Convertible dipole/inverted-F antennas and wireless communicators incorporating the same

• US 6,529,749 B1
• Filed: 05/22/2000
• Issued: 03/04/2003
• Est. Priority Date: 05/22/2000
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Hayes, Gerard James, Sadler, Robert A.
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US09/575,838
• Time in Patent Office: 1,016 Days
• Field of Search: 455/78-83, 455/522, 455/553, 455/103, 455/132, 455/90, 455/269, 455/575, 343/724-730, 343/702, 343/835, 343/846, 343/780, 370/334
• US Class Current: 455/575.7
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/065 Microstrip dipole antennas patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/20 Two collinear substantially straight active elements; Substantially straight single active elements H01Q9/28 takes precedence
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

Multiple frequency band antennas having first and second conductive branches are provided for use within wireless communications devices, such as radiotelephones. First and second conductive branches are in adjacent, spaced-apart relationship. First and second signal feeds extend from the first conductive branch and terminate at respective first and second switches. Third and fourth signal feeds extend from the second conductive branch and terminate at respective third and fourth switches. The first and second conductive branches can jointly radiate as a dipole antenna in a first frequency band when the first and fourth switches are open, and when the second and third switches electrically connect the second and third feeds to a first receiver/transmitter. Antenna structure may be changed by reconfiguring the various switches. For example, the first and second conductive branches may radiate separately as respective inverted-F antennas, or may radiate independently as monopole antennas.

Claims

1. A multiple frequency band antenna, comprising:

a first rectangular conductive branch having a first end and an opposite second free end;

first and second feeds extending from the first rectangular conductive branch adjacent the first rectangular conductive branch first end, wherein the first and second feeds terminate at respective first and second switches, wherein the first switch is configured to selectively connect the first feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to maintain the first feed in an open circuit, and wherein the second switch is configured to selectively connect the second feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to ground, or to maintain the second feed in an open circuit;

a second rectangular conductive branch in adjacent, spaced-apart relationship with the first rectangular conductive branch and having a third end and an opposite fourth free end, wherein the first end of the first rectangular conductive branch is in adjacent, spaced-apart relationship with the third end of the second rectangular conductive branch, and wherein the first and second rectangular conductive branches are co-planar, and wherein the second and fourth free ends extend away from each other in opposite directions; and

third and fourth feeds extending from the second rectangular conductive branch adjacent the second rectangular conductive branch third end, wherein the third and fourth feeds terminate at respective third and fourth switches, wherein the third switch is configured to selectively connect the third feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to ground, or to maintain the third feed in an open circuit, and wherein the fourth switch is configured to selectively connect the fourth feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to maintain the fourth feed in an open circuit;

wherein the first and second rectangular conductive branches jointly radiate as a dipole antenna in a first frequency band when the first and fourth switches are open to electrically isolate the first and fourth feeds, respectively, and when the second and third switches electrically connect the second and third feeds to a first receiver or to a first transmitter; and

wherein the first rectangular conductive branch radiates as an inverted-F antenna in a second frequency band different from the first frequency band, when the first switch is electrically connected to a second receiver or to a second transmitter, and when the second switch is electrically connected to ground.

2. (Amended) The antenna according to claim 1 wherein the first rectangular conductive branch radiates as an inverted-F antenna in a second frequency band different from the first frequency band when the first switch is electrically connected to a second receiver or to a second transmitter, and when the second switch is electrically connected to ground;

and

wherein the second rectangular conductive branch radiates as an inverted-F antenna in a third frequency band different from the first and second frequency bands when the third switch is electrically connected to the ground, and when the fourth switch is electrically connected to a third receiver or to a third transmitter.

3. The antenna according to claim 1 wherein the first or second rectangular conductive branches independently radiate as respective monopole antennas.

4. The antenna according to claim 1 wherein the first and second rectangular conductive branches have respective different electrical lengths.

5. The antenna according to claim 1 wherein the first receiver is selected from the group consisting of AMPS receivers, PCS receivers, GSM receivers, and DCS receivers, and wherein the second receiver is selected from the group consisting of GPS receivers and Bluetooth receivers.

