Wideband Acousto-Optic Processor for UHF Signals

Signal environments nowadays are becoming increasingly complex. To more readily intercept, classify, and analyze wideband signals, additional receiver sophistication is required. In the paper, a hybrid acousto-opto-digital system for processing of such signals is described.

The heart of the processor is a two-dimensional quadrature radio-frequency time-integrating acousto-optic correlator with slanted light beams. Quadrature channel is implemented by using the second spatial axis. Such device can have a processing bandwidth up to 1 GHz. The correlator is complemented by a digital post-processor that performs nonlinear detection and provides spectrum information. Flexible distribution of processing between optical and digital units leads to a compact solution for detection and analysis of wideband spread-spectrum signals.

The following points are discussed: the general structure of the processor, active (deterministic signal detection) and passive (stochastic signal detection) operating modes, post-detector processing algorithms, possible values of sensitivity, dynamic range and frequency resolution. Experimental results obtained in the UHF range are also presented.