| US 7,489,911 B2 | ||
| Signal receiver and method for controlling gain of a tuner | ||
| Sebastian Zylowski, Zielona Gora (Poland) | ||
| Assigned to Advanced Digital Broadcast Polska SP. Z O.O., Zielona Góra (Poland); and Advanced Digital Broadcast, Ltd., Taipei (Taiwan) | ||
| Filed on Jun. 28, 2005, as Appl. No. 11/160,525. | ||
| Claims priority of application No. 04460044 (EP), filed on Oct. 28, 2004. | ||
| Prior Publication US 2006/0094382 A1, May 04, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. H04B 1/06 (2006.01); H04B 7/00 (2006.01) | ||
| U.S. Cl. 455—130 [455/232.1; 455/234.1; 455/250.1] | 10 Claims |
| 1. A method for controlling gain of a dual frequency conversion tuner for reception of a desired signal and provided with
a band-pass high frequency input filter, a band-pass first intermediate frequency filter having a passband width narrower
than the passband width of the input filter, a detector of the intermediate frequency signal level and amplifiers having gain
automatically controlled according to an AGC characteristic of the tuner to provide a constant level of a tuner output signal
IF_OUT, the method comprising the following steps:
identifying a passband of the input filter for the desired signal;
determining a level of the desired signal;
tuning the tuner to successive frequencies within the passband of the input filter;
calculating a level of signals for each tuned frequency on the basis of the detector output for each tuned frequency;
selecting the strongest level of close signals; and
calculating the AGC characteristic of the tuner on the basis of the level of the desired signal and the strongest level of
close signals.
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