The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 10, 2016

Filed:

Jul. 09, 2013
Applicant:

Ntt Docomo, Inc., Tokyo, JP;

Inventors:

Shoichi Narahashi, Tokyo, JP;

Hiroshi Okazaki, Tokyo, JP;

Kunihiro Kawai, Tokyo, JP;

Yuta Takagi, Tokyo, JP;

Takayuki Furuta, Tokyo, JP;

Assignee:

NTT DOCOMO, INC., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04L 5/14 (2006.01); H04B 1/525 (2015.01); H04W 24/08 (2009.01); H04B 1/00 (2006.01);
U.S. Cl.
CPC ...
H04L 5/1461 (2013.01); H04B 1/006 (2013.01); H04B 1/525 (2013.01); H04W 24/08 (2013.01);
Abstract

A front-end circuit includes an RFIC, an antenna, N duplexers, N variable impedance adjustment circuits, a switch for selecting any two of the N variable impedance adjustment circuits, and a control unit which receives a control signal from the RFIC, where 2≦N. The control unit executes switching operations of the N variable impedance adjustment circuits and the switch in accordance with control information. The control signal indicates to 1) control the switch to select two variable impedance adjustment circuits corresponding to a p-th frequency band and a q-th frequency band respectively, 2) control a variable impedance adjustment circuit corresponding to the p-th frequency band to increase input impedance in the q-th frequency band as viewed from the antenna side and 3) control a variable impedance adjustment circuit corresponding to the q-th frequency band to increase input impedance in the p-th frequency band as viewed from the side.


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