A TUNABLE HETERODYNE FILTER DESIGN ON RECONFIGURABLE FABRIC

This paper presents the design of tunable heterodyne filter that can be used very effectively in the elimination of narrowband interference in wide-band communications. The filter makes use of the heterodyne process to create a tunable notch filter from a fixed coefficient high-pass filter. It has been shown that it is possible to generate a signal that can be used to set the heterodyne frequency to match the tunable heterodyne notch filter to the center of the detected interference through the use of a simple second order IIR band-pass filter to detect the narrowband interference. Moreover various options have been illustrated for the implementation of heterodyne filters using Xilinx Virtex field programable gate arrays (FPGAs).