Patent ID: 6269241
Filing Date: 2001-07-31
Classification: H04B

Abstract:
An active filter comprising:a circuit that corrects for impedance mismatch of an input signal, without matching its impedance;a heterodyning unit having an input signal frequency and an output signal frequency that are equal; the heterodyning unit comprising:a first mixer operable to downconvert the input signala second mixer operable to upconvert to the output signala local oscillator for outputting a first frequency signal, the first frequency signal being fixed;a voltage controlled oscillator for outputting a second frequency signal, the second frequency signal selected from a range of frequency signals;a synthesized splitter operable to receive the first frequency signal and the second frequency signal and to combine the first frequency and the second frequency to form a combined frequency and supply the same combined frequency to the first mixer and the second mixer; anda circuit that corrects for impedance mismatch of the output signal, without matching its impedance.