Bandwidth-Enhanced High-Gain Full-Metal Filtering Slot Antenna Array Using TE101 and TE301 Cavity Modes

Abstract

In this letter, a bandwidth-enhanced high-gain full-metal cavity-backed filtering slot antenna array is proposed. By replacing one radiating slot with 2 × 2 radiating slots, the enhanced gain is obtained without enlarging the antenna size. Besides, two cavity modes, i.e., TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">101</sub> and TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">301</sub> , are combined to obtain an enhanced bandwidth. Metal ridges and metal posts are employed to make the two modes close to each other. Due to a similar radiating field of the two specific cavity modes under the proper perturbation and placement of the 2 × 2 radiating slots, a high gain over the enhanced bandwidth is obtained. In addition, the high-quality factor of the two cavity modes can inherently produce a filtering performance in terms of the realized gain and efficiency. The final measurement shows that the proposed slot antenna array can achieve 6.2% bandwidth, 97% total efficiency, and 10.4–11 dBi stable realized gain with a small aperture size of 0.84 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Good agreement between the simulation and measurement has well validated the proposed design concept.