Metamaterial patterning to improve the septum of a GTEM chamber performance: RR - ring resonator cells stamped and tested on the APEX

A Periodic Structure characterized here as a metamaterial, is patterned and was applied to the septum of a GTEM chamber, in order to obtain a more accurate and flexible frequency band on the DUT. The main analysis is carried out on the excitation sector of the GTEM chamber - APEX. The basic metamaterial cell pattern employed here consists of a ring resonator - RR or CLL (Capacitively Loaded Loop) in SRR - Split Ring Resonator and CSRR - Complementary Split Ring Resonator configuration topologies. Experimental results are compared to simulated ones and show the tuning characteristic advantages of the patterned septum in comparison to the conventional -passive- type. Also, to avoid reflections, the match between the connector and the center conductor should be carefully designed. This technique appears as an option to optimize GTEM chambers overcoming its size limitation and improving its overall performance.