Double loop antenna for use in connection to a miniature radio receiver

• US 4,625,212 A
• Filed: 03/19/1984
• Issued: 11/25/1986
• Est. Priority Date: 03/19/1983
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yamasaki, Koji, Oda, Takashi
• Primary Examiner(s): Lieberman, Eli
• Assistant Examiner(s): Wimer, Michael C.
• Application Number:
  US06/590,617
• Time in Patent Office: 981 Days
• Field of Search: 343/702, 343/741, 343/742, 343/743, 343/744, 343/718, 343/746, 343/748, 343/855, 343/867, 455/193, 455/351, 455/269, 455/270, 455/272-274
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna

Abstract

An antenna having an antenna aperture area and an antenna reactance comprises a first antenna element (31) defining a first aperture area and a first reactance and a second antenna element (32) connected in parallel to the first antenna element to put a miniature radio receiver into operation in a desired frequency band. The second antenna element has a second aperture area and a second reactance greater than the first aperture area and reactance, respectively, so that the antenna aperture area and reactance are substantially determined by the second aperture area and the first reactance, respectively. The first and the second aperture areas may be coplanar. Alternatively, the aperture areas may be orthogonal to each other.

Claims

1. An antenna for use in connection with a reactance circuit in a miniature radio receiver, comprising:

a first antenna element having a first pair of ends, a first conductive path which is connected to said first pair of ends and which has a first predetermined reactance, and a first predetermined aperture area determined by a first loop formed by said first conductive path and said reactance circuit when said reactance circuit is connected to said first pair of ends;

a second antenna element having a second pair of ends connected in common to said first pair of ends, a second conductive path which is connected to said second pair of ends and which has a second predetermined reactance greater than said first predetermined reactance, and a second predetermined aperture area which is determined by a second loop formed by said second conductive path and said reactance circuit when said reactance circuit is connected to said second pair of ends and which is greater than said first predetermined aperture area; and

said antenna having an antenna aperture area substantially specified by said second predetermined aperture area and a antenna reactance given by a combination of said first and said second predetermined reactances,

whereby said antenna is adapted to receive high frequency signals with high gain.

2. An antenna as claimed in claim 1, wherein said reactance circuit is capacitive while each of said first and said second predetermined reactances and said antenna reactance is inductive.

3. An antenna as claimed in claim 2, wherein said first and said second predetermined areas are coplanar.

4. An antenna as claimed in claim 1, wherein said second predetermined aperture area is substantially orthogonal to said first predetermined aperture area.

5. An antenna as claimed in claim 2, wherein said second loop is partially superposed on said first loop.