Self-adaptive biasing method and system for radio frequency amplifier

Abstract

The invention discloses a self-adaptive bias method and system for a radio frequency amplifier, and relates to the technical field of radio frequency amplifiers, and the self-adaptive bias method comprises the following steps: connecting a resistance network with a positive temperature coefficient into an output branch of bias output current to form a bias voltage base which is enhanced along with temperature rise; the on-resistance value of Vgs is dynamically changed by adjusting the Vgs of the MOS transistor, self-adaptive bias control is carried out on the working point of the main amplifier tube of the radio frequency amplifier, and Vbias refers to bias node voltage. According to the invention, the problems of reduction of carrier mobility caused by temperature rise and reduction of bias current caused by threshold voltage drift are effectively counteracted, self-adaptive control of the working point of the main amplifier tube is realized, and the problems of inconsistent threshold voltage and drift in the manufacturing process of the carbon-based transistor are effectively solved; the circuit is suitable for the carbon-based radio frequency amplifier, and the adaptive capacity of the circuit under different material systems and process conditions is improved; and the gain fluctuation of the radio frequency amplifier in a wide temperature range is obviously reduced.

Description

Technical Field

[0001] This invention relates to the field of radio frequency amplifier technology, and in particular to an adaptive biasing method and system for radio frequency amplifiers. Background Technology

[0002] Currently, in the design of bias circuits for RF amplifiers, the stability of the operating point directly affects the gain and linearity of the circuit. As the ambient temperature changes, the physical parameters of semiconductor devices will drift, causing fluctuations in the bias current. Among these fluctuations, carrier mobility decreases with increasing temperature, and the threshold voltage will also shift. These changes make it difficult to maintain a constant transconductance of the amplifier. Since transconductance is closely related to bias current, a decrease in current will directly lead to a decrease in gain. Traditional bias structures usually use fixed resistors or simple current sources, which lack the ability to compensate for temperature changes. Therefore, when operating over a wide temperature range, the amplifier performance will degrade significantly, making it difficult to meet the stability requirements of high-performance RF systems.

[0003] Furthermore, in transistors using novel carbon-based semiconductor materials, the instability of the threshold voltage further exacerbates the difficulty of bias design. Due to the immaturity of material properties and manufacturing processes, the threshold voltage of carbon-based transistors varies significantly across different batches, regions, and even within the same chip. This process fluctuation makes it difficult to accurately match the preset bias point with the actual device characteristics, causing the amplifier's actual operating state to deviate from the design expectations, affecting gain consistency and linearity. Existing fixed bias schemes cannot dynamically adapt to this change, especially when facing both temperature and process disturbances, resulting in a significant decrease in performance stability. Therefore, there is an urgent need for a bias circuit structure that can simultaneously cope with temperature drift and process fluctuations to improve the robustness of RF amplifiers in complex environments. Summary of the Invention

[0004] This invention is proposed in view of the problems existing in the adaptive biasing methods for RF amplifiers.

[0005] Therefore, the problem to be solved by this invention is: how to provide a bias circuit for an RF amplifier that can compensate for bias current and transconductance fluctuations caused by temperature changes, and adapt to the process instability of the threshold voltage of carbon-based transistors, thereby achieving adaptive adjustment of the operating point and ensuring the stability of the amplifier's gain and linearity in complex environments.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, embodiments of the present invention provide an adaptive biasing method for an RF amplifier, comprising: generating a reference current with a positive temperature coefficient; replicating the reference current as a bias output current through a current mirror structure; connecting a resistor network with a positive temperature coefficient in the output branch of the bias output current to form a bias voltage base that increases with temperature; connecting a variable resistor unit composed of MOS transistors in parallel with a fixed-value resistor to a bias output node to form an adjustable equivalent resistance structure; dynamically changing the on-resistance value of Vgs by adjusting the Vgs of the MOS transistor, wherein the MOS transistor refers to a metal-oxide-semiconductor transistor, and Vgs refers to the gate voltage; associating the Vgs of the variable resistor unit with the gate-source voltage or process-sensitive parameter of the main amplifying transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifying transistor; adjusting Vbias to complete the adaptive biasing control of the operating point of the main amplifying transistor of the RF amplifier, wherein Vbias refers to the bias node voltage.

[0007] In a preferred embodiment of the adaptive biasing method for an RF amplifier described in this invention, the positive temperature coefficient reference current comprises a PTAT module consisting of transistors M1, M2, M3, M4, and resistor R1. Transistors M1 and M2 operate in the weak inversion region or subthreshold region, and the current characteristics of MOS transistors in the weak inversion region or subthreshold region are used to simulate... ; The simulation This refers to utilizing the temperature characteristics of Vgs in the subthreshold region to mimic the properties of BJTs. The temperature dependence of BJT refers to the bipolar junction transistor. By borrowing the temperature characteristic principle of BJT, a MOS transistor is used to simulate BJT.

