Abstract: An improved communications jamming receiver is disclosed wherein time division multiplexing techniques are utilized that permit monitoring enemy radio frequency transmissions while in essence concurrently transmitting signals to jam selected enemy transmissions. The time division multiplexing alternately enables the communications receiver and a jamming transmitter at a frequency higher than the Nyquist rate of the threat signal being received to effectively continuously receive enemy transmissions while preventing reception of the jamming signals from the associated jammer transmitter. The multiplexing is carried on in a random fashion that prevents the enemy from determining the rate and transmitting during the period that the improved receiver is disabled.

Abstract: Apparatus is herein disclosed for imminent collision detection equipment for acknowledging proximity between a first object carrying the equipment and a second object. The imminent collision detection apparatus is a radio distance measuring device and includes a transmitter and a receiver. The transmitter has a pulsed energy output which is reflected back by a target and mixed with a reference source of pulsed energy generated a predetermined time after the transmitted output and coherent thereto. The coherent feature of the equipment lies in the fact that the transmitter pulsed output and the pulsed reference signals are both generated with the same starting phase each generated pulse. Furthermore, the transmitted and reference signals are jittered to provide a resistance to countermeasures capability.