Controllable Dynamic Bias Power Amplifier

Abstract

The present invention provides a controllable dynamic bias power amplifier, comprising: an input matching circuit, which is used to receive an input signal and provide the matched input signal to the power amplifier circuit, a bias circuit, which is configured to be connected to a first bias power supply, a second bias power supply and a first power supply, and provide a dynamic configuration voltage to the power amplifier circuit, a power amplifier circuit, which is configured to be connected to the input matching circuit to receive the matched input signal, and to be connected to the matching circuit to receive the dynamic matching voltage, and an output matching circuit, which is configured to be connected to the power amplifier circuit to output a matched output signal.

Description

Technical Field

[0001] The present invention relates to power amplifiers, and in particular, to HBT power amplifiers based on controllable dynamic biasing. Background Art

[0002] Power amplifiers are important components for wireless transmission of RF signals. With the upgrade of mobile communication networks, communication equipment needs to be able to select different frequency bands for RF signal transmission in different mobile communication network standards, which requires RF power amplifiers for 3G / 4G / 5G networks to support more and more frequency bands and standards. Communication equipment needs to be able to work normally in different mobile communication network standards, which requires RF power amplifiers for various communication networks to provide higher output power and better linearity.

[0003] In the prior art, the main methods for improving the linear power of a radio frequency terminal are to increase the power supply voltage (APT / ET) and to increase the output current.

[0004] Among the methods of increasing the power supply voltage, both APT and ET require additional modules and bring challenges to the reliability and ruggedness of the chip.

[0005] Common methods of increasing output current include increasing the size of power stage tubes and connecting multiple amplifiers in parallel. The implementation is relatively simple, but it will bring about the problem of increased parasitic parameters.

[0006] In addition, in the prior art, the bias signal provided by the external bias signal source to the power amplifier tube through the bias resistor is fixed in magnitude. Therefore, a power amplifier capable of providing controllable dynamic bias is required. Summary of the invention

[0007] One aspect of the present invention proposes a controllable dynamically biased power amplifier, comprising: an input matching circuit, which is used to receive an input signal and provide the matched input signal to the power amplifier circuit, a bias circuit, which is configured to be connected to a first bias power supply, a second bias power supply and a first power supply, and to provide a dynamic configuration voltage to the power amplifier circuit, a power amplifier circuit, which is configured to be connected to the input matching circuit to receive the matched input signal, and to be connected to the matching circuit to receive the dynamic matching voltage, and an output matching circuit, which is configured to be connected to the power amplifier circuit to output a matched output signal.

[0008] Another aspect of the present invention provides a controllable dynamically biased power amplifier, wherein the bias circuit includes: a mirror transistor, which is configured so that its collector is connected to a first bias power supply and a second bias power supply to receive current from the first bias power supply and the second bias power supply respectively; the base of the mirror transistor is connected to the emitter of a power supply transistor, and the emitter of the mirror transistor is connected to a ground node; a power supply transistor, which is configured so that its collector is connected to the first power supply to receive current from the first power supply; the base of the power supply transistor is connected to the collector of the mirror transistor, and the emitter of the power supply transistor is connected to one end of a bias resistor; and a bias resistor, which is configured so that one end is connected to the emitter of the power supply transistor, and the other end is connected to the power amplifier circuit to provide bias for the power amplifier circuit.

[0009] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the bias circuit further comprises: a first resistor configured to have one end connected to the base of the mirror transistor and the other end connected to the emitter of the power supply transistor.

[0010] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the bias circuit further comprises: a first capacitor configured to have one end connected to the base of the power supply transistor and the other end connected to a ground node.

[0011] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the bias circuit further comprises: a second resistor configured to have one end connected to the collector of the mirror transistor and the other end connected to the base of the power supply transistor.

[0012] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the bias circuit further includes: a fourth resistor configured to be connected between the first bias power supply and the collector of the mirror transistor to provide current to the mirror transistor.

[0013] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the bias circuit further includes: a fifth resistor, one end of which is configured to be connected to the second bias power supply and the other end of which is connected to a third resistor, a third resistor, one end of which is configured to be connected to the fifth resistor and the other end of which is connected to the collector of the mirror transistor, and a first diode and a second diode, wherein the first diode and the second diode are connected in series between one end of the fifth resistor and a ground node.

