A magneto-electric dipole for unidirectional UWB communications

A new magneto-electric dipole antenna is designed. The antenna is composed of a horizontal bowtie electric dipole, a center-fed loop antenna functioning as a magnetic dipole and a rectangular cavity. A microstrip-to-stripline transition is employed as a balun to feed the antenna. A prototype was fabricated and measured. Results show that an impedance bandwidth of 110%, with SWR ≤ 2 from 3.08 to 10.6 GHz, was achieved. A stable gain of 8.7 ± 1.9 dBi was realized by using the rectangular cavity. Stable radiation pattern with low cross polarization ≤ -20 dB, low back radiation (≤ -13 dB) and symmetrical E- and H-plane patterns was found over the operating frequencies. Moreover, the impulse response is analyzed which reveals the antenna with good time domain characteristic. © 2013 IEEE.