Antenna systems having capacitively coupled internal and retractable antennas and wireless communicators incorporating same

• US 6,225,951 B1
• Filed: 06/01/2000
• Issued: 05/01/2001
• Est. Priority Date: 06/01/2000
• Status: Expired due to Term

• Current Assignee: Optis Cellular Technology LLC (Brevet Capital)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sanford, Gary G., Holshouser, Howard E.
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US09/585,514
• Time in Patent Office: 334 Days
• Field of Search: 343/700 MS, 343/702, 343/725, 343/729, 343/829, 343/846, 343/872, 343/900, 343/895
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 9/0442 with particular tuning means

Abstract

Antenna systems for use within wireless communication devices such as radiotelephones are provided and include an internal multi-frequency band antenna and an elongated antenna member that is retractable. The elongated antenna member is extendible from the housing of a communications device so as to have an extended position and a retracted position. The elongated antenna member includes an elongated conductive element that is capacitively coupled with the multi-frequency band antenna when the elongated antenna member is in the extended position. The multi-frequency band antenna is electrically isolated from the elongated conductive element when the elongated antenna member is in the retracted position. When the elongated antenna member is in an extended position, the elongated conductive element is configured to resonate as a half-wave monopole antenna when the internal antenna resonates within a first frequency band. The elongated conductive element is configured to resonate as a full-wave monopole antenna when the internal antenna resonates within a second frequency band.

Claims

1. An antenna system for a wireless communicator, wherein the wireless communicator includes a housing configured to enclose a receiver that receives wireless communications signals or to a transmitter that transmits wireless communications signals, wherein the antenna system comprises:

an antenna configured to be disposed within the housing and electrically connected with the receiver or transmitter; and

an elongated antenna member configured to be movably mounted within the housing and extendible from the housing so as to have an extended position and a retracted position, wherein the elongated antenna member comprises a free end, wherein the elongated antenna member comprises a conductive element that is capacitively coupled with the antenna when the elongated antenna member is in the extended position, wherein the antenna is electrically isolated from the conductive element when the elongated antenna member is in the retracted position, wherein the antenna system resonates around a central frequency in a first frequency band when the elongated antenna member is in the retracted position, and wherein the antenna system resonates around the central frequency in a second frequency band that is wider than the first frequency band when the elongated antenna member is in the extended position.

2. The antenna system according to claim 1 wherein the antenna comprises a multi-frequency band antenna.

3. The antenna system according to claim 1 wherein the antenna comprises an inverted-F antenna.

4. The antenna system according to claim 3 wherein the inverted-F antenna comprises:

a planar conductive element having opposite first and second sides;

a signal feed electrically connected to the planar conductive element and extending outwardly from the planar conductive element first side; and

a ground contact electrically connected to the planar conductive element adjacent the signal feed and extending outwardly from the planar conductive element first side.

5. The antenna system according to claim 4 wherein the planar conductive element is disposed on a dielectric substrate.

6. The antenna system according to claim 4 wherein the planar conductive element is disposed within a dielectric substrate.

7. The antenna system according to claim 3 wherein the inverted-F antenna comprises a plurality of planar conductive elements.

8. The antenna system according to claim 1 wherein the conductive element extends partially within the elongated antenna member towards the free end.

9. An antenna system for a wireless communicator, wherein the wireless communicator includes a housing configured to enclose a receiver that receives wireless communications signals or to a transmitter that transmits wireless communications signals, wherein the antenna system comprises:

a dual-band inverted-F antenna configured to be disposed within the housing and electrically connected with the receiver or transmitter, wherein the dual-band inverted-F antenna is configured to resonate within a first frequency band having a first central frequency and within a second frequency band having a second central frequency, wherein the second central frequency is greater than the first central frequency; and

an elongated antenna member configured to be movably mounted within the housing and extendible from the housing so as to have an extended position and a retracted position, wherein the elongated antenna member comprises a free end, wherein the elongated antenna member comprises a conductive element that extends partially within the elongated antenna member towards the free end, wherein the conductive element is capacitively coupled with the dual-band inverted-F antenna when the elongated antenna member is in the extended position, wherein the dual-band inverted-F antenna is electrically isolated from the conductive element when the elongated antenna member is in the retracted position, wherein the conductive element is configured to resonate as a half-wave monopole antenna when the multi-frequency band antenna resonates within the first frequency band, wherein the conductive element is configured to resonate as a full-wave monopole antenna when the dual-band inverted-F antenna resonates within the second frequency band, and wherein the first and second frequency bands are wider when the elongated antenna member is in the extended position than when the elongated antenna member is in the retracted position.

