Design of Trapezoidal Cavity-Backed Resistance Loaded Bow Tie Antenna with Ultra-Wideband and High Directivity

Aiming to develop an antenna with very low tailing and high directivity for transmitting and receiving time-domain pulse, a new type of trapezoidal cavity-backed resistance loaded bow tie antenna has been designed. In order to improve the tailing feature of the signal, resistance loaded bow tie antenna has been used. And in order to enhance the radiation pattern in the desired direction, the technique with backing cavity is always applied. But for an ultraband time-domain pulse, backing cavity may not match the required band which induces distortions in the transmitted signal. In this paper, a trapezoidal backing cavity is proposed for the first time. This kind of design can not only improve the radiation pattern, but also increases the band of the antenna. Simulation results show that the trapezoidal backing cavity has better performance in antenna gain across the frequency band than the rectangular backing cavity. The trapezoidal cavity-backed resistance loaded bow tie antenna has the advantages of easy manufacturing, good radiation pattern and very small tailing. Measured results validate the good performance of the design.