Regulation circuit and amplifier circuit of stacked power amplifier

Abstract

This disclosure provides an adjustment circuit and an amplifier circuit for a stacked power amplifier. The stacked power amplifier includes multiple stacked transistors, with the output of one transistor connected to the input of the next transistor. The adjustment circuit includes: a voltage swing detection module connected to the output of each transistor, comprising a voltage detection unit and a difference unit, for detecting and comparing the voltage swing between the transistor input and output, and outputting multiple voltage swings; a limiting comparison module connected to the voltage swing detection module, for comparing a preset threshold voltage with the voltage swing of any one or more transistors, and outputting a comparison result; the limiting comparison module is connected to a control module, which outputs a control signal based on the comparison result; and an attenuator connected to the input of each transistor, for attenuating the voltage input to the transistor according to the control signal.

Description

Technical Field

[0001] This disclosure relates to the field of electronic devices, and to, but is not limited to, a conditioning circuit and an amplifier circuit for a stacked power amplifier. Background Technology

[0002] With the continuous development of modern CMOS (Complementary Metal-Oxide-Semiconductor) integrated circuit technology, the channel length of transistors is becoming smaller and smaller. This reduction in size can improve device operating speed, thereby achieving better high-frequency performance. However, correspondingly, the maximum supply voltage (V) of the transistor is also decreasing. DD The size of the circuit also decreases as the dimensions decrease, which poses a challenge for the design of analog RF circuits, especially for modules such as PAs (Power Amplifiers) that require high output power.

[0003] Traditionally, high-power power amplifiers (PAs) are designed using III-V compound transistor processes because these processes allow for higher voltage breakdowns in transistors, enabling greater power output. The PA is then integrated with other silicon-based modules. However, from the perspective of cost reduction and increased chip integration, silicon-based design is clearly more attractive. To address these requirements, and considering the lower voltage breakdown of silicon transistors, stacking transistors is typically chosen for high-power silicon PA design.

[0004] However, stacked power amplifiers may experience voltage drops in one or more stages that exceed the safe range of the transistors, posing a risk of transistor breakdown. Utility Model Content

[0005] In view of this, embodiments of the present disclosure provide an adjustment circuit and an amplifier circuit for a stacked power amplifier, which can ensure that the voltage division of one or more stages of the amplifier in various stacked power amplifiers is within the safe range of the transistors, thereby avoiding transistor breakdown and ensuring transistor reliability.

[0006] On one hand, embodiments of this disclosure provide an adjustment circuit for a stacked power amplifier, the stacked power amplifier including a plurality of stacked transistors, the output terminal of the preceding transistor being connected to the input terminal of the following transistor; the adjustment circuit includes:

[0007] A voltage swing detection module is used to detect the voltage swing between the input and output terminals of the transistor. The voltage swing detection module includes a voltage detection unit and a difference unit. The voltage detection unit is connected to the output terminal of the transistor and detects the voltage magnitude of multiple output terminals of the transistor based on the power or amplitude of the output signal of the transistor to obtain multiple corresponding output voltages. The difference unit calculates the difference between adjacent output voltages to obtain the voltage swing between the input and output terminals of the transistor.

[0008] A limiting comparison module, connected to the voltage swing detection module, is used to compare a preset threshold voltage with the voltage swing of any one or more of the transistors and output the comparison result; the limiting comparison module is connected to the control module, and the control module outputs a control signal based on the comparison result.

[0009] An attenuator, connected to the input terminal of the transistor, is used to attenuate the radio frequency input signal input to the transistor according to the control signal.

[0010] In this embodiment of the disclosure, the risk of transistor breakdown can be determined by whether the swing of the transistor exceeds the threshold voltage, and the signal attenuation can be performed by using an attenuator when the voltage exceeds the threshold voltage, which can effectively reduce the risk of transistor breakdown and improve the reliability of the stacked power amplifier.

