Analysis of parallel coupled-line bandpass filters using a ground plane aperture

Parallel coupled-line bandpass filters using the ground aperture technique is analyzed in this paper. A design guide for this kind of coupled-line bandpass filters on commonly used both high and low permittivity substrates is presented Based on the proposed design curves, two sample bandpass filter configurations are designed. The design is simulated by Ansoft HFSS and validated by the measurement. Good agreement between simulated and measured responses is obtained.