Antenna system with receiver diversity and tunable matching circuit

• US 8,872,706 B2
• Filed: 11/05/2010
• Issued: 10/28/2014
• Est. Priority Date: 11/05/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Caballero, Ruben, Pascolini, Mattia, Narang, Mohit, Mow, Matt A., Schlub, Robert W.
• Primary Examiner(s): SMITH, GRAHAM P
• Application Number:
  US12/941,010
• Publication Number:
  US 20120112969A1
• Time in Patent Office: 1,453 Days
• Field of Search: 343/702, 343/725
• US Class Current: 343/702
• 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 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• 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 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• 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: H04M 1/026 Details of the structure or mounting of specific components
• CPC Class Codes: H04M 1/0266 for a display module assembly

Abstract

Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. An electronic device may include a display mounted within a housing. A peripheral conductive member may run around the edges of the display and housing. Dielectric-filled gaps may divide the peripheral conductive member into individual segments. A ground plane may be formed within the housing from conductive housing structures, printed circuit boards, and other conductive elements. The ground plane and the segments of the peripheral conductive member may form antennas in upper and lower portions of the housing. The radio-frequency transceiver circuitry may implement receiver diversity using both the upper and lower antennas. The lower antenna may be used in transmitting signals. The upper antenna may be tuned using a tunable matching circuit.

Claims

1. An electronic device having a length, a width perpendicular to the length, and a height perpendicular to the width and the length, wherein the width is less than the length and the height is less than the width, comprising:

a housing having conductive structures that form an antenna ground and having a peripheral conductive member that runs around at least some edges of the housing, wherein the peripheral conductive member extends in a direction perpendicular to the antenna ground;

an inverted-F antenna that is formed from the antenna ground and a segment of the peripheral conductive member;

an antenna feed line that carries antenna signals to the segment;

receiver circuitry;

an adjustable impedance matching circuit interposed in the antenna feed line; and

an additional antenna that is formed from the antenna ground and an additional segment of the peripheral conductive member, wherein the additional antenna is configured to transmit and receive radio-frequency signals in a plurality of cellular telephone bands, the receiver circuitry is configured to only receive radio-frequency signals in a subset of the plurality of cellular telephone bands over the inverted-F antenna, the antenna ground comprises a midplate member that extends across the width of the electronic device, the midplate member is separated from the segment of the peripheral conductive member by a first dielectric opening so that the segment and the midplate member define the first dielectric opening, and the midplate member is separated from the additional segment of the peripheral conductive member by a second dielectric opening so that the additional segment and the midplate member define the second dielectric opening.

2. The electronic device defined in claim 1 wherein the peripheral conductive member comprises at least first and second gaps at opposing ends of the segment.

3. The electronic device defined in claim 2 wherein the conductive structures that form the antenna ground include a planar housing member that is connected between portions of the peripheral conductive member on opposing edges of the housing.

4. The electronic device defined in claim 2 wherein the inverted-F antenna has first and second branches that are associated with respective first and second communications band antenna resonances, wherein the first branch is formed from a first portion of the segment and wherein the second branch is formed from a second portion of the segment.

5. The electronic device defined in claim 4 wherein the gaps are filled with polymer.

6. The electronic device defined in claim 2 wherein the segment of the peripheral conductive member and the ground surround a dielectric opening, the electronic device further comprising a conductive structure that bridges the dielectric opening and shorts the peripheral conductive member to the ground.

7. The electronic device defined in claim 1 further comprising a satellite navigation system receiver that is coupled to the additional antenna.

8. The electronic device defined in claim 1 wherein the additional antenna is configured to cover five cellular telephone bands and wherein the inverted-F antenna is configured to cover fewer than five cellular telephone bands.

9. The electronic device defined in claim 8 further comprising:

wireless cellular telephone transceiver circuitry, wherein the adjustable impedance matching circuit is coupled between the inverted-F antenna and the wireless cellular telephone transceiver circuitry.

10. The electronic device defined in claim 9 wherein the adjustable impedance matching circuit is operable in at least a first state and a second state, wherein the inverted-F antenna resonates in a first set of cellular telephone communications bands within the five cellular telephone bands when the adjustable impedance matching circuit is in the first state, wherein the inverted-F antenna resonates in a second set of cellular telephone communications bands within the five cellular telephone bands when the adjustable impedance matching circuit is in the second state, and wherein the first and second sets of cellular telephone communications bands are different.

