The effect of diffraction on the dispersive delay lines performance

This paper describes the influence of the diffraction effect on the compressed signal sidelobes level. The analysis was made using angular spectrum of waves (ASoW) model. This model is very flexible and can be used for various SAW devices. Calculations were carried out for many types of dispersive delay lines with one dispersive and one periodical transducer. The iterative synthesis technique for the correction of diffraction in SAW compressor is described (it will be shown in the first part of the paper that the influence of diffraction on the expander characteristic is usually negligible). Using the results, various pulse-compression and expansion filters were designed and manufactured. A very good agreement between calculations and measurements was observed