A Cavity-Type Broadband Antenna with a Steerable Cardioid Pattern

摘要

This report describes a new vertically polarized cavity-type antenna with a cardioid pattern steerable in the horizontal plane. The front-to-back ratio is better than 15 dB over a 25% bandwidth and better than 20 dB within half that total bandwidth. The average gain is approximately 2 dB above a monopole and the VSWR<2 except at the very end of the band. The beamwidth in the front as well as the nullwidth in the back is so wide that the beam is directed only in the four cardinal directions in the horizontal plane. A working model will be delivered to NRL as part of the contract. (Author)