[0008] As a preferred embodiment of the adaptive biasing method for RF amplifiers described in this invention, the method utilizes the current characteristics of MOS transistors in the weak inversion region or subthreshold region to simulate... This includes simulating the temperature characteristics of the base-emitter voltage difference ΔVbe in a bipolar transistor by using the gate-source voltage difference ΔVgs when the MOS transistor is operating in the subthreshold region, and generating PTAT current; The specific steps for generating the PTAT current are as follows: Based on the current I1 flowing through M1 and the current I2 flowing through M2, since I1 and I2 have different dimensions, their gate-source voltage differences ΔVgs are different. Therefore, the formula for the gate-source voltage difference ΔVgs is: in, Indicates the gate-source voltage difference. This represents the gate-source voltage of transistor M1. This represents the gate-source voltage of transistor M2. Indicates proportional to, Indicates thermal voltage. Represents the natural logarithm; when When it increases, then It increases with rising temperature. A resistor R1 is driven to generate a current that increases with temperature, producing the PTAT current, which is the reference current with a positive temperature coefficient.

[0009] As a preferred embodiment of the adaptive biasing method for an RF amplifier described in this invention, the biasing output node is the output terminal of the entire biasing circuit, and the voltage value is used as the gate bias voltage of the main amplifying transistor of the RF amplifier to set the operating current and transconductance of the main amplifying transistor. The output branch of the bias output current refers to the current path that starts from the drain of the current mirror output transistor M5, passes through the positive temperature coefficient resistor R2, and connects to the bias output node. The positive temperature coefficient resistor network includes R2, which is composed of a diffusion resistor, a polysilicon resistor, or a well resistor. Vbias refers to the bias node voltage, including pull-up paths and pull-down or adjustment paths. The pull-up path includes a power supply, a positive temperature coefficient resistor R2, and a bias output node, while the pull-down or adjustment path includes a bias output node, a variable resistor unit, and a low level.

[0010] As a preferred embodiment of the adaptive bias method for RF amplifiers described in this invention, wherein: the parallel connection of the variable resistor unit composed of MOS transistors with the fixed resistor refers to setting up a parallel structure composed of a metal oxide semiconductor transistor M6 and a fixed resistor R3, wherein the drain of transistor M6 and one end of resistor R3 are connected together to the bias output node, and the source of transistor M6 and the other end of resistor R3 are connected together to a low level, wherein the low level refers to the circuit ground; Transistor M6 operates in the transistor region to receive an adjustable externally applied control voltage; When transistor M6 operates in the bipolar region, its equivalent resistance between drain and source is determined by the gate voltage Vgs. When the gate voltage Vgs increases, the channel conductivity is strong and the equivalent resistance decreases. That is, by changing the gate voltage Vgs, the on-resistance value of Vgs is dynamically changed.

[0011] As a preferred embodiment of the adaptive bias method for an RF amplifier described in this invention, the method of associating the Vgs of the variable resistor unit with the gate voltage or process-sensitive parameter of the main amplifying transistor of the RF amplifier is included in the circuit. The gate voltage of the main amplifying transistor of the RF amplifier is connected to the bias output node. The input terminal of the control circuit module is connected between the gate voltage and the source of the main amplifying transistor for receiving the gate voltage signal of the main amplifying transistor. The adjustment of Vgs according to the change of the threshold voltage of the main amplifier tube includes a control circuit module generating a control voltage according to the received voltage signal and outputting it to the gate voltage of transistor M6. When the threshold voltage of the main amplifier transistor changes due to process fluctuations, the output voltage of the control circuit module is updated accordingly to adapt to the new threshold voltage. The gate voltage of transistor M6 is dynamically updated by the control circuit module, and the on-resistance can be adjusted accordingly based on the change in the threshold voltage of the main amplifier transistor.

[0012] As a preferred embodiment of the adaptive bias method for RF amplifiers described in this invention, the adjustment of Vbias includes adjusting the gate voltage of transistor M6 by applying an external control voltage. Changing the gate voltage of M6 can dynamically adjust the on-resistance value. Since M6 is connected in parallel with R3, the overall equivalent resistance changes accordingly, affecting the bias node voltage. The formula for calculating the bias node voltage is as follows: in, This represents the bias node voltage. Indicates the output current. Indicates positive temperature coefficient resistance. Indicates a resistive element; The voltage of this node is obtained based on the bias node voltage and sent to the main amplifying transistor of the RF amplifier to determine the operating point of the main amplifying transistor, thus completing the adaptive bias control of the operating point of the main amplifying transistor of the RF amplifier.

