Leakage voltage protection circuit, power amplifier circuit, radio frequency power supply and semiconductor device

Abstract

The application provides a drain voltage protection circuit, a power amplification circuit, a radio frequency power supply and a semiconductor device, which can be used in the technical field of radio frequency power supply. The power tube and the output matching circuit constitute a radio frequency link, and the drain voltage protection circuit comprises a voltage division circuit, a comparison circuit and a control circuit connected in sequence. The voltage division circuit is connected between the power tube and the output matching circuit, and is used for voltage division of the drain voltage of the power tube to obtain a divided voltage. The comparison circuit is used for comparing the divided voltage with a threshold voltage, and generating a comparison result signal based on the comparison result of the divided voltage and the threshold voltage. The control circuit is used for controlling at least one of the on-off of the radio frequency link and the output power according to the comparison result signal. The radio frequency link of the power tube is controlled by the monitoring result of the drain voltage of the power tube, so that the power tube is protected in real time, the power tube is prevented from being damaged due to the excessively high drain voltage, the reliability of the power tube is improved, and the service life of the power tube is prolonged.

Description

Technical Field

[0001] This application relates to the field of radio frequency power supply technology, and in particular to a leakage protection circuit, a power amplifier circuit, a radio frequency power supply, and a semiconductor device. Background Technology

[0002] RFG (Radio Frequency Generator) power supplies play a vital role in many industrial and scientific research fields, such as semiconductor manufacturing, plasma processing, and material surface treatment.

[0003] In radio frequency (RF) circuits, a mismatch between the load impedance and the power supply output impedance (i.e., a power supply impedance mismatch scenario) is common. When an RF power supply operates in a mismatch scenario, if the drain voltage exceeds the withstand voltage specification of the power transistor due to large reflections, the internal semiconductor structure of the power transistor will be damaged, leading to power transistor failure. Large reflections refer to the phenomenon where, when a signal encounters an impedance discontinuity during transmission, most of the energy is "bounced back" to the signal source instead of continuing forward transmission. Utility Model Content

[0004] This application provides a leakage protection circuit, a power amplifier circuit, an RF power supply, and a semiconductor device to solve the technical problem that existing power transistors are prone to failure due to large reflections, thus affecting their service life.

[0005] According to the first aspect disclosed in this application, this application provides a leakage protection circuit for protecting a power transistor. The power transistor and an output matching circuit form an RF link. The power transistor is used to amplify an RF signal, and the output matching circuit is used to adjust the RF signal amplified by the power transistor and output the RF signal to a load so that the impedance of the RF signal output to the load is matched with the impedance of the load.

[0006] The leakage protection circuit includes a voltage divider circuit, a comparator circuit, and a control circuit connected in sequence.

[0007] The voltage divider circuit is connected between the power transistor and the output matching circuit, and is used to divide the drain voltage of the power transistor to obtain a divided voltage.

[0008] The comparison circuit is used to compare the divided voltage with the threshold voltage, and generate a comparison result signal based on the comparison result of the divided voltage and the threshold voltage;

[0009] The control circuit is used to control at least one of the on / off state of the radio frequency link and the output power according to the comparison result signal; wherein the output power of the radio frequency link is the power output by the output matching circuit.

[0010] Based on the above technical content, the RF link of the power transistor is controlled by monitoring the drain voltage of the power transistor to provide real-time protection for the power transistor and prevent it from being damaged by excessive drain voltage under large reflection conditions. This ensures that the power transistor operates under safe working conditions, thereby improving the reliability of the power transistor and extending its lifespan.

[0011] Furthermore, in the radio frequency (RF) field, the location of the detection point significantly affects the accuracy of the detection results. In related technologies, the monitoring point is typically placed after the output matching circuit, and the voltage of the power transistor is indirectly determined by detecting the voltage of the output matching circuit, and then the power transistor is protected based on this. The voltage divider circuit in this application is connected between the power transistor and the output matching circuit, which allows for direct detection of the power transistor's drain voltage. This facilitates a more accurate and direct understanding of the power transistor's voltage information, thereby providing more precise protection for the power transistor.

[0012] Finally, compared to current sensing methods, excessive drain current does not necessarily lead to power transistor damage, while excessive drain voltage will. This application controls the RF link based on drain voltage, which helps to avoid power transistor damage.

