GB/T 36654-2018RF technical requirements and test methods for 76GHz vehicle radio equipment (English PDF)

3.1 Terms and definitions

The following terms and definitions apply to this document.

3.1.1 Equivalent isotropic radiation power

The product of the power output to the antenna in the specified direction relative to the antenna gain of the omnidirectional antenna.

3.1.2 Power spectral density

The value of the average equivalent isotropic radiated power per unit bandwidth.

3.1.3 Duty cycle

The ratio of the duration of a positive pulse to the total period of a pulse in a series of pulse trains.

3.1.4 Spurious emission

Unwanted emissions of equipment in the spurious domain.

3.2 Abbreviations

The following abbreviations apply to this document.

RBW. Resolution Bandwidth

RMS. Root Mean Square

VBW. Video Bandwidth

4.1 Environmental requirements

The equipment manufacturer shall state in advance the environmental conditions in which the equipment is to be operated, and the equipment shall operate under its nominal working environment.

4.2 RF technical requirements

4.2.1 Peak equivalent isotropic radiation power

4.2.1.1 Overview

The product of the peak power output to the antenna in the specified direction relative to the antenna gain of the omnidirectional antenna.

4.2.1.2 Limits

The transmitter operates at the maximum power level. The peak equivalent isotropic radiation power limit is 55 dBm.

4.2.2 Frequency range

When the transmitter is operating at the maximum power level. The frequency range of use is 76 GHz to 77 GHz.

4.2.3 Out-of-band emission

4.2.3.1 Overview

The out-of-band emission in this standard refers to the maximum power of the transmitter in the frequency range 73.5GHz~76GHz and 77GHz~79.5GHz. Rate spectral density.

4.2.3.2 Limits

The out-of-band emission limit is 0dBm/MHz.

4.2.4 Transmitter spurious emissions

4.2.4.1 Overview

Transmitter spurious emissions are unwanted emissions in the spurious domain when the device is in the transmitting state.

4.2.4.2 Limits

The transmitter spurious limits are shown in Table 1.

4.2.5 Receiver spurious emissions

4.2.5.1 Overview

Receiver spurious emissions are unwanted emissions in the spurious domain when the device is in the receiving state.

4.2.5.2 Limits

Receiver spurious limits are shown in Table 2.

5.1 Environmental conditions required for testing

The device under test should work in its normal working environment.

a) Temperature. 15 ° C ~ 35 ° C;

b) Relative humidity. 20%~75%.

5.2 Test results and uncertainty

The complete test result expression should consist of the following parts.

a) measured values and corresponding limits; b) Measurement uncertainty.

The measurement uncertainty should not be greater than the values in Table 3.

5.3 Test Configuration

5.3.1 Test fixture

Equipment manufacturers are required to provide appropriate fixtures to allow the equipment to be placed in a stable position and to ensure that the equipment antenna is in the same water as the test receiver antenna Flat line. As shown in Figure 1. The test fixture requirements are as follows.

a) The matching load of the joints and waveguides used in the test shall be 50ohm;

b) The joints and waveguides used in the test shall be matched to the load standing wave ratio of not more than 1.5;

c) The receiving antenna gain should be no less than 20dB.

5.3.2 Test site

The test site shall be a fully shielded room with RF absorbing material in the room to simulate the free space environment in which electromagnetic waves propagate. It is Complete the replacement site for the device's radiation emission test. The test arrangement of the measuring antenna, the device under test and its alternative antenna is the same as the open test field Like, but their erection height from the floor is fixed. as shown in picture 2. The test site requirements are as follows.

a) The shielding efficiency of the anechoic chamber used in the test shall be greater than 105 dB;

b) The anechoic chamber return loss used in the test shall be greater than 30 dB;

c) The equipment used in the test, the measuring antenna and the replacement antenna should be calibrated regularly.

