Title:
【発明の名称】バンドパスフィルタの同調装置および方法
Document Type and Number:
Japanese Patent JP2002503050
Kind Code:
A
Abstract:
A signal having a substantially uniform spectral distribution, e.g., a flat noise signal such as a signal ground, is provided at the input of a bandpass filter such as an IF filter of a receiver circuit, to thereby produce an output signal at the output of the bandpass filter. The output signal is processed in a limiter to produce a limited signal. An average frequency of the limited signal is determined, and the bandpass filter is adjusted based on the determined average frequency. According to one embodiment of the present invention, the bandpass filter comprises a Gm-C filter having a transconductance, and the filter is adjusted by adjusting the transconductance of the Gm-C filter based on the determined average frequency. According to another aspect of the present invention, a desired center frequency for the bandpass filter is identified. A resolution and a desired confidence interval are also identified. The number of samples of the limited signal needed to achieve the identified desired resolution and confidence interval is determined based on the identified desired center frequency. An average frequency is determined by sampling the limited signal to obtain a plurality of samples, the number of the plurality of samples being at least as great as the determined number of samples of the limited signal to achieve the identified desired resolution and confidence level, and determining the average frequency from the plurality of samples. The bandpass filter is adjusted based on the determined average frequency to achieve a center frequency for the bandpass filter that is within a predetermined range with respect to the desired center frequency . Related apparatus are also discussed.
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Inventors:
Holden, Alan, Earl
Montalvo, Antonio
Myers, Richard, H
Montalvo, Antonio
Myers, Richard, H
Application Number:
JP2000530979A
Publication Date:
January 29, 2002
Filing Date:
February 04, 1999
Export Citation:
Assignee:
Ericsson Incorporated
International Classes:
H03J3/18; H04B1/26; H03H11/04; (IPC1-7): H04B1/26; H03H11/04; H03J3/18
Attorney, Agent or Firm:
Akira Asamura (3 outside)