CN213783248U - Doherty power amplifying circuit applied to average power tracking and electronic equipment - Google Patents

Abstract

The utility model provides a Doherty power amplifier circuit for average power trails, include: the output end of the power supply module is directly or indirectly connected to a first pole of the peak power amplifier, a second pole of the peak power amplifier is directly or indirectly grounded, and a grid electrode of the peak power amplifier is used for accessing a signal; the Doherty power amplifying circuit further comprises a bias module, wherein the peak power amplifier is a CMOS device, and the bias module comprises an operational amplifier; the first input end of the operational amplifier is directly or indirectly connected with the output end of the power supply module, the second input end of the operational amplifier is used for accessing reference voltage, the output end of the operational amplifier is directly or indirectly connected with the grid electrode of the peak power amplifier so as to adjust the bias voltage of the grid electrode of the peak power amplifier according to the voltage difference value of the two input ends, and the power supply module is directly or indirectly connected with the average power tracking control module.

Description

Doherty power amplifying circuit applied to average power tracking and electronic equipment

Technical Field

The utility model relates to a signal processing field especially relates to a Doherty power amplifier circuit and electronic equipment for average power trails.

Background

The Doherty power amplifying circuit can be provided with a peak power amplifier and a main power amplifier (also can be understood as an auxiliary power amplifier), the peak power amplifier works until the set peak value is reached, and the peak power amplifier and the main power amplifier can be connected with a power module. The Average Power Track (APT) may be understood as tracking the Average Power, and based on the tracking result, the Power supply voltage of the Power module may be adjusted, and the voltage of the common Power source may be controlled to vary with the tracked Average Power.

In the related art, if the Doherty power amplifying circuit is configured to have a maximum output power, the Doherty load modulation is not suitable when the power supply voltage is reduced using the APT. In this configuration, if the bias to the peak power amplifier gate (e.g., gate) has a fixed supply dc voltage, then: as the supply voltage decreases, the peak power amplifier turns on later, thus resulting in: the efficiency of the Doherty power amplifying circuit with different power supply voltages is reduced, and the Doherty operation can be realized only in a smaller output power range by the circuit, so that the requirements are difficult to meet.

SUMMERY OF THE UTILITY MODEL

The utility model provides a Doherty power amplifier circuit and electronic equipment for average power tracking to solve the shortcoming that adopts fixed offset.

According to a first aspect of the present invention, there is provided a Doherty power amplifying circuit applied to average power tracking, comprising: the output end of the power supply module is directly or indirectly connected to a first pole of the peak power amplifier, a second pole of the peak power amplifier is directly or indirectly grounded, and a grid electrode of the peak power amplifier is used for accessing a signal;

the Doherty power amplifying circuit further comprises a bias module, wherein the peak power amplifier is a CMOS device, and the bias module comprises an operational amplifier;

the first input end of the operational amplifier is directly or indirectly connected with the output end of the power supply module, the second input end of the operational amplifier is used for accessing reference voltage, the output end of the operational amplifier is directly or indirectly connected with the grid electrode of the peak power amplifier so as to adjust the bias voltage of the grid electrode of the peak power amplifier according to the voltage difference value of the two input ends, and the power supply module is directly or indirectly connected with the average power tracking control module.

Optionally, the bias module further includes a first variable resistor, and the first input terminal of the operational amplifier is connected to the output terminal of the power supply module through the first variable resistor.

Optionally, the bias module further includes a second variable resistor, and the second variable resistor is connected between the output end and the second input end of the operational amplifier.

Optionally, the bias module further includes a negative voltage generator, and a power supply end of the operational amplifier is connected to the negative voltage generator.

Optionally, the bias module further includes a bias capacitor, a first end of the bias capacitor is connected to the output end of the operational amplifier, and a second end of the bias capacitor is grounded.

Optionally, the output end of the operational amplifier is connected to the gate of the peak power amplifier through a bias resistor.

Optionally, the Doherty power amplifying circuit further includes a main power amplifier, a first pole of the main power amplifier is directly or indirectly connected to the output end of the power supply module, and a second pole of the main power amplifier is grounded.

Optionally, the Doherty power amplifying circuit further includes a first capacitor and a second capacitor, a gate of the main power amplifier is connected to a signal through the first capacitor, and a gate of the peak power amplifier is connected to a signal through the second capacitor.

