Switchable supply and tunable load impedance power amplifier

• US 9,543,900 B1
• Filed: 06/19/2015
• Issued: 01/10/2017
• Est. Priority Date: 06/19/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lin, Saihua, Choi, Jonghoon
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US14/744,894
• Publication Number:
  US 20160373064A1
• Time in Patent Office: 571 Days
• Field of Search: 455/120, 455/125, 455/127.1, 455/127.4
• US Class Current: 1/1
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/21106 An input signal being distributed in parallel over the inputs of a plurality of power amplifiers
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A transceiver configured to transmit data in a plurality of operating modes including a Wi-Fi mode and two or more different Bluetooth power modes, the transceiver comprising: a first power amplifier configured to amplify Bluetooth signals; a second power amplifier configured to amplify Wi-Fi signals; an antenna coupled to the second power amplifier; and a tunable load circuit, coupled between the first amplifier and the second amplifier, configured to provide a different load impedance for each of the plurality of operating modes, the tunable load circuit consisting of: two impedance paths coupled in parallel between output terminals of the first and second amplifiers; and a number of shunt paths coupled between the tunable load circuit and ground potential.

Claims

1. A transceiver configured to transmit data in a plurality of operating modes including a Wi-Fi mode and two or more different Bluetooth power modes, the transceiver comprising:

a first amplifier configured to amplify Bluetooth signals;

a second amplifier configured to amplify Wi-Fi signals;

an antenna coupled to the second amplifier; and

a tunable load circuit, coupled between the first amplifier and the second amplifier, configured to provide a different load impedance for each of the plurality of operating modes, the tunable load circuit including;

two impedance paths coupled in parallel between output terminals of the first and second amplifiers, the two impedance paths comprising (i) a first impedance path including a first capacitor, one or more first transistors, and a second capacitor coupled in series between the output terminals of the first and second amplifiers, and (ii) a second impedance path including a third capacitor and a fourth capacitor coupled in series between the output terminals of the first and second amplifiers; and

a number of shunt paths coupled between the tunable load circuit and ground potential, the number of shunt paths comprising (i) a first shunt path including a second transistor coupled between ground potential and a common node of the third and fourth capacitors, and (ii) a second shunt path including a third transistor and a fifth capacitor coupled in series between ground potential and the common node.

2. The transceiver of claim 1, wherein the two or more different Bluetooth power modes include a Bluetooth high power mode, a Bluetooth low power mode, and a Bluetooth ultra-low power mode.

3. The transceiver of claim 2, wherein the tunable load circuit is configured to provide a first load impedance during the Bluetooth high power mode, to provide a second load impedance during the Bluetooth low power mode, and to provide a third load impedance during the Bluetooth ultra-low power mode.

4. The transceiver of claim 3, wherein the tunable load circuit is further configured to provide a fourth load impedance during the Wi-Fi mode, wherein the first load impedance is less than the second load impedance, the second load impedance is less than the third load impedance, and the fourth load impedance is less than the first, second, and third load impedances.

5. The transceiver of claim 2, further comprising:

a switchable power supply selectively coupled to the first amplifier, the switchable power supply configured to provide a first supply voltage to the first amplifier during the Bluetooth high power mode, and configured to provide a second supply voltage to the first amplifier during the Bluetooth low power mode and the Bluetooth ultra-low power mode, the second supply voltage less than the first supply voltage.

6. The transceiver of claim 1, wherein:

the one or more first transistors each include a gate to receive a first mode control signal;

the second transistor includes a gate to receive a second mode control signal; and

the third transistor includes a gate to receive a third mode control signal.

7. The transceiver of claim 6, wherein the transceiver is configured to wirelessly transmit either the amplified Bluetooth signals via the antenna or the amplified Wi-Fi signals via the antenna based at least in part on the mode control signals.

8. The transceiver of claim 1, further comprising:

a low noise amplifier (LNA) including an input terminal coupled to the output terminal of the second amplifier; and

a shunt transistor coupled between the input terminal of the LNA and ground potential, the shunt transistor including a gate to receive a transmission enable signal.

9. A method for operating a transceiver to transmit data in a plurality of operating modes including a Wi-Fi mode and two or more different Bluetooth power modes, the method comprising:

amplifying Bluetooth signals for wireless transmission, using a first amplifier, during the two or more different Bluetooth power modes;

amplifying Wi-Fi signals for wireless transmission, using a second amplifier, during the Wi-Fi mode; and

providing a different load impedance for each of the plurality of operating modes using a tunable load circuit including first and second parallel impedance paths and a number of shunt paths coupled to ground potential, wherein;

the first and second parallel impedance paths comprise (i) a first impedance path including a first capacitor, one or more first transistors, and a second capacitor coupled in series between output terminals of the first and second amplifiers, and (ii) a second impedance path including a third capacitor and a fourth capacitor coupled in series between the output terminals of the first and second amplifiers; and

the number of shunt paths comprise (i) a first shunt path including a second transistor coupled between ground potential and a common node of the third and fourth capacitors, and (ii) a second shunt path including a third transistor and a fifth capacitor coupled in series between ground potential and the common node.

10. The method of claim 9, wherein the two or more different Bluetooth power modes include a Bluetooth high power mode, a Bluetooth low power mode, and a Bluetooth ultra-low power mode.

