US 8,618,992 B2Granted

Antenna duplexer and communication device using the same

AssigneePanasonic Corporation

InventorsJoji Fujiwara, Tetsuya Tsurunari, Hiroyuki Nakamura

Life of this patent

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Abstract

An antenna duplexer includes a transmission filter and a reception filter both coupled with an antenna terminal. The transmission filter has a lower pass band than the reception filter. The transmission filter includes a first series resonator coupled with a first terminal, a second series resonator connected to the first series resonator at a first node, a first parallel resonator connected to a first port of the first series resonator, a second parallel resonator connected to a first node and the first parallel resonator at a second node, a third parallel resonator connected to the first node, a fourth parallel resonator connected to the third parallel resonator at a third node, a first inductance element coupled with the second node and a ground, and a second inductance element coupled with the third node and the ground. The second inductance element has a lower inductance than the first inductance element.

Claims8

Dependent claims

An antenna duplexer comprising:

an antenna terminal adapted to be connected with an antenna;
a transmission filter connected to the antenna terminal and adapted to be coupled with a transmission circuit;
and
a reception filter connected to the antenna terminal and adapted to be coupled with the reception circuit, wherein
a pass band of the transmission filter is lower than a pass band of the reception filter, wherein
the transmission filter includes
a first terminal adapted to be coupled with one of the transmission circuit and the antenna terminal,
a second terminal adapted to be coupled with another of the transmission circuit and the antenna terminal,
a first series resonator having a first port and a second port, the first port of the first series resonator being coupled with the first terminal,
a second series resonator having a first port and a second port, the first port of the second series resonator being connected to the second port of the first series resonator at a first node, the second port of the second series resonator being coupled with the second terminal,
a first parallel resonator having a first port and a second port, the first port of the first parallel resonator being connected to the first port of the first series resonator,
a second parallel resonator having a first port and a second port, the first port of the second parallel resonator being connected to the first node, the second port of the second parallel resonator being connected to the second port of the first parallel resonator at a second node,
a third parallel resonator having a first port and a second port, the first port of the third parallel resonator being connected to the first node,
a fourth parallel resonator having a first port and a second port, the first port of the fourth parallel resonator being connected to the second port of the second series resonator, the second port of the fourth parallel resonator being connected to the second port of the third parallel resonator at a third node,
a first inductance element having a first end and a second end, the first end of the first inductance element being connected to the second node, the second end of the first inductance element being coupled with a ground, and
a second inductance element having a first end and a second end, the first end of the second inductance element being connected to the third node, the second end of the second inductance element being coupled with the ground, and
an inductance of the second inductance element is lower than an inductance of the first inductance element.

14 more elements

A communication device comprising:

an antenna;
a transmission circuit;
a transmission filter coupled with the transmission circuit and the antenna;
a reception circuit;
and
a reception filter coupled with the reception circuit and the antenna, wherein
a pass band of the transmission filter is lower than a pass band of the reception filter, wherein
the transmission filter includes
a first terminal adapted to be coupled with one of the transmission circuit and the antenna terminal,
a second terminal adapted to be coupled with another of the transmission circuit and the antenna terminal,
a first series resonator having a first port and a second port, the first port of the first series resonator being coupled with the first terminal,
a second series resonator having a first port and a second port, the first port of the second series resonator being connected to the second port of the first series resonator at a first node, the second port of the second series resonator being coupled with the second terminal,
a first parallel resonator having a first port and a second port, the first port of the first parallel resonator being connected to the first port of the first series resonator,
a second parallel resonator having a first port and a second port, the first port of the second parallel resonator being connected to the first node, the second port of the second parallel resonator being connected to the second port of the first parallel resonator at a second node,
a third parallel resonator having a first port and a second port, the first port of the third parallel resonator being connected to the first node,
a fourth parallel resonator having a first port and a second port, the first port of the fourth parallel resonator being connected to the second port of the second series resonator, the second port of the fourth parallel resonator being connected to the second port of the third parallel resonator at a third node,
a first inductance element having a first end and a second end, the first end of the first inductance element being connected to the second node, the second end of the first inductance element being coupled with a ground, and
a second inductance element having a first end and a second end, the first end of the second inductance element being connected to the third node, the second end of the second inductance element being coupled with the ground, and
an inductance of the second inductance element is lower than an inductance of the first inductance element.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/845,440Filed 18 Mar 2013 · continuation
Priority: JP 2008-30208027 Nov 2008
Published: US 2013/0210374 A115 Aug 2013
Granted: 31 Dec 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H03H 9/46
Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators: filters
H03H 9/725
Networks using surface acoustic waves: duplexers
H04B 1/44
Circuits: transmit/receive switching
H03H
Impedance networks

Family

PCT/JP2009/006256Parent of this continuation · filed 20 Nov 2009
US 2013/0210374 A1Pre-grant publication · published 15 Aug 2013
Application12/989,807Parent of this continuation
US 8,436,778 B2Parent of this continuation
US 2011/0043428 A1Published application
US 8,618,992 B2This patent

From the US filing history. Foreign family members aren’t listed.