Patent ID: 8554267
Filing Date: 2013-10-08
Classification: H03H

Abstract:
1. A method for phase tuning filters in a quadrature signal generator of an electronic device, the method comprising: generating, via a tunable polyphase quadrature ring filter, from first and second input signals having an input frequency, first and second filtered in-phase signals at substantially the input frequency and third and fourth filtered quadrature signals at substantially the input frequency, the first and third filtered in-phase and quadrature signals respectively having first and third amplitudes and a phase offset between one another and the second and fourth filtered in-phase and quadrature signals respectively having second and fourth amplitudes and a second phase offset between one another; outputting the first, second, third, and fourth filtered signals from the polyphase quadrature ring filter to a comparator and to additional circuitry of the electronic device; comparing, via the comparator, the first and third amplitudes of the first and third filtered in-phase and quadrature signals and determining a difference between the first and third amplitudes and comparing the second and fourth amplitudes of the second and fourth filtered in-phase and quadrature signals and determining a second difference between the second and fourth amplitudes; generating separate first and second phase tuning signals having values that are a function of the first and second determined differences; and tuning the tunable polyphase quadrature ring filter using the first and second phase tuning signals so as to adjust a phase of one or more of the first, second, third, and fourth filtered signals as a function of one or both of the first and second phase tuning signals.