5.3.3 Test Block Diagram

For the equipment specified in this standard, the test block diagram shown in Figure 3 should be used for testing. The test attachment requirements are as follows.

a) The matching load of the mixer, signal generator, waveguide flange, etc. used in the test shall be 50ohm;

b) The VSWR of the mixer, signal generator, waveguide flange, etc. used in the test shall be less than 1.5;

c) The mixer, signal generator, waveguide flange, etc. used in the test should be calibrated periodically.

5.4 Peak equivalent isotropic radiation power

5.4.1 Test Block Diagram

The peak equivalent isotropic radiated power shall be measured using the test site described in 5.3.2 and the method in 5.3.3.

5.4.2 Measurement steps

The measurement steps are as follows.

a) Connect the device under test to a matching diode detector or equivalent via a suitable attenuator. Diode detection The output of the unit should be connected to the vertical channel of an oscilloscope or equivalent power measuring device. Diode detector and oscilloscope The combination should be able to accurately reproduce the duty cycle of the transmitter output signal;

b) Use the spectrum analyzer to measure the output power of the transmitter, using the RMS detection method. At this time, the device under test should use the highest power. Level launch. The observed value is recorded as A;

c) The peak equivalent isotropic radiated power Ppeak shall be calculated from the measured power output A and the observed duty cycle x, detailed The calculation method is shown in equation (1). Ppeak=A 10×lg(1/x) (1) In the formula. Ppeak---peak equivalent isotropic radiation power in decibel milliwatts (dBm);

A --- measured output power in decibel milliwatts (dBm); x --- Transmitter output signal duty cycle.

5.5 Frequency range

5.5.1 Test Block Diagram

The frequency range shall be measured using the test site described in 5.3.2 and the method in 5.3.3.

5.5.2 Measurement steps

The measurement steps are as follows.

a) the transmitter is adjusted to the maximum transmission mode;

b) Use the spectrum analyzer to read the start frequency and cutoff frequency of the signal envelope and record it, the value of which shall not exceed the 4.2.2 mid-limit requirement.

5.6 Out-of-band emission

5.6.1 Test Block Diagram

Out-of-band emissions shall be measured using the test site described in 5.3.2 and the method in 5.3.3.

5.6.2 Measurement steps

The measurement steps are as follows.

a) the transmitter is adjusted to the maximum transmission mode;

b) Set the spectrum analyzer start frequency = 73.5GHz, cutoff frequency = 76GHz, RBW = 1MHz, VBW = 1MHz, detector Mode RMS, the maximum tracking mode is maintained;

c) record the maximum value of the out-of-band emission, the value of which shall not exceed the limit of 4.2.3;

d) Set the spectrum analyzer start frequency = 77GHz, cutoff frequency = 79.5GHz, RBW = 1MHz, VBW = 1MHz, detector Mode RMS, the maximum tracking mode is maintained;

e) Record the maximum value of the out-of-band emissions, the value of which shall not exceed the mid-limit of 4.2.3.

5.7 Occupied bandwidth

5.7.1 Test Block Diagram

The occupied bandwidth shall be measured using the test site described in 5.3.2 and the method in 5.3.3.

5.7.2 Measurement steps

The measurement steps are as follows.

a) the transmitter is adjusted to the maximum transmission mode;

b) Set the spectrum analyzer center frequency = the center frequency of the channel under test, RBW = 1MHz, VBW = 1MHz, sweep width 2 times the nominal channel bandwidth, the detector mode RMS, the tracking mode maximum is maintained;

c) Record the bandwidth of the 99% of the signal displayed on the spectrum analyzer.

5.8 Transmitter spurious emissions

5.8.1 Configuration Requirements

If the transmitter uses an antenna array that distributes power symmetrically, only one transmit link (antenna) should be reserved, where practicable, Disable other transmit links (antennas) and, if not feasible, document the method used in the test report.

If only one transmit link is tested, the test results should be corrected to apply to the entire system (all transmit links). One The transmit power (mW) of the transmit link needs to be multiplied by the number of transmit links to obtain the total transmit power of the system.