[0013] In one feasible implementation, the voltage divider circuit includes a first capacitor and a second capacitor;

[0014] The first terminal of the first capacitor is connected to the drain of the power transistor, and the second terminal of the first capacitor is connected to the input terminal of the comparator circuit.

[0015] The first terminal of the second capacitor is connected to the second terminal of the first capacitor, and the second terminal of the second capacitor is grounded.

[0016] Furthermore, by dividing the drain voltage, the drain voltage can be reduced to a voltage range that can be handled by the subsequent comparator circuit.

[0017] In one feasible implementation, the comparison circuit is a comparator;

[0018] The first input terminal of the comparator is connected to the output terminal of the voltage divider circuit, the second input terminal of the comparator is connected to the threshold voltage, and the output terminal of the comparator is connected to the input terminal of the control circuit.

[0019] Furthermore, the comparator can quickly compare the magnitudes of the voltage divider and the threshold voltage, and generate a corresponding signal output based on the comparison result.

[0020] In one feasible implementation, the comparator is a high-speed comparator.

[0021] Furthermore, employing a high-speed comparator can improve the comparison accuracy of voltage signals, thereby enhancing the response efficiency of the protection circuit. In the radio frequency (RF) field, RF signals typically reach megahertz levels, meaning their periods are extremely short and voltage changes very rapidly. Compared to low-speed comparators, high-speed comparators can quickly and accurately compare voltage signals, thus preventing damage to power transistors.

[0022] In one feasible implementation, the control circuit is used to control at least one of the on / off state of the radio frequency link and the output power based on the comparison result signal, including:

[0023] The control circuit is used to control the RF link to disconnect or control the output power of the RF link to decrease when the comparison result signal indicates that the voltage divider voltage is greater than the threshold voltage.

[0024] Furthermore, when the voltage divider voltage exceeds the threshold voltage, it indicates that the drain voltage of the power transistor is too high. In this case, the control circuit protects the power transistor by either disconnecting the RF link or reducing the output power of the RF link.

[0025] In one feasible implementation, the control circuit is a gain control circuit;

[0026] The input terminal of the gain control circuit is connected to the output terminal of the comparator circuit, and the output terminal of the gain control circuit is connected to the power transistor.

[0027] The gain control circuit is used to control the power of the radio frequency signal received by the power transistor, so as to control the output power of the radio frequency link.

[0028] Furthermore, the gain control circuit can reduce the power of the radio frequency signal received by the power transistor, thereby reducing the voltage input to the power transistor and bringing the drain voltage of the power transistor back to the threshold range, thus protecting the power transistor.

[0029] In one feasible implementation, the gain control circuit is a digitally controlled attenuator or an analog attenuator.

[0030] Furthermore, digitally controlled attenuators achieve high-precision, programmable gain adjustment through digital control, significantly improving the stability of gain control; while analog attenuators provide flexible and reliable gain control with low power consumption and continuous smooth adjustment characteristics.

[0031] In one feasible implementation, the control circuit is a switch control circuit;

[0032] The input terminal of the switch control circuit is connected to the output terminal of the comparator circuit, and the output terminal of the switch control circuit is connected to the power transistor.

[0033] The switch control circuit is used to control the on / off state of the radio frequency link.

[0034] Furthermore, by disconnecting the connection between the RF signal received by the power transistor and the power transistor, the power transistor can be protected, enabling a more timely response to overvoltage conditions and providing faster protection.

[0035] In one feasible implementation, the system further includes a logic circuit, the input of which is connected to the output of the comparison circuit, and the output of which is connected to the input of the control circuit.

[0036] The logic circuit is used to detect and determine the comparison result signal, and send a control signal to the control circuit according to the detection and determination result; wherein, the control signal is used to instruct the control circuit to control at least one of the on / off state of the radio frequency link and the output power.

[0037] Furthermore, logic circuits can filter and shape the signals input to the comparison circuit to remove interference signals, avoid unnecessary actions of the control circuit due to misjudgment, and thus improve the stability of the circuit.

[0038] According to a second aspect disclosed in this application, this application provides a power amplifier circuit, including a leakage protection circuit as described in any one of the first aspects, the power transistor, and the output matching circuit.

[0039] Based on the above technical content, by setting a leakage protection circuit in the power amplifier circuit, the power transistor in the power amplifier circuit can be protected, thereby improving the reliability of the power transistor and extending its service life.