[0014] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the bias circuit further includes: a fifth resistor, one end of which is configured to be connected to the second bias power supply and the other end of which is connected to the collector of the mirror transistor, a third resistor, one end of which is configured to be connected to the base of the mirror transistor and the other end of which is connected to one end of a third capacitor, and a third capacitor, one end of which is configured to be connected to the third resistor and the other end of which is connected to the input matching circuit.

[0015] Another aspect of the present invention provides a controllable dynamically biased power amplifier, wherein the power amplifier circuit includes a power amplifier transistor, wherein the power amplifier transistor is configured so that its base is connected to the input matching circuit, its collector is connected to a second power supply, and its emitter is connected to a ground node.

[0016] Another aspect of the present invention provides a controllable dynamically biased power amplifier, wherein the power amplifier circuit further includes a first inductor, the first inductor is configured to have one end connected to the second power supply and the other end connected to the collector of the power amplifier transistor.

[0017] Another aspect of the present invention provides a controllable dynamic bias power amplifier, wherein the mirror transistor and the power supply transistor include at least one of an HBT transistor, a CMOS transistor, a BJT transistor, a BiCMOS transistor, and a GaN transistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a circuit diagram showing an example of an HBT power amplifier;

[0019] Figure 2 is a circuit diagram showing another example of an HBT power amplifier;

[0020] Figure 3 is a circuit diagram showing a HBT power amplifier providing controllable dynamic bias according to an embodiment of the present invention;

[0021] Figure 4 is a diagram showing the variation of bias current I_B with input power in a controllable dynamic bias power amplifier according to an embodiment of the present invention;

[0022] Figure 5 is a diagram showing the variation of current I_3 with input power in a controllable dynamic bias power amplifier according to an embodiment of the present invention;

[0023] Figure 6is a diagram showing the variation of current I_2 with input power in a controllable dynamic bias power amplifier according to an embodiment of the present invention; and

[0024] Figure 7 FIG. 4 is a circuit diagram showing a HBT power amplifier providing controllable dynamic bias according to another embodiment of the present invention. DETAILED DESCRIPTION

[0025] Before proceeding to the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this patent document. The terms "coupling", "connection" and their derivatives refer to any direct or indirect communication or connection between two or more elements, regardless of whether those elements are in physical contact with each other. The terms "transmission", "reception" and "communication" and their derivatives cover direct and indirect communication. The terms "include" and "comprising" and their derivatives refer to including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with..." and its derivatives refer to including, including within, interconnecting, containing, contained within, connecting or connecting with, coupling or coupling with, communicating with, cooperating, interweaving, parallel, close to, binding or binding with, having, having attributes, having a relationship or having a relationship with, etc. The term "controller" refers to any device, system or part thereof that controls at least one operation. Such a controller can be implemented with hardware, or a combination of hardware and software and / or firmware. The functions associated with any particular controller can be centralized or distributed, whether local or remote. The phrase "at least one of", when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one of the items in the list may be required. For example, "at least one of A, B, C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0026] Definitions for other specific words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior and future uses of such defined words and phrases.

[0027] In this patent document, the application combination of modules and the division level of sub-modules are only used for illustration, and the application combination of modules and the division level of sub-modules may have different forms without departing from the scope of the present disclosure.

[0028] In the present invention, a heterojunction bipolar transistor HBT is taken as an example for explanation, but those skilled in the art should understand that the concept of the present invention can also be applied to other fields. For example, it can be designed and implemented through CMOS, BJT, BiCMOS, GaN and other processes.

[0029] Figure 1 is a circuit diagram showing one example of an HBT power amplifier.

[0030] refer to Figure 1 , resistor R1 is connected between the voltage / current source and node N1, and diodes D1 and D2 are connected in series between node N1 and the ground node. The base of transistor HBT2 is connected to node N1, its collector is connected to power supply 1, and its emitter is connected to node N2. Capacitor C1 is connected between node N1 and the ground node. Bias resistor R2 is connected between nodes N2 and N3 to provide bias, and capacitor C2 is used to connect the input matching network and the base of the power amplifier tube HBT1 located at node N3. The collector of the power amplifier tube HBT1 is connected to node N4 to be connected to the inductor L1, and the emitter of the power amplifier tube HBT1 is grounded. Inductor L1 is connected between power supply 2 and node N4 to output a signal through an output matching network.

