Filtering antennas: from innovative concepts to industrial applications

Abstract

A filtering antenna is a device with both filtering and radiating capabilities. It can be used to reduce the cross-band mutual coupling between the closely spaced elements operating at different frequency bands. We review the authors’ work on filtering antenna designs and three related dual-band base-station antenna arrays as application examples. The filtering antenna designs include single- and dual-polarized filtering patch antennas, a single-polarized omni-directional filtering dipole antenna, and a dual-polarized filtering dipole antenna for the base station. The filtering antennas in this paper feature an innovative concept of eliminating extra filtering circuits, unlike other available antennas. For each design, the filtering structure is finely integrated with the radiators or feeding lines. As a result, the proposed designs have the advantages of compact size, simple structure, good in-band radiation performance, and low levels of loss, and do not contain complicated filtering circuits. Based on the proposed filtering antennas, single- and dual-polarized dual-band antenna arrays were developed. Separate antenna elements at different frequency bands were used to achieve the dual-band performance. The cross-band mutual couplings between the elements at different bands were reduced substantially using the antenna inherent filtering performance. The dual-band arrays exhibited better performance as compared to typical industrial products. Some of the proposed technologies have been transferred into the industry.

Keywords

Filtering antenna / Dual-band / Antenna array

RIGHTS & PERMISSIONS

2020 Zhejiang University and Springer-Verlag GmbH Germany, part of Springer Nature