[0013] Secondly, embodiments of the present invention provide an adaptive bias system for an RF amplifier, comprising: a reference current generation module with a positive temperature coefficient, which replicates the reference current into a bias output current through a current mirror structure, and connects a resistor network with a positive temperature coefficient in the output branch of the bias output current to form a bias voltage base that increases with temperature; a dynamic change module, which connects a variable resistor unit composed of MOS transistors in parallel with a fixed resistor to a bias output node to form an adjustable equivalent resistance structure, and dynamically changes the on-resistance value of Vgs by adjusting the Vgs of the MOS transistor, wherein the MOS transistor refers to a metal-oxide-semiconductor transistor, and Vgs refers to the gate voltage; and an adaptive bias control module, which associates the Vgs of the variable resistor unit with the gate-source voltage or process-sensitive parameter of the main amplifying transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifying transistor, and adjusts Vbias to complete the adaptive bias control of the operating point of the main amplifying transistor of the RF amplifier, wherein Vbias refers to the bias node voltage.

[0014] Thirdly, embodiments of the present invention provide a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement any of the steps of the above-described adaptive bias method for a radio frequency amplifier.

[0015] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any of the steps of the above-described adaptive bias method for a radio frequency amplifier.

[0016] The beneficial effects of this invention are as follows: By introducing a current source and resistor network with a positive temperature coefficient, this invention can automatically adjust the bias voltage when the ambient temperature changes, effectively offsetting the reduction in bias current caused by the decrease in carrier mobility and threshold voltage drift due to temperature rise, thereby maintaining the stability of transconductance and gain. Simultaneously, by employing a structure where a variable resistor unit composed of a metal-oxide-semiconductor transistor is connected in parallel with a fixed-value resistor, the control voltage of this variable resistor unit is electrically connected to the gate-source voltage of the main amplifier transistor or a process-sensitive parameter. This allows the resistance value of the variable resistor to be dynamically adjusted according to the change in the threshold voltage of the main amplifier transistor, thereby adjusting the bias node voltage and achieving adaptive control of the operating point of the main amplifier transistor. This invention effectively addresses the threshold voltage inconsistency and drift issues encountered in the manufacturing process of carbon-based transistors. The bias circuit boasts a simple structure, employing only conventional transistors, resistors, and current mirror modules, eliminating the need for complex control logic. This facilitates integration into standard silicon-based or carbon-based processes, offering excellent process compatibility and scalability. The overall solution is applicable not only to carbon-based RF amplifiers but also to silicon-based devices, enhancing the circuit's adaptability to different material systems and process conditions. Simulation results demonstrate that using the bias circuit of this invention significantly reduces gain fluctuations in the RF amplifier over a wide temperature range, exhibiting significantly better performance stability than traditional fixed bias structures. This provides reliable technical support for the design of high-performance, robust RF circuits. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart of an adaptive biasing method for a radio frequency amplifier provided in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of an adaptive biasing method and system for a radio frequency amplifier provided in an embodiment of the present invention.

[0019] Figure 3 The gain curve of a conventional bias circuit versus temperature is provided for an adaptive bias method for an RF amplifier, as illustrated in this embodiment of the invention.

[0020] Figure 4 An adaptive bias method for an RF amplifier provided in this embodiment of the invention is based on... Schematic diagram of a positive temperature coefficient current source based on the be principle.

[0021] Figure 5The positive temperature coefficient resistor value versus temperature curve of an RNDIF resistor process for an adaptive bias method for an RF amplifier provided in this embodiment of the invention.

[0022] Figure 6 This invention provides an adaptive biasing method for radio frequency amplifiers, using an rndifsab resistor process, and presents a curve showing the positive temperature coefficient resistance value versus temperature variation.

[0023] Figure 7 This invention provides an adaptive biasing method for radio frequency amplifiers, using an RNPO resistor process, and presents a curve showing the positive temperature coefficient resistance value versus temperature variation.

[0024] Figure 8 This invention provides an adaptive biasing method for radio frequency amplifiers, using an rnwaa resistor process, and presents a curve showing the positive temperature coefficient resistance value versus temperature variation.

[0025] Figure 9 A variable resistor circuit structure and resistance change curve for an adaptive bias method of an RF amplifier, as provided in this embodiment of the invention, are shown in the figure. gs Control chart.

[0026] Figure 10 This invention provides a variable resistor circuit structure and resistance change curve for an adaptive bias method for an RF amplifier, as shown in the embodiment of the present invention.

[0027] Figure 11 This is a schematic diagram of a carbon-based transistor used in an adaptive biasing method for a radio frequency amplifier, provided as an embodiment of the present invention.

[0028] Figure 12 This is a schematic diagram of the overall circuit of an RF amplifier after adding an adaptive bias circuit, which is provided as an embodiment of the present invention for an adaptive bias method for an RF amplifier.

[0029] Figure 13 The adaptive biasing method for an RF amplifier provided in this embodiment of the invention utilizes the biased temperature S at different temperatures. 21 Simulation curve.

