Patent ID: 7620095

Claim:
A direct sequence spread spectrum radio frequency (RF) modem, comprising: a programmable frequency synthesizer adapted to generate an interrogating pulse and a local oscillator (LO) signal, the frequency of said interrogating pulse and LO signals determined in accordance with a frequency control signal; a pulse generator adapted to generate a shaped pulse from said interrogating pulse, said pulse generator comprising a first pulse shaping circuit adapted to shape the contour of said shaped pulse; a pulse spreader adapted to spread said shaped pulse with a spreading code sequence waveform so as to generate a spread shaped pulse; a transmitter circuit including an upconverter for mixing said spread shaped pulse with said local oscillator (LO) signal having an LO frequency to generate a spread spectrum transmission signal at an RF frequency; a receiver circuit including a downconverter for mixing a received signal with said LO signal so as to generate a received spread pulse at said IF frequency; a correlator adapted to de-spread said received spread pulse in accordance with said code sequence so as to generate a correlator signal; and a detector adapted to generate an output signal in response to said correlator signal.