A Design of 79.2-123.1 GHz Waveguide Bandpass Filter with a Wide Stopband

In this letter, a 79.2-123.1 GHz waveguide bandpass filter with a wide stopband is proposed. The filter effectively suppresses the upper and lower sidebands by increasing the order. Enhanced high-frequency suppression is achieved through an asymmetric design approach. Simulation outcomes demonstrate that the filter’s passband spans from 79.2 to 123.1 GHz, with a fractional bandwidth (FBW) of approximately 43.4%. The return loss within the passband exceeds 18.5 dB. Notably, the filter exhibits superior suppression levels exceeding 60 dB in the frequency ranges of 0-75.3 GHz and 130.6-236.7 GHz. The filter design is characterized by its simplicity, ease of manufacturing. It has promising applications in terahertz communication and instrumentation development.