Patent ID: 7231192

Claim:
A single conversion type high frequency receiver comprising: an input terminal for receiving a high frequency signal; a filter coupled to said input terminal; an image rejection mixer having an input part coupled to an output part of said filter; and an output terminal coupled to an output part of said image rejection mixer, wherein said image rejection mixer comprises: a variable frequency oscillator operable to output a signal; a first phase shifter coupled to an output part of said variable frequency oscillator; a first mixer for mixing the output of said filter and an output of said variable frequency oscillator; a second mixer for mixing the output of said filter and an output of said first phase shifter; and a second phase shifter coupled to an output part of said first mixer, wherein said image rejection mixer is operable to generate a signal having an intermediate frequency, the intermediate frequency being a difference between a frequency of the signal output by said variable frequency oscillator and a frequency of the high frequency signal received by said input terminal; wherein said filter is operable to pass a frequency lower than a predetermined cutoff frequency; and wherein the predetermined cutoff frequency is a frequency not higher than a frequency higher than a third harmonic frequency of said variable frequency oscillator by approximately the intermediate frequency.