11. The method of claim 10, wherein the providing comprises:

selecting a first load impedance during the Bluetooth high power mode;

selecting a second load impedance during the Bluetooth low power mode; and

selecting a third load impedance during the Bluetooth ultra-low power mode.

12. The method of claim 11, wherein the providing further comprises:

selecting a fourth load impedance during the Wi-Fi mode.

13. The method of claim 10, further comprising:

providing a first supply voltage to the first amplifier during the Bluetooth high power mode; and

providing a second supply voltage to the first amplifier during the Bluetooth low power mode and the Bluetooth ultra-low power mode, the second supply voltage less than the first supply voltage.

14. The method of claim 9, further comprising:

receiving, using a low noise amplifier (LNA), Bluetooth and Wi-Fi signals during a receive mode; and

shunting an input terminal of the LNA to ground potential during wireless transmission of the Bluetooth signals and the Wi-Fi signals.

15. A transceiver configured to transmit data in a plurality of operating modes including a Wi-Fi mode and two or more different Bluetooth power modes, the transceiver comprising:

means for amplifying Bluetooth signals, using a first amplifier, for wireless transmission during the two or more different Bluetooth power modes;

means for amplifying Wi-Fi signals, using a second amplifier, for wireless transmission during the Wi-Fi mode; and

means for providing a different load impedance for each of the plurality of operating modes using a tunable load circuit including first and second parallel impedance paths and a number of shunt paths coupled to ground potential, wherein;

the first and second parallel impedance paths comprise (i) a first impedance path including a first capacitor, one or more first transistors, and a second capacitor coupled in series between output terminals of the first and second amplifiers, and (ii) a second impedance path including a third capacitor and a fourth capacitor coupled in series between the output terminals of the first and second amplifiers; and

the number of shunt paths comprise (i) a first shunt path including a second transistor coupled between ground potential and a common node of the third and fourth capacitors, and (ii) a second shunt path including a third transistor and a fifth capacitor coupled in series between ground potential and the common node.

16. The transceiver of claim 15, wherein the two or more different Bluetooth power modes include a Bluetooth high power mode, a Bluetooth low power mode, and a Bluetooth ultra-low power mode.

17. The transceiver of claim 16, wherein the means for providing is to:

select a first load impedance during the Bluetooth high power mode;

select a second load impedance during the Bluetooth low power mode; and

select a third load impedance during the Bluetooth ultra-low power mode.

18. The transceiver of claim 17, wherein the means for providing is to further:

select a fourth load impedance during the Wi-Fi mode.

19. The transceiver of claim 16, further comprising:

means for providing a first supply voltage to the means for amplifying Bluetooth signals during the Bluetooth high power mode; and

means for providing a second supply voltage to the means for amplifying Bluetooth signals during the Bluetooth low power mode and the Bluetooth ultra-low power mode, the second supply voltage less than the first supply voltage.

20. The transceiver of claim 15, further comprising:

means for receiving, using a low noise amplifier (LNA), Bluetooth and Wi-Fi signals during a receive mode; and

means for shunting an input terminal of the LNA to ground potential during wireless transmission of the Bluetooth signals and the Wi-Fi signals.

21. A transceiver configured to transmit data in a plurality of operating modes, the transceiver comprising:

a first amplifier configured to amplify first data signals;

a second amplifier configured to amplify second data signals;

an antenna coupled to the second amplifier; and

a tunable load circuit, coupled between output terminals of the first and second amplifiers, configured to provide a different load impedance for each of the plurality of operating modes, the tunable load circuit comprising;

a first impedance path including a first capacitor, one or more first transistors, and a second capacitor coupled in series between the output terminals of the first and second amplifiers;

a second impedance path including a third capacitor and a fourth capacitor coupled in series between the output terminals of the first and second amplifiers;

a first shunt path including a second transistor coupled between ground potential and a common node of the third and fourth capacitors; and

a second shunt path including a third transistor and a fifth capacitor coupled in series between ground potential and the common node.

22. The transceiver of claim 21, wherein the plurality of operating modes includes a Wi-Fi mode, a Bluetooth high power mode, a Bluetooth low power mode, and a Bluetooth ultra-low power mode.

23. The transceiver of claim 22, wherein the tunable load circuit is configured to provide a first load impedance during the Bluetooth high power mode, to provide a second load impedance during the Bluetooth low power mode, to provide a third load impedance during the Bluetooth ultra-low power mode, and to provide a fourth load impedance during the Wi-Fi mode.

24. The transceiver of claim 22, further comprising:

a switchable power supply selectively coupled to the first amplifier, the switchable power supply configured to provide a first supply voltage to the first amplifier during the Bluetooth high power mode, and configured to provide a second supply voltage to the first amplifier during the Bluetooth low power mode and the Bluetooth ultra-low power mode, the second supply voltage less than the first supply voltage.

25. The transceiver of claim 21, wherein:

the one or more first transistors each include a gate to receive a first mode control signal;

the second transistor includes a gate to receive a second mode control signal; and

the third transistor includes a gate to receive a third mode control signal.

26. The transceiver of claim 21, further comprising:

a low noise amplifier (LNA) including an input terminal coupled to the output terminal of the second amplifier; and

a shunt transistor coupled between the input terminal of the LNA and ground potential, the shunt transistor including a gate to receive a transmission enable signal.