Patent ID: 7783250

Claim:
A method for up converting a transmitted signal from a first frequency to a second frequency and down converting a received signal from the second frequency to the first frequency, the method comprising: splitting the transmitted signal to produce a first lower frequency transmit signal at the first frequency and a second lower frequency transmit signal at the first frequency, the first lower frequency transmit signal and the second lower frequency transmit signal having equal or nearly equal amplitudes and being in phase with each other; coupling the first lower frequency transmit signal into a first frequency multiplier circuit to produce a first higher frequency transmit signal; coupling the second lower frequency transmit signal into a second frequency multiplier circuit to produce a second higher frequency transmit signal; shifting the phase of the second higher frequency transmit signal to produce a phase-shifted second higher frequency transmit signal; adding the first higher frequency transmit signal to the second higher frequency transmit signal to produce an output transmit signal at the second frequency at a first output port; adding the first higher frequency transmit signal to the phase-shifted second higher frequency transmit signal to produce no signal at a second input port; receiving a receive signal at the second frequency at the second input port; splitting the received signal to produce a first higher frequency receive signal at the second frequency and a second higher frequency receive signal at the second frequency, the first higher frequency receive signal and the second higher frequency receive signal having equal or nearly equal amplitudes and being 180 degrees out of phase with each other; coupling the first higher frequency receive signal into the first frequency multiplier circuit to produce a first lower frequency receive signal; coupling the second higher frequency receive signal into the second frequency multiplier circuit to produce a second lower frequency receive signal; shifting the phase of the first lower frequency receive signal to produce a phase-shifted first lower frequency receive signal; and adding the phase-shifted first lower frequency receive signal to the second lower frequency receive signal to produce an output receive signal at the first frequency at a second output port.