Wide-Beamwidth Unilateral Dielectric Resonator Antenna Using Higher-Order Mode

Abstract

For the first time, a unilateral rectangular dielectric resonator (DR) antenna (DRA) is designed using two DR modes, namely the fundamental $\boldsymbol{TE}_{\boldsymbol{\delta }11}^{\boldsymbol{x}}$ mode and higher-order $\boldsymbol{TE}_{2\boldsymbol{\delta }1}^{\boldsymbol{y}}$ mode. The former and latter provide the broadside and quasi-omnidirectional radiation patterns, respectively. By combining the radiation fields of the two resonant modes, unilateral radiation with wide 3 dB beamwidths can be obtained. For demonstration, a unilateral rectangular DRA was designed in 2.4 GHz WLAN band. Across the WLAN band, the DRA has a measured front-to-back ratio (FTBR) of higher than 15 dB. It is found that the measured maximum FTBR of the DRA is 36.6 dB, whereas the measured 3 dB beamwidths of the two principal radiation planes are both wider than 174°.