Antenna apparatus

• US 6,057,803 A
• Filed: 03/19/1997
• Issued: 05/02/2000
• Est. Priority Date: 03/19/1996
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yoshida, Takashi, Hasegawa, Makoto, Adachi, Naoki, Nomura, Noboru, Kane, Joji, Nohara, Akira
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US08/821,178
• Time in Patent Office: 1,140 Days
• Field of Search: 343/711, 343/712, 343/713, 343/715, 343/741, 343/742, 343/866, 343/867, 343/748, 343/743, 343/744, 343/745
• US Class Current: 343/713
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• 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 7/00 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

Abstract

A plurality of antennas are disposed in a predetermined area and wherein size, configuration and mounting condition of the antennas are set so that their directivities formed by interference therebetween are most desirable.

Claims

1. An antenna apparatus, comprising a plurality of antenna devices, the antenna devices:

each being disposed so as to have a same directivity,

each having a feeding point connected to a common feeding terminal,

each having a ground point connected to a common ground, and

each being positioned such that a distance between the antennas is less than or equal to λ

/4 of a wavelength to be carried by the antenna devices

wherein each feeding point directly is connected to an associated ground point without a reactive device therebetween, and a last ground point directly is connected to the common ground without a reactive device therebetween.

2. The antenna apparatus according to claim 1, wherein a conductive ground plane is disposed to face antenna planes of said plurality of antenna devices, and wherein the ground point of each of the antenna devices is connected to said conductive ground plane.

3. The antenna apparatus according to claim 1, wherein a reactance device is disposed between said feeding points of the plurality of antenna devices and said common feeding terminal.

4. The antenna apparatus according to claim 3, wherein said reactance device is a variable reactance device.

5. The antenna apparatus according to claim 1, wherein a reactance device is disposed in parallel between the common feeding terminal and the common ground.