Patent ID: 9077420
Filing Date: 2015-07-07
Classification: H04B

Abstract:
1. A radio frequency (RF) receiver comprising: a first mixer receiving an RF signal; a second mixer receiving the RF signal; a resonant circuit coupled to an input of the second mixer; a direct current circuit coupled to an output of the first mixer to inject a direct current thereto, wherein a resonant frequency of the resonant circuit is set at a frequency such that a voltage on the output of the second mixer is a predetermined voltage, wherein the resonant circuit comprises a switch capacitor, and the frequency of the resonant circuit is set by changing a switching state of the switch capacitor, and wherein the switch capacitor is a first switch capacitor, and the resonant circuit further comprises a second switch capacitor; wherein a capacitance of the first switch capacitor is twice or more of a capacitance of the second switch capacitor.