Optionally, the Doherty power amplifying circuit further includes a first resistor, a second resistor, a first inductor, a second inductor, and a third capacitor;

the first utmost point warp of main power amplifier first resistance connection the one end of third electric capacity, the first utmost point warp of peak power amplifier the second resistance connection the one end of third electric capacity, the first utmost point warp of main power amplifier first inductance is connected power module's output, the first utmost point warp of peak power amplifier the second inductance is connected power module's output.

According to a second aspect of the present invention, there is provided an electronic device comprising the Doherty power amplifying circuit of the first aspect and the alternatives thereof.

The utility model provides an in being applied to average power tracking's Doherty power amplifier circuit and electronic equipment, through the operational amplifier in the biasing module, can be along with the change of the supply voltage that the power module provided and the skew biasing, and then, this circuit can activate peak power amplifier in the APT supply voltage within range to realize the Doherty load modulation of preferred. Also, the bias of the peak power amplifier varies with the supply voltage (in conjunction with appropriate load modulation) may also help achieve a consistent conduction angle at the peak power amplifier using the APT.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a first schematic circuit diagram of a Doherty power amplifier circuit according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a Doherty power amplifying circuit according to an embodiment of the present invention;

fig. 3 is a schematic circuit diagram of a Doherty power amplifying circuit according to an embodiment of the present invention.

Description of reference numerals:

1-a bias module;

11-an operational amplifier;

12-a negative pressure generator;

13-a reference voltage generator;

2-a power supply module;

3-an average power tracking control module;

N1-Peak Power Amplifier;

n2-main power amplifier;

ra1 — first variable resistance;

ra2 — second variable resistance;

rb-a bias resistor;

r1 — first resistance;

r2 — second resistance;

r3 — third resistance;

r4-fourth resistor;

l1 — first inductance;

l2 — second inductance;

l3 — third inductance;

cb-bias capacitance;

c1 — first capacitance;

c2 — second capacitance;

c3-third capacitance.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The technical solution of the present invention will be described in detail with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

The embodiment of the utility model provides a Doherty power amplifier circuit that relates to can be applied to the wireless communication field, simultaneously, also do not exclude the possibility of being applied to other scenes with it, in addition, Doherty power amplifier circuit can form independent chip, device, also can be a partial circuit of whole chip, device.

For the convenience of explaining the scheme of the embodiment of the present invention, the following description is made on part of the related technology:

the Doherty power amplification circuit (which can also be characterized as a Doherty PA) can be load modulated with a high efficiency region at the maximum of 6dB of operation, so that the modulated signal will have a high efficiency close to the maximum output power level. However, most modern communication systems operate over a wide range of output powers. The power amplifying circuit has high efficiency and better working effect in a wider output power range.

The Average Power Tracking (APT) uses different Direct Current (DC) supply voltages to achieve different Radio Frequency (RF) output Power levels, which is a good solution to improve efficiency through Power control;

however, if the Doherty PA is configured for maximum output power, then:

when using APT to reduce the supply voltage, the load modulation of the Doherty PA will not be suitable. In this configuration, the peak power amplifier (as may be understood in view of the peak power amplifier N1 referred to hereinafter) turns on later as the supply voltage decreases. Thus, it will cause: the efficiency of a standard Doherty PA with different supply voltage levels decreases. Of course, in some schemes, the APT itself may improve the efficient operation of the Doherty PA, but this approach is applicable to BJT devices, and the peaking PA may be turned on slowly, thus affecting the 6dB compensation efficiency.

The utility model discloses power amplifier (for example later on relevant peak power amplifier N1, main power amplifier N2) specifically can be the CMOS device, and CMOS wherein specifically is: a Complementary Metal Oxide semiconductor can be understood as a Complementary Metal Oxide semiconductor. In the illustrated example, NMOS may be employed.

The Doherty PA for APT has the bias of the peak power amplifier at the APT when active load modulation is performed between the main power amplifier and the peak power amplifier, and if the bias of the peak power amplifier has a fixed dc supply voltage, then for the peak power amplifier, its negative proportional bias corresponds to the supply voltage, the highest operating X dB (where X may range from 46dB, depending on the setting of the programmable components). However, with additional compensation, the efficiency drops, depending on the main power amplifier bias. If the bias of the peak power amplifier is fixed at all APT supply voltages, the Doherty action can only be achieved over a small output power range.