[0040] In one feasible implementation, an input matching circuit is also included;

[0041] The input terminal of the input matching circuit is connected to the output terminal of the control circuit, and the output terminal of the input matching circuit is connected to the power transistor. It is used to adjust the radio frequency signal output by the control circuit so that the impedance of the radio frequency signal received by the power transistor matches the impedance of the power transistor.

[0042] Furthermore, the input matching circuit maximizes power transmission, reduces signal reflection, and effectively improves circuit stability by matching the impedance of the RF signal received by the power transistor with the impedance of the power transistor, thereby avoiding the risk of self-oscillation.

[0043] According to a third aspect disclosed in this application, this application provides an radio frequency power supply, including a power amplifier circuit as described in any one of the second aspects.

[0044] Based on the above technical content, a leakage protection circuit is set in the RF power supply. When the drain voltage of the power transistor in the RF power supply exceeds the set safety threshold, protective measures are quickly taken. By reducing the output power of the power transistor RF link or shutting down the RF link, the power transistor is protected from damage, thereby improving the reliability of the power transistor and extending its service life.

[0045] According to the fourth aspect disclosed in this application, this application provides a semiconductor device including a radio frequency power supply as described in the third aspect.

[0046] Compared with the prior art, this application has the following advantages:

[0047] This application provides a drain voltage protection circuit, a power amplifier circuit, an RF power supply, and a semiconductor device. The circuit uses a voltage divider circuit to acquire the drain voltage of a power transistor and divides it to reduce the drain voltage to a range that can be processed by a subsequent comparator circuit. The comparator circuit receives the divided voltage and compares it with a threshold voltage to determine if the drain voltage of the power transistor exceeds a safe range. It then outputs a comparison result signal based on the comparison result. The control circuit receives the comparison result signal from the comparator circuit and controls at least one of the following on / off states and output power to control the RF link of the power transistor, providing real-time protection against damage caused by excessively high drain voltage under conditions of high reflection. This ensures the power transistor operates under safe conditions, thereby improving its reliability and extending its lifespan. Attached Figure Description

[0048] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0049] Figure 1 This is a schematic diagram of a leakage protection circuit provided in an embodiment of this application;

[0050] Figure 2 This is a schematic diagram of another leakage protection circuit provided in an embodiment of this application;

[0051] Figure 3 A schematic diagram of another leakage protection circuit provided in the embodiments of this application;

[0052] Figure 4 This is a schematic diagram of another leakage protection circuit provided in an embodiment of this application.

[0053] Explanation of reference numerals in the attached figures:

[0054] 100 - Control circuit;

[0055] 101 - Gain control circuit;

[0056] 102 - Switch control circuit;

[0057] 200-Input matching circuit;

[0058] 300-Power transistor;

[0059] 400- Output matching circuit;

[0060] 500-Voltage Divider Circuit;

[0061] C1 - First capacitor;

[0062] C2 - Second capacitor;

[0063] 600-Comparator Circuit;

[0064] 601 - Comparator;

[0065] 700-Logic Circuits;

[0066] 701 logic chip.

[0067] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0068] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0069] RF (Radio Frequency Generator) power supplies play a crucial role in numerous industrial and scientific research fields, such as semiconductor manufacturing, plasma processing, and material surface treatment. Their high output power allows them to meet the demands of various high-power processes. However, this high-power output also brings many challenges, one of the most prominent being their frequent operation under mismatch conditions. In the field of radio frequency (RF) and electronic circuits, a mismatch condition refers to a situation where the output impedance of the signal source (such as an RF power supply) is not equal to the load impedance. Impedance is a measure of the resistance to alternating current in a circuit, encompassing the combined impediment effect of components such as resistors, inductors, and capacitors. It is usually expressed in complex form, including a real part (resistance) and an imaginary part (reactance).

[0070] In radio frequency (RF) circuits, a mismatch between the load impedance and the power supply output impedance (i.e., a mismatch scenario) is common. When an RF power supply operates in a mismatch scenario, the signal will be reflected. This reflected wave superimposed on the incident wave will generate a large voltage fluctuation at the output of the power amplifier (power transistor). For a power transistor, its drain (collector) voltage is one of the important parameters for measuring its operating state. Once the drain voltage exceeds the power transistor's withstand voltage specification due to large reflections, the internal semiconductor structure of the power transistor will be damaged. Large reflections refer to the phenomenon where, when a signal encounters an impedance discontinuity during transmission, most of the energy is "bounced back" to the signal source instead of continuing forward.

