US 7,477,879 B1
	Transceiver system with common receiver and transmitter oscillator
Ramkishore Ganti, Dripping Springs, Tex. (US); and Caiyi Wang, Austin, Tex. (US)
Assigned to Silicon Laboratories, Inc., Austin, Tex. (US)
Filed on Jun. 30, 2005, as Appl. No. 11/172,039.
Int. Cl. H04B 1/40 (2006.01)

U.S. Cl. 455—88  [455/86; 455/76; 455/84; 455/78; 375/332; 375/376]

19 Claims

1. A transceiver system comprising: transmitter circuitry configured to generate a transmitter radio frequency (RF) signal; a first oscillator coupled to a mixer in the transmitter circuitry and configured to provide a transmit frequency signal to the mixer to generate the transmitter RF signal; receiver circuitry configured to receive a receiver RF signal; wherein the first oscillator is coupled to a first stage mixer in the receiver circuitry and configured to provide the transmit frequency signal to the first stage mixer to down-convert the receiver RF signal from a receive frequency to an intermediate frequency (IF); wherein the first stage mixer is configured to down-convert the transmitter feedthrough RF signal from the transmit frequency to a baseband frequency; and a capacitor coupled in series to an output of the first stage mixer and configured to filter out a transmitter RF feedthrough signal at the baseband frequency.