[0030] Figure 14 This is a schematic diagram of the structure of a dielectric material for an adaptive biasing method for a radio frequency amplifier, provided in an embodiment of the present invention.

[0031] Figure 15 This is a schematic diagram of a computing device for an adaptive biasing method for a radio frequency amplifier, provided as an embodiment of the present invention. Detailed Implementation

[0032] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0033] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0035] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0036] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Example Reference Figures 1-15This is the first embodiment of the present invention, which provides an adaptive biasing method for a radio frequency amplifier, comprising: S1: Generate a reference current with a positive temperature coefficient. The reference current is copied into a bias output current through a current mirror structure. A resistor network with a positive temperature coefficient is connected in the output branch of the bias output current to form a bias voltage basis that increases with temperature.

[0039] The positive temperature coefficient reference current includes a PTAT module composed of transistors M1, M2, M3, M4 and resistor R1. Transistors M1 and M2 operate in the weak inversion region or subthreshold region, and the current characteristics of MOS transistors in the weak inversion region or subthreshold region are used to simulate the current characteristics of MOS transistors in the weak inversion region or subthreshold region. ; simulation This refers to utilizing the temperature characteristics of Vgs in the subthreshold region to mimic the properties of BJTs. The temperature dependence of BJT refers to the bipolar junction transistor. Borrowing the temperature characteristic principle of BJT, MOS transistors are used to simulate BJT.

[0040] S1.1: Simulating the current characteristics of a MOS transistor in the weak inversion region or subthreshold region This includes simulating the temperature characteristics of the base-emitter voltage difference ΔVbe in a bipolar transistor by using the gate-source voltage difference ΔVgs when the MOS transistor is operating in the subthreshold region, and generating PTAT current; The specific steps for generating PTAT current are as follows: Based on the current I1 flowing through M1 and the current I2 flowing through M2, since I1 and I2 have different dimensions, their gate-source voltage differences ΔVgs are different. Therefore, the formula for the gate-source voltage difference ΔVgs is: in, Indicates the gate-source voltage difference. This represents the gate-source voltage of transistor M1. This represents the gate-source voltage of transistor M2. Indicates proportional to, Indicates thermal voltage. Represents the natural logarithm; when When it increases, then It increases with rising temperature. A resistor R1 is driven to generate a current that increases with temperature, producing the PTAT current, which is the reference current with a positive temperature coefficient.

[0041] S2: A variable resistor unit composed of MOS transistors is connected in parallel with a fixed resistor and connected to the bias output node to form an adjustable equivalent resistance structure. The on-resistance value of Vgs is dynamically changed by adjusting the Vgs of the MOS transistor. MOS transistor refers to metal oxide semiconductor transistor, and Vgs refers to gate voltage.

[0042] Among them, the bias output node is the output terminal of the entire bias circuit. The voltage value serves as the gate bias voltage of the main amplifier transistor of the RF amplifier, which is used to set the operating current and transconductance of the main amplifier transistor. The output branch of the bias output current refers to the current path that starts from the drain of the current mirror output transistor M5, passes through the positive temperature coefficient resistor R2, and connects to the bias output node. The positive temperature coefficient resistor network includes R2, which is composed of a diffusion resistor, a polysilicon resistor, or a well resistor. Vbias refers to the bias node voltage, including pull-up paths and pull-down or adjustment paths. The pull-up path includes the power supply, the positive temperature coefficient resistor R2, and the bias output node, while the pull-down or adjustment path includes the bias output node, the variable resistor unit, and the low level.

[0043] S2.1: Connecting a variable resistor unit composed of MOS transistors in parallel with a fixed resistor means setting up a parallel structure composed of a metal oxide semiconductor transistor M6 and a fixed resistor R3. The drain of transistor M6 and one end of resistor R3 are connected to the bias output node, and the source of transistor M6 and the other end of resistor R3 are connected to a low level. The low level refers to the circuit ground. Transistor M6 operates in the transistor region to receive an adjustable externally applied control voltage; When transistor M6 operates in the bipolar region, its equivalent resistance between drain and source is determined by the gate voltage Vgs. When the gate voltage Vgs increases, the channel conductivity is strong and the equivalent resistance decreases. That is, by changing the gate voltage Vgs, the on-resistance value of Vgs is dynamically changed.

[0044] S3: Associate the Vgs of the variable resistor unit with the gate-source voltage or process-sensitive parameter of the main amplifier transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifier transistor. Adjusting Vbias completes the adaptive bias control of the operating point of the main amplifier transistor of the RF amplifier. Vbias refers to the bias node voltage.