The device under test should be configured to operate at the maximum duty cycle and maximum output power level.

5.8.2 Stray emission test method not greater than 40 GHz

5.8.2.1 Test Block Diagram

When detecting spurious emissions less than or equal to 40 GHz, use the test site described in Appendix A and the relevant measurement procedures in Appendix B. Make measurements.

5.8.2.2 Measurement steps

The measurement steps are as follows.

a) Measure spurious emissions in the range of 30MHz~1GHz, set the spectrum analyzer RBW=100kHz, VBW=100kHz check Wave filter RMS, tracking mode maximum value is maintained;

b) measuring spurious emissions in the range of 1 GHz to 40 GHz, setting the spectrum analyzer RBW = 1 MHz, VBW = 1 MHz detector RMS, the tracking mode maximum is maintained;

c) Any emissions found in the scan that are within 6 dB below the limit shall be recorded. If the measurement is outside the specified distance To carry out, the calculation result of the equivalent field strength value should be given.

5.8.3 Spurious emission test method greater than 40 GHz

5.8.3.1 Test block diagram

When detecting spurious emissions greater than 40 GHz, measurements shall be made using the test sites described in 5.3.2 and the methods in 5.3.3.

5.8.3.2 Measurement steps

The measurement steps are as follows.

a) Test the spurs of the highest frequency band and record when the device supports, set the spectrum analyzer RBW=1MHz, VBW= 1MHz, detector RMS, tracking mode maximum hold;

b) Any emissions found in the scan that are within 6 dB below the limit shall be recorded. Analyze the mixer for the results The impact of mirroring.

5.9 Receiver spurious emissions

5.9.1 Configuration Requirements

If the receiver is in the form of an antenna array, only one transmit link (antenna) should be reserved, and other emissions should be disabled, where practicable.

Link (antenna), if not feasible, the method used should be documented in the test report.

If only one receive link is tested, the test results should be corrected to apply to the entire system (all receive links).

The spurious transmit power (mW) of a receive link needs to be multiplied by the number of receive links to obtain the total receiver spurious emissions of the system. Shooting power.

The device under test should be configured to operate in a state of continuous reception or no transmission.

5.9.2 Stray emission test method not greater than 40 GHz

5.9.2.1 Test Block Diagram

Use the test site described in Appendix A and the relevant measurement procedures in Appendix B when detecting spurious emissions less than or equal to 40 GHz. Make measurements.

5.9.2.2 Measurement steps

The measurement steps are as follows.

a) Measure spurious emissions in the range of 30MHz~1GHz, set the spectrum analyzer RBW=100kHz, VBW=100kHz check Wave filter RMS, tracking mode maximum value is maintained;

b) measuring spurious emissions in the range of 1 GHz to 40 GHz, setting the spectrum analyzer RBW = 1 MHz, VBW = 1 MHz detector RMS, the tracking mode maximum is maintained;

c) Any emissions found in the scan that are within 6 dB below the limit shall be recorded. If the measurement is outside the specified distance To carry out, the calculation result of the equivalent field strength value should be given.

5.9.3 Spurious emission test method greater than 40 GHz

5.9.3.1 Test block diagram

When detecting spurious emissions greater than 40 GHz, measurements shall be made using the test sites described in 5.3.2 and the methods in 5.3.3.

5.9.3.2 Measurement steps

The measurement steps are as follows.

a) Test the spurs of the highest frequency band and record when the device supports, set the spectrum analyzer RBW=1MHz, VBW= 1MHz, detector RMS, tracking mode maximum hold;

b) Any emissions found in the scan that are within 6 dB below the limit shall be recorded. Analyze the mixer for the results The impact of mirroring.

A.1 Open test field or semi-anechoic darkroom

Open test or semi-anechoic darkrooms shall comply with the requirements of the test site in Appendix A of GB/T 9254-2008.

