WEAKLY COUPLED RF NETWORK BASED POWER AMPLIFIER ARCHITECTURE

• US 20150094008A1
• Filed: 11/26/2014
• Published: 04/02/2015
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: RF Micro Devices Incorporated (Qorvo, Inc.)
• Inventors: Maxim, George, Scott, Baker, Leipold, Dirk Robert Walter
• Granted Patent: US 9,444,417 B2
• Time in Patent Office: Days
• US Class Current: 455/245.1
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/222 A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/546 A tunable capacitance being present in an amplifier circuit
• CPC Class Codes: H03F 3/195 in integrated circuits
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H03H 7/0115 comprising only inductors and capacitors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H03H 7/0161 Bandpass filters H03H7/12 takes precedence
• CPC Class Codes: H03H 7/09 Filters comprising mutual inductance
• 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: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence

Abstract

RF communications circuitry, which includes a first group of RF power amplifier circuits and a first weakly coupled RF network, is disclosed. The first group of RF power amplifier circuits includes a first RF power amplifier circuit, which receives and amplifies a first RF amplifier input signal to provide a first RF amplifier output signal, and a second RF power amplifier circuit, which receives and amplifies a second RF amplifier input signal to provide a second RF amplifier output signal. The first weakly coupled RF network includes a first pair of weakly coupled RF resonators coupled to the first RF power amplifier circuit and a second pair of weakly coupled RF resonators coupled to the second RF power amplifier circuit.

Claims

1. An apparatus comprising:

a first plurality of RF power amplifier circuits comprising;

a first RF power amplifier circuit configured to receive and amplify a first RF amplifier input signal to provide a first RF amplifier output signal; and

a second RF power amplifier circuit configured to receive and amplify a second RF amplifier input signal to provide a second RF amplifier output signal; and

a first weakly coupled RF network comprising;

a first pair of weakly coupled RF resonators coupled to the first RF power amplifier circuit, wherein the first weakly coupled RF network is configured to process an RF signal associated with the first RF power amplifier circuit using the first pair of weakly coupled RF resonators; and

a second pair of weakly coupled RF resonators coupled to the second RF power amplifier circuit, wherein the first weakly coupled RF network is further configured to process an RF signal associated with the second RF power amplifier circuit using the second pair of weakly coupled RF resonators.

2. The apparatus of claim 1 wherein:

a coupling coefficient between each of the first pair of weakly coupled RF resonators is less than about thirty percent; and

a coupling coefficient between each of the second pair of weakly coupled RF resonators is less than about thirty percent.

3. The apparatus of claim 1 wherein:

each of the first pair of weakly coupled RF resonators comprises a corresponding resonating inductive element to form a first pair of resonating inductive elements, such that a magnetic coupling coefficient between each of the first pair of resonating inductive elements is less than about 0.3; and

each of the second pair of weakly coupled RF resonators comprises a corresponding resonating inductive element to form a second pair of resonating inductive elements, such that a magnetic coupling coefficient between each of the second pair of resonating inductive elements is less than about 0.3.

4. The apparatus of claim 1 wherein the first weakly coupled RF network further comprises a unidirectional coupling stage coupled to the first pair of weakly coupled RF resonators, such that the unidirectional coupling stage is configured to provide amplification in a forward direction.

5. The apparatus of claim 1 wherein the first weakly coupled RF network further comprises a bidirectional coupling stage coupled to the first pair of weakly coupled RF resonators, such that the bidirectional coupling stage is configured to provide amplification in a forward direction and a reverse direction.

6. The apparatus of claim 1 wherein:

the first RF power amplifier circuit is further configured to receive and amplify the first RF amplifier input signal using an envelope power supply signal; and

the second RF power amplifier circuit is further configured to receive and amplify the second RF amplifier input signal using the envelope power supply signal.

7. The apparatus of claim 1 wherein:

the first RF power amplifier circuit is further configured to receive and amplify the first RF amplifier input signal using a first envelope power supply signal; and

the second RF power amplifier circuit is further configured to receive and amplify the second RF amplifier input signal using a second envelope power supply signal, such that the second envelope power supply signal is about phase-aligned with the first envelope power supply signal.

8. The apparatus of claim 1 wherein:

the first RF power amplifier circuit is further configured to receive and amplify the first RF amplifier input signal using a first envelope power supply signal; and

the second RF power amplifier circuit is further configured to receive and amplify the second RF amplifier input signal using a second envelope power supply signal, such that the second envelope power supply signal is phase-shifted from the first envelope power supply signal.

9. The apparatus of claim 1 wherein a first network control signal is based on an expected frequency range of the first RF amplifier input signal and the second RF amplifier input signal, such that a configuration of the first weakly coupled RF network is based on the first network control signal.

10. The apparatus of claim 9 further comprising control circuitry configured to provide the first network control signal.

11. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein:

the first weakly coupled RF network has a first network output; and

the first weakly coupled RF network is configured to receive, phase-shift, process, and combine the first RF amplifier output signal and the second RF amplifier output signal to provide a combined transmit signal via the first network output, wherein the first weakly coupled RF network is a weakly coupled RF output network.

12. The apparatus of claim 11 wherein the first weakly coupled RF network is further configured to compensate for phase error between the first RF amplifier output signal and the second RF amplifier output signal.

13. The apparatus of claim 11 wherein the first weakly coupled RF network is further configured to reduce noise from the first RF amplifier output signal and the second RF amplifier output signal.

14. The apparatus of claim 1 further comprising a first RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein:

the first weakly coupled RF network has a first network input, a second network input, and a first network output;

the first weakly coupled RF network is configured to receive the first RF amplifier output signal via the first network input; and

the first weakly coupled RF network is further configured to receive the second RF amplifier output signal via the second network input.

15. The apparatus of claim 14 wherein the first weakly coupled RF network is further configured to:

provide a first impedance transformation between the first network input and the first network output based on a first impedance response of the first weakly coupled RF network; and

provide a second impedance transformation between the second network input and the first network output based on a second impedance response of the first weakly coupled RF network.

16. The apparatus of claim 15 wherein the first weakly coupled RF network is further configured to receive a first network control signal, such that the first impedance response and the second impedance response are based on the first network control signal.

17. The apparatus of claim 14 wherein the first weakly coupled RF network is further configured to:

provide first filtering between the first network input and the first network output based on a first frequency response of the first weakly coupled RF network; and

provide second filtering between the second network input and the first network output based on a second frequency response of the first weakly coupled RF network.

18. The apparatus of claim 17 wherein the first weakly coupled RF network is further configured to receive a first network control signal, such that the first frequency response and the second frequency response are based on the first network control signal.

19. The apparatus of claim 14 wherein the first weakly coupled RF network is further configured to:

provide a first impedance transformation and first filtering between the first network input and the first network output based on a first impedance response and a first frequency response of the first weakly coupled RF network; and

provide a second impedance transformation and second filtering between the second network input and the first network output based on a second impedance response and a second frequency response of the first weakly coupled RF network.

20. The apparatus of claim 14 wherein the first weakly coupled RF network is further configured to:

reduce insertion loss between the first network input and the first network output; and

reduce insertion loss between the second network input and the first network output.

21. The apparatus of claim 1 wherein the RF power amplifier further comprises a final RF power amplifier stage, which comprises the first RF power amplifier circuit and the second RF power amplifier circuit.

22. The apparatus of claim 21 wherein the RF power amplifier further comprises a driver RF power amplifier stage, which comprises a third RF power amplifier circuit and a fourth RF power amplifier circuit.

23. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein the first weakly coupled RF network is configured to receive and process a first network input signal and a second network input signal to provide the first RF amplifier input signal and the second RF amplifier input signal.

24. The apparatus of claim 23 further comprising a second weakly coupled RF network configured to receive and process the first RF amplifier output signal and the second RF amplifier output signal.

25. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein the first weakly coupled RF network is configured to receive, split, and process a first network input signal to provide the first RF amplifier input signal and the second RF amplifier input signal.

26. The apparatus of claim 25 further comprising a second weakly coupled RF network configured to receive and process the first RF amplifier output signal and the second RF amplifier output signal.

27. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein:

the RF power amplifier is a quadrature RF power amplifier;

the quadrature RF power amplifier comprises an in-phase RF power amplifier and a quadrature-phase RF power amplifier;

the in-phase RF power amplifier comprises the first RF power amplifier circuit; and

the quadrature-phase RF power amplifier comprises the second RF power amplifier circuit.

28. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein:

the RF power amplifier is a Doherty RF power amplifier;

the Doherty RF power amplifier comprises a main Doherty RF power amplifier and a first peaking Doherty RF power amplifier;

the main Doherty RF power amplifier comprises the first RF power amplifier circuit; and

the first peaking Doherty RF power amplifier comprises the second RF power amplifier circuit.

29. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein:

the RF power amplifier is an out-phasing RF power amplifier;

the out-phasing RF power amplifier comprises a clockwise (CW) out-phasing RF power amplifier and a counter-clockwise (CCW) out-phasing RF power amplifier;

the CW out-phasing RF power amplifier comprises the first RF power amplifier circuit; and

the CCW out-phasing RF power amplifier comprises the second RF power amplifier circuit.

30. The apparatus of claim 1 further comprising an RF power amplifier, which comprises the first plurality of RF power amplifier circuits, wherein:

the RF power amplifier is a split RF power amplifier;

the Split RF power amplifier comprises a first split RF power amplifier and a second split RF power amplifier;

the first split RF power amplifier comprises the first RF power amplifier circuit; and

the second split RF power amplifier comprises the second RF power amplifier circuit.