6. The antenna according to claim 1 wherein the first and second rectangular conductive branches are in spaced-apart, mirror-image relationship.

7. The antenna according to claim 1 wherein the first, second, third, and fourth switches comprise micro-electromechanical system (MEMS) switches.

8. The antenna according to claim 1 wherein a portion of at least one of the first and second rectangular conductive branches is disposed on a respective surface of a dielectric substrate.

9. The antenna according to claim 1 wherein a portion of at least one of the first and second rectangular conductive branches is disposed within a dielectric substrate.

10. A wireless communicator, comprising:

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

a ground plane disposed within the housing; and

a multiple frequency band antenna, comprising;

a first rectangular conductive branch having a first end and an opposite second free end, wherein the first rectangular conductive branch is in adjacent, spaced-apart relationship with the ground plane;

first and second feeds extending from the first rectangular conductive branch adjacent the first rectangular conductive branch first end, wherein the first and second feeds terminate at respective first and second switches, wherein the first switch is configured to selectively connect the first feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to maintain the first feed in an open circuit, and wherein the second switch is configured to selectively connect the second feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to ground, or to maintain the second feed in an open circuit;

a second rectangular conductive branch in adjacent, spaced-apart relationship with the first rectangular conductive branch and having a third end and an opposite fourth free end, wherein the second rectangular conductive branch is in adjacent, spaced-apart relationship with the ground plane, wherein the first end of the first rectangular conductive branch is in adjacent, spaced-apart relationship with the third end of the second rectangular conductive branch, and wherein the first and second rectangular conductive branches are co-planar, and wherein the second and fourth free ends extend away from each other in opposite directions; and

third and fourth feeds extending from the second rectangular conductive branch adjacent the second rectangular conductive branch third end, wherein the third and fourth feeds terminate at respective third and fourth switches, wherein the third switch is configured to selectively connect the third feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to ground, or to maintain the third feed in an open circuit, and wherein the fourth switch is configured to selectively connect the fourth feed to a receiver that receives wireless communications signals, or to a transmitter that transmits wireless communications signals, or to maintain the fourth feed in an open circuit;

wherein the first and second rectangular conductive branches jointly radiate as a dipole antenna in a first frequency band when the first and fourth switches are open to electrically isolate the first and fourth feeds, respectively, and when the second and third switches electrically connect the second and third feeds to a first receiver or to a first transmitter; and

wherein the first rectangular conductive branch radiates as an inverted-F antenna in a second frequency band different from the first frequency band, when the first switch is electrically connected to a second receiver or to a second transmitter, and when the second switch is electrically connected to ground.

11. The wireless communicator according to claim 10 wherein the first rectangular conductive branch radiates as an inverted-F antenna in a second frequency band different from the first frequency band when the first switch is electrically connected to a second receiver or to a second transmitter, and when the second switch is electrically connected to ground;

and

wherein the second rectangular conductive branch radiates as an inverted-F antenna in a third frequency band different from the first and second frequency bands when the third switch is electrically connected to ground, and when the fourth switch is electrically connected to a third receiver or to a third transmitter.

12. The wireless communicator according to claim 10 wherein the first or second rectangular conductive branches independently radiate as monopole antennas.

13. The wireless communicator according to claim 10 wherein the first and second rectangular conductive branches have respective different electrical lengths.

14. The wireless communicator according to claim 10 wherein the first receiver is selected from the group consisting of AMPS receivers, PCS receivers, GSM receivers, and DCS receivers, and wherein the second receiver is selected from the group consisting of GPS receivers and Bluetooth receivers.

15. The wireless communicator according to claim 10 wherein the first and second rectangular conductive branches are in spaced-apart, mirror-image relationship.

16. The wireless communicator according to claim 10 wherein the first, second, third, and fourth switches comprises micro-electromechanical systems MEMS switches.

17. The wireless communicator according to claim 10 wherein a portion of at least one of the first and second rectangular conductive branches is disposed on a respective surface of a dielectric substrate.

18. The wireless communicator according to claim 10 wherein a portion of at least one of the first and second rectangular conductive branches is disposed within a dielectric substrate.

19. The wireless communicator according to claim 10 wherein the wireless communicator comprises a radiotelephone.