[0031] exist Figure 1 In the example of FIG. 1 , a buffer bias circuit including a resistor R1, diodes D1 and D2, a capacitor C1, a transistor HBT2, and a bias resistor R2 is used to provide a bias for the power amplifier HBT1, thereby amplifying the input signal through the input matching network. The signal amplified by the power amplifier HBT1 is output through the inductor and the output matching network.

[0032] Figure 2 is a circuit diagram showing another example of the HBT power amplifier.

[0033] refer to Figure 2 , resistor R1 is connected between the voltage / current source and node N1, and capacitor C1 is connected between node N1 and the ground node. Node N1 is also connected to the collector of transistor HBT2, and the base of transistor HBT2 is connected to node N2 to be connected to resistor R2, and the emitter of transistor HBT2 is connected to the ground node. The collector of transistor HBT3 is connected to power supply 1, its base is connected to node N1, and its emitter is connected to node N3. One end of bias resistor R3 is connected to node N3 to be connected to resistor R2, and the other end thereof is connected to N4 for providing bias. Capacitor C2 is used to connect the input matching network and the base of power amplifier tube HBT1 at node N4. The collector of power amplifier tube HBT1 is connected to node N5 to be connected to inductor L1, and the emitter of power amplifier tube HBT1 is grounded. Inductor L1 is connected between power supply 2 and node N5 to output a signal through an output matching network.

[0034] exist Figure 2In the example, a current-controlled voltage source bias circuit including a resistor R1, a capacitor C1, a transistor HBT2, a transistor HBT3, a resistor R2, and a bias resistor R3 is used to provide a bias for the power amplifier HBT1, thereby amplifying the input signal through the input matching network. The signal amplified by the power amplifier HBT1 is output through the inductor and the output matching network.

[0035] In the above example of a power amplifier, the bias signal provided by the bias circuit to the power amplifier tube is fixed. As the input power increases, the input signal is gradually clamped by the power amplifier tube, resulting in low gain, and the power amplifier enters the saturation state early, which ultimately reduces the maximum linear power. In order to improve the linear power of the power amplifier, the bias current provided by the bias circuit to the power amplifier tube should change with the change of input power.

[0036] Figure 3 An HBT power amplifier providing controllable dynamic bias according to an embodiment of the present invention is shown, but it should be clear to those skilled in the art that modifications may be made to the above example without departing from the scope of the present invention.

[0037] refer to Figure 3 , resistor R5 is connected between voltage / current source 2 and node N1, and diodes D1 and D2 are connected in series between node N1 and ground node. Resistor R3 is connected between node N1 and node N2. Node N2 is also connected to the collector of transistor HBT2, and the base of transistor HBT2 is connected to node N4 to be connected to resistor R1, and the emitter of transistor HBT2 is connected to the ground node. One end of resistor R4 is connected to voltage / current source 1, and the other end thereof is connected to node N2. One end of resistor R2 is connected to node N2, and the other end thereof is connected to node N3. The collector of transistor HBT3 is connected to power supply 1, its base is connected to node N3, and its emitter is connected to node N5. One end of bias resistor R6 is connected to node N5 to be connected to resistor R1, and the other end thereof is connected to N7 for providing bias. One end of resistor R1 is connected to node N4, and the other end thereof is connected to node N5. Capacitor C1 is used to connect node N3 and ground node. Capacitor C2 is used to connect the input matching network and the base of the power amplifier tube HBT1 at the node N7. The collector of the power amplifier tube HBT1 is connected to the node N8 to be connected with the inductor L1, and the emitter of the power amplifier tube HBT1 is grounded. The inductor L1 is connected between the power supply 2 and the node N8 to output the signal through the output matching network.

[0038] refer to Figure 3The HBT controllable dynamic bias circuit is composed of a mirror HBT tube HBT2, a power supply HBT tube HBT3, a filter capacitor C1, a bias resistor R6, a voltage-stabilizing diode D1-D2, and a current-limiting resistor R1-R5. By adding a bias current or voltage, more bias current is provided to the power amplifier under large signals, further improving the saturation power and maximum linear power of the power amplifier.