[0011] On the other hand, embodiments of this disclosure also provide an amplifier circuit, including:

[0012] A stacked power amplifier includes multiple stacked transistors, wherein the output of a former transistor is connected to the input of a latter transistor;

[0013] Any of the adjustment circuits described in the above embodiments is connected to the stacked power amplifier.

[0014] The adjustment circuit provided in this embodiment compares the threshold voltage with the voltage swing of each stage of the transistors using a limiting comparison module. If the voltage swing is too large, the control module outputs a control signal to control the attenuator to reduce the swing of the RF input signal, thereby reducing the voltage swing of each stage of the transistors. This reduces the risk of transistor breakdown and improves transistor reliability.

[0015] In some embodiments, the attenuator is connected to the control terminal of the first-stage transistor. Since the first-stage transistor provides the voltage base for the subsequent transistors, attenuating the RF input signal of the first-stage transistor can reduce the voltage swing of all transistors, which can conveniently and effectively reduce the risk of transistor breakdown. Attached Figure Description

[0016] Figure 1This is a schematic diagram of a stacked power amplifier.

[0017] Figure 2 A schematic diagram of the adjustment circuit of a stacked power amplifier provided in an embodiment of this disclosure;

[0018] Figure 3 This is a schematic diagram of the voltage swing detection module in the adjustment circuit provided in the embodiments of this disclosure;

[0019] Figure 4 Circuit diagram of an analog comparator provided in embodiments of this disclosure;

[0020] Figure 5 Circuit diagram of a digital comparator provided in embodiments of this disclosure;

[0021] Figure 6 A circuit diagram of a π-type attenuator provided in an embodiment of this disclosure;

[0022] Figure 7 A circuit diagram of a bridge T-type attenuator provided in an embodiment of this disclosure;

[0023] Figure 8 A circuit diagram of a T-type attenuator provided in an embodiment of this disclosure;

[0024] Figure 9 Circuit diagram of a digital attenuator provided in an embodiment of this disclosure;

[0025] Figure 10 This is a block diagram illustrating the structural composition of an amplifier circuit provided in an embodiment of the present disclosure. Detailed Implementation

[0026] To facilitate understanding of this disclosure, a more complete description will now be given with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein in the specification of this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. In embodiments of this disclosure, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature.

[0028] It should be understood that, in the description of the embodiments disclosed herein, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can be fixed connections, detachable connections, or integral connections; they can be direct connections or indirect connections through an intermediate medium; and they can be internal connections between two components.

[0029] The terms used in this disclosure are explained as follows:

[0030] A stacked power amplifier (Stack PA) is a technique used to improve the output power and efficiency of a power amplifier. It achieves higher voltage operation by stacking multiple transistors together, with each transistor sharing a portion of the voltage. A stacked power amplifier consists of multiple transistors connected in series, with the drain of each transistor connected to the source of the next transistor. In this way, the supply voltage is distributed among the transistors, allowing the entire stacked structure to withstand higher voltages.

[0031] A common-gate (CG) transistor is a basic transistor circuit configuration. In a CG transistor, the gate serves as the common terminal for both input and output, and is grounded or connected to a fixed DC voltage; the source serves as the input terminal, and the drain serves as the output terminal. The gate is grounded or connected to a fixed potential through a DC bias voltage. Common-gate transistors are characterized by low input impedance, high output impedance, and high voltage gain.

[0032] A common-source (CS) transistor is a basic transistor circuit configuration. In a CS transistor, the source terminal serves as the common terminal for both input and output signals, and is grounded or connected to a fixed DC voltage; the gate terminal serves as the input terminal, and the drain terminal serves as the output terminal. CS transistors are characterized by high input impedance, high output impedance, and high voltage gain.

[0033] For stacked power amplifiers, the first-stage transistors have a common-source connection structure, while the other transistors have a common-gate connection structure.

[0034] The output power at 1dB compression point (OP1dB) is a key performance indicator for power amplifiers, representing the output power at which the amplifier's gain decreases by 1dB relative to the small-signal gain. Increasing OP1dB means that the power amplifier can maintain linear operation at higher output power.

