Analysis of parasitic effects of GHz-range SAW matched filters for wireless pulse communication systems

The feed-through signals leaking directly from input to output transducers of a SAW matched filter degrade correlation performance, especially for wireless pulse communication systems operating in the gigahertz range, such as an ultra wide band (UWB) communication system. The parasitic effects of the gigahertz-range SAW matched filter were analyzed by combining a SAW simulator and an electromagnetic wave simulator, in order to provide a high-performance gigahertz-range SAW matched filter. Based on the analysis, the new SAW matched filter with symmetrical configuration, at 4 GHz with high isolation, was designed and fabricated on 42/spl deg/ Y-X LT. The measured results showed a good suppression of the feed-through. The correlation result using the new SAW matched filter indicated that the correlation signal has a sufficiently large ratio of desired correlation signal to unwanted signals (D/U ratio).