Electronic device with shared antenna structures and balun

• US 9,997,828 B2
• Filed: 03/16/2016
• Issued: 06/12/2018
• Est. Priority Date: 03/03/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Ouyang, Yuehui, Darnell, Dean F., Ayala Vazquez, Enrique, Tong, Erica J., Hu, Hongfei, Mow, Matthew A., Pascolini, Mattia, Tsai, Ming-Ju, Jin, Nanbo, Schlub, Robert W.
• Primary Examiner(s): NGUYEN, LINH V
• Application Number:
  US15/071,795
• Publication Number:
  US 20160197401A1
• Time in Patent Office: 818 Days
• Field of Search: 343702, 343700 MS, 343745, 343767
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/48 Earthing means; Earth screens; Counterpoises
• 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 3/247 by switching different parts of a primary active element
• CPC Class Codes: H01Q 5/35 using two or more simultaneously fed points
• CPC Class Codes: H01Q 5/371 Branching current paths
• 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
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: H04B 5/26 using coils

Abstract

An electronic device may be provided with shared antenna structures that can be used to form both a near-field-communications antenna such as a loop antenna and a non-near-field communications antenna such as an inverted-F antenna. The antenna structures may include conductive structures such as metal traces on printed circuits or other dielectric substrates, internal metal housing structures, or other conductive electronic device housing structures. A main resonating element arm may be separated from an antenna ground by an opening. A non-near-field communications antenna return path and antenna feed path may span the opening. A balun may have first and second electromagnetically coupled inductors. The second inductor may have terminals coupled across differential signal terminals in a near-field communications transceiver. The first inductor may form part of the near-field communications loop antenna.

Claims

1. An electronic device, comprising:

an antenna having a resonating element arm, an antenna ground, an antenna feed path, and an antenna return path coupled between the resonating element arm and the antenna ground;

non-near-field communications transceiver circuitry coupled to the antenna that handles non-near-field communications using the antenna;

near-field communications transceiver circuitry coupled to the antenna, wherein the near-field communications circuitry handles near-field communications using a loop antenna that includes at least part of the return path of the antenna; and

an inductor coupled between the near-field communications transceiver circuitry and the resonating element arm.

2. The electronic device defined in claim 1, further comprising:

a balun that couples the near-field communications circuitry to the antenna.

3. The electronic device defined in claim 1, wherein the antenna comprises an inverted-F antenna.

4. The electronic device defined in claim 1, wherein the non-near-field communications circuitry handles non-near-field communications in a cellular telephone communications band using the antenna.

5. The electronic device defined in claim 1, wherein the non-near-field communications circuitry handles communications at frequencies greater than 700 MHz.

6. The electronic device defined in claim 1, wherein the loop antenna further includes a portion of the resonating element arm.

7. The electronic device defined in claim 1, wherein the loop antenna further includes a portion of the antenna feed path.

20. The electronic device defined in claim 1, wherein the loop antenna includes an additional path having an additional inductor thereon and the additional path couples the resonating element arm to the antenna ground via the additional inductor.

8. An electronic device, comprising:

an inverted-F antenna having an antenna resonating element, an antenna ground, an antenna feed path, and an antenna return path coupled between the resonating element arm and the antenna ground;

wireless communications circuitry coupled to the inverted-F antenna that transmits and receives wireless signals in a frequency band using the inverted-F antenna;

wireless circuitry that receives wireless signals at a frequency that is below the frequency band using a loop antenna that includes at least part of the inverted-F antenna; and

an inductor coupled between the antenna resonating element and the wireless circuitry.

9. The electronic device defined in claim 8, wherein the loop antenna includes at least part of the antenna return path of the inverted-F antenna.

10. The electronic device defined in claim 8, wherein the loop antenna includes at least part of the antenna resonating element of the inverted-F antenna.

11. The electronic device defined in claim 8, wherein the loop antenna includes at least part of the antenna feed path of the inverted-F antenna.

12. The electronic device defined in claim 8, wherein the frequency band includes frequencies that are greater than or equal to 700 MHz.

13. The electronic device defined in claim 12, wherein the frequency is less than 700 MHz.

14. The electronic device defined in claim 8, wherein the wireless communications circuitry comprises cellular telephone transceiver circuitry that transmits and receives wireless signals in a cellular telephone communications band.

15. An electronic device, comprising:

first wireless transceiver circuitry that transmits and receives first wireless signals in a frequency band;

second wireless transceiver circuitry that receives second wireless signals at a frequency that is lower than the frequency band;

an inverted-F antenna that transmits and receives the first wireless signals for the first wireless transceiver circuitry; and

a loop antenna that includes a portion of the inverted-F antenna and that receives the second wireless signals for the second wireless transceiver circuitry, wherein the loop antenna comprises an inductor coupled between the portion of the inverted-F antenna and the second wireless transceiver circuitry.

16. The electronic device defined in claim 15, further comprising:

power management circuitry coupled to the second wireless circuitry.

17. The electronic device defined in claim 15, wherein the first wireless circuitry comprises cellular telephone transceiver circuitry that transmits and receives the first wireless signals in a cellular telephone communications band that includes frequencies greater than 700 MHz.

18. The electronic device defined in claim 15, wherein the first wireless circuitry comprises wireless local area network transceiver circuitry that transmits and receives the first wireless signals in a wireless local area network communications band that includes frequencies greater than 700 MHz.

19. The electronic device defined in claim 15, wherein the loop antenna includes at least a portion of a return path of the inverted-F antenna.