A Ka-band substrate-integrated waveguide diplexer with wide frequency spread

摘要

A compact 20 GHz/30 GHz diplexer for satellite communication systems is presented. It consists of a T-junction and two bandpass filters implemented in substrate-integrated waveguide (SIW) technology. The 30 GHz filter relies on a standard design, whereas a wide stopband approach is used for the 20 GHz filter to suppress a parasitic passband at the upper frequency. The design procedure is explained and simulation as well as measurement results are presented. The complete diplexer is fabricated in a standard PCB process. The measurement results validate the approach.