Patent ID: 7741926
Filing Date: 2010-06-22
Classification: H03B

Abstract:
1. A frequency synthesizer, comprising: first and second CMOS quadrature voltage-controlled oscillators for generating four-phase signals; a CMOS selector for selecting either one of the two four-phase signals generated by said first and second CMOS quadrature voltage-controlled oscillators; a CMOS SSB mixer for multiplying the four-phase signal selected by said CMOS selector by a four-phase input signal input from an external source to generate and output a signal having a frequency represented by the sum of, or the difference between, the frequency of said four-phase signal and the frequency of said four-phase input signal; a CML buffer for adjusting the level of the output signal from said CMOS SSB mixer and outputting the adjusted signal to another circuit; and a four-phase input signal level adjusting CML buffer for converting said four-phase input signal into a signal having a CML level.