Economical Compact Filters with Coupled Shorting Stubs

A compact filter with coupled shorting stubs is proposed, which also has excellent out-of-band elimination. The structure can produce transmission zeros at both sides of the pass-band of a broadband or a narrow band filter. The configuration parameters and simulated results are presented. Tested results from a sample filter show that the insertion loss is lower than 0.4 dB in the pass-band from 7.65 GHz to 8.7 GHz and elimination higher than 40 dB from 8.81 GHz up.