FPGA implementation of a tunable band-pass filter using the "basic heterodyne block"

Any Band-Pass filter may be converted into a tunable filter with a single tuning parameter through the use of a new Tunable Heterodyne Band-Pass Filter concept in which the frequency of the heterodyne signal is adjusted thereby translating the entire filter transfer function in frequency. If the fixed filter is selected to be a narrow-band band-pass filter, the new Tunable Heterodyne Band-Pass Filter concept can be used very effectively in the elimination of narrow band interference in wide-band communications or control systems. A single-chip version of this tunable filter can be constructed using a Xilinx Virtex XCV800 chip. The resulting filter is a flexible tunable band-pass filter that can be varied from DC to π/2 or from π/2 to π depending on the parameters of the fixed output low-pass filter.