TEM cell

TEM Cell is a rectangular double conductor transmission line structure. The piece under test is placed on its middle partition plate (i.e. core plate). The two ends of the conductor in the TEM chamber are tapered. The transmission line is closed, with an input measurement port and an output measurement port at both ends. The tapered end is matched with a 50 Ω port coaxial connector through a transition in the middle section.

The approximate large volume that can be used for anti-interference testing in a TEM Cell is: 1/3 multiplied by the distance between the middle partition (core plate) and the upper surface, and then multiplied by 1/3 multiplied by the width of the TEM chamber, and this result can be almost extrapolated to 1/2 multiplied by 1/2. In a typical TEM cell, it is still possible to maintain and obtain a field uniformity of ± 1dB.

TEM chamber test

EUT includes automotive electronics, ICs and other electronic products. Conduct immunity testing and radiated emission testing. The test is based on the following standards:

(1)YD/T 1690.2-2007 "Communications Industry Standards of the People's Republic of China"-Technical requirements and measurement methods for diagnosis of internal electromagnetic emissions from telecommunications equipment (150KHz ~1GHz)-Part 2: Measurement of radiated emissionsTEM celland broadbandTEM cellmethod

(2)IEC 61967-2: Integrated circuits - Measurement of electromagnetic emissions, 150 kHz to 1GHz -Part 2: Measurement of radiated emissions, TEM-cell method and wideband TEM-cell method (150 kHz to 8 GHz)

（3）IEC62132-2 Integrated circuits – Measurement of electromagnetic immunity –Part 2: Measurement of radiated immunity – TEM cell and wideband TEM cell method

（4）GB/T 17626.20-2014 Electromagnetic Compatibility, Testing and Measurement Technology Emission and immunity testing in transverse electromagnetic wave (TEM) waveguides

（5）GJB151B-2013 "Requirements and measurements for electromagnetic emissions and sensitivity of equipment and subsystems"-RS105 Transient electromagnetic field radiation sensitivity

（6）ISO 11452-3/SAE J1113-24 "Test Method for Electronic Interference Components of Road Vehicles Using Narrow-Band Emission Electromagnetic Energy"-TEM Cell method

radiated emission test

Measure radiated emissions from the EUT or integrated circuit (IC) under test.EUTThe emission field of is coupled through the transmission mode of the TEM Cell and from this it is coupled to a voltage at one port of the cell. There is a square opening at the top of the outer conductor of the chamber for mounting a test circuit board. Among them, one side of the integrated circuit is mounted inside the chamber, and one side of the interconnection lines and peripheral circuits faces outwards. This allows the measured radiation emissions to come mainly from the IC chip being tested. The high-frequency current generated by the chip under test flows on the interconnected wires, and those solder pins and package wires act as radiating transmitting antennas. at this timeTEM cellThe test voltage of the port has a good quantitative relationship with the emission size of the disturbance source, which is used for radiated disturbance testing.TEM cellYou need to have an access port that matches the IC test board. The test diagram is as follows:

radiated immunity test

TEMchamberThe input terminal of is connected to the signal source and power amplifier, and the other terminal is connected to a 50Ω matched load.TEM cellThe inner cavity can form a high-intensity electromagnetic field, which is suitable for electromagnetic immunity testing. At the same time, monitoring equipment can also be connected to the interface board of the cabinet to monitor the working status of the EUT under test in real time.