[0045] The circuit includes the association of the variable resistor unit's Vgs with the gate voltage or process-sensitive parameter of the RF amplifier's main amplifying transistor. The gate voltage of the RF amplifier's main amplifying transistor is connected to the bias output node. The input terminal of the control circuit module is connected between the gate voltage and source of the main amplifying transistor to receive the gate voltage signal of the main amplifying transistor. The control circuit module adjusts Vgs according to the change of the threshold voltage of the main amplifier transistor, generating a control voltage based on the received voltage signal and outputting it to the gate voltage of transistor M6. When the threshold voltage of the main amplifier transistor changes due to process fluctuations, the output voltage of the control circuit module is updated accordingly to adapt to the new threshold voltage. The gate voltage of transistor M6 is dynamically updated by the control circuit module, and the on-resistance can be adjusted accordingly based on the change in the threshold voltage of the main amplifier transistor.

[0046] S3.1: Adjusting Vbias involves adjusting the gate voltage of transistor M6 by applying an external control voltage. Changing the gate voltage of M6 can dynamically adjust the on-resistance value. Since M6 is connected in parallel with R3, the overall equivalent resistance changes accordingly, affecting the bias node voltage. The formula for calculating the bias node voltage is: in, This represents the bias node voltage. Indicates the output current. Indicates positive temperature coefficient resistance. Indicates a resistive element; The voltage of this node is obtained based on the bias node voltage and sent to the main amplifying transistor of the RF amplifier to determine the operating point of the main amplifying transistor, thus completing the adaptive bias control of the operating point of the main amplifying transistor of the RF amplifier.

[0047] Furthermore, the bias circuit of the RF amplifier includes an RF input terminal, an RF output terminal, an input matching terminal, an output matching terminal, an NMOS transistor, a PMOS transistor, a positive temperature coefficient resistor, a variable resistor, and an inductor.

[0048] Based on the characteristic of MOSFETs operating in the weak inversion region, the BJT is simulated. The principle of be, when At that time, A circuit is used to generate a current I_out that increases with temperature to counteract the decrease in current caused by the decrease in mobility.

[0049] Selecting devices whose resistance increases with temperature, such as diffusion resistors, polysilicon resistors, or trap resistors, can further enhance the temperature compensation effect and stabilize the bias point within a reasonable range.

[0050] Preferred materials for resistors and their physical layers include: diffused resistors, formed through N+ / P+ doped regions, with high resistance values, suitable for high-resistance applications; negative polysilicon resistors, formed through phosphorus, arsenic, or boron doping, with controllable resistance values ​​and positive temperature coefficients, suitable for medium-resistance applications; well resistors, formed based on N-well regions, with isolation methods including STI or deep well isolation, and resistance values ​​that can be large or small, suitable for flexible process applications; and metal resistors, utilizing M1–M8 metal layers, with lower resistance values ​​but weaker temperature characteristics, which can be used as auxiliary materials in low-resistance scenarios.

[0051] A resistor unit is constructed using a MOSFET and connected in parallel with an adjustable resistor R3. Its equivalent resistance can be dynamically adjusted by Vgs, thereby changing the bias voltage. This is particularly suitable for carbon-based transistors, as their threshold voltage is unstable. This resistor unit can be adjusted by feedback from Vgs to counteract threshold drift.

[0052] Prior to this, the size of the MOSFET can be designed to be adjustable to cover a wide range of circuit applications. The resistance value can be continuously adjusted by adjusting the external control voltage Vgs. In the parallel structure, a wider range of resistance adjustment can be achieved by changing the resistance value of R3 to be compatible with the offset of different batches of carbon-based devices.

[0053] The radio frequency amplifier of the present invention mainly comprises input-output matching, an amplifying transistor, a capacitor, and an inductor, and operates at a center frequency of 3.3 GHz. It is combined with the above-mentioned bias circuit to form a complete circuit.

[0054] Preferably, carbon-based transistors can be used as amplifying transistors in the amplifier. Due to their excellent thermal stability, high carrier mobility, and high saturation velocity, they can further improve the gain of the amplifier.

[0055] Prioritize the inclusion of a current mirror feedback adjustment unit in the circuit structure to further enhance the stability of the bias current. An adaptive control module can be integrated to automatically adjust Vgs to accommodate Vth fluctuations in carbon-based devices. During integrated implementation, both resistors and MOSFETs utilize process-compatible standard cells, ensuring the circuit can be implemented using conventional CMOS / carbon-based processes.

[0056] In a preferred embodiment, an adaptive bias system for an RF amplifier includes a module for generating a reference current with a positive temperature coefficient (PTC). This module replicates the reference current as a bias output current using a current mirror structure. A resistor network with a PTC is connected to the output branch of the bias output current to form a bias voltage base that increases with temperature. A dynamic adjustment module connects a variable resistor unit composed of MOS transistors in parallel with a fixed-value resistor to the bias output node, forming an adjustable equivalent resistance structure. The module dynamically changes the on-resistance value of Vgs by adjusting the Vgs of the MOS transistors. (MOS transistors refer to metal-oxide-semiconductor transistors, and Vgs refers to the gate voltage). An adaptive bias control module correlates the Vgs of the variable resistor unit with the gate-source voltage or a process-sensitive parameter of the RF amplifier's main amplifying transistor, adjusting Vgs according to changes in the threshold voltage of the main amplifying transistor. This adjusts Vbias to achieve adaptive bias control of the operating point of the RF amplifier's main amplifying transistor. (Vbias refers to the bias node voltage.)

