Design of a TEM cell using both multi-step and piecewise linear tapering

摘要

The transverse electromagnetic (TEM) cell is used for electromagnetic interference/compatibility (EMI/EMC) tests of the small RF devices in a laboratory environment. The standard electromagnetic (EM) fields created in the shielded environment of a TEM cell can also be used for calibration of the EM field probes. In this paper, a 50 Ω open TEM cell is designed to generate standard EM fields from 1 MHz up to 1 GHz. The inner conductor of the cell is tapered using two new methods named as multi-step and piecewise linear tapering to adapt to the standard coaxial connectors and achieve a good matching. The resulted matching conditions of these new methods are compared through some simulations to those of the conventional simple linear tapering.