Antenna device and communication terminal apparatus

Patent metadata

Field	Value
Publication number	US-9997834-B1
Application number	US-201815878554-A
Country	US
Kind code	B1
Filing date	Jan 24, 2018
Priority date	Feb 15, 2011
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

An antenna device includes a base including a planar conductor disposed thereon, and a coil antenna. The coil antenna includes a coil conductor wound around a magnetic core. The coil antenna is arranged such that a coil opening of the coil conductor is closed to an edge of the planar conductor. A current passing through the coil conductor induces a current in the planar conductor. Thus, a first magnetic flux occurs in the coil antenna, and a second magnetic flux occurs in the planar conductor. Therefore, a third magnetic flux occurs in an area of the planar conductor. Accordingly, the antenna device achieves a small footprint, a small-sized communication terminal apparatus and a desired communication distance.

First claim

What is claimed is:

1. A communication terminal apparatus comprising:
an antenna device that includes a coil antenna, a planar conductor, and a magnetic material, the coil antenna being a chip coil antenna and including a coil conductor wound around a winding axis and a coil opening through which the winding axis passes, the planar conductor is coupled to the coil antenna through an electromagnetic field, and the magnetic material is arranged between the planar conductor and all portions of the coil conductor; and
a communication circuit connected to the antenna device; wherein
the coil antenna partially overlaps with the planar conductor;
at least a portion of the coil opening does not overlap with the planar conductor;
the winding axis is perpendicular to a plane of the planar conductor or an angle between the winding axis and a normal of the planar conductor is in a range of ±45 degrees; and
the planar conductor is made of a non-magnetic material and is a ground conductor of a main substrate on which the coil antenna is mounted.

2. The communication terminal apparatus according to claim 1 , further comprising:
an elongated casing that houses the communication circuit, wherein the antenna device is arranged such that the planar conductor is adjacent to an end of the casing.

3. The communication terminal apparatus according to claim 2 , wherein the coil antenna is provided between the planar conductor and the end of the casing.

4. The antenna device according to claim 1 , wherein the coil conductor is arranged outside of the magnetic material.

5. The communication terminal apparatus according to claim 1 , wherein the coil conductor is arranged outside of the magnetic material.

Assignees

• Murata Manufacturing Co

Inventors

• Miura Teppei
• Ikemoto Nobuo
• Sasaki Jun
• Kato Noboru
• Tsubaki Nobuhito

Classifications

• H01Q7/08

  Ferrite rod or like elongated core · CPC title

• H01Q7/06 Primary

  with core of ferromagnetic material (H01Q7/02 takes precedence) · CPC title

• H01Q1/243

  with built-in antennas · CPC title

• H01Q1/2283 Primary

  mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package · CPC title

• H01Q9/27

  Spiral antennas · CPC title