Signal modulating method, involves directly modulating signal that is input to voltage controlled oscillator associated with frequency synthesizer, and suppressing modulation signal from feedback path of frequency synthesizer

摘要

The method involves directly modulating a signal, which is input to a voltage controlled oscillator (16) that is associated with a frequency synthesizer (12), where the synthesizer has a modulation signal with a bandwidth greater than a closed-loop bandwidth of the synthesizer. The modulation signal is suppressed from a feedback path of the synthesizer by a modulation suppressor (20). The signal is directly modulated by converting data to a wideband modulation signal and combining the wideband modulation signal and an output of a loop filter associated with the synthesizer. Independent claims are also included for the following: (1) a frequency synthesizer (2) a wireless communication device including the frequency synthesizer.