The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 14, 2014
Filed:
Oct. 18, 2012
Han Wang, Beijing, CN;
Yi Yang, Beijing, CN;
Zhen LI, Beijing, CN;
Pei Yang, Beijing, CN;
Dianyu Chen, Beijing, CN;
Haiqing Lin, Ladera Ranch, CA (US);
Yihai Xiang, Rancho Santa Margarita, CA (US);
Zhongzhi Liu, Beijing, CN;
Han Wang, Beijing, CN;
Yi Yang, Beijing, CN;
Zhen Li, Beijing, CN;
Pei Yang, Beijing, CN;
Dianyu Chen, Beijing, CN;
Haiqing Lin, Ladera Ranch, CA (US);
Yihai Xiang, Rancho Santa Margarita, CA (US);
Zhongzhi Liu, Beijing, CN;
Beijing KT Micro, Ltd., Beijing, CN;
Abstract
A circuit for a front-end tunable filter of a communication and broadcast receiver and a tuning method thereof are described herein. In one aspect, the circuit of the tunable filter may be independent of the signal reception link of the receiver. The pre-filter () includes a variable capacitance () which is adjusted by a tuning signal (). A negative resistance element () and the pre-filter () may form an oscillator. The negative resistance element () is controlled by an amplitude control signal () outputted from an oscillation amplitude control circuit (). The oscillation amplitude control circuit () stabilizes the amplitude of a radio frequency signal () in a preset range. An oscillation frequency control circuit () stabilizes the frequency of the signal () in a preset frequency range by a tuning signal (). The tuning is completed until both of the amplitude and the frequency of the oscillation signal meet the preset ranges.