Wireless communication apparatus with housing changing between open and closed states

• US 8,154,460 B2
• Filed: 07/17/2009
• Issued: 04/10/2012
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Sakata, Tsutomu, Yamamoto, Atsushi, Amari, Satoru
• Primary Examiner(s): Choi, Jacob Y
• Assistant Examiner(s): Buchanan, Shawn
• Application Number:
  US12/504,980
• Publication Number:
  US 20100013720A1
• Time in Patent Office: 998 Days
• Field of Search: 343/700.MS, 343/702, 343729-730, 343/745, 343749-752, 343845-846, 343/850, 343860-861, 343/876
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

When first and second housings are in an open state, first and second switches are electrically opened, and thus, a first antenna element and a ground conductor operate as a first dipole antenna, and a second antenna element and the ground conductor operate as a second dipole antenna with isolation from the first dipole antenna by the slit. When the first and second housings are in the closed state, the first and second switches are electrically closed, and thus, the first antenna element operates as a first inverted F antenna on the ground conductor, and the second antenna element operates as a second inverted F antenna on the ground conductor with isolation from the first inverted F antenna by the slit.

Claims

1. A wireless communication apparatus comprising:

first and second housings coupled to each other through a coupling portion so as to change between open and closed states;

first and second antenna elements provided to the first housing with a distance between the first and second antenna elements;

a slit between the first and second antenna elements in the first housing;

first and second feeding points respectively provided on the first and second antenna elements such that the slit is located between the first and second feeding points;

a ground conductor provided to the second housing;

a first switch for electrically connecting and disconnecting the first antenna element to and from the ground conductor; and

a second switch for electrically connecting and disconnecting the second antenna element to and from the ground conductor,

wherein when the first and second housings are in the open state, the first and second switches are electrically opened, whereby the first antenna element and the ground conductor operate as a first dipole antenna, and the second antenna element and the ground conductor operate as a second dipole antenna with isolation from the first dipole antenna by the slit, and

wherein when the first and second housings are in the closed state, the first and second switches are electrically closed, whereby the first antenna element operates as a first inverted F antenna on the ground conductor, and the second antenna element operates as a second inverted F antenna on the ground conductor with isolation from the first inverted F antenna by the slit.

2. The wireless communication apparatus as claimed in claim 1, further comprising:

a third switch for electrically connecting and disconnecting the first and second antenna elements with each other at a first end of the slit;

a fourth switch for electrically connecting and disconnecting the first and second antenna elements with each other at a second end of the slit; and

a controller for controlling the third and the fourth switch,

wherein when the first and second housings are in the open state, the controller closes the third switch and opens the fourth switch, and when the first and second housings are in the closed state, the controller opens the third switch and closes the fourth switch.

3. The wireless communication apparatus as claimed in claim 2, further comprising:

a first variable capacitance element connected between the first and second antenna elements at the first end of the slit; and

a second variable capacitance element connected between the first and second antenna elements at the second end of the slit,

wherein when the first and second housings are in the open state, the controller controls a reactance value of the second variable capacitance element so as to minimize reflection coefficients of the first and second dipole antennas, and when the first and second housings are in the closed state, the controller controls a reactance value of the first variable capacitance element so as to minimize reflection coefficients of the first and second inverted F antennas.

4. The wireless communication apparatus as claimed in claim 2, further comprising a variable capacitance element connected between the first and second antenna elements at a position between the first and second ends of the slit,

wherein when the first and second housings are in the open state, the controller controls a reactance value of the variable capacitance element so as to minimize reflection coefficients of the first and second dipole antennas, and when the first and second housings are in the closed state, the controller controls the reactance value of the variable capacitance element so as to minimize reflection coefficients of the first and second inverted F antennas.

5. The wireless communication apparatus as claimed in claim 1, further comprising:

a first variable capacitance element connected between the first and second antenna elements at a first end of the slit;

a second variable capacitance element connected between the first and second antenna elements at a second end of the slit; and

a controller for controlling the first and second variable capacitance elements,

wherein when the first and second housings are in the open state, the controller controls a reactance value of the first variable capacitance element such that the first variable capacitance element is substantially short-circuited, and controls a reactance value of the second variable capacitance element so as to minimize reflection coefficients of the first and second dipole antennas, and when the first and second housings are in the closed state, the controller controls the reactance value of the second variable capacitance element such that the second variable capacitance element is substantially short-circuited, and controls the reactance value of the first variable capacitance element so as to minimize reflection coefficients of the first and second inverted F antennas.

6. The wireless communication apparatus as claimed in claim 2,

wherein the controller further controls the first and second switches such that when the first and second housings are in the open state, the first and second switches are electrically opened, and when the first and second housings are in the closed state, the first and second switches are electrically closed.

7. The wireless communication apparatus as claimed in claim 1,

wherein the first and second housings are coupled to each other so as to change between the open and closed states in a two-fold manner at the coupling portion.

8. The wireless communication apparatus as claimed in claim 1,

wherein the coupling portion includes a rotating shaft that penetrates the first and second housings in their thickness direction, and

wherein the first and second housings are coupled to each other so as to change between the open and closed states by rotating about the rotating shaft.