Radiation shielding and range extending antenna assembly

• US 6,095,820 A
• Filed: 10/27/1995
• Issued: 08/01/2000
• Est. Priority Date: 10/27/1995
• Status: Expired due to Fees

• Current Assignee: Tyco Electronics Logistics AG (TE Connectivity Limited)
• Original Assignee: Rangestar International Corp
• Inventors: Daniels, John J., Milelli, R. Joseph, Luxon, Norval N.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US08/549,063
• Time in Patent Office: 1,740 Days
• Field of Search: 343/702, 343/841, 343/790, 343/791, 343/818, 343/819, 455/89, 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 reflector reflects the radio signal transmitted by the driven antenna member, and a support member supports the driven antenna member and the radiation reflector so that a predetermined gap is precisely maintained between the driven antenna member and the radiation reflector. A shielding member shields a portion of the radio signal transmitted by the driven antenna member in a direction toward the shielding member. The antenna unit is pivotally mounted so that it is disposable at selectable positions relative to the shielding member. The output of the radio signal transmitted by the driven antenna member can be controlled depending on a position of the antenna unit. The dipole driven antenna member comprises a first and a second segment made from a metal foil. To reduce the overall length of the antenna, each segment has an unfolded portion and a folded portion. The radiation reflector is a metal wire, also having an unfolded portion and folded portions. This construction makes the inventive antenna assembly compact, while being effective both as a transmitting and receiving unit. The radiation reflector directs a portion of the radio signal toward the open transmission area, so as to extend a transmission range of the antenna assembly, and thus extend the transmission range of the radio signal transmitting device. By this construction, at least some of the radiation signal that is emitted from the driven antenna member in directions toward the user is blocked by the shielding member. Thus, the inventive antenna assembly has a compact construction, prevents unwanted exposure of the user to potentially harmful radiation, and provides an enhanced and extended transmission signal to enable improved communication.

Claims

1. An antenna assembly for transmitting a radio signal from a communication device for use by a user, said antenna assembly comprising:

an antenna structure, including a driven element and at least one parasitic element, and further including a support structure for supporting the driven element and the at least one parasitic element and for maintaining a gap distance between the driven element and the at least one parasitic element effective to direct at least a portion of the radio signal in a direction away from the user;

a radiation-shielding structure for blocking at least a portion of the radio signal directed toward the user of the communication device, said radiation-shielding structure including a radiation-shielding material and a conductive element, said conductive element disposed during use between the radiation-shielding material and the user; and

a pivot structure for pivotally securing the support structure relative to the radiation shielding structure, the radiation shielding structure being disposed during use between the antenna structure and the user.

2. The antenna assembly of claim 1 wherein the radio signal has a wavelength and the gap distance between the driven element and the at least one parasitic element is approximately one tenth of the wavelength of the radio signal.

3. The antenna assembly of claim 1 wherein the radio signal has a wavelength and the driven element has an effective antenna length of approximately one-half of the wavelength.

4. The antenna assembly of claim 1 wherein the radio signal has a wavelength and the at least one parasitic element has a length of approximately one-half of the wavelength.

5. The antenna assembly of claim 1 wherein the conductive element is a metal layer.

6. The antenna assembly of claim 1 wherein the radiation shielding material is a conductive material dispersed in a non-conductive matrix.

7. The antenna assembly of claim 6 wherein the conductive material is 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.

8. An antenna assembly for emitting a radio signal generally in a transmission direction from a communication device for use by a user, said antenna assembly comprising:

an antenna structure, said antenna structure including a driven element and a radiation redirecting element, said antenna structure further including a support member for supporting said driven element and said radiation redirecting element and for maintaining a distance between said driven element and said radiation redirecting element effective to redirect at least a portion of the radio signal;

a radiation-shielding structure displaced away from the antenna structure in a direction generally opposite the transmission direction, the radiation-shielding structure including a radiation-shielding material and a conductive member; and

a pivotal connection member for pivotally securing the antenna structure relative to the radiation-shielding structure, the radiation shielding-structure being disposed during use between the antenna structure and the user.

9. The antenna assembly of claim 8 wherein the radiation-shielding material is a conductive material dispersed in a non-conductive matrix.

10. The antenna assembly of claim 9 wherein the conductive material is 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.

11. An antenna assembly for emitting a radio frequency signal generally in a transmission direction, said antenna assembly comprising:

a conductive member including a face surface generally directed in the transmission direction;

a radiation shielding member conformingly engaging the face surface;

a directional antenna including a driven element and a radiation redirecting element, said radiation redirecting element displaced a first distance from said driven element to effectively redirect at least a portion of the radio frequency signal toward the transmission direction; and

a mounting structure for pivotally connecting the directional antenna relative to the radiation shielding member, the driven element and the radiation shielding member being spaced apart a distance which is variable as the directional antenna is pivoted.