Duplexer and electronic device

• US 8,274,342 B2
• Filed: 06/23/2011
• Issued: 09/25/2012
• Est. Priority Date: 12/26/2008
• Status: Active Grant

• Current Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Original Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Inventors: Tsutsumi, Jun, Matsumoto, Kazuhiro, Inoue, Shogo
• Primary Examiner(s): Summons, Barbara
• Application Number:
  US13/167,620
• Publication Number:
  US 20110254639A1
• Time in Patent Office: 460 Days
• Field of Search: 333/126, 333/129, 333132-135, 455/78, 455/82, 455/83
• US Class Current: 333/126
• CPC Class Codes: H01P 1/213 combining or separating two or more different frequencies H01P1/215 takes precedence
• CPC Class Codes: H03H 9/0571 including bulk acoustic wave [BAW] devices
• CPC Class Codes: H03H 9/0576 including surface acoustic wave [SAW] devices
• CPC Class Codes: H03H 9/70 Multiple-port networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source
• CPC Class Codes: H03H 9/725 Duplexers

Abstract

A duplexer includes a transmission filter connected between a common terminal and a transmission terminal, a reception filter connected between the common terminal and a reception; and a capacitor connected in parallel with the transmission filter and the reception filter between the transmission terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the transmission terminal to the reception terminal through the transmission filter and the reception filter and a signal passing from the transmission terminal to the reception terminal through the capacitor, or connected in parallel with the reception filter between the common terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the common terminal to the reception terminal through the reception filter and a signal from the common terminal to the reception terminal through the capacitor.

Claims

1. A duplexer comprising:

a transmission filter connected between a common terminal and a transmission terminal;

a reception filter connected between the common terminal and a reception terminal;

a capacitor connected in parallel with the transmission filter and the reception filter between the transmission terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the transmission terminal to the reception terminal through the transmission filter and the reception filter and a signal passing from the transmission terminal to the reception terminal through the capacitor is a range of 180±

85°

, or connected in parallel with the reception filter between the common terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the common terminal to the reception terminal through the reception filter and a signal from the common terminal to the reception terminal through the capacitor is a range of 180±

85°

; and

a package on which the transmission filter and the reception filter are mounted, the package including the capacitor.

2. The duplexer according to claim 1, wherein a plurality of capacitors each being said capacitor are connected in series.

3. The duplexer according to claim 1, wherein the capacitor is formed by two lines formed on an identical surface of an insulation layer within the package.

4. The duplexer according to claim 1, wherein the capacitor is connected between the transmission terminal and the reception terminal.

5. A duplexer comprising:

a transmission filter connected between a common terminal and a transmission terminal;

a reception filter connected between the common terminal and a reception terminal;

a capacitor connected in parallel with one of the transmission filter and the reception filter between at least two terminals out of the common terminal, the transmission terminal and the reception terminal;

a package on which the transmission filter and the reception filter are mounted, the package including the capacitor; and

a microstrip line formed on a surface of an insulation layer within the package,

a plurality of capacitors each being said capacitor being connected in series, the plurality of capacitors being respectively connected to two of the common terminal, the transmission terminal and the reception terminal, and being formed by lines formed on the surface of the insulation layer and both ends of the microstrip line.

6. An electronic device comprising:

a duplexer;

a transmission circuit connected to the duplexer; and

a reception circuit connected to the duplexer,

the duplexer including;

a transmission filter connected between a common terminal and a transmission terminal connected to the transmission circuit;

a reception filter connected between the common terminal and a reception terminal connected to the reception circuit;

a capacitor connected in parallel with the transmission filter and the reception filter between the transmission terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the transmission terminal to the reception terminal through the transmission filter and the reception filter and a signal passing from the transmission terminal to the reception terminal through the capacitor is a range of 180±

85°

, or connected in parallel with the reception filter between the common terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the common terminal to the reception terminal through the reception filter and a signal from the common terminal to the reception terminal through the capacitor is a range of 180±

85°

; and

a package on which the transmission filter and the reception filter are mounted, the package including the capacitor.