Patent ID: 7826814
Filing Date: 2010-11-02
Classification: H03B

Abstract:
1. A frequency synthesizer comprising: a single-tone signal generator which outputs signals of a single frequency; a frequency multiplier which generates one or more intermediate signals having different frequencies based on frequencies of input signals and outputs the same as output signals, and controls output or output stop of the intermediate signal by a frequency multiplier control signal; a frequency selector which includes one or more input terminals and outputs an input signal selected by a frequency selector control signal; a mixer which performs frequency mixing to two input signals and generates an output signal; and a frequency synthesizer control circuit which includes a frequency synthesizer control terminal, wherein an output of the single-tone signal generator is set as an input of the frequency multiplier, wherein one or more outputs of the frequency multiplier are set as one or more inputs of the frequency selector, wherein an output of the frequency selector and one output of the outputs of the frequency multiplier are set as first and second inputs of the mixer, wherein an output of the mixer is set as an output of the frequency synthesizer, wherein the frequency multiplier comprises: a frequency divider unit provided with one or more frequency divider circuits having different frequency dividing numbers; and a mixer unit which outputs a signal of frequency generated by adding and subtracting of frequencies by frequency mixing based on the signals generated by the frequency divider unit, wherein the frequency divider unit of the frequency multiplier comprises: a first path which inputs a differential input signal of the frequency multiplier as its input signal, divides the signal by two, and outputs a four-phase signal thereof; a second path which inputs a differential input signal of the frequency multiplier as its input signal, divides the signal by four, and outputs a four-phase signal thereof; a third path which inputs a differential input signal of the frequency multiplier as its input signal, divides the signal by ten, and outputs a four-phase signal thereof; a fourth path which inputs a differential input signal of the frequency multiplier as its input signal, divides the signal by twenty, and outputs a four-phase signal thereof; and a fifth path which inputs a differential input signal of the frequency multiplier as its input signal, divides the signal by thirty, and outputs a four-phase signal thereof, wherein, in the mixer unit of the frequency multiplier, a first input terminal of two inputs of a first mixer is connected to an output terminal of the second path and a second input terminal thereof is connected to an output terminal of the third path, and an output of the first mixer is set as a first output of the frequency multiplier, a first input terminal of two inputs of a second mixer is connected to an output terminal of the first path and a second input terminal thereof is connected to an output terminal of the fourth path, and an output of the second mixer is set as a second output of the frequency multiplier, and a first input terminal of two inputs of a third mixer is connected to an output terminal of the second mixer and a second input terminal thereof is connected to the output terminal of the third path, and an output of the third mixer is set as a third output of the frequency multiplier, and wherein the fifth path is set as a fourth output of the frequency multiplier.