[0057] The above-mentioned unit modules can be embedded in the processor of the computer device in hardware form or independent of it, or they can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of the above modules.

[0058] In one embodiment, a computer device is provided, which may be a terminal. The computer device includes a processor, memory, a communication interface, a display screen, and an input device connected via a system bus. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The communication interface of the computer device is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen of the computer device may be an LCD screen or an e-ink display screen. The input device of the computer device may be a touch layer covering the display screen, or buttons, a trackball, or a touchpad located on the casing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0059] In summary, this invention, by introducing a current source and resistor network with a positive temperature coefficient, can automatically adjust the bias voltage when the ambient temperature changes. This effectively counteracts the decrease in bias current caused by the decrease in carrier mobility and threshold voltage drift due to temperature rise, thereby maintaining the stability of transconductance and gain. Simultaneously, by employing a structure where a variable resistor unit composed of a metal-oxide-semiconductor transistor is connected in parallel with a fixed-value resistor, the control voltage of this variable resistor unit is electrically connected to the gate-source voltage of the main amplifier transistor or a process-sensitive parameter. This allows the resistance value of the variable resistor to be dynamically adjusted according to the threshold voltage of the main amplifier transistor, thereby regulating the bias node voltage and achieving adaptive control of the operating point of the main amplifier transistor. This invention addresses the threshold voltage inconsistency and drift issues present in carbon-based transistors during manufacturing. The bias circuit boasts a simple structure, employing only conventional transistors, resistors, and current mirror modules, eliminating the need for complex control logic. This facilitates integration into standard silicon-based or carbon-based processes, offering excellent process compatibility and scalability. The overall solution is applicable not only to carbon-based RF amplifiers but also to silicon-based devices, enhancing the circuit's adaptability to different material systems and process conditions. Simulation results demonstrate that using the bias circuit of this invention significantly reduces gain fluctuations in the RF amplifier over a wide temperature range, exhibiting significantly better performance stability than traditional fixed-bias structures. This provides reliable technical support for the design of high-performance, robust RF circuits.

[0060] After introducing the method and system of exemplary embodiments of the present invention, the following references are made. Figure 14 A computer-readable storage medium according to exemplary embodiments of the present invention will be described, please refer to... Figure 14 The computer-readable storage medium shown is an optical disc 30, on which a computer program (i.e., a program product) is stored. When the computer program is run by a processor, it implements the steps described in the above method implementation, such as generating a reference current with a positive temperature coefficient, replicating the reference current as a bias output current through a current mirror structure, connecting a resistor network with a positive temperature coefficient in the output branch of the bias output current to form a bias voltage base that increases with temperature; connecting a variable resistor unit composed of MOS transistors in parallel with a fixed-value resistor to the bias output node to form an adjustable equivalent resistance structure, and dynamically changing the on-resistance value of Vgs by adjusting the Vgs of the MOS transistor (MOS transistor refers to a metal-oxide-semiconductor transistor, and Vgs refers to the gate voltage); associating the Vgs of the variable resistor unit with the gate-source voltage or process-sensitive parameter of the main amplifier transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifier transistor, and adjusting Vbias to complete the adaptive bias control of the operating point of the main amplifier transistor of the RF amplifier (Vbias refers to the bias node voltage). The specific implementation of each step will not be repeated here.

[0061] It should be noted that examples of computer-readable storage media may also include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical and magnetic storage media, which will not be elaborated here.

[0062] After introducing the methods and media of exemplary embodiments of the present invention, the following references are made. Figure 4 A computational device for adaptive recovery of low-voltage power grid self-healing control according to an exemplary embodiment of the present invention.

[0063] Figure 15 A block diagram is shown of an exemplary computing device 40 suitable for implementing embodiments of the present invention. The computing device 40 may be a computer system or a server. Figure 15 The computing device 40 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of the present invention.

[0064] like Figure 15 As shown, the components of computing device 40 may include, but are not limited to: one or more processors or processing units 401, system memory 402, and bus 403 connecting different system components (including system memory 402 and processing unit 401).

[0065] The computing device 40 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computing device 40, including volatile and non-volatile media, and removable and non-removable media.