[0035] Linearity is a key performance indicator in wireless communication and radio frequency systems, describing the ability of a power amplifier to maintain a linear relationship between the input and output signals when outputting the signal. Specifically, transmit linearity refers to the degree to which the amplitude and phase relationship between the input and output signals remains linear in a power amplifier or transmitter.

[0036] Saturation output power (Psat) is a key performance indicator of a power amplifier. It represents the output power at which the output power no longer increases significantly or remains essentially unchanged with the increase of input power after the input power of the power amplifier has increased to a certain level.

[0037] Figure 1 A schematic diagram of a stacked power amplifier is shown, comprising four stacked transistors (M1-M4), with NMOS transistors used as an example. The source of the first-stage transistor M1 is grounded, and its drain is connected to the source of the second-stage transistor M2. The drain of the second-stage transistor M2 is connected to the source of the third-stage transistor M3. The drain of the third-stage transistor M3 is connected to the source of the fourth-stage transistor M4. The drain of the fourth-stage transistor M4 is connected to the power supply terminal V via an inductor L. DD Meanwhile, the drain of the fourth-stage transistor M4 is also connected to the RF output terminal RFout through the output capacitor C0.

[0038] Furthermore, the gate of the first-stage transistor M1 is connected to the input capacitor C1 and receives the radio frequency input signal RFin through Cin. Additionally, the gate of the first-stage transistor M1 is also connected to the first resistor R1 and receives the first bias voltage Vg1 through the first resistor R1.

[0039] The control gates of the second to fourth transistors M2-M4 are grounded through the grounding capacitors C2, C3 and C4, respectively, and are connected to the second resistor R2 to the fourth resistor R4, respectively, and receive the second bias voltage Vg2 to the fourth bias voltage Vg4.

[0040] By adjusting the V of PADD Voltage can improve the key performance of a power amplifier (PA). For linear operating scenarios, such as communication systems, increasing the PA's voltage (V) can improve performance. DD Voltage can increase the transmit OP1dB, improving transmit linearity. For saturation operation scenarios, such as radar applications, increasing the PA's V... DD Voltage can increase the emission P sat (Saturated output power). It should be noted that here, the V of the PA is increased. DD It is to choose V relative to any regular value. DD Higher power supply voltages (such as 1.8V, 3.3V, 5V).

[0041] However, raising PA's V DD Voltage may cause the voltage drop of one or more stages of the stacked power amplifier to exceed the safe range of the transistors, posing a risk of transistor breakdown.

[0042] Based on the above analysis, embodiments of this disclosure provide an adjustment circuit for a stacked power amplifier, such as... Figure 2 As shown, the stacked power amplifier includes multiple stacked transistors Mi (i is a positive integer, and in the figure, i is 1 to 4 as an example). The output terminal of the previous transistor Mi-1 is connected to the input terminal of the next transistor Mi. The gate of each transistor Mi receives its own bias voltage Vg1-Vg4. Except for the first stage, there are grounding capacitors C2-C4 between the gate and ground of the transistors. The multiple stacked transistors may include two or more; in this embodiment, four transistors are used as an example. The adjustment circuit includes:

[0043] A voltage swing detection module 110 is used to detect the voltage swing between the input and output terminals of a transistor. The voltage swing detection module 110 includes a voltage detection unit 111 and a difference unit 112. The voltage detection unit 111 is connected to the output terminal of the transistor and detects the voltage magnitude of the output terminals of multiple transistors based on the power or amplitude of the output signal of the transistor to obtain the corresponding multiple output voltages. The difference unit 112 calculates the difference between adjacent output voltages to obtain the voltage swing between the input and output terminals of the transistor.

[0044] The limiting comparison module 150 is connected to the voltage swing detection module 110 and is used to compare a preset threshold voltage with the voltage swing of any one or more transistors and output the comparison result. The limiting comparison module is connected to the control module 130, and the control module outputs a control signal based on the comparison result. The threshold voltage can be used as a reference to determine whether the voltage swing is too large. The threshold voltage can be set to the breakdown voltage of the transistor or less than the breakdown voltage of the transistor.

