Radiation shielding and range extending antenna assembly

• US 6,249,256 B1
• Filed: 09/28/1999
• Issued: 06/19/2001
• Est. Priority Date: 08/01/1994
• Status: Expired due to Fees

• Current Assignee: Tyco Electronics Logistics AG (TE Connectivity Limited)
• Original Assignee: RangeStar Wireless Inc.
• Inventors: Luxon, Norval N., Johnson, Greg F.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/407,813
• Time in Patent Office: 630 Days
• Field of Search: H01/Q.124, 343/702, 343/841, 455/90
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/084 Pivotable antennas
• CPC Class Codes: H01Q 1/244 extendable from a housing along a given path
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• CPC Class Codes: H01Q 17/00 Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
• CPC Class Codes: H01Q 19/108 Combination of a dipole with a plane reflecting surface H01Q19/106 takes precedence; strip line H01Q9/065
• CPC Class Codes: H01Q 19/13 the primary radiating source being a single radiating element, e.g. a dipole, a slot, a waveguide termination H01Q19/15 takes precedence
• CPC Class Codes: H01Q 19/24 the primary active element being centre-fed and substantially straight, e.g. H-antenna
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Abstract

An antenna assembly for transmitting a radio signal from a radio signal transmitting-device includes an antenna unit comprised of a dipole driven antenna member for transmitting a radio signal from the radio signal transmitting device. A radiation shielding member shields a user from a portion of the radio signal transmitted by the driven antenna member. The antenna unit may be pivotally mounted so that it is disposable at selectable positions relative to the shielding member. The dipole driven antenna member may include a first and a second segment made from a metal foil. The radiation reflector directs a portion of the radio signal away from the user toward an open transmission area, so as to extend a transmission range of the antenna assembly. At least some of the RF signal that is emitted from the driven antenna member toward the user is blocked by the radiation shielding member. Thus, the inventive antenna assembly has a compact construction, prevents unwanted exposure of the user to RF radiation, and provides an enhanced and extended transmission signal to enable improved communication.

Claims

1. An assembly comprising:

a hand-held communications device having a ground plane circuit and having a rear side directed away from an intended user of said communications device;

a driven element operatively coupled to the communications device, said driven element radiating a transmitted signal;

a conductor element disposed upon the communications device and having a major surface directed toward the user, said conductor element disposed between the driven element and a user of the communications device, said conductor element coupled to the ground plane circuit; and

a radiation-shielding structure for blocking at least a portion of a user-directed transmitted signal of the communication device, said radiation-shielding structure disposed upon the major surface of the conductor element so that the radiation-shielding structure is between the conductor element and the user, and said radiation-shielding structure including a plurality of conductive particles disposed within a non-conductive matrix.

2. The antenna assembly of claim 1, wherein the driven element is a quarter-wave wire antenna element.

3. The antenna assembly of claim 1, wherein the driven element is a substantially planar conductor.

4. The antenna assembly of claim 1, wherein the driven element includes a meander section disposed upon a dielectric substrate.

6. The antenna assembly of claim 1, wherein the conductor element is substantially planar.

7. The antenna assembly of claim 1, wherein the conductor element is a parabolic radiation reflector defining an interior region, and wherein the driven element is disposed within said interior region.

8. The antenna assembly of claim 1, wherein the conductor element and driven element are both substantially planar.

9. The antenna assembly of claim 1 wherein the plurality of conductive particles are selected from a group consisting of:

a conductive free metal, FeO₂, titanium oxide, a ferromagnetic material, carbonyl iron, ferrite oxide, garnet, magnesium, nickel, lithium, yttrium, and calcium vanadium.

5. The antenna assembly of 1, wherein the conductor element is defined by a circuit ground trace of a printed wiring board of the communications device.

10. An assembly comprising:

a hand-held communications device, said communications device having a front side and a rear side directed away from a user;

an active radiating element operatively coupled to the communications device for transmitting a signal, said active radiating element disposed proximate the rear side and away from a user'"'"'s hand during operation;

a substantially planar ground circuit structure disposed upon the communications device proximate the active radiating element, said structure having a major surface, said structure being disposed between the active radiating element and the user; and

a radiation-shielding element operatively coupled to the communications device, said radiation-shielding element including a plurality of conductive particles disposed within a non-conductive matrix, said radiation-shielding element disposed upon the major surface of the structure so that the radiation-shielding element is between the ground circuit structure and the user.

11. The antenna assembly of claim 10, wherein the active radiating element is a quarter-wave wire antenna element.

12. The antenna assembly of claim 10, wherein the active radiating element is a substantially planar conductor.

13. The antenna assembly of claim 10, wherein the active radiating element includes a meander section disposed upon a dielectric substrate.

15. The antenna assembly of claim 10, wherein the conductive element is a parabolic radiation reflector defining an interior region, and wherein the driven element is disposed within said interior region.

16. The antenna assembly of claim 10 wherein the plurality of conductive particles are selected from a group consisting of:

a conductive free metal, FeO₂, titanium oxide, a ferromagnetic material, carbonyl iron, ferrite oxide, garnet, magnesium, nickel, lithium, yttrium, and calcium vanadium.

14. The antenna assembly of 10, wherein the ground circuit structure is defined by a circuit ground trace of a printed wiring board of the communications device.

17. A communications device for transmitting a radio signal, said device comprising:

a device body capable of being hand held by a user;

an antenna disposed upon the device body for transmitting the radio signal generally in a direction of propagation opposite the user, said antenna including an active element and a substantially planar ground plane circuit structure disposed away from said active element; and

a radiation-shielding structure disposed upon the ground plane circuit structure and displaced away from the antenna in a direction generally opposite the direction of propagation, said radiation-shielding structure having a plurality of conductive particles disposed within a non-conductive matrix.

18. The device of claim 17 wherein the active element is a wire antenna member.

19. The device of claim 17 wherein the plurality of conductive particles are selected from a group consisting of:

a conductive free metal, FeO₂, titanium oxide, a ferromagnetic material, carbonyl iron, ferrite oxide, garnet, magnesium, nickel, lithium, yttrium, and calcium vanadium.

21. The device of claim 17, wherein the conductor element is a parabolic radiation reflector defining an interior region, and wherein the active element is disposed within said interior region.

20. The device of 17, wherein the ground plane circuit structure is defined by a circuit ground trace of a printed wiring board of the communications device.