11. The electronic device defined in claim 10 further comprising a satellite navigation system receiver that is coupled to the additional antenna, wherein the satellite navigation system receiver is configured to receive satellite navigation system signals from the inverted-F antenna when the adjustable impedance matching circuit is in the first state and when the adjustable impedance matching circuit is in the second state.

12. The electronic device defined in claim 11 wherein the inverted-F antenna is configured to operate in a 850 MHz receive band, a 1575 MHz Global Positioning System band, and a 1900 MHz receive band when the adjustable impedance matching circuit is in the first state and is configured to operate in a 900 MHz receive band, the 1575 MHz Global Positioning System band, and a 2100 MHz receive band when the adjustable impedance matching circuit is in the second state.

13. The electronic device defined in claim 11 wherein the segment of the peripheral conductive member and the conductive structures that the antenna ground are separated by a dielectric opening, the electronic device further comprising a wireless local area network antenna mounted within the opening.

14. An electronic device having a length, a width perpendicular to the length, and a height perpendicular to the width and the length, wherein the width is less than the length and the height is less than the width, comprising:

a housing having opposing first and second ends;

a display mounted within the housing, wherein the display has four edges;

a peripheral conductive member that runs along the four edges of the display, wherein the peripheral conductive member extends across the height of the electronic device;

an antenna ground that is formed at least partly from conductive portions of the housing;

a first antenna that is formed from at least a first segment of the peripheral conductive member and the antenna ground;

a second antenna that is formed from at least a second segment of the peripheral conductive member and the antenna ground, wherein the second antenna comprises a T-shaped multiband antenna;

radio-frequency transceiver circuitry that transmits and receives radio-frequency antenna signals through the first antenna in a plurality of cellular telephone communications bands and that only receives radio-frequency antenna signals through the second antenna in a subset of the cellular telephone communications bands, wherein the antenna ground comprises a midplate member that extends across the width of the electronic device, the midplate member is separated from the second segment of the peripheral conductive member by a dielectric opening so that the second segment and the midplate member define the dielectric opening; and

a conductive shorting structure that bridges the dielectric opening to short the second segment of the peripheral conductive member to the midplate member.

15. The electronic device defined in claim 14, wherein the radio-frequency transceiver circuitry is configured to receive the radio-frequency antenna signals in at least five cellular telephone receive bands via the first antenna and is configured to transmit the radio-frequency antenna signals in at least five cellular telephone transmit bands via the first antenna.

16. The electronic device defined in claim 15, wherein the radio-frequency transceiver circuitry is configured to receive the radio-frequency antenna signals in no more than four of the five cellular telephone receive bands via the second antenna.

17. The electronic device defined in claim 15 further comprising a tunable matching circuit coupled between the radio-frequency transceiver circuitry and the second antenna, wherein the tunable matching circuit is operable in a first mode in which the radio-frequency antenna signals are received by the second antenna in only first and second cellular telephone receive bands among the five cellular telephone receive bands and is operable in a second mode in which the radio-frequency antenna signals are received by the second antenna in only third and fourth cellular telephone receive bands among the five cellular telephone receive bands and wherein the first and second cellular telephone receive bands are different than the third and fourth cellular telephone receive bands.

18. The electronic device defined in claim 15, wherein the first antenna comprises a loop antenna, wherein the conductive portions of the housing and the first segment surround a first dielectric opening and form the loop antenna, wherein the second antenna comprises an inverted-F antenna, and wherein the conductive portions of the housing and the second segment surround a second dielectric opening and form the inverted-F antenna.

19. The electronic device defined in claim 18 wherein the first end of the electronic device comprises a lower end of the electronic device, wherein the second end of the electronic device comprises an upper end of the electronic device, and wherein the peripheral conductive member comprises at least three gaps that define at least three separate segments of the peripheral conductive member including the first and second segments.

