Simple adaptive heterodyne filter

The tuning of the band pass filter in the simple heterodyne filter structure can be done over a range of 90-degrees by changing the heterodyne frequency. However in this, the heterodyne frequency is constant and can be made adaptive by introducing a Numerical Controlled Oscillator. The proposed design structure uses the Numerical Controlled Oscillator output that can be used as the heterodyne frequency so as to tune the band pass filter effectively.