Patent ID: 7164897

Claim:
A modulation or demodulation circuit comprising: a synthesizer for generating a first aperiodic mixing signal φ 1 and second aperiodic mixing signals φ 2 , where φ 1 * φ 2 has significant power at the frequency of a local oscillator signal being emulated, and neither said first aperiodic mixing signal φ 1 nor said second aperiodic mixing signal φ 2 has significant power at the frequency of said local oscillator signal being emulated; an active mixer for receiving an input signal and mixing said input signal with a first aperiodic mixing signal φ 1 , said active mixer having adjustable performance; a high pass filter electrically connected to the output of said active mixer, generating a filtered, mixed signal; and a passive mixer connected to the output of said high pass filter, for receiving said filtered, mixed signal and said second aperiodic mixing signal φ 2 , said second aperiodic mixing signal φ 2 being different from said first aperiodic mixing signal, and mixing said filtered, mixed signal with said second aperiodic mixing signal φ 2 , to generate a modulated or demodulated signal.