Calvin C Chen

US Patent:

8358991, Jan 22, 2013

Filed:

Jan 26, 2010

Appl. No.:

12/693981

Inventors:

Xinyu Chen - Irvine CA, US
Calvin (Shr-Lung) Chen - Irvine CA, US
John Leete - Huntington Beach CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/06

US Classification:

4552321, 4552341, 455341, 330261, 330301

Abstract:

Embodiments of an RF receiver front-end are presented herein. In an embodiment, the RF receiver front-end comprises a transconductance LNA, a passive mixer, and a g-enhanced common-gate buffer. The transconductance LNA is configured to convert an RF voltage signal to an RF current signal and provide the RF current signal at an output. The passive mixer is coupled to the output of the transconductance LNA and is configured to mix the RF current signal with a local oscillator signal to produce a frequency translated current signal. The g-enhanced common-gate buffer is configured to receive the frequency translated current signal at an input and convert the frequency translated current signal to a frequency translated voltage signal. In an embodiment, the input of the gm-enhanced common-gate buffer is configured to provide a low input impedance to limit a voltage swing of the frequency translated current signal.

US Patent:

8421556, Apr 16, 2013

Filed:

Oct 16, 2009

Appl. No.:

12/580916

Inventors:

Calvin (Shr-Lung) Chen - Irvine CA, US
Ethan Chang - Aliso Viejo CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H03H 7/00
H01G 4/00

US Classification:

333174, 333175

Abstract:

A switched capacitor includes a capacitor and a switch. The capacitor is coupled between a p-node and an n-node and includes interleaved p-fingers and n-fingers. A number of the p-fingers is greater than a number of the n-fingers. The switch is coupled between the n-node and ground.

US Patent:

20110090017, Apr 21, 2011

Filed:

Jan 26, 2010

Appl. No.:

12/693993

Inventors:

Calvin (Shr-Lung) CHEN - Irvine CA, US
Morteza Vadipour - Woodland Hills CA, US
Xinyu Chen - Irvine CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H03B 5/12

US Classification:

331117FE

Abstract:

Embodiments of a multi-band voltage controlled oscillator (VCO) are provided herein. The multi-band VCO is configured to adjust a frequency of an output signal based on an input signal. The multi-band VCO includes a tank module, an active module, and a control module. The tank module includes a parallel combination of a capacitor and an inductor. The active module includes a pair of cross-coupled transistors that are configured to provide a negative conductance that cancels out a positive conductance associated with the tank module. To improve the phase noise associated with the multi-band VCO, the control module is configured to adjust the body voltage of the cross-coupled transistors.