[0045] Attenuator 160, connected to the input terminal of a transistor, is used to attenuate the radio frequency (RF) input signal of the input transistor according to a control signal. Attenuator 160 can attenuate the RF input signal of any one or more transistors. For example, attenuator 160 can be connected to the input terminal of any one or more transistors to attenuate the RF signal input to that transistor. After the RF signal input to the transistor is attenuated, the swing of the RF input signal decreases, and the voltage swing of the transistor output signal decreases.

[0046] It is understandable that when the power supply voltage is increased, the voltage swing of each transistor stage may exceed the source-drain breakdown voltage. The limiting comparison module 150 compares the threshold voltage with the voltage swing of each transistor stage. If the voltage swing is too large, the attenuator 160 reduces the swing of the RF input signal, thereby reducing the voltage swing of each transistor stage. In this embodiment, the presence of a transistor breakdown risk can be determined by whether the transistor swing exceeds the threshold voltage. If it does, the signal is attenuated using an attenuator, effectively reducing the transistor breakdown risk and improving the reliability of the stacked power amplifier.

[0047] In some embodiments, attenuator 160 can attenuate the RF input signal of any one of the input transistors. For example, attenuator 160 can attenuate the RF input signal of the first-stage transistor M1, the second-stage transistor M2, the third-stage transistor M3, or the fourth-stage transistor M4. For example, in Figure 2 In this circuit, the attenuator is connected to the control terminal of the first-stage transistor M1, which is also its input terminal. Specifically, the attenuator's output is connected to the control terminal of the first-stage transistor, and its input is coupled to the RF input terminal, which receives the RF input signal RFin. Because the first-stage transistor M1 provides the voltage base for the subsequent transistors M2-M4, attenuating the RF input signal RFin of the first-stage transistor M1 can reduce the voltage swing of all transistors M1-M4.

[0048] In some embodiments, such as Figure 2 As shown, the adjustment circuit also includes a control module 130, which includes a counter 135 and a decoder 136;

[0049] Counter 135 is used to count when the comparison result indicates that the voltage swing is greater than the threshold voltage;

[0050] Decoder 136 is used to decode the counter's count value, and the resulting decoded value is used to determine the control signal.

[0051] In one embodiment, when the amplitude limiting comparison module 150 outputs a comparison result indicating that the current transistor voltage swing is greater than the threshold voltage, a counter 135 is used to count. After each count, the signal is attenuated by an attenuator to reduce the voltage swing. Specifically, each time the amplitude limiting comparison module 150 outputs a comparison result indicating that the current transistor (e.g., the first-stage transistor) voltage swing is greater than the threshold voltage, the counter 135 counts. Then, the control module 130 outputs a control signal to the attenuator 160, which controls the attenuator 160 to attenuate the RF input signal RFin. Then, the amplitude limiting comparison module 150 continues to compare whether the current voltage swing is greater than the threshold voltage. If it is still greater than the threshold voltage, the counting continues, and the attenuation is further increased to reduce the voltage swing. When the amplitude limiting comparison module 150 detects that the current voltage swing is less than or equal to the threshold voltage, the counting stops. In addition, after each count, the decoder 136 decodes the current count value to obtain the control signal corresponding to the attenuator, thereby adjusting the attenuation value. Once the counting stops, the decay value no longer changes, and the current decay value can be maintained during subsequent operation, thus ensuring that the transistors at each stage are not damaged due to overvoltage.

[0052] In some embodiments, the control module 130 may be located on the same chip as the stacked power amplifier; in other embodiments, the control module 130 may be located on a different chip than the stacked power amplifier.

[0053] In some embodiments, the decoder 136 may be located in the control module 130, and in other embodiments, the decoder 136 may also be located in the attenuator 160.

