MMIC and fiber optic delay line hybrid transversal filter

Microwave transversal filters suffer from bandwidth limitations and the inability to provide long time delays due to losses and dispersion in the microstrip delay line. Purely optical transversal filter disadvantages include inaccurate weighting and the inability to provide negative weighting coefficients. Therefore, a novel hybrid transversal filter configuration that utilizes the optical fiber as a delay mechanism, with negligible loss and wide bandwidth, and an existing monolithic microwave integrated circuit (MMIC) transversal filter to provide the necessary accurate positive and negative weighting is presented. The noise performance, dispersion due to the delay line, and a comparison of frequency responses of the existing MMIC advanced transversal filter, the hybrid transversal filter and an ideal filter are reported. The optimum hybrid filter configuration is determined from an analysis of various configurations