Antenna with integrated proximity sensor for proximity-based radio-frequency power control

• US 8,577,289 B2
• Filed: 02/17/2011
• Issued: 11/05/2013
• Est. Priority Date: 02/17/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Schlub, Robert W., Jiang, Yi, Li, Qingxiang, Zhu, Jiang, Caballero, Ruben
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Mathew, Max
• Application Number:
  US13/029,581
• Publication Number:
  US 20120214412A1
• Time in Patent Office: 992 Days
• Field of Search: 455/41.1, 455/41.3, 455/41.7, 455/550.1
• US Class Current: 455/41.1
• CPC Class Codes: G01B 7/023 for measuring distance between sensor and object G01B7/082 and G01B7/102 take precedence
• 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 1/243 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 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion telephones including GPS signal receivers H04M2250/10

Abstract

An electronic device may have a housing in which an antenna is mounted. An antenna window may be mounted in the housing to allow radio-frequency signals to be transmitted from the antenna and to allow the antenna to receive radio-frequency signals. Near-field radiation limits may be satisfied by reducing transmit power when an external object is detected in the vicinity of the dielectric antenna window and the antenna. A capacitive proximity sensor may be used in detecting external objects in the vicinity of the antenna. The proximity sensor and the antenna may be formed using integral antenna resonating element and proximity sensor capacitor electrode structures. These structures may be formed from identical first and second patterned conductive layers on opposing sides of a dielectric substrate. A transceiver and proximity sensor may be coupled to the structures through respective high-pass and low-pass circuits.

Claims

1. An electronic device, comprising:

a radio-frequency transceiver;

capacitive proximity sensor circuitry;

ground structures; and

conductive structures that are coupled to the radio-frequency transceiver through high-pass circuitry and that are coupled to the capacitive proximity sensor circuitry through low-pass circuitry, wherein the conductive structures include at least one patterned conductor that forms an antenna resonating element that operates with the ground structures to form an antenna through which the radio-frequency transceiver transmits and receives radio-frequency data signals and wherein the at least one patterned conductor forms a capacitor electrode with which the capacitive proximity sensor circuitry makes capacitance measurements.

2. The electronic device defined in claim 1 wherein the high-pass circuitry comprises at least two capacitors.

3. The electronic device defined in claim 2 further comprising a transmission line having positive and ground signal lines, wherein the transceiver circuitry is coupled to the at least one patterned conductor through the positive signal line and a first of the two capacitors and is coupled to the at least one patterned conductor through the ground signal line and a second of the two capacitors.

4. The electronic device defined in claim 3 wherein the at least one patterned conductor comprises one of a pair of patterned conductor layers in the conductive structures and wherein the conductive structures include a dielectric layer interposed between the pair of patterned conductor layers.

5. The electronic device defined in claim 4 wherein the low-pass circuitry comprises a first inductor coupled between the proximity sensor circuitry and a first of the pair of patterned conductors and a second inductor coupled between the proximity sensor circuitry and a second of the pair of patterned conductors.

6. The electronic device defined in claim 5 wherein the first and second patterned conductors have substantially identical patterns.

7. The electronic device defined in claim 6 wherein the first and second patterned conductors have substantially identical inverted-F antenna resonating element patterns.

8. The electronic device defined in claim 2 wherein the ground structures comprise conductive housing structures.

9. The electronic device defined in claim 8 further comprising a dielectric window in the conductive housing structures, wherein the conductive structures are mounted adjacent to the dielectric window.

10. The electronic device defined in claim 9 wherein the conductive structures comprise a flex circuit substrate having a bent edge.

11. The electronic structures defined in claim 10 wherein the conductive structures include a patterned trace that forms an inverted-F antenna resonating element structure for the antenna resonating element.

12. The electronic device defined in claim 2 wherein the conductive structures include first and second patterned conductive layers on opposing sides of a dielectric substrate, the electronic device further comprising:

a positive antenna feed terminal connected to the first of the patterned conductive layers through a first of the capacitors; and

a ground antenna feed terminal connected to the first of the patterned conductive layers through a second of the capacitors.

13. An electronic device, comprising:

a ground;

radio-frequency transceiver circuitry configured to transmit data through an antenna;

capacitive proximity sensor circuitry;

integral antenna resonating element and proximity sensor capacitor electrode structures that are coupled to the capacitive proximity sensor circuitry; and

positive and ground antenna feed terminals coupled to the integral antenna resonating element and proximity sensor capacitor electrode structures, wherein the radio-frequency transceiver circuitry is coupled to the positive and ground antenna feed terminals and wherein the ground and the integral antenna resonating element and proximity sensor capacitor electrode structures form the antenna.

14. The electronic device defined in claim 13 wherein the integral antenna resonating element and proximity sensor capacitor electrode structures comprises first and second patterned conductor layers on opposing sides of a dielectric layer.

15. The electronic device defined in claim 14 further comprising a first capacitor interposed between the positive antenna feed terminal and the first patterned conductor layer and a second capacitor interposed between the ground antenna feed terminal and the first patterned conductor layer.

16. The electronic device defined in claim 15 wherein the first and second patterned conductor layers have identical shapes and are electrically isolated by the dielectric layer.

17. The electronic device defined in claim 13 wherein the ground comprises conductive housing structures, the electronic device further comprising a dielectric window in the conductive housing structure adjacent to the integral antenna resonating element and proximity sensor capacitor electrode structures.

18. An electronic device, comprising:

conductive structures having first and second patterned conductive layers formed on opposing sides of a dielectric substrate layer;

proximity sensor circuitry that is coupled to the first and second patterned conductive layers and that is configured to use capacitance measurements from the first and second patterned conductive layers to produce proximity data reflective of distance between the printed circuit structures and objects external to the electronic device;

wireless transceiver circuitry; and

a transmission line that couples the wireless transceiver circuitry to the printed circuit structures, wherein the wireless transceiver circuitry transmits data signals using the first and second patterned conductive layers.

19. The electronic device defined in claim 18 wherein the transmission line comprises first and second signal lines and wherein the electronic device further comprises a first capacitor interposed between the first signal line and the conductive structures and a second capacitor interposed between the second signal line and the conductive structures.

20. The electronic device defined in claim 19 wherein the first and second patterned conductive layers have identical patterns and wherein the first and second patterned conductive layers have an inverted-F antenna resonating element shape with at least a feed branch and a short circuit branch.

21. The electronic device defined in claim 18 wherein the first and second patterned conductive layers have identical patterns and wherein the first and second patterned conductive layers have at least two branches.