On the design of shallow depth T-bar fed slot antennas

The results of an intensive experimental effort directed toward the electrical improvement and size reduction of the T-bar fed, cavity-backed slot antenna are described. The experimental investigation, conducted over the four to one frequency range of 500 to 2000 MHz, was concerned primarily with optimizing the T-bar geometry of an earlier investigation conducted by Newman and Thiele [1]. In the course of this investigation the performance of the T-bar antenna was evaluated with respect to such variable parameters of the T-bar antenna as cavity depth, the T-bar depth from the aperture, and cavity tuning. As a result of these experimental investigations, a T-bar slot antenna evolved that offers a viable solution to some of the unusual design requirements experienced in receiving situations. The T-bar antenna evolving from this investigation is small in size, may be flush mounted with little cavity depth required, and possesses favorable electromagnetic characteristics over a 4:1 frequency range. The results of this investigation can be scaled to other frequency ranges.