[0066] System memory 402 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 4021 and / or cache memory 4022. Computing device 40 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, ROM 4023 may be used to read and write non-removable, non-volatile magnetic media (…). Figure 15 (Not shown in the image, usually referred to as "hard drive"). Although not shown in... Figure 15The diagram illustrates that disk drives for reading and writing to removable non-volatile disks (e.g., "floppy disks") and optical disc drives for reading and writing to removable non-volatile optical discs (e.g., CD-ROMs, DVD-ROMs, or other optical media) can be provided. In these cases, each drive can be connected to bus 403 via one or more data media interfaces. System memory 402 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0067] A program / utility 4025 having a set (at least one) of program modules 4024 may be stored, for example, in system memory 402, and such program modules 4024 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment. Program modules 4024 typically perform the functions and / or methods described in the embodiments of the present invention.

[0068] The computing device 40 can also communicate with one or more external devices 404 (such as a keyboard, pointing device, display, etc.). This communication can be performed via the input / output (I / O) interface 405. Furthermore, the computing device 40 can also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter 406. Figure 15 As shown, network adapter 406 communicates with other modules of computing device 40 (such as processing unit 401) via bus 403. It should be understood that, although... Figure 15 As not shown, it can be used in conjunction with computing device 40 with other hardware and / or software modules.

[0069] The processing unit 401 executes various functional applications and data processing by running programs stored in the system memory 402. For example, it generates a reference current with a positive temperature coefficient, replicates the reference current as a bias output current through a current mirror structure, connects a resistor network with a positive temperature coefficient in the output branch of the bias output current to form a bias voltage base that increases with temperature; it connects a variable resistor unit composed of MOS transistors in parallel with a fixed resistor to the bias output node to form an adjustable equivalent resistance structure, and dynamically changes the on-resistance value of Vgs by adjusting the Vgs of the MOS transistor (MOS transistor refers to a metal-oxide-semiconductor transistor, and Vgs refers to the gate voltage); it associates the Vgs of the variable resistor unit with the gate-source voltage or process-sensitive parameters of the main amplifier transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifier transistor, and adjusts Vbias to complete the adaptive bias control of the operating point of the main amplifier transistor of the RF amplifier (Vbias refers to the bias node voltage).

[0070] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0071] In the several embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interface; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0072] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0073] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0074] If the functionality is implemented as a software functional unit and sold or used as an independent product, it can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0075] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0076] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An adaptive biasing method for a radio frequency amplifier, characterized in that: include, A reference current with a positive temperature coefficient is generated, and the reference current is copied into a bias output current through a current mirror structure. A resistor network with a positive temperature coefficient is connected in the output branch of the bias output current to form a bias voltage basis that increases with temperature. A variable resistor unit composed of MOS transistors is connected in parallel with a fixed resistor and connected to a bias output node to form an adjustable equivalent resistance structure. The on-resistance value of Vgs is dynamically changed by adjusting the Vgs of the MOS transistor. The MOS transistor refers to a metal-oxide-semiconductor transistor, and Vgs refers to the gate voltage. The variable resistor unit's Vgs is associated with the gate-source voltage or process-sensitive parameter of the main amplifier transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifier transistor. By adjusting Vbias, adaptive bias control of the operating point of the main amplifier transistor of the RF amplifier is completed. Vbias refers to the bias node voltage.

2. The adaptive biasing method for an RF amplifier as described in claim 1, characterized in that: The positive temperature coefficient reference current comprises a PTAT module consisting of transistors M1, M2, M3, M4 and resistor R1. Transistors M1 and M2 operate in the weak inversion region or subthreshold region, and the current characteristics of MOS transistors in the weak inversion region or subthreshold region are used to simulate... ; The simulation This refers to utilizing the temperature characteristics of Vgs in the subthreshold region to mimic the properties of BJTs. The temperature dependence of BJT refers to the bipolar junction transistor. By utilizing the temperature characteristics of BJT, a MOS transistor is used to simulate BJT.

3. The adaptive biasing method for a radio frequency amplifier as described in claim 2, characterized in that: The simulation utilizes the current characteristics of MOS transistors in the weak inversion region or subthreshold region. This includes simulating the temperature characteristics of the base-emitter voltage difference ΔVbe in a bipolar transistor by using the gate-source voltage difference ΔVgs when the MOS transistor is operating in the subthreshold region, and generating PTAT current; The specific steps for generating the PTAT current are as follows: Based on the current I1 flowing through M1 and the current I2 flowing through M2, since I1 and I2 have different dimensions, their gate-source voltage differences ΔVgs are different. Therefore, the formula for the gate-source voltage difference ΔVgs is: in, Indicates the gate-source voltage difference. This represents the gate-source voltage of transistor M1. This represents the gate-source voltage of transistor M2. Indicates proportional to, Indicates thermal voltage. Represents the natural logarithm; when When it increases, then It increases with rising temperature. A resistor R1 is driven to generate a current that increases with temperature, producing the PTAT current, which is the reference current with a positive temperature coefficient.

