A simple wideband unidirectional antenna with stable symmetrical radiation patterns

In this paper, a simple wideband unidirectional antenna is proposed. The antenna is originated from the basic magneto‐electric (ME) dipole antenna. A pair of half‐wavelength horizontal patches are used to excite the basic electric dipole mode. In order to excite the basic magnetic dipole mode, the horizontal patches are extended inward. As a result, the quarter‐wavelength vertical patches are well excited and the impedance matching is improved in the high frequency band. In addition, a pair of vertical patches are employed, it can not only reduce the resonant frequency of the basic electric dipole mode but also form a new magnetic dipole mode at low‐end frequency. Therefore, the impedance matching in the low frequency band is further improved. The proposed antenna is fabricated and measured. A wide bandwidth of 100% from 2.0 to 6.0 GHz for VSWR 10 dB. Moreover, the radiation patterns are stable, symmetrical, and have no side lobe. The proposed antenna is suitable for wideband unidirectional wireless systems.