[0039] When a small signal is input, its working state is the same as the current-controlled voltage source bias circuit, providing a constant bias current to the amplifier tube. At this time, the current I_1 of the voltage / current source 2 flows through R5 and flows into the diodes D1 and D2. When the input signal gradually increases, the current I_2 of the bias voltage / current source 2 flowing into the diodes D1 and D2 decreases, while the current I_3 flowing into the HBT2 mirror tube through R3 slowly increases. Due to the mirror effect, the bias current of the power amplifier tube HBT1 increases with the increase of the input signal amplitude, thereby offsetting the influence of the input signal being gradually clamped by the power amplifier tube, improving the AM distortion, and increasing the linear power of the power amplifier.

[0040] exist Figure 3 In the example shown, the bias resistor R6 is a thermal protection resistor. When the bias current is too large, a voltage drop is generated to reduce the bias voltage of the power amplifier tube HBT1, thereby providing protection. Resistors R1 and R6 are used to adjust the amplitude of the input signal entering the mirror transistor tube HBT2, thereby adjusting the sensitivity of the dynamic bias to the input signal. The current limiting resistor R3 can control the magnitude of the current flowing from the voltage / current source 2 into the HBT2 mirror tube. On the one hand, it can adjust the sensitivity of the dynamic bias to the input signal. On the other hand, the voltage drop it generates effectively limits the maximum current flowing into the transistor HBT2. Therefore, the bias current of the power amplifier tube HBT1 will not increase infinitely with the input power, providing protection for the circuit.

[0041] Figure 4 is a diagram showing the variation of bias current I_B with input power in a controllable dynamic bias power amplifier according to an embodiment of the present invention; Figure 5 is a diagram showing the variation of current I_3 with input power in a controllable dynamic bias power amplifier according to an embodiment of the present invention; and Figure 6 FIG. 2 is a diagram showing the variation of the current I_2 with the input power in the controllable dynamic bias power amplifier according to an embodiment of the present invention. Figure 4-6 It can be seen that as the input power increases, the bias current I_B increases, the current I_3 increases, and the current I_2 decreases, thereby offsetting the effect of the input signal being gradually clamped by the power amplifier tube, improving the AM distortion, and increasing the linear power of the power amplifier.

[0042] Figure 7An HBT power amplifier providing controllable dynamic bias according to another embodiment of the present invention is shown, but it should be apparent to those skilled in the art that modifications may be made to the above example without departing from the scope of the present invention.

[0043] refer to Figure 7 , resistor R5 is connected between voltage source 2 and node N1. Resistor R2 is connected between node N1 and node N2. Node N1 is also connected to the collector of transistor HBT2, and the base of transistor HBT2 is connected to node N3 to be connected to resistor R1, and the emitter of transistor HBT2 is connected to the ground node. One end of resistor R4 is connected to current source 1, and the other end thereof is connected to node N1. The collector of transistor HBT3 is connected to power supply 1, its base is connected to node N2, and its emitter is connected to node N6. One end of bias resistor R6 is connected to node N6 to be connected to resistor R1, and the other end thereof is connected to N7 for providing bias. One end of resistor R1 is connected to node N3, and the other end thereof is connected to node N6. Capacitor C1 is used to connect node N2 and the ground node. One end of capacitor R3 is connected to node N3, and the other end thereof is connected to node N4 to be connected to capacitor C3. One end of the capacitor C3 is connected to the node N4, and the other end thereof is connected to the node N5 to be connected to the capacitor C2. The capacitor C2 is used to connect the input matching network and the base of the power amplifier tube HBT1 located at the node N7. The collector of the power amplifier tube HBT1 is connected to the node N8 to be connected to the inductor L1, and the emitter of the power amplifier tube HBT1 is grounded. The inductor L1 is connected between the power supply 2 and the node N8 to output the signal through the output matching network.

