Wenwei Pan

US Patent:

8248170, Aug 21, 2012

Filed:

Nov 22, 2010

Appl. No.:

12/952154

Inventors:

Dariush Dabiri - San Jose CA, US
Dongwoon Bai - Sunnyvale CA, US
Nils Graef - Sunnyvale CA, US
Wenwei Pan - Irvine CA, US

Assignee:

Applied Micro Circuit Corporation - San Diego CA

International Classification:

H03K 3/03

US Classification:

331 57, 301 45, 327156, 327159

Abstract:

A stabilized quadrature oscillator providing consistently high signal quality is disclosed. The stabilized quadrature oscillator includes an iterative quadrature oscillator and a quadrature signal stabilizer. The iterative quadrature oscillator generates an iterative cosine signal and an iterative sine signal using a stabilized cosine signal and a stabilized sine signal from the quadrature signal stabilizer. The quadrature signal stabilizer generates the stabilized cosine signal and the stabilized sine signal based on an energy measure of the iterative cosine signal and the iterative sine signal. Specifically, if the energy measure is less than a low threshold then the quadrature signal stabilizer generates the stabilized sine signal and the stabilized cosine signal to have a greater magnitude than the iterative sine signal and the iterative cosine signal, respectively. Conversely, if the energy measure is greater than a high threshold then the quadrature signal stabilizer generates the stabilized sine signal and the stabilized cosine signal to have a lesser magnitude than the iterative sine signal and the iterative cosine signal, respectively.