Study of triple transit echo for time sidelobe of SAW matched filter

Surface Acoustic Wave (SAW) matched filter is a key-device for Spread Spectrum (SS) communication. We have shown that the Triple Transit Echo (TTE) level of a matched filter for the SS signal is lower than that of an ordinary SAW transversal filter for CW signals even if the external circuit impedance is fully matched to the SAW matched filter. A time-domain analysis using a circuit network tool for various kinds of construction has been used for the matched filter with a 25-chip low autocorrelation sequence. The analysis agreed with the experiments to verify this TTE behavior.