Antenna device and electronic apparatus

Patent metadata

Field	Value
Publication number	US-10033113-B2
Application number	US-201715807697-A
Country	US
Kind code	B2
Filing date	Nov 9, 2017
Priority date	Dec 21, 2012
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A square bracket-shaped radiation element is in a non-ground region of a board. A first reactance element that equivalently enters a short-circuited state in a second frequency band is connected between a second end of the radiation element and a ground conductor. A second reactance element that equivalently enters a short-circuited state in a first frequency band s connected between a first end of the radiation element and the ground conductor. In the UHF band, the radiation element and the ground conductor function as an inverted F antenna that contributes to field emission. In the HF band, a loop including the radiation element and the ground conductor functions as a loop antenna that contributes to magnetic field emission.

First claim

What is claimed is:

1. An antenna device comprising:
a radiation element including a first feeding point and a second feeding point that is different from the first feeding point;
a first feeder circuit that feeds a communication signal of a first frequency band to the radiation element with the first feeding point; and
a second feeder circuit that feeds a communication signal of a second frequency band that is lower than the first frequency band to the radiation element with the second feeding point; wherein
the radiation element is an electric field type antenna and is a metal portion of a housing;
the radiation element defines a part of a loop unit of a magnetic field type antenna;
the radiation element is an antenna element for the first frequency band, and the loop unit is an antenna element for the second frequency band; and
the loop unit of the magnetic field type antenna is an antenna for an HF band RFID system.

2. The antenna device according to claim 1 , wherein the first feeder circuit is connected to the first feeding point between a first end and a second end of the radiation element, and the second feeder circuit is connected to the radiation element closer to the first end than the first feeder circuit.

3. The antenna device according to claim 1 , wherein the radiation element has a U shape.

4. The antenna device according to claim 1 , further comprising:
a ground conductor arranged so as to oppose the radiation element; wherein
the radiation element does not overlap the ground conductor in a planar view of the ground conductor.

5. The antenna device according to claim 1 , further comprising:
a ground conductor arranged so as to oppose the radiation element; and
at least one first reactance element connected between the radiation element and the ground conductor; wherein
the radiation element, the first reactance element, and the ground conductor define the loop unit of the magnetic field type antenna.

6. The antenna device according to claim 5 , wherein the first reactance element and the second feeder circuit are connected between the radiation element and the ground conductor, and the first reactance element and the second feeder circuit are included in a single high frequency module.

7. The antenna device according to claim 1 , wherein the radiation element is an antenna for cellular communication.

8. An electronic apparatus comprising:
the antenna device according to claim 1 .

9. The electronic apparatus according to claim 8 , wherein the radiation element is disposed on an end portion of the housing.

Assignees

• Murata Manufacturing Co

Inventors

• Yosui Kuniaki

Classifications

• H01Q1/243

  with built-in antennas · CPC title

• H01Q1/2216 Primary

  used in interrogator/reader equipment · CPC title

• H01Q5/335

  at the feed, e.g. for impedance matching · CPC title

• H01Q5/328

  between a radiating element and ground · CPC title

• H01Q5/371

  Branching current paths · CPC title