A compact highpass filter with broad passband

A highpass filter is designed, which is based on shorting stubs in cascade. The design considerations for broad passband and compactness are presented, together with simulated and tested results. Tested results show that the sample filter has a passband from 3 to 12.75GHz, with an insertion loss less than 1dB and a rejection of 60dB for frequencies lower than 2.4GHz. Further work to improve the return loss is also discussed.