Fig. 1 is a first schematic circuit diagram of a Doherty power amplifier circuit according to an embodiment of the present invention; fig. 2 is a schematic circuit diagram of a Doherty power amplifying circuit according to an embodiment of the present invention; fig. 3 is a schematic circuit diagram of a Doherty power amplifying circuit according to an embodiment of the present invention.

Referring to fig. 1 to 3, a Doherty power amplifying circuit for average power tracking includes: the peak power amplifier N1 and the power supply module 2, the output end of the power supply module 2 is directly or indirectly connected to the first pole of the peak power amplifier N1, the second pole of the peak power amplifier N1 is directly or indirectly grounded, the grid of the peak power amplifier N1 is used for accessing signals, and the accessed signals can be understood as partial or all signals needing to be amplified.

The embodiment of the utility model provides an in, power module 2 directly or indirectly connects average power and tracks up control module 3, and then, and control module 3 is tracked to the average power of accessible, realizes the change of the mains voltage, the power that power module 2 exported, and wherein, the mains voltage that power module 2 exported can characterize to be: vsupply. Any circuit configuration available in the art for achieving average power tracking, whether existing or modified, may be applied to embodiments of the present invention to form average power tracking control module 3 and power supply module 2.

The embodiment of the utility model provides an in, Doherty power amplifier circuit still includes biasing module 1, peak power amplifier N1 is the CMOS device, biasing module 1 includes operational amplifier 11.

The first input end of the operational amplifier 11 is directly or indirectly connected to the output end of the power supply module, and may be configured to access a collected voltage, where the collected voltage may be obtained by collecting a power supply voltage output by the power supply module, for example, in the examples shown in fig. 2 and fig. 3, the collected voltage may be obtained by dividing the voltage by a resistor (e.g., a variable resistor Ra1), and in other examples, the power supply voltage may also be directly used.

The second input terminal of the operational amplifier 11 is configured to receive a reference voltage Vref, where the reference voltage Vref may be any voltage configured as required, and in the examples shown in fig. 2 and fig. 3, the reference voltage Vref may be generated by the reference voltage generator 13, and in other examples, the reference voltage Vref may be obtained from other circuit locations.

The output end of the operational amplifier 11 is directly or indirectly connected to the gate of the peak power amplifier N1, so as to adjust the bias voltage of the gate of the peak power amplifier according to the difference between the voltages of the two input ends, and further, the operational amplifier 11 and the bias module 1 can also be understood as forming a subtractor circuit.

In the above scheme, the offset bias can be shifted along with the change of the power supply voltage provided by the power supply module through the operational amplifier in the bias module, and further, the circuit can activate the peak power amplifier within the range of the APT power supply voltage so as to realize better Doherty load modulation. Meanwhile, under the condition that the bias of the peak power amplifier changes along with the power supply voltage (under the condition of matching with proper load modulation)

It may also help to achieve a consistent conduction angle at peak power amplification using APT.

In one embodiment, the bias module 1 further includes a first variable resistor Ra1, and the first input terminal of the operational amplifier 11 is connected to the output terminal of the power supply module 2 through the first variable resistor Ra 1.

The bias module 1 may further include a second variable resistor Ra2, the second variable resistor Ra2 being connected between the output terminal and the second input terminal of the operational amplifier 11.

The variable resistor can also be understood as an adjustable resistor, and the values of the first variable resistor Ra1, the second variable resistor Ra2 and the reference voltage Vref can be controlled by the rf front-end unit, wherein the rf front-end unit can be characterized as an RFFE unit, which specifically includes: the Radio Frequency Front End can be optimized for process and temperature variations by controlling and varying the values of the first variable resistor Ra1, the second variable resistor Ra2, and the reference voltage Vref.

In some embodiments, the digital RFFE unit may be used as a part of the bias module 1, that is: the bias module 1 further comprises a digital RFFE unit, which is connected to the first variable resistor Ra1, the second variable resistor Ra2, and the reference voltage generator to control the values of the corresponding resistance value and the reference voltage Vref.

In an example, in a state of partial normal operation, the first variable resistor Ra1 may be adjusted to 10K ohms, the second variable resistor Ra2 may be adjusted to 4K ohms, and the reference voltage Vref may be 0.5V.

