A miniaturized UWB bandpass filter using open stub T- shaped line loaded resonators

Abstract

In this paper, a miniature planar ultra-wideband (UWB) bandpass filter has been proposed and simulated by using loop resonators. The occupied size of the proposed filter is 123 mm2 The studied filter is not only compact but also delivers excellent scattering parameters with magnitude of insertion loss, S21 lower than 0.09dB and return loss found better than 20 dB. The bandpass filter has 3-dB fractional bandwidth of 65% of center frequency (5.46 GHz), in the range of 3.7 GHz to 7.22GHz. A new feature of the loop resonator filter is constructed by ring resonator and T-shaped stub loaded at the line center.