A Mutual-Coupling-Suppressed Dual-Band Dual-Polarized Base Station Antenna Using Multiple Folded-Dipole Antenna

Abstract

An interleaved shared-aperture dual-band dualpolarized base station array antenna is proposed in this article. The lower-band (LB) element is realized by using a multiple folded-dipole antenna (MFDA) and four parasitic loops. To interpret the working principle of the MFDA, a double folded-dipole antenna (DFDA) is firstly analyzed by using the transmission line (TL) model. Then, by combining two bended DFDAs and introducing four parasitic loops, a low cross-band scattering LB element with a high out-of-band rejection level of 16 dB is obtained to cover 2.3-2.7 GHz. The higher-band (HB) element with a wide impedance bandwidth of 42.5% (3.0-4.6 GHz), a high roll-off rate (RoR) of 249.2 dB/GHz, and a high out-of-band rejection level of 17 dB is obtained by introducing a meander line loop (MLL), a rectangular loop (RL), and V-shaped strips (VSS) near the dipole arms. By combining the proposed lowscattering low-pass LB element and the high-RoR high-pass HB element, a novel interleaved shared-aperture dual-band dualpolarized array antenna with a small frequency ratio of 1.46 and a high cross-band isolation level of 25 dB is realized. Due to the low-scattering characteristic and filtering response of the LB element, the radiation patterns of the wideband HB sub-arrays are almost unaffected.

Wideband Dual-Polarized Filtering Antenna for Base Station Applications

“…Some filtering antennas were presented in [15]- [25] to reject the unwanted radiation. By combining the high-pass property of the ME dipole and the low-pass feeding network, a wideband dual-polarized antenna with bandpass response was presented in [18].…”

Compact dual-band antenna design for sub-6 GHz 5G application

“…The dual-band antenna is developed in many ways as reported in the literature. A folded dipole dual-band antenna with rogers substrate was reported in [4]. The large size of the folded dipole antenna makes it unsuitable for 5G applications.…”

An Inductor-Loaded Single-Port Planar Dual-Broadband Antenna with Stable Gains

“…Instead of single-band performance, antennas with dual-band operation are much preferred because of the above advantages. For most mobile communication systems, it is popular for the frequency bands from 0.69 GHz to 0.96 GHz and from 1.71 GHz to 2.69 GHz to be covered simultaneously [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. The dual-frequency antennas can be divided into single-port and dual-port.…”