Patent ID: 6137997
Filing Date: 2000-10-24
Classification: H04B

Abstract:
A circuit for receiving and transmitting Radio Frequency (RF) signals, comprising:a mixer having a first input terminal, a second input terminal, and an output terminal;a synthesizer having a first input terminal, a second input terminal, and an output terminal coupled to the second input terminal of the mixer; anda first summing device having a first input terminal coupled to the output terminal of the mixer, a second input terminal coupled to the second input terminal of the synthesizer, and an output terminal,wherein the synthesizer comprises:a phase detector having a first input terminal coupled to the first input terminal of the synthesizer, a second input terminal, and an output terminal;a loop filter having an input terminal coupled to the output terminal of the phase detector and an output terminal;a second summing device having a first input terminal coupled to the output terminal of the loop filter, a second input terminal coupled to the second input terminal of the synthesizer, and an output terminal; andan oscillator having an input terminal coupled to the output terminal of the second summing device and an output terminal coupled to the output terminal of the synthesizer and to the second input terminal of the phase detector.