In one embodiment, the bias module 1 further includes a negative voltage generator 12, and a power supply terminal of the operational amplifier 11 is connected to the negative voltage generator 12 to obtain a voltage Vneg generated thereby.

In an example, the negative voltage generator 12 can be implemented based on a negative charge pump and an LDO, such that the circuit supports negative bias, wherein the LDO is specifically a Low Dropout Regulator, which is understood to be a Low Dropout linear Regulator, for example, an output terminal of the negative charge pump can be connected to an input terminal of the LDO, and an input terminal of the LDO can be connected to a power supply terminal of the operational amplifier 11.

In one embodiment, referring to fig. 2 and fig. 3, the bias module 1 further includes a bias capacitor Cb, a first end of the bias capacitor Cb is connected to the output end of the operational amplifier 11, and a second end of the bias capacitor Cb is grounded. The biasing capacitor Cb can help to provide a stable voltage for the gate of the peak power amplifier N1.

In one embodiment, referring to fig. 3, the output terminal of the operational amplifier 11 is connected to the gate of the peak power amplifier N1 through a bias resistor Rb, so as to ensure that the voltage at the gate is adapted.

In the bias module provided in the above scheme, in order to support the Doherty power amplifying circuit with APT, the peak power amplifier bias module may adjust the peak bias voltage VG _ peak, which may be actually understood as a function of the supply voltage Vsupply.

The area of the bias module may be, for example, 0.4mm × 1.7mm, which includes but is not limited to: fig. 3 shows the parts, and a digital RFFE module.

In one embodiment, the Doherty power amplifying circuit further includes a main power amplifier N2, a first pole of the main power amplifier N2 is directly or indirectly connected to the output end of the power supply module 2, and a second pole of the main power amplifier N2 is grounded.

In one embodiment, the Doherty power amplifying circuit further includes a first capacitor C1 and a second capacitor C2, the gate of the main power amplifier N2 is connected to a signal through the first capacitor C1, and the gate of the peak power amplifier N1 is connected to a signal through the second capacitor C2.

In one embodiment, the Doherty power amplifying circuit further includes a first resistor R1, a second resistor R2, a first inductor L1, a second inductor L2, and a third capacitor C3.

The first utmost point warp of main power amplifier N2 first resistance R1 is connected the one end of third electric capacity C3, the first utmost point warp of peak power amplifier N1 second resistance R2 is connected the first end of third electric capacity C3, the first utmost point warp of main power amplifier N2 first inductance L1 is connected the output of power module 2, the first utmost point warp of peak power amplifier N1 second inductance L2 is connected the output of power module 2.

In a further specific embodiment, referring to fig. 3, the other end of the third capacitor C3 may be connected to the first end of the third resistor R3, and the second end of the third resistor R3 is grounded. The gate of the main power amplifier N2 can be connected to a bias voltage through a third inductor L3, and the second capacitor C2 can be connected to a signal through a fourth resistor R4.

Any variation on the basis of fig. 1 can be understood as a variation of the embodiment of the present invention.

The bias module provided by the specific solution of the utility model can be actually regarded as a peak power amplifier bias module for an Average Power Tracking (APT) CMOS Doherty PA, wherein the common power supply voltage varies with the variation of the average power as a tracking target. In order to have the Doherty efficiency characteristic in the APT, the peaking amplifier (which can also be characterized as peaking PA) must have an adaptive bias module that will shift the bias with the variation of the supply voltage, so in order to keep the output in the linear region, the output can be backed off by 6dB from the saturation compensation to activate the peaking amplifier.

In a practical example, the bias module can be demonstrated on a CMOS Doherty PA using a standard 0.18um SOI. The Doherty PA can have a WCDMA performance (with DPD) in compliance with the specification, up to 29dBm Pout, with PAE of 40-50% (25-29dBm Pout) when the supply voltage ranges from 1.5V to 4V. Wherein PAE specifically refers to the ratio of rf output power to dissipated dc power, and can be characterized as: (output power-input power)/dc power consumption.

