Miniaturized Broadband Dual-Polarized Magnetoelectric Dipole Antenna With High Isolation and Filtering Response

Abstract

A miniaturized broadband dual-polarized magnetoelectric (ME) dipole antenna with extremely high isolation and bandpass filtering response is proposed. A miniaturized $\Pi $ -shaped folded ME dipole antenna is presented to introduce extra capacitor and inductance for achieving a wide bandwidth. Then, a special feed network, which includes a microstrip-to-slot feed scheme and a $\Gamma $ -shaped feeding probe, is utilized to excite the ME dipole antenna for realizing current cancellation between the two ports, thus resulting in extremely high isolation.In addition, good filtering performance is generated by using the $\Pi $ -shaped folded ME dipole radiator and low-pass filters in the feed network. By employing this new structure, a wideband ME dipole antenna having high isolation, excellent out-of-band suppression, and small size is designed. It achieves very high isolation of beyond 45 dB over a wide bandwidth of 47.7% (1.68–2.73 GHz) and small size of $0.38\lambda _{0} \; \times \; 0.38\lambda _{0} \; \times \; 0.15\lambda _{0}$ ( $\lambda _{0}$ is the wavelength at the center frequency). Our antenna also achieves a good bandpass filtering response and the out-of-band sup(pression level) is beyond 18 dB.