Ali Faghfuri

US Patent:

20060208820, Sep 21, 2006

Filed:

Apr 20, 2004

Appl. No.:

10/554020

Inventors:

Ali Parsa - Los Angeles CA, US
Ali Fotowat-Ahmady - Richmond Hill, CA
Ali Faghfuri - Stanford CA, US
Mahta Jenabi - Richmond Hill, CA
Emmanuel Riou - Santa Clara CA, US
Wilhelm Hahn - Los Altos CA, US

Assignee:

KONINKLIJKE PHILIPS ELECTRONICS N.V. - EINDHOVEN

International Classification:

H04L 27/20

US Classification:

332103000

Abstract:

A quadrature modulator and a method of calibrating same by applying a first test tone signal to an in-phase modulation branch input of the modulator and a ninety degree phase-shifted version of the first test tone signal to a quadrature modulation branch input of the modulator. The carrier leakage level in an output signal of the modulator is measured and in response base band dc offset voltages are adjusted to minimize the carrier leakage. A second test tone signal is applied to the in-phase modulation branch input and a ninety degree phase-shifted version of the second test tone signal to the quadrature modulation branch input. The level of an undesired upper sideband frequency component in the output signal is measured and in response base band gains the in-phase and quadrature modulation branches and a local oscillator phase error are adjusted to minimize the undesired sideband.