Wideband transverse electromagnetic cell design and its application in frequency selective surface measurement

Abstract

An open transverse electromagnetic cell (TEM cell) that covers L-band, S-band, and C-band is proposed in this paper. According to impedance matching theory analysis, the characteristic impedance of coaxial connector and microstrip with air as substrate are considered, which are combined with a taper gradient section to realize the function of TEM cell. The proposed TEM cell was modeled and simulated in CST Microwave Studio. Through full-wave simulation, the proposed TEM cell demonstrates a wideband transmission characteristic, S11 less than −10 dB from 1 to 8 GHz, which is relatively rare among the designs that have been reported. The test flow and data post-processing method are given. To verify the effectiveness of the test method, an example of measuring a classical square slot frequency selective surface that their resonance frequency is 3.7 GHz is designed and simulated in the TEM cell. To verify the simulated results, a prototype is fabricated and measured with the proposed TEM cell. The experimental result demonstrates a good agreement with the simulated result, which indicates that the designed TEM cell has good test performance.