A Novel Wideband Unidirectional Antenna Composed of a Shorted Bowtie Patch Antenna and a Printed Dipole

Abstract

In this paper, a novel wideband unidirectional antenna composed of a shorted bowtie patch antenna and a printed dipole is proposed. A shorted bowtie patch antenna that works as a magnetic dipole and a printed dipole are connected together and excited simultaneously by an air microstrip line. By adding a pair of parasitic patches above the printed dipole, the bandwidth of the antenna is broadened. A U-shaped reflector is employed to achieve stable gain and radiation patterns over the operating frequencies. Measurement results show that an impedance bandwidth of 84.7% for SWR ≤ 2 from 2.09 to 5.16 GHz is achieved. Stable radiation pattern with low cross polarization, low back radiation and an antenna gain of 9±2.2dBi was found over the operating frequencies.