System and methods for performing antenna transmit diversity

• US 20130149975A1
• Filed: 09/28/2012
• Published: 06/13/2013
• Est. Priority Date: 12/08/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Yu, Qishan, Yang, James T.
• Granted Patent: US 9,444,540 B2
• Time in Patent Office: Days
• US Class Current: 455/78
• CPC Class Codes: H04B 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0868 Hybrid systems, i.e. switching and combining

Abstract

A wireless electronic device may include switching circuits that perform time division duplexing by toggling between a first configuration in which radio-frequency signals received from antennas are routed to the transceivers and a second configuration in which the antennas are coupled to antenna switching circuitry. The antenna switching circuitry may receive radio-frequency transmission signals from the transceivers and route the transmission signals to a selected one of the antennas. The antenna switching circuitry may be controlled by control circuitry such as baseband circuitry and/or storage and processing circuitry on the device. The antenna switching circuitry may be controlled to accommodate antenna transmit diversity without affecting reception of radio-frequency signals, because the switching circuits that perform time division duplexing may form signal reception paths that are unaffected by the configuration of the antenna switching circuitry.

Claims

1. A wireless electronic device, comprising:

first and second antennas;

transceiver circuitry;

an antenna switching circuit configured to route radio-frequency transmission signals from the transceiver circuitry to a selected antenna of the first and second antennas; and

switching circuitry coupled between the antenna switching circuit and the first and second antennas, wherein the switching circuitry is operable to repeatedly toggle between a first configuration in which radio-frequency reception signals are routed from the first and second antennas to the transceiver circuitry and a second configuration in which the radio-frequency transmission signals are provided from the antenna switching circuit to the selected antenna.

2. The wireless electronic device defined in claim 1 wherein the switching circuitry comprises:

a first switch coupled between the first antenna and the antenna switching circuit; and

a second switch coupled between the second antenna and the antenna switching circuit.

3. The wireless electronic device defined in claim 2 wherein the first switch is coupled between the first antenna and the transceiver circuitry and wherein the first switch couples the first antenna to the antenna switching circuit during the second configuration.

4. The wireless electronic device defined in claim 3 wherein the first switch couples the first antenna to the transceiver circuitry during the first configuration.

5. The wireless electronic device defined in claim 4 wherein the second switch is coupled between the second antenna and the transceiver circuitry, wherein the second switch couples the second antenna to the antenna switching circuit during the second configuration.

6. The wireless electronic device defined in claim 5 wherein the second switch couples the second antenna to the transceiver circuitry during the second configuration.

7. The wireless electronic device defined in claim 6 further comprising:

at least one low noise amplifier coupled between the first switch and the transceiver circuitry, wherein the low noise amplifier is operable to amplify the radio-frequency reception signals.

8. The wireless electronic device defined in claim 1 further comprising:

at least one power amplifier coupled between the transceiver circuitry and the antenna switching circuit, wherein the power amplifier is operable to amplify the radio-frequency transmission signals.

9. A method of operating a wireless electronic device having first and second antennas, the method comprising:

with switching circuitry having a plurality of receive ports and a plurality of transmit ports, routing radio-frequency signals received from the first and second antennas to a selected receive port of the plurality of receive ports during a first time period; and

with the switching circuitry, routing radio-frequency transmit signals received at the transmit ports to a selected antenna of the first and second antennas during a second time period.

10. The method defined in claim 9 further comprising:

with control circuitry, selecting which antenna of the first and second antennas should be used for wireless transmission; and

with the control circuitry, directing the switching circuitry to route the radio-frequency transmit signals from the transmit ports to the selected antenna during the second time period.

11. The method defined in claim 10 wherein the control circuitry comprises a baseband processor and wherein selecting which antenna of the first and second antennas should be used for wireless transmission comprises:

with the baseband processor, selecting which antenna of the first and second antennas should be used for wireless transmission.

12. The method defined in claim 9 further comprising:

with transceiver circuitry, providing the radio-frequency transmit signals to the transmit ports of the switching circuitry during the second time period.

13. The method defined in claim 12 further comprising:

with the transceiver circuitry, receiving the radio-frequency signals from the selected receive port of the switching circuitry during the first time period.

14. The method defined in claim 12 wherein routing the radio-frequency transmit signals received at the transmit ports to the selected antenna of the first and second antennas during the second time period comprises:

routing the radio-frequency transmit signals received at the transmit ports to the selected antenna of the first and second antennas during the second time period without changing which receive port is selected during the first time period.

15. Wireless communications circuitry that wirelessly communicates using at least first and second antennas, the wireless communications circuitry comprising:

transceiver circuitry configured to repeatedly toggle between wireless reception operations and wireless transmission operations; and

switching circuitry configured to provide radio-frequency transmit signals from the transceiver circuitry to a selected antenna of the first and second antennas during the wireless transmission operations and further configured to route radio-frequency receive signals from the first and second antennas to the transceiver circuitry during wireless reception operations.

16. The wireless communications circuitry defined in claim 15 wherein the switching circuitry comprises:

an antenna switching circuit having a first port coupled to the first antenna, a second port coupled to the second antenna, and a third port that receives the radio-frequency transmit signals from the transceiver circuitry, wherein the antenna switching circuit is operable in a first configuration in which the first port is coupled to the third port and a second configuration in which the second port is coupled to the third port.

17. The wireless communications circuitry defined in claim 16 wherein the switching circuitry further comprises:

a switch coupled between the first port of the antenna switching circuit and the first antenna and between the first antenna and the transceiver circuitry, wherein the switch is configured to couple the first antenna to the transceiver circuitry during wireless reception operations and wherein the switch is configured to couple the first antenna to the first port of the antenna switching circuit during wireless transmission operations.

18. The wireless communications circuitry defined in claim 17 wherein the switching circuitry further comprises:

an additional switch coupled between the second port of the antenna switching circuit and the second antenna and between the second antenna and the transceiver circuitry, wherein the additional switch is configured to couple the second antenna to the transceiver circuitry during wireless reception operations and wherein the additional switch is configured to couple the second antenna to the second port of the antenna switching circuit during wireless transmission operations.

19. The wireless communications circuitry defined in claim 15 further comprising:

control circuitry operable to determine which antenna of the first and second antennas is provided with the radio-frequency transmit signals by the switching circuitry during wireless transmission operations.

20. The wireless communications circuitry defined in claim 19 wherein the control circuitry comprises baseband circuitry.