MINIATURE PLANAR UWB BANDPASS FILTERS WITH CIRCULAR SLOTS IN GROUND

Abstract—In this paper, miniature planar UWB filters with circular slots in ground is presented and we are using a new technique by etching a wideband circular-shape slot resonator in the ground plane of the filters. The proposed filters have compact size of 15 × 12.4 mm2. Two filters are introduced and the final design achieves flat insertion loss and linear phase of S12 throughout the passband (3.14–8.28 GHz) but occasional slight ripple occurs. Two different results are shown and the minimum insertion loss is less than 0.13 dB for both of presented filters. 1