Dual-Band Shared-Aperture Base-Station Antenna Array With Dual Polarization Using Filtering Magnetoelectric Dipole Antenna

This paper presents a dual-band shared-aperture antenna array using a filtering magnetoelectric (ME) dipole antenna for the application of mobile-communication base station. It is realized by interleaving a lower-band (LB) filtering ME dipole antenna operating from 1.7 to 2.8 GHz and four higher-band (HB) patch antennas in the band of 3.3-3.9 GHz. The filtering performance of the proposed ME dipole antenna is realized by U-shaped slots etched on the radiating arms and a cross-shaped microstrip line inside the aperture of the magnetic dipole, and used to realize a high cross-band isolation. The loss caused by the filtering structure is quite low. The gain suppression of the LB filtering ME dipole antenna reaches about 18 dB in the HB. Results demonstrate that both the HB and LB antennas can maintain stable broadside radiation patterns within their operating bandwidths. The magnitude of the cross-band isolation reaches more than 25 dB.