Abstract: A privacy system in which an analog information-bearing signal is linearly combined with a noiselike coding waveform to produce a composite waveform of unrecognizable, scrambled signal for transmission to an authorized system user at a remote receiving terminal. The noiselike waveform is developed from the original information signal, and the original signal reproduced from the composite waveform, to eliminate any need for synchronization between transmitter and receiver. At the transmitting terminal, the composite waveform is infinitely clipped and amplified to produce a digital format which is serially fed through a shift register in accordance with shift pulses derived from the clipped signal transitions. Various outputs of the several stages of the shift register are selectively applied, via a switching matrix, to an encoder which generates the noiselike or pseudo-random signal therefrom.

Abstract: An n.times.m wideband RF switching matrix constructed from modules which are interconnected by simple series paths. As many modules as required can be juxtaposed to form switching matrices of any order. Each module includes n inputs and a different lumped element directional coupler connected to each input, each directional coupler having a coupled output. Each module further includes a conductor coupled to a matrix output. The coupled outputs of the directional couplers on a given module are connected through single-pole, single-throw switches to the conductor. The direct outputs of the directional couplers are coupled to the inputs of the n directional couplers on the next module in the series.