are covered with a layer of RF absorbing material, typically a foam urethane cone-shaped layer. The floor of the test chamber is made of bare metal (uncoated) and is flat. Typically, the test chamber includes an antenna mast at one end and a turntable at the other. Figure B.3 illustrates a typical fully reflective test chamber with a ground plane.

 

    

Figure B.3 - Typical fully reflective test chamber with ground plane

This type of test chamber aims to simulate the outdoor measurement position (OATS) characterized primarily by an ideal ground plane that is infinitely extended.

Shielding the test chamber combined with the use of RF absorbing materials serves to control the environment within the test chamber. Shielding creates a measurement space, reducing surrounding signal noise levels and other external effects, while RF absorbing materials minimize unwanted reflections from walls and ceilings, which may affect the measurement.

In reality, it is easy to shield to eliminate high-level surrounding noise (80 dB to 140 dB) (surrounding noise is often negligible), no RF absorber material is designed to absorb all energy sources. For example, if it is not produced and configured perfectly, its reflection loss (a measure of effectiveness) also varies with frequency and angle of incidence. In some cases, it is also affected by the high power level of RF energy. To improve reflection loss over a wider frequency range, ferrite tiles, ferrite mesh, and hybrid materials between foam urethane and ferrite bricks are used to meet requirements.

The ground plane generates desired reflections, thus the receiving antenna receives a signal that is the sum of the directly transmitted signal and the reflected signal. For each height of the transmitting antenna (or EUT) and the receiving antenna height relative to the ground plane, the phase difference between these two signals creates a unique received level.

In practice, the antenna mast must have adjustable height, so that the exact position of the measurement antenna can be selected in combination with the turntable, where the total signal between the azimuth angle with the antenna, or between an EUT and a measurement antenna is maximized.

Both absolute and relative measurements can be carried out in a fully non-reflective room. The measurement room must be calibrated either at the location where absolute measurements are performed or at the location where recognized measurements are conducted. This calibration involves comparing the measurement performance with that of an ideal theoretical measurement room, and acceptance is based on the maximum difference between the two types of rooms not exceeding a predetermined limit.

B.2.2.4. Fully Non-Reflective Measurement Room

A fully non-reflective measurement room is typically a sealed room covered internally with walls, ceiling, and floor coated with radio wave absorbing material, usually a foam urethane with pyramidal shapes. It usually includes an antenna support at one end and a turntable at the other. A typical fully non-reflective measurement room is illustrated in Figure B.4 with dual-pole antennas at both ends.

 

 

Figure B.4 - Typical Fully Non-Reflective Measurement Room

Shielding the measurement room combined with the use of radio wave absorbing materials creates a controllable environment during the measurement process. This type of measurement room aims to simulate free space conditions as closely as possible. Shielding reduces interference from surrounding signals and external effects, while radio wave absorbing materials minimize unwanted reflections from walls, floors, and ceilings, which could affect the measurement.

In reality, it is easy to shield to eliminate high-level surrounding noise (80 dB to 140 dB) (surrounding noise is often negligible), no RF absorber material is designed to absorb all energy sources. For example, if it is not produced and configured perfectly, its reflection loss (a measure of effectiveness) also varies with frequency and angle of incidence. In some cases, it is also affected by the high power level of RF energy. To improve reflection loss over a wider frequency range, ferrite tiles, ferrite mesh, and hybrid materials between foam urethane and ferrite bricks are used to meet requirements.

Generally, a fully non-reflective measurement room has many advantages over other measurement rooms. It is less affected by surrounding interference, has fewer wall, ceiling, and floor reflections, and is independent of weather conditions. However, it also has some disadvantages such as limited measurement distance (due to room size, cost, etc.) and lower frequency usage due to room size limitations and pyramidal absorber materials.

