GB/T 33012.3-2016Road vehicles -- Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy -- Part 3: On-board transmitter simulation (English PDF)

6.4 Antennas

6.4.1 Transmitters with antenna outside the vehicle

6.4.1.1 Simulated on-board transmitters

When an OEM antenna is not installed on the vehicle, the antenna(s) described below

shall be used.

- For frequency ranges lower than 30 MHz, loaded antennas shall be used. Loaded

antennas employ lumped or distributed reactive components with a radiating

element physically shorter than quarter wave at resonance.

- For frequency ranges higher than 30 MHz, e.g. for the very high frequency (VHF)

and ultra-high frequency (UHF) bands, quarter wave antennas shall be given

preference over 5/8 wave antennas, since there are higher skin currents created

by quarter wave antennas.

All antennas shall be tuned on the vehicle for minimum voltage standing wave ratio

(VSWR, typically less than 2.1), unless otherwise specified in the test plan. As a

minimum, the VSWR value shall be recorded with the antenna on the vehicle at the

lower and upper band edge and at a middle frequency (see Annex B).

NOTE. The resulting VSWR is compatible with the design of the RF source.

When an OEM antenna is actually installed on the vehicle, this antenna shall be used

for the test in the appropriate frequency range. In this case, the VSWR shall not be

adjusted, but shall be recorded.

6.4.1.2 Commercial on-board transmitters

The vehicle OEM antenna shall be used for the test in the appropriate frequency range.

In this case, the VSWR shall not be adjusted.

6.4.2 Transmitters with antenna inside the vehicle

6.4.2.1 Simulated portable transmitter

A passive antenna (e.g. quarter wave antenna with counterpoise, sleeve antenna,

patch antenna) shall be used.

All antennas shall be tuned on the vehicle for minimum VSWR (typically less than 2.1),

unless otherwise specified in the test plan. The antenna shall be tuned in the laboratory

to obtain minimum required VSWR with the counterpoise that is intended to be used

with the antenna while testing in the vehicle.

As a minimum, the VSWR value shall be recorded with the antenna in the vehicle at

8.1 General

The general arrangement of vehicle, transmitter(s) and associated equipment

represents a standardized test condition. Any deviations from the standard test

configuration shall be agreed upon prior to testing and recorded in the test report.

The vehicle shall be made to operate under typical loading and operating conditions.

These operating conditions shall be clearly defined in the test plan.

8.2 Test plan

Prior to performing the tests, a test plan shall be generated which shall include.

- test set-up;

- frequency range(s) and associated modulation(s);

- duration of transmission;

- antenna location and polarization;

- routing of the coaxial cable to the antenna in the vehicle (for simulated on-board

transmitters);

- vehicle orientation;

- vehicle mode of operation;

- vehicle monitoring conditions;

- vehicle acceptance criteria;

- definition of test severity levels;

- maximum antenna VSWR value (if necessary);

- test report content;

- any special instructions and changes from the standard test.

8.3 Test method

8.3.1 Transmitters with antenna outside the vehicle

8.3.1.1 Simulated on-board transmitters

When required in the test plan, the immunity threshold shall be determined.

8.3.1.2 Commercial on-board transmitters

The vehicle is installed in the test facility as described in 7.1.2.

The test shall be performed with unmodified commercial on-board transmitter

characteristics (power, modulation, etc.) and the unmodified vehicle OEM antenna.

Any exception to this practice shall be specified in the test plan. Operate the

commercial on-board transmitter connected to the OEM antenna in the configuration(s)

indicated in the test plan, noting any anomalies.

Continue testing until all on-board transmitter(s) specified in the test plan are

completed.

8.3.2 Transmitters with antenna inside the vehicle

8.3.2.1 Simulated portable transmitters

The vehicle, antenna(s) and associated equipment are installed as described in 7.2.2.

The reference parameter for the test is the net power at the simulated portable

transmitter feed-point. The adjustment of the net power level shall be performed with

the simulated portable transmitter placed outside the vehicle (at a mini...

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