Abstract: Aircraft decoy arrangement and method for generating a decoy signal from an aircraft having an isolated decoy. An aircraft receiver detects a threat signal from a threat source targeting the aircraft. An aircraft signal processor produces a decoy relay signal based on the threat signal, where the decoy relay signal frequency is significantly lower than the threat signal frequency and is slowly attenuated through air, the signal processor calibrating the decoy relay signal in accordance with a received test signal to compensate for inaccuracies. An aircraft transmitter transmits the decoy relay signal and an optional reference signal to the decoy, where it is received by a decoy receiver, converted back to a decoy signal by a decoy frequency converter, and transmitted by a decoy transmitter, causing the threat source to detect the decoy signal and lock onto the decoy rather than the aircraft.

Abstract: A system for monitoring a multiplicity of doors including at least two optical transceivers mounted on each of the multiplicity of doors and communication apparatus for communicating with the optical transceivers mounted on each of the multiplicity of doors thereby to verify their position, the communication apparatus being operative to communicate with the optical transceivers on each of the multiplicity of doors via plural serial communications pathways, at least one of the plural pathways extending via optical transceivers mounted on a plurality of different doors.

Abstract: A waveguide-fed microwave system particularly for cavity-backed spiral antennas for the Ka band comprises a waveguide transmission line; a microwave device having a pair of balanced, parallel feed wires; and a doubled tapered ridge transformer directly connecting the waveguide transmission line to the balanced, parallel feed wires of the microwave device providing a direct symmetrical transition between the waveguide transmission line and the microwave device.