[0054] In some embodiments, such as Figure 3 As shown, the voltage detection unit 111 includes: multiple detectors (such as...) Figure 3 The detectors 01 to 04 shown (the number of detectors can be equal to the number of transistors) are connected to the output terminals of the corresponding transistors Mi (drains M1d-M4d of M1-M4) to detect the voltage magnitude at the output terminal of transistor Mi and obtain the corresponding output voltage Vdi (Vd1-Vd4).

[0055] Transistors can be either junction field-effect transistors (JFETs) or metal-oxide-semiconductor field-effect transistors (MOSFETs). Due to the voltage division effect of the transistors, the drain voltage at the output of each stage of the transistor increases proportionally, thereby amplifying the radio frequency signal, such as... Figure 3The waveform change is shown. The voltage swing detection module 110 can obtain the voltage swing of each transistor by comparing or taking the difference between the output voltages Vdi of two adjacent transistors.

[0056] Detectors are generally electronic devices or circuits used to extract the original signal from a modulated signal. They can separate the low-frequency modulated signal from a high-frequency carrier signal, and can also convert the amplitude or power of a high-frequency radio frequency signal into a DC voltage signal output. In the embodiments of this disclosure, an RMS (root mean square) detector can be used. By performing square, average, and square root operations on multiple sampled values ​​of the input signal, a DC voltage value reflecting the signal power is finally output. Because signal power is related to signal amplitude, the DC voltage value output by the RMS detector can reflect the voltage value of the transistor output signal and can be used to determine the voltage division of the transistor.

[0057] The subtraction unit 112 includes: multiple subtractors (such as...) Figure 3 Subtractors 01 to 04 shown are used to calculate the difference based on the detected output voltage and output multiple voltage swings; the first input terminal of the first subtractor is grounded and the second input terminal is connected to the output terminal of the first detector; the first input terminal and the second input terminal of the remaining subtractors are respectively connected to the output terminals of the adjacent detectors.

[0058] In this way, by subtracting adjacent output voltages Vd1 to Vd4 from each of the multiple subtractors, the difference between them can be determined, thereby obtaining the voltage swings Vds1 to Vds4. ​​Among them, the voltage swing Vds1 is obtained by subtracting the first output voltage Vd1 from 0V, or the first output voltage Vd1 can be directly used as the voltage swing Vds1.

[0059] Here, voltage swing refers to the magnitude of the voltage difference change between the input and output terminals of transistor Mi. The voltage swing detection module 110 detects the voltage swing of each transistor and outputs this voltage swing as an output signal. Therefore, the voltage swing detection module 110 has multiple output terminals, each outputting the voltage swing signal for each transistor Mi.

[0060] In some embodiments, the limiting comparison module 150 includes an analog comparator. The analog comparator 151 is an analog signal-based circuit primarily used to compare the magnitudes of two analog input signals. Its output is typically a high or low level, representing the relative magnitudes of the input signals. Analog comparator 151 is as follows... Figure 4As shown, the analog comparator 151 can compare any voltage swing (e.g., voltage swing Vds1) with a threshold voltage Vth to obtain a comparison result. The comparison result may include a logic signal, which can be either high or low; different comparison results correspond to different levels. For example, when the voltage swing is greater than the threshold voltage Vth, the comparison result is high; when the voltage swing is less than the threshold voltage Vth, the comparison result is low.

[0061] In some embodiments, the limiting comparison module 150 includes an analog comparator 151. The limiting comparison module 150 can compare a preset threshold voltage Vth with the voltage swing of any transistor and output a comparison result. This comparison result can attenuate the input RF signal of any transistor (e.g., the first-stage transistor).

[0062] exist Figure 3 , Figure 4 In this embodiment, the voltage swing detection module 110 and the limiting comparison module 150 are described using analog circuits as an example. In other embodiments, the voltage swing detection module 110 and the limiting comparison module 150 can also be digital circuits. For example:

[0063] In some embodiments, the voltage detection unit 111 includes: a plurality of analog-to-digital converters connected to the output terminals of corresponding transistors, used to sample the voltage values ​​at the transistor output terminals and convert them into digital signals.

