A Compact Microstrip Band-pass Filter for S/C-band Applications

This paper presents a compact planar ultrawideband (UWB) band-pass filter (BPF). Initially, it employs a compact BPF with a reversible notched band to reject unwanted signals. The second phase entails determining and establishing the conventional microstrip feed’s input impedance at a fixed value of 50 ohms. Then, to eliminate the unwanted signal, a triangleshaped patch is etched from an L-shaped parallel linked transmission line. The bottom part of the BPF receives grounding. The BPF is designed, simulated, and fabricated in the laboratory. The measured fractional impedance bandwidth of 4.42 and 25.83%, minimum insertion loss of 1.40 and 0.32 dB, and minimum total loss of 15 and 8%, along with flat group delay at first and second resonant frequencies, respectively. Notably, BPF exhibits minimal loss, exceptionally low distortion, and acceptable speed. It demonstrates that the simulation and experimental results support the conclusions. The proposed BPF is suitable for S/C-band applications.