Cavity antennas for electronic devices

• US 8,896,487 B2
• Filed: 07/09/2009
• Issued: 11/25/2014
• Est. Priority Date: 07/09/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chiang, Bing, Kough, Douglas B., Ayala Vazquez, Enrique, Springer, Gregory A., Xu, Hao, Schlub, Robert W., Camacho, Eduardo Lopez, Pascolini, Mattia, Guterman, Jerzy, Jiang, Yi, Gomez Angulo, Rodney Andres, Caballero, Ruben
• Primary Examiner(s): SMITH, GRAHAM P
• Application Number:
  US12/500,570
• Publication Number:
  US 20110006953A1
• Time in Patent Office: 1,965 Days
• Field of Search: 343/702
• US Class Current: 343/702
• CPC Class Codes: G06F 1/1616 with folding flat displays, e.g. laptop computers or notebooks having a clamshell configuration, with body parts pivoting to an open position around an axis parallel to the plane they define in closed position
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1698 the I/O peripheral being a sending/receiving arrangement to establish a cordless communication link, e.g. radio or infrared link, integrated cellular phone details of antennas disposed inside a computer H01Q1/2266
• CPC Class Codes: H01Q 1/2266 disposed inside the computer
• 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 13/18 the slot being backed by, or formed in boundary wall of, a resonant cavity longitudinally slotted cylinder H01Q13/12 ; Open cavity antennas

Abstract

Antennas are provided for electronic devices such as portable computers. An electronic device may have a housing in which an antenna is mounted. The housing may have an antenna window for the antenna. The antenna window may be formed from dielectric or from antenna window slots in a conductive member such as a conductive wall of the electronic device housing. An antenna may have an antenna resonating element that is backed by a conductive antenna cavity. The antenna resonating element may have antenna resonating element slots or may be formed using other antenna configurations such as inverted-F configurations. The antenna cavity may have conductive vertical sidewalls and a conductive rear wall. The antenna cavity walls may be formed from conductive layers on a dielectric antenna support structure.

Claims

1. An electronic device, comprising:

a housing having a curved housing surface; and

a cavity-backed antenna mounted in the housing that includes an antenna cavity formed from a dielectric support structure covered with a layer of conductive material and an antenna resonating element, wherein the layer of conductive material comprises a curved conductive wall formed opposite to the antenna resonating element, wherein the curved conductive wall extends parallel to the curved housing surface, wherein the dielectric support structure forms a separate structure from the housing and wherein the antenna resonating element comprises a multi-branch inverted-F antenna resonating element formed from conductive antenna traces on a printed circuit board, and wherein the housing is an integral piece that encloses the dielectric support structure.

2. The electronic device defined in claim 1 wherein the dielectric support structure comprises a plastic support structure and wherein the layer of conductive material comprises metal.

3. The electronic device defined in claim 2 wherein the conductive antenna traces form an inverted-F antenna resonating element arm having at least two branches.

4. The electronic device defined in claim 2 further comprising:

radio-frequency transceiver circuitry; and

a transmission line that couples the radio-frequency transceiver circuitry to the cavity-backed antenna.

5. The electronic device defined in claim 4 wherein the cavity-backed antenna comprises a positive antenna feed terminal connected to the conductive antenna traces and comprises a ground antenna feed terminal connected to the layer of conductive material.

6. The electronic device defined in claim 2 wherein the printed circuit board comprises a flex circuit and wherein the conductive antenna traces and the layer of conductive material comprise copper.

7. The electronic device defined in claim 1 wherein the housing comprises a conductive housing wall having antenna window slots that form a slot-based antenna window for the cavity antenna.

8. The electronic device defined in claim 7 wherein the conductive housing wall comprises a curved portion of a portable computer lid.

9. The electronic device defined in claim 7 wherein the antenna window slots are less than 100 microns in width and are more than 5 mm in length.

10. The electronic device defined in claim 7 wherein the antenna window slots are filled with a solid dielectric.

17. The electronic device defined in claim 1, wherein the dielectric support structure is solid.

18. The electronic device defined in claim 1, wherein the curved conductive wall is formed adjacent to the curved housing surface.

19. The electronic device defined in claim 18, wherein the curved conductive wall lies flush with the curved housing surface.

11. An antenna in an electronic device housing having a curved housing surface, the antenna comprising:

a dielectric support structure;

a metal layer on the dielectric support structure that forms a conductive antenna cavity, wherein the conductive antenna cavity has a curved conductive wall formed from part of the metal layer; and

an antenna resonating element having a printed circuit board with an inverted-F antenna resonating element trace, wherein the curved conductive wall is formed opposite to the antenna resonating element, and wherein the curved conductive wall extends parallel to the curved housing surface.

12. The antenna defined in claim 11 further comprising a slot-based antenna window that is located adjacent to the conductive antenna cavity and the antenna resonating element.

13. The antenna defined in claim 12 wherein the slot-based antenna window comprises a metal housing structure having a plurality of antenna window slots each having a width of less than 100 microns and each having a length of at least five millimeters.

14. The antenna defined in claim 13 wherein the inverted-F antenna resonating element trace has multiple branches and resonates in at least two communications bands.

20. The antenna defined in claim 11, wherein the curved conductive wall lies flush with the curved housing surface.

15. A portable computer, comprising:

an upper housing portion having a continuous metal housing structure;

an antenna window formed from a plurality of antenna window slots in the metal housing structure

a lower housing portion that is pivotably attached to the upper housing portion;

radio-frequency transceiver circuitry;

a transmission line that is coupled to the radio-frequency transceiver circuitry; and

a cavity-backed antenna that is located under the antenna window, that is coupled to the transmission line, and that has an antenna cavity formed from a plastic support with vertical metal sidewalls and a rear metal layer, wherein the plastic support forms a separate structure from the upper and lower housing portions, and wherein the upper housing portion has a curved surface, the rear metal layer of the antenna cavity comprises a curved metal layer, and the curved metal layer extends parallel to the curved surface of the upper housing portion.

16. The portable computer defined in claim 15 wherein the upper housing portion has a curved edge region in which the antenna window slots are formed.

21. The portable computer defined in claim 15, wherein the rear metal layer is formed adjacent to the curved surface of the upper housing portion.