Signal processing unit

Claim 1

A signal processing unit comprising: a receiver for receiving a signal; an amplifier coupled to said receiver for amplifying said received signal; a first distributor means coupled to said amplifier for producing two output signals from said amplified signal; an oscillator; a first phase shifter connected to said oscillator; a second distributor means coupled to said output of said phase shifter for producing a plurality of outputs; a second phase shifter coupled to one of said outputs of said second distributor means for shifting said signal 90°; two phase detectors each receiving one of said outputted signals from said first distributor means for performing synchronous detection of the outputted signals with one of said phase detectors being coupled to and responsive to a signal outputted by said second distributor means not passing through said second phase shifter and the other of said phase shifter that shifts said signal by 90°; two A/D converters each connected respectively to said phase detectors for converting the output of each of said phase detectors to a digital signal; and a digital processing means for accepting the digital signals produced by said A/D converters and for constantly and automatically producing an automatic error compensation of said received signal.