Title:
FILTER CIRCUIT, DUPLEXER, AND COMMUNICATION APPARATUS
Document Type and Number:
WIPO Patent Application WO/2021/104505
Kind Code:
A1
Abstract:
A filter circuit (100) having good passive intermodulation performance, a duplexer (100a) comprising the filter circuit (100), and a communication apparatus (1). The filter circuit (100) comprises an input end (In) for receiving a radio frequency signal, a series resonator unit (110), a parallel resonator unit (120), and an output end (Out); the series resonator unit (110) is connected between the input end (In) and the output end (Out); the parallel resonator unit (120) and the series resonator unit (110) work in conjunction to filter the radio frequency signal and output same from the output end (Out). The parallel resonator unit (120) at least comprises two parallel resonator branches (120a, 120b) which are connected in parallel to each other; the parallel resonator branches (120a, 120b) are both connected between first nodes (Nout) between the input end (In) and the output end (Out) and a ground end (GND); the parallel resonator branches (120a, 120b) each comprise at least one parallel resonator; the parallel resonator unit is the parallel resonator unit at a stage closest to the output end (Out). The parallel resonator comprises a first electrode and a second electrode, and the electrodes in each parallel resonator branch connected to the first node (Nout) refer to electrodes of a same type.
Inventors:
GU JIAN (CN)
WANG WEIBIAO (CN)
LIU ZHIYU (CN)
TANG QINGWU (CN)
ZHANG LEI (CN)
WANG WEIBIAO (CN)
LIU ZHIYU (CN)
TANG QINGWU (CN)
ZHANG LEI (CN)
Application Number:
PCT/CN2020/132536
Publication Date:
June 03, 2021
Filing Date:
November 28, 2020
Export Citation:
Assignee:
HUAWEI TECH CO LTD (CN)
International Classes:
H03H9/54
Foreign References:
| CN107078719A | 2017-08-18 | |||
| CN104253592A | 2014-12-31 | |||
| CN102611410A | 2012-07-25 | |||
| CN106253876A | 2016-12-21 | |||
| US20080055021A1 | 2008-03-06 | |||
| CN201911211785A | 2019-11-29 |
Other References:
See also references of EP 4057507A4
Attorney, Agent or Firm:
SCIHEAD IP LAW FIRM (CN)
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