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 n/2 or from n/2

to n depending on the parameters of the fixed output low-pass

filter.