Yu.G. Antonov, L.A. Aronov, S.V. Grachev, V.N. Ushakov
Acousto-optic processors (AOP) allow to perform spectrum analysis and correlation processing of wideband signals (with bandwidth up to 2 GHz) and to be real alternative to general-purpose digital processors.
This paper introduces the results of experimental examination of automated radiotechnical complex mock up, meant for receiving, detecting and characterization of wideband compound radio signals and direction finding of their sources in UHF-SHF ranges.
Automated radiotechnical complex performs panoramic receiving, detecting and characterization of radio signals. At the same time it performs direction finding of signal sources in wide range of angles (90).
Received by antenna system, which is two wideband vibrator antennas, radio signals are amplified and then heterodyned by two-channel wideband UHF-tuner to a working bank of AOP. Tuner output signals drive the inputs of AOP, which performs processing of intermediate frequency signals on a light wave carrier. Output signals of AOP are digital, they contain the information about frequency and bearing of observed signals. AOP is based on scheme of Young interferometer and to be an acousto-optic spectrometer-phasometer. The products of processing in optical core then post processed by digital signal processor (DSP). During this post processing signals are detected and then their characterization is performed. It gives such parameters as: amplitude, carrier frequency, spectrum bandwidth, bearing and the moment of signal determination and signal loss. These parameters are then transmitted to the CPU of the computer, which correlates them with information in database and fill it up with the information about determined signals. The results of radio environment monitoring are routinely displayed on computer interface in a user-friendly way. Complex supports two operating modes: spectrum analyzer with bearing and spectrum analyzer with enhanced dynamic range.
The results achieved during examination show that the combining the acousto-optic processors and digital signal processing allows radio signals parallel spectrum analysis in a band of 500 MHz with frequency resolution of 1 MHz and direction finding of their sources to within 2.5º in the angle range of 90.