A convolver having at least a first interdigital transducer for generating a first surface acoustic wave in response to an input signal and a second interdigital transducer for generating a second surface acoustic wave counter to the first surface acoustic wave in response to a time reversed-time multiplexed...http://www.google.com.hk/patents/US4675839?utm_source=gb-gplus-share專利 US4675839 - Receiver for a spread spectrum communication system having a time-multiplexed convolver
