Antenna for an electronic apparatus

• US 5,508,709 A
• Filed: 01/18/1995
• Issued: 04/16/1996
• Est. Priority Date: 05/03/1993
• Status: Expired due to Term

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Phillips, James P., Krenz, Eric L.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US08/375,339
• Time in Patent Office: 454 Days
• Field of Search: 343/702,820,821,822,850,855,856,865,882,722,749,866, 455/89,90,347,348
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H

Abstract

An antenna for an electronic apparatus is located in a flip element of the apparatus housing. A transformer, having a winding in the flip element and a winding in the housing couples electromagnetic energy across the hinge while impedance matching and performing a balun function.

Claims

1. An antenna apparatus comprising:

a balanced conductive electromagnetic energy radiating or receiving portion having a first impedance value; and

a transformer, coupled to said balanced conductive electromagnetic energy radiating or receiving portion, having a predetermined value of inductive coupling, having at least two windings movable relative to each other without substantial variation in said value of inductive coupling of said transformer, and including (a) an impedance transformation portion whereby said first impedance value is transformed to a second impedance value, and (b) a balun portion whereby said balanced conductive electromagnetic energy radiating or receiving portion is converted to unbalanced;

one of said at least two windings connected to said balanced conductive electromagnetic energy radiating or receiving portion to form an uninterrupted conductor.

2. An antenna apparatus in accordance with claim 1 further comprising a capacitive reactance, coupled to one of said at least two transformer windings, having a magnitude equal to the magnitude of the self inductance reactance of said one of said at least two transformer windings.

3. An antenna apparatus in accordance with claim 1 wherein said conductive electromagnetic energy radiating or receiving portion further comprises an essentially "C" shaped monoplanar conductive strip.

4. An antenna apparatus in accordance with claim 1 wherein the antenna apparatus is to radiate or receive electromagnetic energy having a predetermined wavelength and wherein said radiating or receiving portion further comprises a conductive strip having a total electrical length equal to a predetermined amount less than a half of said predetermined wavelength.

5. An antenna apparatus in accordance with claim 1 wherein each of said at least two windings further comprise a monoplanar conductive loop having an axis and being disposed coaxially to said axis of another of said at least two windings.

6. A portable electronic apparatus employing antenna diversity including a radio and a movable housing element, the portable electronic apparatus comprising:

a balanced antenna for diversity having a first impedance value;

a hinge, having at least two portions which are rotatable relative to each other about an axis of rotation, one of said at least two portions connected to said movable housing and another of said at least two portions connected to the portable electronic apparatus; and

a transformer, electrically coupled between the radio and said balanced antenna for diversity and having a first winding disposed in said one of said at least two hinge portions and a second winding disposed in said another of said at least two hinge portions, and including an impedance transformation portion for matching a second impedance value of the radio to said first impedance value, and a balun portion for converting said balanced antenna for diversity to unbalanced, said second winding coupling said balanced antenna for diversity to form a single unbroken conductor.