In the frequency band below 1 GHz, the test distance of the transmitting and receiving antennas is not less than 3 m. Select the appropriate test in the frequency band above 1 GHz distance. The size of the device under test should be less than 20% of the test distance. The height of the equipment to be tested or the height of the replacement antenna frame is 1.5m, the measurement day The height of the wire frame is adjusted within the range of 1m~4m.

In order to ensure that the reflected wave signal generated by obstacles near the test site has no effect on the test results, the test site should meet the following requirements. condition.

a) There shall be no conductive objects in the vicinity of the test site that are larger than the test maximum frequency lambda/4 (lambda is the wavelength of the electric wave);

b) Connect the cables as far as possible along the floor surface, preferably under the floor, and shielded cables for low-impedance cables. A typical test site layout is shown in Figure A.1.

A.2 Full anechoic chamber

A.2.1 Overview

The full anechoic chamber is a fully shielded room with RF absorbing material inside, which is used to simulate the free space environment of electromagnetic wave propagation. It is Complete the replacement site for the device's radiation emission test. The test arrangement of the measuring antenna, the device under test and its alternative antenna is the same as the open test field Like, but their erection height from the floor is fixed.

See Table A.1, Table A.2 for the requirements for the shielding effectiveness and wall reflection loss of the full anechoic chamber. Requires full-wave darkroom to be tested The deviation of the space transmission loss from the device to the measuring antenna to the transmission loss in the free space environment is within ±4 dB.

A.2.2 Test antenna

The physical size of the measuring antenna cannot exceed 20% of the test distance. The measuring antenna should be suitable for the reception of polarized waves and should be installed at the level The end of the arm should allow the antenna to be positioned and mounted according to the horizontal or vertical component of the measured electric field. When oriented vertically and at the lowest When installing the position, the low end of the antenna should be at least 0.3m from the ground.

A.2.3 Alternative antenna

The gain accuracy of the alternative antenna is within ±1 dB.

B.1 Radiation spurious test

The radiated spur test shall be carried out in the full anechoic chamber in accordance with the arrangement of Figure B.1. When testing, the measuring antenna is facing the most of the device under test.

The large radiation level orientation is recorded in the test report and measured in that direction. The radiation spur test steps are as follows.

a) The test site shall meet the test requirements of the specified test frequency band, and the device under test shall be placed on the standard turntable (or bracket) unless otherwise required Therefore, the measuring antenna should be vertically polarized to the device under test, and the height of the antenna is the same as the height of the device under test.

b) Set the spectrum analyzer to peak detection. Scanning within the specified radiated spurious test frequency band, searching for the exemption band A valid spurious spectral component produced by the device under test. If necessary, raise and lower the measuring antenna in a small range, Allows the spectrum analyzer to obtain the maximum power reading of the effective output spectral components.

c) Rotate the device under test to get the maximum level reading of the spectrum analyzer. If necessary, again, the measuring antenna is in a smaller range.

Line up and down, allowing the spectrum analyzer to obtain a larger level reading based on the above maximum level reading, recording the frequency of the effective spectral components The rate and maximum level readings are in the test report.

d) Set the measurement antenna to the horizontal polarization position and repeat the above test procedure.

B.2 Alternative measurement

The test data obtained by the test method of B.1 is not the final test result, and the actual transmit power of the spurious signal generated by the device under test.

Ping needs to be determined by an alternative test. The principle of the alternative test is to replace the device under test with a known signal generator to give a quantitative measurement.

The emission level of each signal generated by the device, the test connection is shown in Figure B.2. Instead of using an antenna to replace the device under test in the original position, And it is a vertical polarization mode, and the signal generator frequency is tuned to the test frequency of each signal in the B.1 test process. Adjustment signal generation The output power is such that the measurement spectrum analyzer achieves the same test level as recorded during the B.1 test. Corresponding frequency letter The radiation emission power of the number is the sum of the signal generator output level and the gain of the replacement antenna minus the calculated value after the connection cable loss. This gives the actual radiated power of each frequency signal.