20. The electronic device defined in claim 15 wherein the radio-frequency transceiver circuitry is configured to receive signals through the first antenna and the second antenna and wherein the radio-frequency transceiver circuitry is configured to transmit signals through only the first antenna and not the second antenna, so that the electronic device supports receiver diversity and not transmitter diversity.

21. An electronic device, comprising:

a housing having opposing upper and lower ends;

a display mounted within the housing, wherein the display has four edges;

a peripheral conductive member that runs along the four edges of the display;

at least two dielectric-filled gaps in the peripheral conductive member that separate the peripheral conductive member into at least first and second respective segments;

an antenna ground plane within the housing;

an upper cellular telephone antenna that is formed from at least the first segment and the antenna ground plane at the upper end of the housing, wherein the upper cellular telephone antenna comprises a T-shaped multiband antenna;

a lower cellular telephone antenna that is formed from at least the second segment and the antenna ground plane at the lower end of the housing, wherein the lower cellular telephone antenna comprises a loop antenna; and

radio-frequency transceiver circuitry that is configured to transmit and receive radio-frequency antenna signals in a plurality of radio-frequency bands through the lower cellular telephone antenna and that is configured to receive antenna radio-frequency antenna signals in only a subset of the plurality of radio-frequency bands through the upper cellular telephone antenna without transmitting any radio-frequency signals through the upper cellular telephone antenna, wherein the peripheral conductive member runs across at least four exterior surfaces of the electronic device, the electronic device has a length, a width perpendicular to the length, and a height perpendicular to the width and the length, wherein the width is less than the length and the height is less than the width, and wherein the at least two dielectric-filled gaps extend across the height of the electronic device from a rear face of the electronic device to a front face of the electronic device.

22. The electronic device defined in claim 21, wherein the radio-frequency transceiver circuitry is configured to cover at least five cellular telephone communications bands including an 850 MHz band, a 900 MHz band, an 1800 MHz band, an 1900 MHz band, and a 2100 MHz band using the lower cellular telephone antenna and wherein the radio-frequency transceiver circuitry is configured to cover fewer than five of the five cellular telephone communications bands using the upper cellular telephone antenna.

23. The electronic device defined in claim 22 further comprising a fixed matching circuit coupled between the radio-frequency transceiver circuit and the lower cellular telephone antenna and an adjustable matching circuit coupled between the radio-frequency transceiver circuit and the upper cellular telephone antenna, the electronic device further comprising:

control circuitry that is configured to control the adjustable matching circuit to tune the upper cellular telephone antenna.

24. The electronic device defined in claim 21, wherein the antenna ground plane comprises a midplate member that extends across the width of the electronic device, wherein the peripheral conductive member is separate from the antenna ground plane, wherein the midplate member is separated from the first segment of the peripheral conductive member by a first dielectric opening so that the first segment and the midplate member surround the first dielectric opening, wherein the midplate member is separated from the second segment of the peripheral conductive member by a second dielectric opening so that the second segment and the midplate member surround the second dielectric opening, wherein the electronic device further comprises a conductive shorting structure that bridges the first dielectric opening to short the first segment of the peripheral conductive member to the midplate member.

25. The electronic device defined in claim 24, further comprising:

a fixed matching circuit coupled between the radio-frequency transceiver circuit and the lower cellular telephone antenna;

an adjustable matching circuit coupled between the radio-frequency transceiver circuit and the upper cellular telephone antenna;

a power amplifier coupled between a transmitter circuit in the radio-frequency transceiver circuit and the fixed matching circuit;

a low noise amplifier coupled between a receiver circuit in the radio-frequency transceiver circuit;

a satellite navigation system receiver circuit that is separate from the radio-frequency transceiver circuit and that is coupled to the adjustable matching circuit;

filtering circuitry coupled between the satellite navigation system receiver circuit and the adjustable matching circuit;

an additional low noise amplifier coupled between the filtering circuitry and an additional receiver circuit in the radio-frequency transceiver circuit; and

control circuitry, wherein the control circuitry is configured to provide control signals to the radio-frequency transceiver circuit over a first control path to selectively activate the receiver circuit and the additional receiver circuit, and wherein the control circuitry is configured to provide additional control signals over an additional control path to the adjustable matching circuit to tune the upper cellular telephone antenna.