Flexible antenna for a personal communications device

• US 5,451,965 A
• Filed: 07/08/1993
• Issued: 09/19/1995
• Est. Priority Date: 07/28/1992
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Matsumoto, Wataru
• Primary Examiner(s): Hajec, Donald
• Assistant Examiner(s): LE, HOANGANH T
• Application Number:
  US08/088,792
• Time in Patent Office: 803 Days
• Field of Search: 343/702, 343/741, 343/742, 343/866, 343/867
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• 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

An antenna for a portable radiotelephone which is configured in consideration of the nature of the electromagnetic wave and of the antenna-user relation in order to improve antenna performance in terms of received gain and directivity. Specifically, this is a multi-directional antenna configuration, including two or more planes of antenna oriented in different directions, for receiving electromagnetic waves in various angles or directions. The invention deals with at least two different cases in order to achieve satisfactory reception by a portable radiotelephone: when an antenna is relatively close to the user or a virtual ground, it should be provided normal to the user, and on the other hand, at another angle or parallel to the user when relatively far from the user or virtual ground.

Claims

1. A loop antenna disposed substantially within a housing of a personal communications device and oriented with respect to a virtual ground plane, comprising:

a first partial-loop antenna having a plurality of ends, the first partial-loop antenna having a directivity which is oriented to substantially cross said virtual ground plane;

a second partial-loop antenna having a plurality of ends, a directivity of said second partial-loop antenna being oriented in a direction different from that of said first partial loop antenna; and

a plurality of conductors for connecting said plurality of ends of said first and second partial-loop antennas;

wherein at least one of said first and second partial-loop antennas is symmetric about an axis, said loop antenna further comprising a microphone disposed along said axis substantially in a center of said at least one symmetric partial-loop antenna.

2. A loop antenna disposed substantially within a housing of a personal communications device and oriented with respect to a virtual ground plane, comprising:

a first partial-loop antenna having a plurality of ends, the first partial-loop antenna having a directivity which is oriented to substantially cross said virtual ground plane;

a second partial-loop antenna having a plurality of ends, a directivity of said second partial-loop antenna being oriented in a direction different from that of said first partial loop antenna; and

a plurality of conductors for connecting said plurality of ends of said first and second partial-loop antennas;

wherein at least one of said first and second partial-loop antennas is symmetric about an axis of symmetry, said antenna further comprising a matching capacitor disposed along said axis of symmetry within the at least one symmetric partial-loop antenna.

3. A loop antenna disposed substantially within a housing of a personal communications device and oriented with respect to a virtual ground plane, comprising:

a first partial-loop antenna having a plurality of ends, the first partial-loop antenna having a directivity which is oriented to substantially cross said virtual ground plane;

a second partial-loop antenna having a plurality of ends, a directivity of said second partial-loop antenna being oriented in a direction different from that of said first partial loop antenna; and

a plurality of conductors for connecting said plurality of ends of said first and second partial-loop antennas;

wherein at least the second partial-loop antenna is symmetrically disposed about an axis of symmetry and includes at least two matching capacitors symmetrically disposed about the axis of symmetry.