The Average Power Tracking (APT) among them, using different DC supply voltages to achieve different RF (radio frequency) output power levels, is a good solution to improve efficiency through power control; in a particular aspect of the embodiments of the present invention, a new bias module is provided for peak power amplification, which can activate a peak power amplifier within an Average Power Tracking (APT) supply voltage range to achieve optimal Doherty load modulation.

In order to achieve an efficient Doherty PA across the voltage range of the Average Power Tracking (APT), the peak bias must vary with the Average Power Tracking (APT) supply voltage and maintain proper Doherty load modulation, and thus, in order to achieve a consistent conduction angle across the peak PA using the APT, a subtractor circuit can be implemented with a bias module.

Experiments have shown that the above-mentioned bias block is achieved with a standard 0.18um CMOS SOI and measurements show that the PAE of the R99 signal is higher than 40% for Average Power Tracking (APT) operation.

According to a second aspect of the present invention, there is provided an electronic device comprising the Doherty power amplifying circuit of the first aspect and the alternatives thereof.

The electronic device may be any electronic device with a communication function, and for example, may be a mobile phone, a tablet computer, a smart wearable device, a network device, an in-vehicle device, and other communication-dedicated or non-communication-dedicated devices.

To sum up, the embodiment of the present invention provides a Doherty power amplifier circuit and an electronic device for average power tracking, which can shift and bias along with the change of the power voltage provided by the power supply module through the operational amplifier in the bias module, and further, the circuit can activate the peak power amplifier within the APT voltage range to realize the preferred Doherty load modulation. Also, the bias of the peak power amplifier varies with the supply voltage (in conjunction with appropriate load modulation) may also help achieve a consistent conduction angle at the peak power amplifier using the APT.

In the description herein, references to the description of the term "one embodiment," "an embodiment," or the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the disclosure. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (10)

1. A Doherty power amplifying circuit for average power tracking application, comprising: the output end of the power supply module is directly or indirectly connected to a first pole of the peak power amplifier, a second pole of the peak power amplifier is directly or indirectly grounded, and a grid electrode of the peak power amplifier is used for accessing a signal; the peak power amplifier is a CMOS device, and the bias module comprises an operational amplifier;

the first input end of the operational amplifier is directly or indirectly connected with the output end of the power supply module, the second input end of the operational amplifier is used for accessing reference voltage, the output end of the operational amplifier is directly or indirectly connected with the grid electrode of the peak power amplifier, and the power supply module is directly or indirectly connected with the average power tracking control module.

2. The Doherty power amplification circuit of claim 1 wherein the bias module further comprises a first variable resistor, the first input of the operational amplifier being connected to the output of the power supply module through the first variable resistor.

3. The Doherty power amplification circuit of claim 1 wherein the bias module further comprises a second variable resistor connected between the output terminal and a second input terminal of the operational amplifier.

4. The Doherty power amplification circuit of claim 1 wherein the bias block further comprises a negative voltage generator, a power supply terminal of the operational amplifier being connected to the negative voltage generator.

5. The Doherty power amplification circuit of any one of claims 1 to 4, wherein the bias module further comprises a bias capacitor, a first end of the bias capacitor is connected to the output terminal of the operational amplifier, and a second end of the bias capacitor is grounded.

6. The Doherty power amplification circuit of any one of claims 1 to 4, wherein the output terminal of the operational amplifier is connected to the gate of the peaking amplifier through a bias resistor.

7. The Doherty power amplifying circuit of any one of claims 1 to 4, further comprising a main power amplifier, a first pole of the main power amplifier being directly or indirectly connected to the output terminal of the power supply module, and a second pole of the main power amplifier being grounded.

8. The Doherty power amplifying circuit of claim 7, further comprising a first capacitor and a second capacitor, wherein the gate of the main power amplifier is connected to a signal through the first capacitor, and the gate of the peak power amplifier is connected to a signal through the second capacitor.

9. The Doherty power amplifying circuit of claim 7 further comprising a first resistor, a second resistor, a first inductor, a second inductor, a third capacitor;

the first utmost point warp of main power amplifier first resistance connection the one end of third electric capacity, the first utmost point warp of peak power amplifier the second resistance connection the one end of third electric capacity, the first utmost point warp of main power amplifier first inductance is connected power module's output, the first utmost point warp of peak power amplifier the second inductance is connected power module's output.

10. An electronic device comprising the Doherty power amplifying circuit of any one of claims 1 to 9.

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