TEM-камера открытого исполнения для испытаний малогабаритных радиоэлектронных средств на электромагнитную совместимость

Abstract

This paper presents the design and fabrication of an open TEM cell. It allows you to measure the radiated emission and immunity of radioelectronic devices. The size of the EUT should not exceed 184×162×30 mm. Performed analytical and quasi-static analysis of the regular part of the TEM cell. In the frequency range up to 1.4 GHz the reflection coefficient |S11| of the regular part does not exceed minus 45 dB. The electrodynamic model of the TEM cell is developed and the geometric parameters are optimized using a genetic algorithm. Analysis of the electrodynamic model showed that in the frequency range up to 920 MHz the voltage standing wave ratio (VSWR) does not exceed 1.3. The inequality of the electric field in the area of EUT placement is not more than 6 dB in the frequency range up to 875 MHz. The validity of the obtained results is checked using the numerical methods of finite elements and the transmission line matrix. A solid-state model of the TEM cell is developed to evaluate the effect of the design features of the assembly. The frequency dependences of |S11| of the solid‑state model do not exceed minus 17.69 dB in the frequency range up to 916 MHz. The TEM cell is fabricated by laser cutting and bending aluminum sheet metal. Using a vector circuit analyzer Micran R4M-18 measured S‑parameters of the fabricated TEM cell. The transmission coefficient |S21| of the fabricated TEM cell in the frequency range up to 936 MHz does not exceed minus 2.2 dB. The reflection coefficient |S11| does not exceed minus 17.69 dB. The results of radiated emission measurements of the Altera Cyclone IV FPGA debug board in the frequency range up to 1 GHz with a fabricated TEM cell is presented.