A Bandpass Filter with Triple-Narrow Notch Bands Based on Metamaterials SRR Configurations for UWB Applications

Abstract

This paper presents a bandpass filter (BPF) with three narrow notched bands designed for ultra-wideband (UWB) applications. Initially, a basic UWB BPF is designed using a microstrip multimode resonator (MMR) with an open stepped impedance stub loaded at its center. Following that, the Split-Ring Resonator (SRR) is used to generate a triple narrow notched band, allowing undesired signals to be rejected. The frequency range is 2.81 GHz to 10.2 GHz. Beyond this range, there is a strong rejection. Notably, three narrowly notched bands at 5.29, 5.83, and 7.99 GHz are used to achieve in-band interference cancellation, with - 3dB fractional bandwidths of 2.64%, 2.91%, and 1.77%, and rejection levels of -17.15 dB, -11.65 dB, and -11.56 dB, respectively. This filter simultaneously has three main advantages: it is simple, rejects unwanted signals within the bandwidth without affecting the adjacent signals, and achieved high selectivity, the simulation and measurement results show a good agreement, demonstrating effective filtering performance, with a compact dimension of 25.9 x 13.7 mm2.