The application of acoustic charge transport technologies to wideband communication systems

The strengths and weaknesses of ACT (acoustic charge transport) devices for communication-related signal processing applications are discussed. The main strength of ACT devices is in PTFs (programmable transversal filters), where they offer a high degree of flexibility in very small physical volumes and with lower power dissipation in comparison with competing technologies. The main limitation of ACT PTFs is their limited dynamic range. A radio receiver breadboard was designed to perform both time-domain and frequency-domain signal processing of arbitrary input waveforms. The performance of this breadboard was demonstrated and documented. This breadboard design was then incorporated into a complete radio receiving system design intended for application to LPI (low-probability-of-intercept) communications. The system design exploits the advantages of ACT devices while minimizing the impact of their limitations. The multimode ability of the receiver is used to advantage to perform an adaptive excision of narrowband interference which provides additive processing gain to the very substantial spread spectrum processing gain.<
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