Patent ID: 6373559
Filing Date: 2002-04-16
Classification: G01S

Abstract:
An optoelectronic mixer for demodulating a high-frequency light signal amplitude modulated at a signal frequency (fsig), the optoelectronic mixer comprising:a light sensor for receiving and converting said light signal into free charge carriers; said light sensor having at least two individually drivable sensor electrodes on which respective voltage signals are outputted; a reference frequency generator for supplying an alternating-current voltage at a reference frequency (fref); said reference frequency generator being connected to said sensor electrodes to alternately conduct said charge carriers to the one or the other of said sensor electrodes at said reference frequency (fref); high-impedance amplifiers connected to corresponding ones of said sensor electrodes for buffering and lowpass filtering said voltage signals, respectively; and, a difference amplifier having first and second inputs for receiving corresponding ones of the buffered and lowpass filtered signals to form an output signal having a difference frequency (fsigâˆ’fref).