Quasi-lumped approach of suspended stripline BPF with zero implantation and cross coupling feed

The bandpass filter of suspended stripline design using the quasi-lumped approach is presented in this letter. An equivalent circuit model of LC lumped elements is developed to analyze the proposed filter. The LC circuit model is optimized and validated by the HFSS simulation. The cross-coupling feed design together with zero implantation structure are used in the filter to create the transmission zeros by the passband for signal selectivity enhancement. The proposed filter has achieved the benefits of size compactness, extremely low insertion losses, low dispersion, and high immunity to environmental noise interference. Experiment is conducted to validate the proposed bandpass filter's design.