Broadband Bandpass Filter Utilizing a Multi-Mode Resonator for Wireless Communication Applications

This paper presents a novel broadband bandpass filter that utilizes a multiple-mode resonator (MMR) for communication applications. The filter is designed using Rogers RT/duroid 5880 substrate, which has a relative permittivity of 2.2, a dielectric loss tangent of 0.0009, and a thickness of 0.8 mm. The design process was carried out using the High Frequency Structure Simulator (HFSS). The filter's overall dimensions are 14.8 x 2.9 mm². Simulated S-parameters indicate a bandwidth of 17.46 GHz (6.00 - 23.46 GHz) for the filter. It achieves a 3-dB fractional bandwidth (FBW) of 149.23%, an insertion loss of less than 0.2 dB, and a return loss greater than 48.85 dB, while maintaining a nearly constant group delay across the passband. These exceptional performance characteristics make it highly suitable for a variety of communication systems, including 5G (4–8 GHz), satellite communications, and radar systems operating in the X-band (8–12 GHz) and Ku-band (12–18 GHz).