Duplexer and communication device

• US 7,808,935 B2
• Filed: 03/07/2007
• Issued: 10/05/2010
• Est. Priority Date: 03/08/2006
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Ikuta, Takanori, Koga, Wataru, Takenoshita, Takeshi
• Primary Examiner(s): Lee; Andrew
• Application Number:
  US12/281,975
• Publication Number:
  US 20090147707A1
• Time in Patent Office: 1,308 Days
• Field of Search: 370/275, 370/282
• US Class Current: 370/282
• CPC Class Codes: H01P 1/213 combining or separating two or more different frequencies H01P1/215 takes precedence
• CPC Class Codes: H03H 9/725 Duplexers
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/52 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa

Abstract

Provided is a demultiplexer capable of improving attenuation characteristic and isolation characteristic of a filter having a lower transmission frequency band among two filters having different transmission frequency bands, outside the transmission frequency band of a high-frequency side. A communication device using the demultiplexer is also disclosed. A first spiral wiring portion (55) and a sixth wiring portion (56) are formed so that an angle defined by a direction of a part (L1) of the first spiral wiring portion (55) and a direction of a part (L2) of the sixth spiral wiring portion (56) on a predetermined virtual plane is, for example, 0 degree and the direction of the current flowing in the part (L1) of the first spiral wiring portion (55) is opposite to the direction of the current flowing in the part (L2) if the sixth wiring portion (56).

Claims

1. A duplexer comprising:

a first filter having a first signal input portion, a first signal output portion, a first ground portion connected to a parallel arm including at least one of a resonator and a capacitor, and having a predetermined passband;

a second filter having a second signal input portion, a second signal output portion and a second ground portion, and having a passband higher than the passband of the first filter;

a common terminal connected to the first signal output portion and the second signal input portion;

a first interconnection connected to the first signal output portion and the second signal input portion;

a second interconnection connected to the first ground portion; and

a ground terminal connected to the first and second interconnections and the second ground portion and to be supplied with a ground potential,

wherein the first and second interconnections are formed so that one of angles between an extending direction of part of the first interconnection and an extending direction of part of the second interconnection on a predetermined virtual plane is smaller than 90 degrees and a direction of current flow through the part of the first interconnection is opposite to a direction of current flow through the part of the second interconnection.

2. The duplexer according to claim 1, further comprising:

a multilayer interconnection substrate in which the first filter, the second filter, the common terminal, the first interconnection, the second interconnection, and the ground terminal are provided,

wherein the part of the first interconnection and the part of the second interconnection are formed on an identical layer of the multilayer interconnection substrate.

3. The duplexer according to claim 2, wherein the part of the first interconnection and the part of the second interconnection are formed on different layers of the multiplayer interconnection substrate.

4. A communication device comprising:

a duplexer according to any one of claims 1 to 3;

an antenna connected to the common terminal; and

a transmission/reception processing unit that supplies a signal to the first signal input portion and is supplied with a signal from the second signal output portion.