Planar Filtering Ultra-Wideband (UWB) Antenna With Shorting Pins

A class of UWB filter-antenna is proposed. The proposed filter-antenna is compact, high inband selectivity and insensitive to ground plane size. A via-fed monopole antenna is proposed with tapered shape between the radiator and ground plane. This tapered shape supports two resonant modes to provide wideband matching. Four shorting pins are added to this antenna to improve the selectivity of the filter-antenna performance. Furthermore, a shunt LC-resonator is used to generate the notched-band in the UWB band without extra circuit size. To verify the predicted results, two prototype filter-antennas with and without notched-band are fabricated and measured on a low-cost two-side printed circuit board. The measured results exhibit a good selectivity, the measured return loss is below - 12.5 dB within the desired passband and the size is compact with overall dimension of 28.5×28×0.8 mm³.