Design scheme of electronic equipment radiation emission test platform

Radiated Emission (Radiated Emission) test is to measure the intensity of the radiated disturbance field propagated by EUT through space. It can be divided into magnetic field radiation and electric field radiation. The former is aimed at lamps and induction cookers, while the latter is widely used. In addition, home appliances, power tools, and auxiliary equipment for AV products have power radiation emission requirements (called disturbance power).
2. Radiated emission (RE) test standard
A) Electric field radiation: CISPR22/EN55022 (information technology products), CISPR13/EN55013 (audio products), CISPR11/EN55011 (engineering medicine), CISPR14-1, CISPR15/EN55015 (lamps);
B) Magnetic field radiation: CISPR15 (lamps whose working current frequency exceeds 100Hz), CISPR11 (induction cooker);
C) Disturbance power: CISPR14-1 (except for some equipment whose working frequency does not exceed 9kHz), CISPR13 (only for auxiliary equipment).
3. Radiated emission (RE) test method
1) Radiated emission test equipment and equipment:
A) Electric field radiation: receiver (below 1G), spectrum analyzer (above 1G), anechoic chamber, antenna (under 1G, generally double
a combination of cone and logarithmic period or broadband composite antenna, horn antenna above 1G);
B) Magnetic field radiation: receiver, three loop antenna or single small loop antenna;
C) Disturbance power: receiver, power absorption clamp.
The receiver complies with the requirements of CISPR16-1-1, the antenna and site complies with the requirements of CISPR16-1-4, and the absorption clamp complies with the requirements of CISPR16-1-3.
Radiated emission (RE) test SETUP
Figure 1 shows the layout of the radiation emission test according to the requirements of CISPR16, CISPR11, CISPR13, CISPR15, CISPR22 and EN55022. During the radiation emission test, the EUT is placed inside the semi-anechoic chamber and rotates on the turntable. The radiating point found when the receiving antenna is in vertical polarization and horizontal polarization respectively. After the radiated signal is received by the receiving antenna, it is transmitted to the receiver outside the semi-electric wave anechoic chamber through the cable.

Figure 1: Layout of radiated emission test
The layout of the desktop tested equipment is shown in Figure 2. The specific requirements are as follows:
(1) The distance between the interconnecting I/O cable and the ground should not be less than 40cm;
(2) In addition to the actual load connection, the device under test can also be connected to an analog load, but the analog load should be able to comply with the impedance relationship and at the same time be able to represent the actual situation of the product application;
(3) The power cords of the equipment under test and the auxiliary equipment AE are directly plugged into the socket on the ground, and the socket should not be extended;
(4) The distance between the tested equipment and the auxiliary equipment AE is 10cm;
(5) If the device under test has more cables, it should be carefully sorted out, handled separately, and recorded during the test in order to obtain the reproducibility of the test again.

The layout of the vertical tested equipment is shown in Figure 3. The specific requirements are as follows:
(1) The I/O interconnection lines between the cabinets should be placed naturally. If they are too long, they must be tied into a 30～40cm wire harness;
(2) The device under test is placed on a metal plane with an insulation distance of about 10 cm from the metal plane; the cable connected to the analog load or the port of the dark room should pay attention to its insulation with the metal plane;
(3) The power cord of the device under test is too long and should be tied into a wire harness with a length of 30-40cm, or shortened to just enough;
(4) If the device under test has more cables, it should be carefully sorted out, handled separately, and recorded during the test to obtain the repeatability of the test again.

For the radiation emission test of automotive electronic equipment, the radiation emission test arrangement required by the CISPR25 standard is shown in Figure 4. During the radiation emission test, the vehicle electronic equipment under test (EUT) is placed inside the semi-anechoic chamber, the receiving antenna is 1m away from the EUT harness, and the radiation is found when the receiving antenna is in vertical polarization and horizontal polarization. After the point radiation signal is received by the receiving antenna, it is transmitted to the receiver outside the semi-electric wave anechoic chamber through the cable.