Antenna system for a jamming transmitter

摘要

This invention relates to an antenna system for a jamming transmitter which is intended to protect a remote object which is remote from the jamming transmitter as well as itself or an object in the immediate vicinity of the jamming transmitter. Known jammer antennas for this purpose radiate either a pencil beam which presents considerable problems in the alignment and orientation and tracking in two planes or alternatively such known antennas are designed as omni directional antenna which however have low antenna gain and are easily detected. In the present invention the difficulties of the prior art are eliminated in that a separate antenna is provided for external or foreign protection and a separate antenna for self protection which antennas produced in the first plane a sharply focused pattern and in a plane perpendicular thereto a radiation pattern (7, 8) which is optimized for external or foreign protection or self protection, respectively. The two antennas can be switched and are structurally combined and designed to be jointly rotatable in the first plane. A single antenna can also be provided which can be tilted between two positions one for external or foreign protection and the other position for self protection so as to transmit and radiate instead of two separately optimized patterns a single pattern which is a mean of the two desired patterns.