Distributed loop speaker enclosure antenna

• US 9,425,496 B2
• Filed: 09/27/2012
• Issued: 08/23/2016
• Est. Priority Date: 09/27/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhu, Jiang, Li, Qingxiang, Schlub, Robert W., Caballero, Ruben
• Primary Examiner(s): Elahee, Md S
• Application Number:
  US13/629,061
• Publication Number:
  US 20140086441A1
• Time in Patent Office: 1,426 Days
• Field of Search: 345/173, 455/41.1, 455/41.2, 455/77, 455/566, 343/700.MS, 343/702, 343/846, 343/848, 343/866, 343/893, 381/315, 381/332, 379/431
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/44 using equipment having another main function to serve additionally as an antenna , e.g. means for giving an antenna an aesthetic aspectH01Q1/27 - H01Q1/34 take precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

An electronic device may be provided with antenna structures. The antenna structures may be formed using a dielectric carrier structure such as a speaker enclosure, so that interior space within the electronic device that is occupied by a speaker can be used in forming an antenna. A speaker driver may be mounted in the speaker enclosure. Openings in the speaker enclosure may allow sound from the speaker driver to be emitted from the speaker enclosure. The antenna structures may have first and second loop antenna resonating elements. The first loop antenna resonating element may indirectly feed the second loop antenna resonating element. The second loop antenna resonating element may be a distributed loop element formed from a strip of metal with a width that loops around the speaker enclosure. Openings in the second loop antenna resonating element may be aligned with the speaker enclosure openings.

Claims

1. An antenna, comprising:

a hollow speaker enclosure with first and second opposing sides;

a loop antenna resonating element that surrounds the hollow speaker enclosure, wherein a first portion of the loop antenna resonating element is adjacent to the first side of the hollow speaker enclosure and a second portion of the loop antenna resonating element is adjacent to the second side of the hollow speaker enclosure; and

a plurality of openings in the hollow speaker enclosure, wherein the loop antenna resonating element has a plurality of openings that align with the plurality of openings in the hollow speaker enclosure.

2. The antenna defined in claim 1 further comprising a speaker driver in the hollow speaker enclosure.

3. The antenna defined in claim 1 further comprising an indirect antenna feed element that is configured to feed the antenna by electromagnetically coupling to the loop antenna resonating element.

4. The antenna defined in claim 1 wherein the loop antenna resonating element comprises a metal trace that forms a loop, the antenna further comprising a capacitance and an inductance interposed in the loop.

5. The antenna defined in claim 4 wherein the loop antenna resonating element comprises metal segments separated by openings in the loop antenna resonating element and wherein the metal segments collectively provide the inductance.

6. The antenna defined in claim 5 wherein the metal trace is formed on a surface of the hollow speaker enclosure.

7. The antenna defined in claim 1 further comprising:

an additional loop antenna resonating element on the hollow speaker enclosure that has antenna feed terminals; and

a speaker driver within the hollow speaker enclosure under the additional loop antenna resonating element.

8. The apparatus defined in claim 1, the hollow speaker enclosure further comprising third and fourth opposing sides connected by the first and second opposing sides, wherein the first, second, third, and fourth sides of the hollow speaker enclosure define a cavity and a speaker driver is positioned in the cavity.

9. The antenna defined in claim 3, wherein the indirect feed element comprises an additional loop antenna resonating element on the hollow speaker enclosure.

10. The apparatus defined in claim 1, further comprising:

radio-frequency transceiver circuitry; and

transmission line structures coupled between the radio-frequency transceiver circuitry and the first loop antenna resonating element.

11. An electronic device, comprising:

a metal housing having a plurality of speaker openings;

a speaker enclosure that extends along a longitudinal axis, wherein the longitudinal axis has first and second opposing sides; and

antenna structures having a loop antenna resonating element that surrounds the speaker enclosure, wherein the loop antenna resonating element has a first portion on the first side of the longitudinal axis and a second portion on the second side of the longitudinal axis, and wherein the speaker enclosure has openings aligned with the plurality of speaker openings in the metal housing and the loop antenna resonating element has a plurality of openings aligned with the plurality of speaker openings in the metal housing.

12. The electronic device defined in claim 11 wherein the loop antenna resonating element comprises a strip of metal traces that surround at least some of the speaker enclosure.

13. The electronic device defined in claim 12 wherein segments of the metal traces that are interposed between the openings in the loop antenna resonating element are configured to form an inductance in the loop antenna resonating element.

14. The electronic device defined in claim 13 further comprising conductive material that electrically couples the metal traces to the metal housing.

15. The electronic device defined in claim 11 further comprising a speaker driver in the speaker enclosure.

16. The electronic device defined in claim 15 wherein the speaker driver has an insulating coating and electrically floats relative to the antenna structures.

17. The electronic device defined in claim 11, wherein the metal housing comprises a sidewall structure for the electronic device and the plurality of speaker openings are formed in the sidewall structure.

18. The electronic device defined in claim 17 wherein the sidewall structure comprises a curved housing surface and the plurality of speaker openings are formed in the curved housing surface.

19. The electronic device defined in claim 11, further comprising:

a display having a display cover layer, wherein the antenna structures are configured to transmit radio-frequency signals through a portion of the display cover layer.

20. Apparatus, comprising:

an elongated hollow plastic speaker enclosure that extends along a first longitudinal axis;

a speaker driver within the hollow speaker enclosure; and

metal structures on the hollow plastic speaker enclosure, wherein the metal structures are configured to form a distributed loop antenna having first and second loop antenna resonating elements, the first loop antenna resonating element indirectly feeds the second loop antenna resonating element using near-field electromagnetic coupling, the second loop antenna resonating element extends around the first longitudinal axis, and the first loop antenna resonating element extends around a second longitudinal axis that is substantially perpendicular to the first longitudinal axis.

21. The apparatus defined in claim 20 wherein the hollow plastic speaker enclosure has speaker enclosure openings, the apparatus further comprising:

openings in the metal structures that overlap the speaker enclosure openings, wherein segments of the metal structures are formed between the openings in the metal structures and wherein the segments of the metal structures collectively form an inductance in the second loop antenna resonating element.

22. The apparatus defined in claim 21 further comprising a metal electronic device housing wall having openings that are aligned with the speaker enclosure openings.

23. The apparatus defined in claim 20, wherein the second loop antenna resonating element extends entirely around the longitudinal axis.