[0064] Here, the output signal of the transistor is sampled by an analog-to-digital converter and converted into a digital signal for calculating the voltage swing of the transistor.

[0065] In some embodiments, the difference unit 112 includes: one or more computing units connected to the output of the analog-to-digital converter, which extract peak-to-peak values ​​based on the digital signal to obtain the voltage swing.

[0066] By taking the peak-to-peak value of the digital signal Vd at the output terminal of the transistor, the maximum and minimum values ​​can be determined, thereby determining the voltage swing.

[0067] like Figure 5 As shown, the limiting comparison module 150 includes a digital comparator 152. The digital comparator 152 is a digital logic-based circuit used to compare the magnitudes of two digital signals (such as binary numbers), and can also be called a numerical comparator. Its output is typically multiple signals indicating the magnitude relationship of the input signals (such as greater than, less than, or equal to). The digital comparator 152 is as follows... Figure 5As shown, the digital comparator 152 includes an inverter 1, an AND gate Φ1, and a NOR gate Φ1. The digital comparator 152 can compare any voltage swing (e.g., voltage swing Vds1) with a threshold voltage Vth to obtain a comparison result Y.

[0068] In some embodiments, the attenuator includes a digital attenuator and an analog attenuator. The analog attenuator includes a π-type attenuator, a bridge T-type attenuator, and a T-type attenuator.

[0069] In this embodiment of the disclosure, the π-type attenuator is as follows: Figure 6 As shown, the π-type attenuator consists of a main circuit switching transistor M5, two branch circuit switching transistors M6, a resistor R5 connected in parallel with switching transistor M5, and resistors R6 connected in series with each of the two switching transistors M6. When the π-type attenuator is in the reference state, a control signal (e.g., Vc1) controls switching transistor M5 to be on, equivalent to an on-resistance, and a control signal (e.g., Vc2) controls both switching transistors M6 to be off, equivalent to off-capacitors, thus not attenuating the RF input signal RFin, resulting in the output signal Vout. When the π-type attenuator is in the attenuation state, a control signal (e.g., Vc1) controls switching transistor M5 to be off, equivalent to an off-capacitor, and a control signal (e.g., Vc2) controls both switching transistors M6 to be on, equivalent to on-resistance, thus attenuating the RF input signal RFin, resulting in the output signal Vout. The output signal Vout is connected to the input terminal of a transistor Mi. Among them, Vc1 and Vc2 change in opposite trends. When the voltage value of Vc1 increases, the voltage value of Vc2 decreases. The voltage values ​​of Vc1 and Vc2 change gradually with the control of the control module, thus the attenuation of the π-type attenuator changes gradually.

[0070] In this embodiment of the disclosure, the bridge T-type attenuator is as follows: Figure 7As shown, the bridge T-type attenuator consists of a switching transistor M7, a switching transistor M8, a resistor R7 connected in parallel with the switching transistor M7, two resistors Z0 connected in series and in parallel with the switching transistor M7, and a resistor R8 connected in series with the switching transistor M8 and connected to the two resistors Z0. When the bridge T-type attenuator is in the reference state, the control signal (e.g., Vc1) controls the switching transistor M7 to be in the on state, which is equivalent to an on-resistance, and the control signal (e.g., Vc2) controls the switching transistor M8 to be in the off state, which is equivalent to a off-capacitor, thus not attenuating the input signal RFin, and obtaining the output signal Vout. When the bridge T-type attenuator is in the attenuation state, the control signal (e.g., Vc1) controls the switching transistor M7 to be in the off state, which is equivalent to an off-capacitor, and the control signal (e.g., Vc2) controls the switching transistor M8 to be in the on state, which is equivalent to an on-resistance, thus achieving attenuation of the RF input signal RFin, and obtaining the output signal Vout. The output signal Vout is connected to the input terminal of a transistor Mi. Among them, Vc1 and Vc2 change in opposite trends. When the voltage value of Vc1 increases, the voltage value of Vc2 decreases. The voltage values ​​of Vc1 and Vc2 change gradually with the control of the control module, thus the attenuation of the π-type attenuator changes gradually.

