I/Q mismatch calibration of direct conversion receivers using radio frequency noise

US7496340B1 · kind B1 · utility

Assignee

• RF Micro Devices, Inc. · US

Inventors

• Jesse Chen · Lake Forest, US
• Patrick Vandenameele · Oud-Heverlee, BE
• Steven Mark Thoen · Leuven, BE
• Alex Zenkin · Allentown, US
• Pengfei Zhang · Hong Kong, CN
• Peter Hanson · Fremont, US
• Dmitri Varsanofiev · San Diego, US
• Peter Cnudde · Los Altos, US

Key dates

• Filing date: Jun 2, 2005
• Grant date: Feb 24, 2009
• Expiry date: Apr 27, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B1/30
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A system and method are provided for calibrating for an I/Q mismatch of a direct conversion receiver based on a random signal having a two-dimensional I versus Q trajectory, such as radio frequency (RF) noise. In general, the random signal is received and downconverted to a quadrature baseband signal having an in-phase component and a quadrature component. The variance of the in-phase component, the variance of the quadrature component, and the covariance of the in-phase component with the quadrature component are computed based on samples of the quadrature baseband signal. A correction matrix used to compensate for the I/Q mismatch of the receiver and/or I/Q mismatch including a gain mismatch and a phase mismatch of the receiver is then computed based on the variance of the in-phase component, the variance of the quadrature component, and the covariance of the in-phase component with the quadrature component.