Title:
LADDER-TYPE VARIABLE-FREQUENCY FILTER, MULTIPLEXER, HIGH-FREQUENCY FRONT END CIRCUIT, AND COMMUNICATION TERMINAL
Document Type and Number:
WIPO Patent Application WO/2018/012274
Kind Code:
A1
Abstract:
According to the present invention, an attenuation amount necessary for a specific frequency band outside a passband is obtained even when the frequency characteristics are changed according to a plurality of communication bands. A variable-frequency filter (10) is provided with a plurality of series arm resonators (111, 112, 113), a plurality of parallel arm resonators (121, 122, 123), a variable capacitor (21), and an inductor (31) having a fixed inductance. The plurality of series arm resonators (111, 112, 113) and the plurality of parallel arm resonators (121, 122, 123) are connected in a ladder form. The variable capacitor (21) is connected in series with the parallel arm resonator (121). The fixed inductor (31) is connected in series with the parallel arm resonator (123).
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Inventors:
TANI MASAKAZU (JP)
Application Number:
PCT/JP2017/023481
Publication Date:
January 18, 2018
Filing Date:
June 27, 2017
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/64; H03H9/72; H04B1/525
Domestic Patent References:
| WO2015099105A1 | 2015-07-02 | |||
| WO2013154113A1 | 2013-10-17 |
Foreign References:
| JP2016504872A | 2016-02-12 | |||
| JP2009207116A | 2009-09-10 |
Attorney, Agent or Firm:
KAEDE PATENT ATTORNEYS' OFFICE (JP)
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