Wide Bandwidth Acoustoelectric Convolvers

The use of convolvers as programmable matched filters for spread-spectrum comnunication provides the ability to change the coding waveform from bit-to-bit, thus offering improved security and protection against r epeat jamming. In many applications, maximum signal bandwidth is desired because increased bandwidth provides for improved tolerance to effects of multipath and fading, increased c overtness, and larger p otential processing gains when maximum bit lengths a re limited, e.g. by Doppler shifts. In order to better meet these needs, the bandwidth of acoustoelectric convolvers has been extended by a factor of two over previously demonstrated convolver bandwidths. A gap-coupled convolver for decoding differential phase-shi ft-keyed (DPSK) signals having a 200-MHz bandwidth and a time-bandwidth product of 2400 has been developed and evaluated. range of 46 dB and a conversion efficiency (F-factor) of -77 dBm have been obtained. formance details are presented and compared with theoretical Predictions. A device dynamic Design and per