Electronic device antenna with isolation mode

Patent metadata

Field	Value
Publication number	US-9972891-B2
Application number	US-201514819280-A
Country	US
Kind code	B2
Filing date	Aug 5, 2015
Priority date	Aug 5, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

An electronic device may have wireless circuitry with antennas. An antenna resonating element arm for a given antenna may be formed from metal structures supported by a plastic carrier. The antenna resonating element arm may be coupled to switching circuitry to isolate the antenna resonating element arm when the antenna resonating element arm is not being used to handle communications in a communications band. The electronic device may have a metal housing. A slot may separate a peripheral portion of the housing such as a sidewall portion from a planar rear portion. The sidewall portion and the planar rear portion may form an additional antenna that operates at communications frequencies outside of the communications band handled by the given antenna. A parasitic antenna resonating element arm may be formed in the slot to enhance the frequency response of the additional antenna.

First claim

What is claimed is:

1. An electronic device, comprising:
a housing having a peripheral conductive structure;
a first antenna that has a first resonating element arm formed from the peripheral conductive structure, that has an antenna ground that is separated from the first antenna resonating element arm by a slot that runs parallel at least one edge of the housing, and that has a first antenna feed;
a second antenna formed from a second resonating element arm and the antenna ground, wherein the second antenna has a second antenna feed and the peripheral conductive structure forms a parasitic antenna resonating element for the second antenna;
a first transmission line coupled to the first antenna feed;
switching circuitry; and
a second transmission line coupled to the second antenna feed by the switching circuitry.

2. The electronic device defined in claim 1 further comprising control circuitry that is configured to place the switching circuitry in a freespace mode of operation in which the second transmission line transmits and receives antenna signals for the second antenna through the switching circuitry.

3. The electronic device defined in claim 2 wherein the control circuitry is further configured to place the switching circuitry in an isolation mode of operation in which the second antenna is electrically isolated from the second transmission line.

4. The electronic device defined in claim 3 wherein the control circuitry is further configured to place the switching circuitry in at least one additional mode of operation in which the antenna is tuned to ensure operation at a desired frequency range when gripped by a user.

5. The electronic device defined in claim 3 wherein the second antenna further comprises a plastic carrier that supports the second resonating element arm.

6. The electronic device defined in claim 5 further comprising a flexible printed circuit, wherein the second transmission line includes conductive lines on the flexible printed circuit.

7. The electronic device defined in claim 6 further comprising an additional parasitic antenna resonating element in the slot.

8. The electronic device defined in claim 7 wherein the switching circuitry is mounted on the flexible printed circuit.

9. The electronic device defined in claim 3 wherein the second antenna comprises a tunable inverted-F antenna.

10. The electronic device defined in claim 9 wherein the second antenna is configured to resonate in a frequency band that includes a frequency of 1400 MHz.

11. The electronic device defined in claim 1 wherein the first antenna feed has a first positive antenna feed terminal coupled to the first antenna resonating element arm and wherein the second antenna feed has a second positive antenna feed terminal coupled to the second antenna resonating element arm.

12. The electronic device defined in claim 1 wherein the second antenna resonating element arm has at least four segments and three right-angle bends.

13. An electronic device, comprising:
a metal housing with a slot that separates the metal housing into a peripheral conductive housing structure that forms a first antenna resonating element arm and an antenna ground, wherein the first antenna resonating element arm and the antenna ground form a first antenna;
switching circuitry having first and second states; and
a second antenna coupled to the switching circuitry, wherein the second antenna includes a second antenna resonating element arm and the antenna ground, the second antenna resonating element arm is coupled to radio-frequency transceiver circuitry when the switching circuitry is in the first state, and the second antenna resonating element arm is configured to serve as a parasitic antenna resonating element for the first antenna when the switching circuitry is in the second state.

14. The electronic device defined in claim 13 further comprising a transmission line that couples the transceiver circuitry to the switching circuitry.

15. The electronic device defined in claim 14 further comprising control circuitry that is configured to adjust the switching circuitry to place the switching circuitry in a selected one of the first and second states.

16. The electronic device defined in claim 15 wherein the transceiver circuitry is configured to transmit and receive antenna signals with the first antenna while the switching circuitry is in the second state.

17. The electronic device defined in claim 16 further comprising a plastic carrier that supports the second antenna resonating element.

18. The electronic device defined in claim 17 wherein the second antenna resonating element arm is configured to resonate at a communications band including a frequency of 1400 MHz.

19. An electronic device, comprising:
a metal housing having a sidewall portion that runs along an edge of the electronic device and having a planar rear wall portion that forms a portion of a ground, wherein the sidewall portion and the planar rear wall portion are separated by a slot;
an antenna resonating element arm formed from a metal structure on at least two sides of a plastic carrier;
switching circuitry coupled to the antenna resonating element arm; and
transceiver circuitry coupled to the antenna resonating element arm by the switching circuitry, wherein the switching circuitry is operable in a first mode in which the switching circuitry couples the transceiver circuitry to the antenna resonating element arm and a second mode in which the switching circuitry isolates the transceiver circuitry from the antenna resonating element arm.

20. The electronic device defined in claim 19 wherein the antenna resonating element arm serves as part of an antenna that operates in a communications band, the electronic device further comprising a parasitic antenna resonating element arm in the slot, wherein the sidewall portion, the parasitic antenna resonating element arm, and the ground form an additional antenna that operates at frequencies that are outside of the communications band.

21. The electronic device defined in claim 20 wherein the antenna resonating element arm of the antenna serves as a parasitic antenna resonating element for the additional antenna at the frequencies that are outside of the communications band while the switching circuitry is operated in the second mode.

Assignees

• Apple Inc

Inventors

• Ayala Vazquez Enrique
• Hu Hongfei
• Jin Nanbo
• Mow Matthew A
• Han Liang
• Pascolini Mattia

Classifications

• H01Q1/2258

  used with computer equipment · CPC title

• H01Q5/335

  at the feed, e.g. for impedance matching · CPC title

• H01Q13/106

  Microstrip slot antennas (patch antenna elements H01Q9/0407) · CPC title

• H01Q1/22

  by structural association with other equipment or articles · CPC title

• H01Q1/243 Primary

  with built-in antennas · CPC title