Title: Apparatus and method for tuning center frequency of a filter
Application Number: 200610146835 Application Date: 2006.11.23
Publication Number: 1972121 Publication Date: 2007.05.30
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03H11/04;H03H11/08
Applicant(s) Name: Mediatek Inc. Address:
Inventor(s) Name: Tu Wei-hsuan;Hsu Tse-hsiang
Attorney & Agent: renmo wen
Abstract:
    A tuning method, a tuning apparatus for tuning a filter and a trans-conductor circuit are disclosed. The tuning method includes: configuring the filter as a VCO; utilizing the VCO to generate an oscillation signal according to a driving signal; comparing a frequency of the oscillation signal with a reference frequency to generate a comparison result; converting the comparison result into the driving signal in order to establish a feedback mechanism. Therefore, the inner components such as the gm and capacitance inside the VCO are completely tuned when the VCO generates an oscillation signal having a wanted frequency. Since the VCO is inside the filter and the components of the filter and the VCO are similar, the driving signal can be utilized to make the filter operate in a desired center frequency under a well-designed relationship between the frequency of the oscillation signal and the center frequency.
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