10. The antenna system according to claim 9 wherein the inverted-F antenna comprises:

a planar conductive element having opposite first and second sides;

a signal feed electrically connected to the planar conductive element and extending outwardly from the planar conductive element first side; and

a ground contact electrically connected to the planar conductive element adjacent the signal feed and extending outwardly from the planar conductive element first side.

11. The antenna system according to claim 10 wherein the planar conductive element is disposed on a dielectric substrate.

12. The antenna system according to claim 10 wherein the planar conductive element is disposed within a dielectric substrate.

13. The wireless communicator according to claim 12 wherein the wireless communicator comprises a radiotelephone.

14. The antenna system according to claim 10 wherein the inverted-F antenna comprises a plurality of planar conductive elements.

15. A wireless communicator, comprising:

a housing configured to enclose a receiver that receives wireless communications signals or a transmitter that transmits wireless communications signals;

a multi-frequency band antenna disposed within the housing and electrically connected with the receiver or transmitter; and

an elongated antenna member movably mounted within the housing and extendible from the housing so as to have an extended position and a retracted position, wherein the elongated antenna member comprises a free end, wherein the elongated antenna member comprises a conductive element that is capacitively coupled with the multi-frequency band antenna when the elongated antenna member is in the extended position, wherein the multi-frequency band antenna is electrically isolated from the conductive element when the elongated antenna member is in the retracted position, wherein the antenna system resonates around a central frequency in a first frequency band when the elongated antenna member is in the retracted position, and wherein the antenna system resonates around the central frequency in a second frequency band that is wider than the first frequency band when the elongated antenna member is in the extended position.

16. The wireless communicator according to claim 15 wherein the multi-frequency band antenna comprises an inverted-F antenna.

17. The wireless communicator system according to claim 16 wherein the wireless communicator further comprises a ground plane disposed within the housing, and wherein the inverted-F antenna comprises:

a planar conductive element having opposite first and second sides and maintained in adjacent, spaced-apart relationship with the ground plane;

a signal feed electrically connected to the planar conductive element and extending outwardly from the planar conductive element first side; and

a ground contact electrically connected to the planar conductive element adjacent the signal feed and extending outwardly from the planar conductive element first side.

18. The wireless communicator according to claim 17 wherein the planar conductive element is disposed on a dielectric substrate.

19. The wireless communicator according to claim 17 wherein the planar conductive element is disposed within a dielectric substrate.

20. The wireless communicator according to claim 17 wherein the inverted-F antenna comprises a plurality of conductive elements maintained in adjacent, spaced-apart relationship with the ground plane.

21. A wireless communicator, comprising:

a housing configured to enclose a transceiver that transmits and receives wireless communications signals;

a ground plane disposed within the housing;

a dual-band inverted-F antenna disposed within the housing and electrically connected with the transceiver, wherein the dual-band inverted-F antenna is configured to resonate within a first frequency band having a first central frequency and within a second frequency band having a second central frequency, wherein the second central frequency is greater than the first central frequency; and

an elongated antenna member movably mounted within the housing and extendible from the housing so as to have an extended position and a retracted position, wherein the elongated antenna member comprises a conductive element that is capacitively coupled with the dual-band inverted-F antenna when the elongated antenna member is in the extended position, wherein the dual-band inverted-F antenna is electrically isolated from the conductive element when the elongated antenna member is in the retracted position, and wherein the conductive element is configured to resonate as a half-wave monopole antenna when the multi-frequency band antenna resonates within the first frequency band, and wherein the conductive element is configured to resonate as a full-wave monopole antenna when the dual-band inverted-F antenna resonates within the second frequency band, and wherein the first and second frequency bands are wider when the elongated antenna member is in the extended position than when the elongated antenna member is in the retracted position.

22. The wireless communicator according to claim 21 wherein the inverted-F antenna comprises:

a planar conductive element having opposite first and second sides and maintained in adjacent, spaced-apart relationship with a ground plane within the housing;

a signal feed electrically connected to the planar conductive element and extending outwardly from the planar conductive element first side; and

a ground contact electrically connected to the planar conductive element adjacent the signal feed and extending outwardly from the planar conductive element first side.

23. The wireless communicator according to claim 22 wherein the planar conductive element is disposed on a dielectric substrate.

24. The wireless communicator according to claim 22 wherein the planar conductive element is disposed within a dielectric substrate.

25. The wireless communicator according to claim 22 wherein the inverted-F antenna comprises a plurality of conductive elements maintained in adjacent, spaced-apart relationship with a ground plane within the housing.

26. The wireless communicator according to claim 21 wherein the wireless communicator comprises a radiotelephone.