Both absolute and relative measurements can be carried out in a fully non-reflective room. The measurement room must be calibrated either at the location where absolute measurements are performed or at the location where recognized measurements are conducted. This calibration involves comparing the measurement performance with that of an ideal theoretical measurement room, and acceptance is based on the maximum difference between the two types of rooms not exceeding a predetermined limit.

A typical fully non-reflective measurement room is illustrated in Figure C.5. This type of room is constructed to simulate free space conditions as closely as possible.

 

Figure B.5 - Typical Fully Non-Reflective Measurement Room

The measurement room contains suitable antennas and supports at both ends.

Antenna mounting equipment for testing and EUT hanging must be made of materials with low super high frequency attenuation and low relative dielectric constant values.

A fully non-reflective measurement room must be shielded. The internal walls, floor, and ceiling must be covered with radio wave absorbing material. Shielding and reflection attenuation create perpendicular waves at the frequency. In commonly measured frequency bands:

• Shielding attenuation is 105 dB;
• Reflection attenuation is 30 dB.

Both relative and absolute measurements must be carried out in a fully non-reflective measurement room. The measurement room must be calibrated at the locations where absolute measurements are performed.

The position of the fully non-reflective measurement room must be calibrated and verified within the applicable frequency bands.

NOTE 1: Information on measurement uncertainty and calibration procedures is detailed in Articles 5 and 6 of standard TR 102 273-2.

NOTE 2: The measurement setup is introduced and procedures are based on best practices in low band ranges. Settings may need to be adjusted according to the specific requirements of millimeter-wave systems, especially frequencies above 100 GHz. Measurement results should clearly indicate the measurement setup configuration. The introduced measurement setup is primarily intended for power measurements as defined within the scope of this standard.

When measuring in a fully non-reflective measurement room above 1 GHz without scanning the height of the comparison antenna, instead of rotating 360 degrees⁰ with the EUT turntable, it must be moved across all surfaces to measure the maximum RF radiation power due to narrow antenna models appearing at high frequencies.

B.2.2.5. Minimum Requirements for Measurement Positions Above 18 GHz

Generally, measurement positions must be sufficient to perform far-field measurements of the EUT. Therefore, the measurement position must be a room without electromagnetic reflection or at least have a surface covered with radio wave absorbing material or a maximum of six surrounding surfaces covered with radio wave absorbing material. Absorbing materials must reduce reflections by at least 30 dB. The effectiveness of this reflection reduction must be verified. Measurement positions have the following dimensions:

- Width of 2 meters.

- Length of 3 meters.

- Height of 2 meters (only applies to a room with more than one reflective surface).

The height of the directional receiving antenna reduces reflections. It is recommended to use a standard gain horn antenna. Note that if the antenna aperture is smaller than the EUT, measurements must be performed at both azimuth and elevation angles to ensure the determination of maximum radiation. The measurement distance must be chosen to avoid antenna coupling effects. Therefore, a minimum distance of 0.5 m is recommended. The EUT can be placed at any height to minimize floor reflections.

Due to the large attenuation of coaxial cables at high frequencies, the connection from the receiving antenna to the measurement receiver should not exceed 1 meter, thus requiring the measurement receiver to be placed close to the receiving antenna. This is particularly true when using an external harmonic mixer connected very short to the measurement receiver. Therefore, the measurement receiver must be covered with radio wave absorbing material in the direction of the magnetic field measurement to reduce reflections. Figure B.6 illustrates an example of a measurement position above 18 GHz with one reflective surface.

 

 

Figure B.6 - Example of a measurement position above 18 GHz with one reflective surface

Attenuation according to the measurement position must be determined. Measurement positions with relatively ideal characteristics can use free space loss (FSL) theory as shown in examples from Table B.1 to Table B.3.

Table B.1 - Example of Free Space Loss at 1 Meter Distance

Table B.2 - Example of free space path loss at a distance of 0.5 meters

Table B.3 - Example of free space path loss at a distance of 0.25 meters

Where:

λ = c/f

[FSL] = 10 log (4πr/λ)²