[0071] In this embodiment of the disclosure, the T-type attenuator is as follows: Figure 8 As shown, the T-type attenuator consists of a switching transistor M9, a switching transistor M10, two resistors R9 connected in series and parallel with the switching transistor M9, and a resistor R10 connected in series with the switching transistor M10 and connected to the two resistors R9. When the T-type attenuator is in the reference state, the control signal (e.g., Vc1) controls the switching transistor M9 to be in the on state, which is equivalent to an on-resistance, and the control signal (e.g., Vc2) controls the switching transistor M10 to be in the off state, which is equivalent to a off-capacitor. Therefore, the input signal RFin is not attenuated, and the output signal Vout is almost lossless. When the T-type attenuator is in the attenuation state, the control signal (e.g., Vc1) controls the switching transistor M9 to be in the off state, which is equivalent to an off-capacitor, and the control signal (e.g., Vc2) controls the switching transistor M10 to be in the on state, which is equivalent to an on-resistance. Therefore, the input signal RFin is attenuated, and the output signal Vout is obtained. The output signal Vout is connected to the input terminal of a transistor Mi. Among them, Vc1 and Vc2 change in opposite trends. When the voltage value of Vc1 increases, the voltage value of Vc2 decreases. The voltage values ​​of Vc1 and Vc2 change gradually with the control of the control module, thus the attenuation of the π-type attenuator changes gradually.

[0072] In some embodiments, the digital attenuator includes: a plurality of attenuation units 161 connected in parallel; a switch k1 located in the branch where each attenuation unit 161 is located; the switch k1 controls the on and off states of the branch, such as... Figure 9As shown. The digital attenuator can achieve precise attenuation by switching different resistor network paths using a switch. Switch k1 is controlled by a control signal, and the number of times switch k1 is turned on changes gradually with the control of the control module, thereby gradually changing the attenuation of the digital attenuator. One end A1 of the digital attenuator is connected to the input terminal of a transistor Mi, and the other end A2 is grounded. In some embodiments, the attenuation unit 161 includes a diode or a resistor.

[0073] In some embodiments, the limiting comparison module 150 can compare a preset threshold voltage with the voltage swing of any number of transistors Mi, where "number of" means two or more. For example, the limiting comparison module 150 is used to monitor whether the voltage swing of multiple transistors Mi exceeds the preset threshold voltage. The limiting comparison module 150 includes multiple analog comparators 151 or digital comparators 152, each comparator being responsible for monitoring the voltage swing of a specific transistor Mi and outputting the corresponding comparison result.

[0074] The multiple comparison results output by the limiting comparison module 150 are sent to the control module, and there are two control schemes:

[0075] The first control scheme: The comparison results of all comparators are sent to a common counter. The counter starts counting whenever any comparison result indicates that the voltage swing of its corresponding transistor exceeds a threshold voltage. The output of the counter is decoded by a decoder that controls a common attenuator to attenuate the (affected) RF signal. For example, the limiting comparator module 150 includes four analog comparators 151, each used to compare a preset threshold voltage with the voltage swings of four transistors M1-M4, and outputs four comparison results. The four counters count the four comparison results, and the four count values ​​are decoded by four decoders. The four decoders are connected to four attenuators, which attenuate the RF signals of transistors M1-M4. If the voltage swing of transistor M2 is greater than the threshold voltage, the RF signal of transistor M2 is attenuated, while the RF signals of the other transistors are not attenuated.

[0076] This disclosure also provides an amplifier circuit, such as... Figure 10 As shown, the amplifier circuit 300 includes:

[0077] The stacked power amplifier 100 includes multiple stacked transistors, with the output of one transistor connected to the input of the next transistor.

