A UWB bandpass filter using interdigital and periodic UC-PBG structures

Abstract

The conventional microstrip bandpass filter has very narrow passband, and its performance is not excellently good. This paper presents a novel ultra-wideband (UWB) filter with good performance by using periodic uniplanar compact photonic bandgap (UC-PBG) cells and multi-interdigital structures. This novel filter owns a passband of 5.6GHz (1.2-6.8GHz) whose fractional bandwidth is 140%. The simulation results and measurement data verified the proposed UWB filter. In addition, the proposed UWB filter only occupies one and a half wavelength in length or 24.2 mm.