4. The adaptive biasing method for a radio frequency amplifier as described in claim 3, characterized in that: The bias output node is the output terminal of the entire bias circuit. Its voltage value serves as the gate bias voltage of the main amplifier transistor of the RF amplifier, and is used to set the operating current and transconductance of the main amplifier transistor. The output branch of the bias output current refers to the current path that starts from the drain of the current mirror output transistor M5, passes through the positive temperature coefficient resistor R2, and connects to the bias output node. The positive temperature coefficient resistor network includes R2, which is composed of a diffusion resistor, a polysilicon resistor, or a well resistor. Vbias refers to the bias node voltage, including pull-up paths and pull-down or adjustment paths. The pull-up path includes a power supply, a positive temperature coefficient resistor R2, and a bias output node, while the pull-down or adjustment path includes a bias output node, a variable resistor unit, and a low level.

5. The adaptive biasing method for an RF amplifier as described in claim 4, characterized in that: The parallel connection of the variable resistor unit composed of MOS transistors with the fixed resistor refers to setting up a parallel structure composed of a metal oxide semiconductor transistor M6 and a fixed resistor R3. The drain of transistor M6 and one end of resistor R3 are connected to the bias output node, and the source of transistor M6 and the other end of resistor R3 are connected to a low level, which refers to the circuit ground. Transistor M6 operates in the transistor region to receive an adjustable externally applied control voltage; When transistor M6 operates in the bipolar region, its equivalent resistance between drain and source is determined by the gate voltage Vgs. When the gate voltage Vgs increases, the channel conductivity is strong and the equivalent resistance decreases. That is, by changing the gate voltage Vgs, the on-resistance value of Vgs is dynamically changed.

6. The adaptive biasing method for a radio frequency amplifier as described in claim 5, characterized in that: The association of the variable resistor unit's Vgs with the gate voltage or process-sensitive parameter of the RF amplifier's main amplifying transistor is included in the circuit. The gate voltage of the RF amplifier's main amplifying transistor is connected to the bias output node. The input terminal of the control circuit module is connected between the gate voltage and the source of the main amplifying transistor to receive the gate voltage signal of the main amplifying transistor. The adjustment of Vgs according to the change of the threshold voltage of the main amplifier tube includes a control circuit module generating a control voltage according to the received voltage signal and outputting it to the gate voltage of transistor M6. When the threshold voltage of the main amplifier transistor changes due to process fluctuations, the output voltage of the control circuit module is updated accordingly to adapt to the new threshold voltage. The gate voltage of transistor M6 is dynamically updated by the control circuit module, and the on-resistance can be adjusted accordingly based on the change in the threshold voltage of the main amplifier transistor.

7. The adaptive biasing method for a radio frequency amplifier as described in claim 6, characterized in that: The adjustment of Vbias includes adjusting the gate voltage of transistor M6 by applying an external control voltage. Changing the gate voltage of M6 can dynamically adjust the on-resistance value. Since M6 is connected in parallel with R3, the overall equivalent resistance changes accordingly, affecting the bias node voltage. The formula for calculating the bias node voltage is as follows: in, This represents the bias node voltage. Indicates the output current. Indicates positive temperature coefficient resistance. Indicates a resistive element; The voltage of this node is obtained based on the bias node voltage and sent to the main amplifying transistor of the RF amplifier to determine the operating point of the main amplifying transistor, thus completing the adaptive bias control of the operating point of the main amplifying transistor of the RF amplifier.

8. An adaptive biasing system for a radio frequency amplifier, based on the adaptive biasing method for a radio frequency amplifier according to any one of claims 1 to 7, characterized in that: include, A reference current module with a positive temperature coefficient is generated. It replicates the reference current into a bias output current through a current mirror structure. A resistor network with a positive temperature coefficient is connected in the output branch of the bias output current to form a bias voltage basis that increases with temperature. The dynamic change module connects a variable resistor unit composed of MOS transistors in parallel with a fixed resistor to the bias output node, forming an adjustable equivalent resistance structure. By adjusting the Vgs of the MOS transistor, the on-resistance value of Vgs is dynamically changed. The MOS transistor refers to a metal-oxide-semiconductor transistor, and Vgs refers to the gate voltage. The adaptive bias control module correlates the Vgs of the variable resistor unit with the gate-source voltage or process-sensitive parameter of the main amplifier transistor of the RF amplifier, so that Vgs is adjusted according to the change of the threshold voltage of the main amplifier transistor, and Vbias is adjusted to complete the adaptive bias control of the operating point of the main amplifier transistor of the RF amplifier. Vbias refers to the bias node voltage.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the adaptive biasing method for a radio frequency amplifier as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the adaptive biasing method for a radio frequency amplifier as described in any one of claims 1 to 7.

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