[0078] Any of the adjustment circuits 200 is connected to the stacked power amplifier 100.

[0079] It should be understood that the phrases "some embodiments," "one embodiment," or "an embodiment" used throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure. The sequence numbers of the embodiments in this disclosure are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0080] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0081] The above are merely embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A regulating circuit for a stacked power amplifier, characterized in that, The stacked power amplifier includes multiple stacked transistors, with the output of one transistor connected to the input of the next transistor; the adjustment circuit includes: A voltage swing detection module is used to detect the voltage swing between the input and output terminals of the transistor. The voltage swing detection module includes a voltage detection unit and a difference unit. The voltage detection unit is connected to the output terminal of the transistor and detects the voltage magnitude of multiple output terminals of the transistor based on the power or amplitude of the output signal of the transistor to obtain multiple corresponding output voltages. The difference unit calculates the difference between adjacent output voltages to obtain the voltage swing between the input and output terminals of the transistor. A limiting comparison module, connected to the voltage swing detection module, is used to compare a preset threshold voltage with the voltage swing of any one or more of the transistors and output the comparison result; the limiting comparison module is connected to the control module, and the control module outputs a control signal based on the comparison result. An attenuator, connected to the input terminal of the transistor, is used to attenuate the radio frequency input signal input to the transistor according to the control signal.

2. The adjustment circuit according to claim 1, characterized in that, The attenuator is connected to the control terminal of the first-stage transistor, which is also the input terminal of the first-stage transistor.

3. The adjustment circuit according to claim 1, characterized in that, The control module includes: a counter and a decoder; The counter is used to count when the comparison result indicates that the voltage swing is greater than the threshold voltage; The decoder is used to decode based on the count value of the counter, and the resulting decoded value is used to determine the control signal.

4. The adjustment circuit according to claim 3, characterized in that, Both the counter and the decoder are located in the control module; or, the counter is located in the control module and the decoder is located in the attenuator.

5. The adjustment circuit according to claim 1, characterized in that, The voltage detection unit includes multiple detectors, each connected to the output terminal of each transistor, for detecting the voltage magnitude at the output terminal of the transistor.

6. The adjustment circuit according to claim 5, characterized in that, The subtraction unit includes: multiple subtractors for outputting multiple voltage swings; the first input terminal of the first subtractor is grounded, and the second input terminal is connected to the output terminal of the first detector; the first input terminals and the second input terminals of the remaining subtractors are respectively connected to the output terminals of adjacent detectors.

7. The adjustment circuit according to claim 1, characterized in that, The attenuator may be a digital attenuator or an analog attenuator.

8. The adjustment circuit according to claim 7, characterized in that, The simulated attenuators include: π-type attenuators, bridge T-type attenuators, and T-type attenuators.

9. The adjustment circuit according to claim 7, characterized in that, The digital attenuator includes: Multiple attenuation units connected in parallel; A switch located in the branch where each attenuation unit is located; the switch is controlled by the control signal to control the conduction and disconnection of the branch.

10. The adjustment circuit according to claim 9, characterized in that, The attenuation unit includes a diode or a resistor.

11. The adjustment circuit according to claim 1, characterized in that, The limiting comparison module includes an analog comparator or a digital comparator.

12. The adjustment circuit according to any one of claims 1 to 11, characterized in that, The voltage detection unit includes multiple analog-to-digital converters connected to the output terminals of the corresponding transistors, used to sample the voltage values ​​at the transistor output terminals and convert them into digital signals.

13. The adjustment circuit according to claim 12, characterized in that, The difference unit includes a calculation unit connected to the output of the analog-to-digital converter, which extracts the peak-to-peak value based on the digital signal to obtain the voltage swing.

14. An amplifier circuit, characterized in that, include: A stacked power amplifier includes multiple stacked transistors, wherein the output of a former transistor is connected to the input of a latter transistor; The adjustment circuit as described in any one of claims 1 to 13 is connected to the stacked power amplifier.

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