On the design of moderate time-bandwidth SAW convolver for indoor and mobile radio applications

The main applications of surface acoustic wave (SAW) convolvers have previously been military and have required high processing gain values. Rather complex hybrid fabrication technologies have to be employed needing large packages and resulting in expensive devices. Applications in radio frequency (RF) consumer communications use relatively short code sequences. For these systems, low-cost SAW convolvers with moderate time-bandwidth products on the order of a few hundred have many interesting features. To meet the demands for low price and high reliability, precise reproducible designs and economic mass production of the devices are indispensable. The authors report on the design and performance of a small and compact prototype SAW convolver. Input center frequency, integration time and time-bandwidth product are 350 MHz, 3 μs and 150, respectively