Antenna device and communication terminal device

Patent metadata

Field	Value
Publication number	US-9576238-B2
Application number	US-201414219066-A
Country	US
Kind code	B2
Filing date	Mar 19, 2014
Priority date	Feb 1, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

An antenna device includes a planar conductor, a coiled antenna element, and a feed coil. The feed coil includes a coil conductor wound around a magnetic core. The planar conductor includes a ground conductor provided with a printed wiring substrate. In a portion of a circumferential portion of the planar conductor, a coupling portion is provided and defined by an aperture and a slit. In a planar view of the antenna element, at least a portion of the coil aperture of the feed coil and a portion of the aperture overlap with each other. In addition, at least a portion of the coil aperture of the feed coil and a portion of the coil aperture of the antenna element overlap with each other.

First claim

What is claimed is:

1. An antenna device comprising:
a planar conductor;
a coiled antenna element; and
a feed circuit coupled to the planar conductor or connected to the planar conductor; wherein
the antenna element is disposed at a position at which the antenna element is coupled to the planar conductor through an electromagnetic field;
the antenna element is coupled to the feed circuit through the planar conductor; and
the antenna element is not directly electrically connected to the feed circuit.

2. The antenna device according to claim 1 , wherein a coupling portion of the planar conductor, to which the feed circuit is coupled, is an aperture or a cutout of the planar conductor.

3. The antenna device according to claim 2 , wherein the feed circuit includes a feed coil including a coil conductor wound so as to have a coil aperture therewithin, and in a planar view, at least a portion of the coil aperture of the feed coil and a portion of the aperture of the planar conductor overlap with each other.

4. The antenna device according to claim 3 , wherein the feed coil is integrated with an RFIC.

5. The antenna device according to claim 3 , wherein the antenna element is a coil antenna including a conductor pattern wound so as to have a coil aperture therewithin, and in the planar view, at least a portion of the coil aperture of the feed coil and a portion of the coil aperture of the coil antenna overlap with each other.

6. The antenna device according to claim 2 , wherein the antenna element is disposed at a position of the coupling portion.

7. The antenna device according to claim 1 , wherein the antenna element is disposed at a position of an end portion of the planar conductor.

8. The antenna device according to claim 1 , wherein the antenna element is disposed on both of a first main surface side and a second main surface side of the planar conductor.

9. The antenna device according to claim 1 , wherein the antenna element is disposed at positions of a plurality of coupling portions of the planar conductor.

10. The antenna device according to claim 1 , wherein the planar conductor is a ground conductor provided with a substrate, and the feed circuit is provided with the substrate.

11. The antenna device according to claim 10 , wherein the antenna element is provided on a first main surface side of the substrate, and the feed circuit is provided on a second main surface side of the substrate.

12. The antenna device according to claim 1 , wherein the antenna element has a resonant frequency corresponding to a carrier frequency of a communication signal.

13. A communication terminal device comprising:
a substrate;
a planar conductor provided with the substrate;
an antenna element;
a feed circuit coupled to the planar conductor or connected to the planar conductor; and
a chassis; wherein
the planar conductor includes a coupling portion;
the antenna element is disposed at a position at which the antenna element is coupled to the planar conductor through an electromagnetic field, generated by at least the coupling portion of the planar conductor;
the antenna element is coupled to the feed circuit through the planar conductor;
the antenna element is not directly electrically connected to the feed circuit;
the planar conductor is a ground conductor;
the antenna element is provided in the chassis;
the feed circuit is provided on or in the substrate; and
a communication circuit connected to the feed circuit is provided on or in the substrate.

14. The communication terminal device according to claim 13 , wherein the coupling portion of the planar conductor is an aperture or a cutout of the planar conductor and the planar conductor is connected to the feed circuit.

15. The communication terminal device according to claim 14 , wherein the feed circuit includes a feed coil including a coil conductor wound so as to have a coil aperture therewithin, and in a planar view, at least a portion of the coil aperture of the feed coil and a portion of the aperture of the planar conductor overlap with each other.

16. The communication terminal device according to claim 15 , wherein the feed coil is integrated with an RFIC.

17. The communication terminal device according to claim 15 , wherein the antenna element is a coil antenna including a conductor pattern wound so as to have a coil aperture therewithin, and in the planar view, at least a portion of the coil aperture of the feed coil and a portion of the coil aperture of the coil antenna overlap with each other.

18. The communication terminal device according to claim 14 , wherein the antenna element is disposed at a position of the coupling portion.

19. The communication terminal device according to claim 13 , wherein the antenna element is disposed at a position of an end portion of the planar conductor.

20. The communication terminal device according to claim 13 , wherein the antenna element is disposed on both of a first main surface side and a second main surface side of the planar conductor.

Assignees

• Murata Manufacturing Co

Inventors

• Yosui Kuniaki

Classifications

• H01Q1/2216

  used in interrogator/reader equipment · CPC title

• G06K19/07783 Primary

  the coil being planar · CPC title

• H04M1/02

  Constructional features of telephone sets · CPC title

• H01Q7/00

  Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop · CPC title

• G06K19/07749

  the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card · CPC title