Patent ID: 6069537
Filing Date: 2000-05-30
Classification: H04B,H04L

Abstract:
A double mode modulator for supporting both analog frequency modulation and digital frequency modulation, comprising:a frequency synthesizer for receiving an external reference clock signal, synthesizing a particular frequency from said external reference clock signal and outputting said synthesized particular frequency;a digital modulator for receiving said output of said frequency synthesizer and performing a quadrative modulation; andan analog modulator for receiving said output of said frequency synthesizer and performing a frequency modulation;wherein said digital modulator comprises:an inphase/quadrative phase signal generator for receiving said output of said frequency synthesizer and generating an inphase/quadrative phase signal in response to said output signal; anda mixer for receiving said inphase/quadrative phase signal, an external inphase input signal and an external quadrative phase input signal and adding a first value comprising said inphase/quadrative phase signal multiplied by said external inphase input signal to a second value comprising said inphase/quadrative phase signal multiplied by said external quadrative phase input signal;wherein said analog modulator comprises:a time delaying circuit for receiving and delaying said output signal from said frequency synthesizer; anda time delay control section for controlling an amount of time delay of said time delaying circuit.