Development and commissioning of a test system based on a TEM cell for RF exposure

In the development of a low-cost two-port TEM cell, a new analytical model of the capacitance of the terminations has been performed. The model has been verified by calculating the termination capacitance by means of a commercial 3D code. A TEM cell modified in accordance with the obtained results has been tested, with reference to the voltage standing wave ratio (VSWR) parameter, and the obtained improvements on VSWR versus frequency are reported. The TEM cell is the principal part of a test system for RF exposure (up to 230 MHz), including signal generator, power amplifier, dual directional coupler, 50 Ω load attenuator and 1 GHz bandwidth oscilloscope, whose commissioning has been performed. A numerical analysis has been performed also for calculating the stationary electric field in the TEM cell. Experimental measurements of electric field inside the TEM cell, by means of an electric field meter (100 kHz – 6 GHz broadband) were done, and the results are in good agreement with the numerical data.