Antenna device and wireless apparatus employing the same

• US 5,642,120 A
• Filed: 09/27/1995
• Issued: 06/24/1997
• Est. Priority Date: 03/29/1993
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Fujisawa, Teruhiko
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US08/534,582
• Time in Patent Office: 636 Days
• Field of Search: 343/702, 343/700 MS, 343/745, 343/749, 343/767, 455/89, 455/90
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/24 with receiving set
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 13/106 Microstrip slot antennas patch antenna elements H01Q9/0407
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H05K 1/182 associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]

Abstract

An antenna device with superior antenna characteristics, including gain, for use with a compact portable wireless apparatus is disclosed. Compactness is achieved by using the space provided by the antenna device without harming antenna characteristics. The antenna device includes two conductive plates spaced from each other so as to define a gap between them. The conductive plates are short-circuited at one end portion of the conductive plates by a short-circuit plate. A capacitance element for tuning is connected at the opposite end portion of the conductive plates. The positions of feed points on the conductive plates connected to a circuit device of the wireless apparatus are different from the position at which the capacitance element is connected.

Claims

1. An antenna device comprising:

two rectangular conductive plates placed substantially parallel to each other with a gap between said two rectangular conductive plates;

a short-circuit plate electrically connecting said rectangular conductive plates at first end portions of said rectangular conductive plates to short-circuit said rectangular conductive plates;

a capacitance element electrically connecting said rectangular conductive plates at second end portions of said rectangular conductive plates on a side of said rectangular conductive plates opposite to said first end portions; and

electrical feed points of said rectangular conductive plates provided at portions of said rectangular conductive plates different from said second end portions, wherein said short-circuit plate and said capacitance element are located at approximately diagonally opposite corner positions of said rectangular conductive plates.

2. A portable wireless apparatus, comprising an antenna device, wherein the antenna device comprises:

two rectangular conductive plates placed substantially parallel to each other with a gap between said two rectangular conductive plates;

a short-circuit plate electrically connecting said rectangular conductive plates at first end portions of said rectangular conductive plates to short-circuit said rectangular conductive plates;

a capacitance element electrically connecting said rectangular conductive plates at second end portions of said rectangular conductive plates on a side of said rectangular conductive plates opposite to said first end portions; and

electrical feed points of said rectangular conductive plates provided at portions of said rectangular conductive plates different from said second end portions, wherein said short-circuit plate and said capacitance element are located at approximately diagonally opposite corner positions of said rectangular conductive plates.

3. The portable wireless apparatus of claim 2, wherein said portable wireless apparatus includes a circuit device, and said circuit device is positioned in said gap.

4. A portable wireless apparatus having an antenna device, the antenna device comprising:

two conductive plates placed substantially parallel to each other with a gap between said two conductive plates;

a short-circuit plate electrically connecting said conductive plates at first end portions of said conductive plates to short-circuit said conductive plates;

a capacitance element electrically connecting said conductive plates at second end portions of said conductive plates on a side of said conductive plates opposite to said first end portions; and

electrical feed points of said conductive plates provided at portions of said conductive plates different from said second end portions, wherein each of said conductive plates is rectangular, and said electrical connections of said short-circuit plate and said capacitance element to said conductive plates are located at or nearly at diagonally opposite positions of said conductive plates, said portable wireless apparatus including a circuit device, and said circuit device being positioned in said gap, an aperture being provided in at least one of said conductive plates, and said circuit device being aligned with said aperture in a direction perpendicular to the parallel direction of said conductive plates.

5. The portable wireless apparatus of claim 4, wherein a portion of an outer periphery of at least one of the two conductive plates is bent toward an other one of the two conductive plates.

6. An antenna device comprising:

conductive plate means for defining a gap of substantially uniform width over a substantial area, said conductive plate means including rectangular conductive plates on opposite sides of said gap;

short-circuit means for electrically connecting through a short-circuit said rectangular conductive plates, wherein the electrical connections are at first end portions of said conductive plate means;

capacitance means for electrically connecting and providing capacitance between said rectangular conductive plates at second end portions of said conductive plate means, wherein said short-circuit means and said capacitance means are located at approximately diagonally opposite corner positions of said rectangular conductive plates; and

feed means for feeding electricity to said conductive plate means at portions of said conductive plate means different from said second end portions.

7. A portable wireless apparatus, comprising an antenna device, wherein the antenna device comprises:

conductive plate means for defining a gap of substantially uniform width over a substantial area, said conductive plate means including rectangular conductive plates on opposite sides of said gap;

short-circuit means for electrically connecting through a short-circuit said rectangular conductive plates, wherein the electrical connections are at first end portions of said conductive plate means;

capacitance means for electrically connecting and providing capacitance between said rectangular conductive plates at second end portions of said conductive plate means, wherein said short-circuit means and said capacitance means are located at approximately diagonally opposite corner positions of said rectangular conductive plates; and

feed means for feeding electricity to said conductive plate means at portions of said conductive plate means different from said second end portions.

8. The portable wireless apparatus of claim 7, wherein said portable wireless apparatus includes circuit means, and said circuit means is positioned in said gap.

9. A portable wireless apparatus having an antenna device, the antenna device comprising:

conductive plate means for defining a gap of substantially uniform width over a substantial area, said conductive plate means including different portions on opposite sides of said gap;

short-circuit means for electrically connecting through a short-circuit said different portions, wherein the electrical connections are at first end portions of said conductive plate means;

capacitance means for electrically connecting and providing capacitance between said different portions at second end portions of said conductive plate means, wherein said first and second end portions are located on opposite sides of said area;

feed means for feeding electricity to said conductive plate means at portions of said conductive plate means different from said second end portions, said conductive plate means including rectangular conductive plates, and said electrical connections of said short-circuit means and said capacitance means being located at or nearly at diagonally opposite positions of said conductive plates, said portable wireless apparatus including circuit means, and said circuit means being positioned in said gap; and

aperture means being provided in at least one of said conductive plates, and said circuit means being aligned with said aperture means in a direction perpendicular to the direction across said gap.

10. The portable wireless apparatus of claim 9, wherein a portion of an outer periphery of at least one of the different portions of the conductive plate means is bent toward an other one of the different portions of the conductive plate means.

11. A method of forming an antenna device, comprising:

placing two rectangular conductive plates substantially parallel to each other with a gap provided between said two rectangular conductive plates;

electrically connecting said rectangular conductive plates at first end portions of said rectangular conductive plates using a short-circuit plate to short-circuit said rectangular conductive plates;

electrically connecting said rectangular conductive plates with a capacitance connection at second end portions of said rectangular conductive plates, said short-circuit plate and said capacitance connection being located at approximately diagonally opposite corner positions of said rectangular conductive plates; and

electrically connecting electrical feed points to said rectangular conductive plates at portions of said rectangular conductive plates different from said second end portions.

12. The method of claim 11, further comprising forming a portable wireless apparatus, wherein the portable wireless apparatus includes the antenna device.

13. The method of claim 12, further comprising the step of positioning a circuit device in said gap.