Antenna System With Tuning From Coupled Antenna

• US 20140292598A1
• Filed: 03/27/2013
• Published: 10/02/2014
• Est. Priority Date: 03/27/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bevelacqua, Peter, Xu, Hao, Nath, Jayesh, Pascolini, Mattia, Edwards, Jennifer M.
• Granted Patent: US 9,293,828 B2
• Time in Patent Office: Days
• US Class Current: 343/745
• CPC Class Codes: H01Q 1/2266 disposed inside the computer
• 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 5/392 the parasitic elements having dual-band or multi-band characteristics
• CPC Class Codes: H01Q 9/0442 with particular tuning means
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

Electronic devices may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may form a dual arm inverted-F antenna and an additional antenna such as a monopole antenna sharing a common antenna ground. The antenna structures may have three ports. A first antenna port may be coupled to an inverted-F antenna resonating element at a first location and a second antenna port may be coupled to the inverted-F antenna resonating element at a second location. A third antenna port may be coupled to the additional antenna. An adjustable component may be coupled to the first antenna port to tune the inverted-F antenna. The inverted-F antenna may be near-field coupled to the additional antenna so that the inverted-F antenna may serve as a tunable parasitic antenna resonating element that tunes the additional antenna.

Claims

1. Electronic device antenna structures, comprising:

an antenna ground;

a first antenna resonating element that forms a first antenna with the antenna ground; and

a second antenna resonating element that forms a second antenna with the antenna ground, wherein the second antenna is tunable, wherein the second antenna is near-field coupled to the first antenna, and wherein the second antenna serves as a tunable parasitic antenna resonating element for the first antenna.

2. The electronic device antenna structures defined in claim 1 further comprising an adjustable component that is configured to tune the second antenna.

3. The electronic device antenna structures defined in claim 2 wherein the adjustable component comprises an adjustable capacitor.

4. The electronic device antenna structures defined in claim 3 wherein the second antenna has at least one port and wherein the adjustable capacitor is coupled to the port.

5. The electronic device antenna structures defined in claim 4 wherein the first antenna has a port that is free of coupled adjustable antenna tuning components.

6. The electronic device antenna structures defined in claim 1 wherein the second antenna comprises an inverted-F antenna.

7. The electronic device antenna structures defined in claim 6 wherein the second antenna resonating element comprises a peripheral conductive electronic device housing member.

8. The electronic device antenna structures defined in claim 1 wherein the second antenna has first and second ports, wherein an adjustable capacitor is coupled to the first port to tune the second antenna during operation of the second antenna and to tune the tunable parasitic antenna resonating element during operation of the first antenna through a third port.

9. An electronic device, comprising:

antenna structures having first, second, and third antenna ports, wherein the antenna structures include an antenna ground, an inverted-F antenna resonating element that forms an inverted-F antenna with the antenna ground, and an additional antenna resonating element that forms an additional antenna with the antenna ground, wherein the first and second antenna ports are coupled to different locations on the inverted-F antenna resonating element and wherein the third antenna port is coupled to the additional antenna;

wireless circuitry that is coupled to the first, second, and third antenna ports; and

a tunable component coupled to the first port, wherein the inverted-F antenna serves as a tunable parasitic antenna resonating element for the additional antenna during transmission and reception of wireless signals through the third antenna port using the wireless circuitry.

10. The electronic device defined in claim 9 wherein the tunable component comprises an adjustable capacitor.

11. The electronic device defined in claim 10 wherein the inverted-F antenna is configured to cover cellular telephone frequencies from 0.7 to 0.96 GHz by tuning a low band antenna resonance of the inverted-F antenna using the adjustable capacitor.

12. The electronic device defined in claim 11 wherein the wireless circuitry comprises a satellite navigation system receiver coupled to the second port.

13. The electronic device defined in claim 12 wherein the inverted-F antenna is configured to handle cellular telephone frequencies in a band between 1.7 and 2.2 GHz.

14. The electronic device defined in claim 13 wherein the additional antenna is configured to handle signal frequencies between 2.3 and 2.7 GHz.

15. The electronic device defined in claim 14 wherein the adjustable capacitor is configured to exhibit a first capacitance when the additional antenna is handling wireless local area network signals and is configured to exhibit a second capacitance when the additional antenna is handling cellular telephone signals.

16. The electronic device defined in claim 15 wherein the third port is free of adjustable components and wherein the additional antenna is configured to handle wireless signals at 5 GHz.

17. An electronic device, comprising:

radio-frequency transceiver circuitry configured to handle wireless local area network signals, satellite navigation system signals, and cellular telephone signals;

a first antenna;

a second antenna that is coupled to the radio-frequency transceiver circuitry using a transmission line without adjustable antenna tuning components, wherein the first antenna is near-field coupled to the second antenna and serves as a tunable parasitic antenna resonating element for second antenna; and

an adjustable capacitor coupled between the radio-frequency transceiver circuitry and the first antenna, wherein the adjustable capacitor is configured to tune the first antenna to handle at least some of the cellular telephone signals and wherein the adjustable capacitor is configured to adjust the tunable parasitic antenna resonating element to tune the second antenna.

18. The electronic device defined in claim 17 further comprising a peripheral conductive housing member, wherein the first antenna comprises an inverted-F antenna and wherein a portion of the peripheral conductive housing member forms a portion of the inverted-F antenna.

19. The electronic device defined in claim 17 wherein the second antenna comprises a monopole antenna.

20. The electronic device defined in claim 17 further comprising a conductive structure that serves as antenna ground for the first and second antennas.