An improvement in electrical characteristics of a short backfire antenna

A short backfire (SBF) antenna is considered to be a favorable option for a compact and high efficiency shipboard antenna in maritime satellite communications. Though the SBF antenna has many attractive characteristics, it has a demerit of narrow frequency bandwidths because of its leaky cavity operation in principle. The electrical characteristics of a conventional SBF antenna have been improved by changing its main reflector from a flat disk to a conical plane and by adding a second small reflector. Frequency bandwidths of 20 percent for VSWR's under 1.5 can be obtained by the improved SBF antenna.