A broadband patch antenna with wide slits

Abstract

Broadband patch antennas with a thick air or foam substrate have been of considerable interest owing to their simple structure, easy fabrication, and good radiation characteristics over a wide operating bandwidth. However, when such broadband patch antennas are to be excited using a probe feed, achievable bandwidth is usually limited to be less than 10%, due to the large inductance associated with the longer probe in the thick substrate layer. To overcome this problem, there are usually some compensations or modifications to be introduced in the feed arrangement or some slot loadings to be added to the radiating patch. In this article we demonstrate a new and simple broadband design of a patch antenna with a pair of wide slits. The wide slits are inserted at the boundary of a circular patch or at one of the radiating edges of a rectangular patch. The proposed broadband patch antenna can have similar wide impedance bandwidth and good radiation characteristics as those reported for a U-slotted patch antenna. Details of the antenna design and experimental results are presented and discussed.