A SIGNAL-TO-NOISE ENHANCER USING 2 MSSW FILTERS AND ITS APPLICATION TO NOISE-REDUCTION IN DBS RECEPTION

This paper describes the design and development of a new type of MSW s ignal-to-noise enhancer which consists of a microwave circuit using tw o MSSW filters, one of which operates as a frequency selective power l imiter. It also describes the first application of such an enhancer to DBS reception. Compared with a conventional enhancer, the threshold l evel and the limiting action level of this enhancer are 13 dB and 27 d B lower, respectively, and the slope from the former to the latter is much steeper. As a result, the enhancer makes it possible to achieve 2 0-dB lower-power operation (below +10 dBm) of periphery driving circui ts. In DBS reception below the FM threshold, the enhancer improves the S/N of the video signal by 2 to 8 dB.