[0044] refer to Figure 7 The HBT controllable dynamic bias circuit is a bias circuit that controls the voltage source through the voltage and current formed by the mirror HBT tube HBT2, the power supply HBT tube HBT3, the filter capacitor C1, the bias resistor R6 and the resistors R1-R5. Compared with the ordinary current-controlled voltage source bias, it adds the isolation resistor R2, the current limiting resistor R5 and the RF path formed by the resistor R3 and the capacitor C3. The current source 1 first acts on the transistor HBT2, and the transistor HBT2 produces a mirror effect with the transistor HBT1 power amplifier tube through the resistor R1, thereby providing a fixed bias for the transistor HBT1. The resistor R3 and the capacitor C3 are used to adjust the input power. When the input signal increases, the voltage source 2 will provide current to the transistor HBT2 through the resistor R5. At this time, the bias voltage of the power amplifier tube HBT1 increases with the increase of the input power, avoiding the reduction of the gain of the power tube when the signal is large, improving the AM distortion of the power amplifier, and increasing the P1dB power of the power amplifier.

[0045] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

[0046] Any description in the present invention should not be construed as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of the patented subject matter is limited solely by the claims.

Claims

1. A controllable dynamic bias power amplifier, comprising: An input matching circuit is used to receive an input signal and provide the matched input signal to a power amplifier circuit. a bias circuit, which is configured to be connected to the first bias power supply, the second bias power supply and the first power supply, and to provide a dynamic configuration voltage to the power amplifier circuit, a power amplifier circuit configured to be connected to an input matching circuit to receive a matched input signal, and to be connected to the matching circuit to receive a dynamic matching voltage, and an output matching circuit, which is configured to be connected to the power amplifier circuit to output a matched output signal, Wherein, the bias circuit comprises: a mirror transistor configured such that its collector is connected to a first bias power supply and a second bias power supply to receive currents from the first bias power supply and the second bias power supply, respectively, a base of the mirror transistor is connected to an emitter of the power supply transistor, and an emitter of the mirror transistor is connected to a ground node, a power supply transistor configured such that its collector is connected to the first power supply to receive current from the first power supply, the base of the power supply transistor is connected to the collector of the mirror transistor, and the emitter of the power supply transistor is connected to one end of the bias resistor, and The bias resistor is configured such that one end thereof is connected to the emitter of the power supply transistor and the other end thereof is connected to the power amplifier circuit to provide a bias for the power amplifier circuit.

2. The controllable dynamic bias power amplifier according to claim 1, wherein: The bias circuit further includes a first resistor configured to have one end connected to the base of the mirror transistor and the other end connected to the emitter of the power supply transistor.

3. The controllable dynamic bias power amplifier according to claim 1, wherein: The bias circuit further includes a first capacitor configured to have one end connected to the base of the power supply transistor and the other end connected to a ground node.

4. The controllable dynamic bias power amplifier according to claim 1, wherein: The bias circuit further includes a second resistor configured to have one end connected to the collector of the mirror transistor and the other end connected to the base of the power supply transistor.

5. The controllable dynamic bias power amplifier according to claim 1, wherein: The bias circuit further includes a fourth resistor configured to be connected between the first bias power supply and a collector of the mirror transistor to provide a current to the mirror transistor.

6. The controllable dynamic bias power amplifier according to claim 1, wherein: The bias circuit further comprises: a fifth resistor configured to have one end connected to the second bias power supply and the other end connected to the third resistor, a third resistor configured to have one end connected to the fifth resistor and the other end connected to the collector of the mirror transistor, and A first diode and a second diode are connected in series between one end of the fifth resistor and a ground node.

7. The controllable dynamic bias power amplifier according to claim 1, wherein: The bias circuit further comprises: a fifth resistor configured to have one end connected to the second bias power supply and the other end connected to the collector of the mirror transistor, a third resistor configured to have one end connected to the base of the mirror transistor and the other end connected to one end of a third capacitor, and A third capacitor is configured to have one end connected to the third resistor and the other end connected to the input matching circuit.

8. The controllable dynamic bias power amplifier according to claim 1, wherein: The power amplification circuit includes a power amplification transistor, wherein the power amplification transistor is configured such that its base is connected to the input matching circuit, its collector is connected to the second power supply, and its emitter is connected to a ground node.

9. The controllable dynamic bias power amplifier according to claim 8, wherein: The power amplification circuit further includes a first inductor configured to have one end thereof connected to the second power supply and the other end thereof connected to the collector of the power amplification transistor.

10. The controllable dynamic bias power amplifier according to claim 1, wherein: The mirror transistor and the power supply transistor include at least one of a HBT transistor, a CMOS transistor, a BJT transistor, a BiCMOS transistor, and a GaN transistor.

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