| 摘要 |
<p>Methods and apparatus for frequency synthesization are shown for generating an output signal of desired frequency. The frequency synthesizer (54) includes an oscillator (48) for generating an output signal at the desired frequency in response to a control signal. A first detector (182) compares the output signal to a reference signal and generates a first difference signal representative of the differences, preferably in phase and frequency, between the output and the reference signals. A second detector (180) compares the output signal to the reference signal and generates a second difference signal. A controller (26) generates the control signal in response to either the first or the second difference signal. A selector member (108) selects between the first and second detectors to provide either the first or second control signal to the controller (30) in response to a selection signal.</p> |