[0071] This damage can be instantaneous breakdown or a long-term cumulative effect. Instantaneous breakdown will directly cause the power transistor to lose its amplification function and fail to work properly; while long-term cumulative effects will gradually reduce the performance of the power transistor, shorten its lifespan, and eventually lead to failure. The failure of the power transistor will not only prevent the entire RF power supply from outputting power normally, but may also trigger a series of chain reactions, affecting the stability and reliability of the entire system. For example, in a plasma scenario, due to the load characteristics of plasma, the impedance changes dynamically with gas composition, pressure, and power, causing a sudden change in VSWR (voltage standing wave ratio). A high VSWR causes a surge in reflected power, and the power transistor burns out due to excessive voltage / current stress.

[0072] To address the aforementioned technical problems, this application proposes a leakage voltage protection circuit, a power amplifier circuit, an RF power supply, and a semiconductor device. By monitoring the drain voltage of the power transistor, the RF link of the power transistor is controlled to provide real-time protection for the power transistor, preventing damage due to excessive drain voltage. This ensures that the power transistor operates under safe working conditions, thereby improving the reliability of the power transistor and extending its lifespan.

[0073] The technical solutions for the leakage protection circuit, power amplifier circuit, RF power supply, and semiconductor device provided in this application are described in detail below through specific embodiments. It should be noted that the following embodiments may exist independently or in combination with each other; for the same or similar content, descriptions may not be repeated in different embodiments.

[0074] Figure 1 This is a schematic diagram of a leakage protection circuit provided in an embodiment of this application. (See attached diagram.) Figure 1 In some embodiments, the power transistor 300 and the output matching circuit 400 form an RF link. The power transistor 300 is used to amplify the RF signal, and the output matching circuit 400 is used to adjust the RF signal amplified by the power transistor 300 and output the RF signal to the load so that the impedance of the RF signal output to the load is matched with the impedance of the load.

[0075] The leakage protection circuit includes a voltage divider circuit 500, a comparator circuit 600, and a control circuit 100 connected in sequence. The voltage divider circuit 500 is connected between the power transistor 300 and the output matching circuit 400 to divide the drain voltage of the power transistor 300 to obtain a divided voltage. The comparator circuit 600 is used to compare the divided voltage with a threshold voltage and generate a comparison result signal based on the comparison result. The control circuit 100 is used to control at least one of the on / off state of the RF link and the output power according to the comparison result signal. The output power of the RF link is the power output by the output matching circuit 400.

[0076] In this embodiment, the drain voltage of the power transistor 300 is acquired by a voltage divider circuit 500 and divided to reduce the drain voltage to a range that the subsequent comparator circuit 600 can handle. After receiving the divided voltage, the comparator circuit 600 compares it with a threshold voltage to determine whether the drain voltage of the power transistor 300 exceeds a safe range, and then outputs a comparison result signal based on the comparison result. The control circuit 100 receives the comparison result signal from the comparator circuit 600 and controls at least one of the following based on the comparison result signal: the on / off state of the RF link and the output power, thereby controlling the RF link of the power transistor 300 to provide real-time protection for the power transistor 300. This prevents damage to the power transistor 300 due to excessively high drain voltage under conditions of large reflection, ensuring that the power transistor 300 operates under safe working conditions, thus improving the reliability of the power transistor 300 and extending its lifespan.

[0077] Furthermore, the inventors noted that in the radio frequency field, the location of the detection point significantly affects the accuracy of the detection results. In related technologies, the monitoring point is typically set after the output matching circuit 400, and the voltage of the power transistor 300 is indirectly determined by detecting the voltage of the output matching circuit 400, and then the power transistor 300 is protected based on this. In this embodiment, the voltage divider circuit 500 is connected between the power transistor 300 and the output matching circuit 400, and the voltage is detected directly at the drain output terminal of the power transistor 300, rather than after the output matching circuit 400. This allows for direct detection of the drain voltage of the power transistor 300, which is beneficial for obtaining the voltage information of the power transistor 300 more accurately and directly, thereby improving the detection accuracy of the power transistor 300 voltage.

[0078] Finally, compared to current sensing, excessive drain current does not necessarily damage the power transistor 300, while excessive drain voltage will. In this embodiment, controlling the RF link based on drain voltage helps to avoid damage to the power transistor 300.

[0079] Optionally, the control circuit 100 is used to control at least one of the on / off state of the RF link and the output power based on the comparison result signal, including: the control circuit 100 controls the RF link to disconnect or controls the output power of the RF link to decrease when the comparison result signal indicates that the voltage divider voltage is greater than the threshold voltage.

[0080] When the voltage divider voltage is greater than the threshold voltage, it indicates that the drain voltage of the power transistor 300 is too high. At this time, the control circuit 100 protects the power transistor 300 by controlling the RF link to disconnect or by controlling the output power of the RF link to decrease.

[0081] See Figure 1 Optionally, the voltage divider circuit 500 includes a first capacitor C1 and a second capacitor C2; the first end of the first capacitor C1 is connected to the drain of the power transistor 300, and the second end of the first capacitor C1 is connected to the input of the comparator circuit 600; the first end of the second capacitor C2 is connected to the second end of the first capacitor C1, and the second end of the second capacitor C2 is grounded.

[0082] In this circuit, the first capacitor C1 and the second capacitor C2, connected in series, have one end connected to the drain of the power transistor 300 and the other end grounded. Due to the characteristics of a series circuit, the voltage across the power transistor 300 is distributed according to the impedance ratio of each component, thus achieving voltage division of the drain voltage of the power transistor 300. Since high-power RF power supplies typically have output power of several kilowatts or even tens of thousands of watts, voltage division of the drain voltage is used to reduce the drain voltage to a range that the subsequent comparator circuit 600 can handle.

[0083] Specifically, the impedance presented by a capacitor to an AC signal is called capacitive reactance. The capacitive reactance of the first capacitor C1 and the second capacitor C2 is equivalent to the resistance value in a series resistor circuit. Therefore, the first capacitor C1 and the second capacitor C2, through their own capacitive reactance characteristics, divide the drain voltage signal in the series circuit, providing a detection signal of appropriate amplitude for the subsequent comparator 601, thereby realizing the monitoring and protection function of the drain voltage of the power transistor 300.

[0084] See Figure 2 Optionally, the comparator circuit 600 is a comparator 601; the first input terminal of the comparator 601 is connected to the output terminal of the voltage divider circuit 500, the second input terminal of the comparator 601 is connected to the threshold voltage, and the output terminal of the comparator 601 is connected to the input terminal of the control circuit 100.

[0085] The comparator 601 is used to compare the magnitudes of two voltage signals and generate a corresponding signal output based on the comparison result. Specifically, the comparator 601 represents the relative magnitude relationship between the input signals through its signal output.

[0086] Specifically, the first input terminal is one of the non-inverting input terminal or the inverting input terminal of comparator 601, and the second input terminal is the other of the non-inverting input terminal or the inverting input terminal of comparator 601.

[0087] For example, if the voltage divider voltage is greater than the threshold voltage, comparator 601 outputs a high-level pulse signal; if the voltage divider voltage is less than the threshold voltage, comparator 601 outputs a low-level pulse signal.

[0088] Optionally, comparator 601 is a high-efficiency comparator.

[0089] The high-speed comparator is a special type of comparator 601, featuring fast response time and high frequency characteristics, specifically designed for applications requiring high-speed signal processing and precise comparison. Since radio frequency (RF) signals are sinusoidal signals with frequencies varying over time, and these frequencies typically reach megahertz levels, their periods are extremely short, and voltage changes very rapidly. Therefore, a high sampling rate is necessary for accurate signal measurement. Compared to low-speed comparators, high-speed comparators offer extremely fast response times, reacting to changes in the input signal in a very short time. Using a high-speed comparator allows for rapid and accurate comparison of voltage signals, improving comparison accuracy and consequently enhancing the response efficiency of protection circuits.

[0090] See Figure 3Optionally, the control circuit 100 is a gain control circuit 101; the input terminal of the gain control circuit 101 is connected to the output terminal of the comparator circuit 600, and the output terminal of the gain control circuit 101 is connected to the power transistor 300; the gain control circuit 101 is used to control the power of the RF signal received by the power transistor 300, so as to control the output power of the RF link.

[0091] The control circuit 100 is a gain control circuit 101, which controls the power of the input power transistor 300. When the comparator 601 in the circuit detects that the drain voltage of the power transistor 300 exceeds the safety threshold, it sends a control signal to the gain control circuit 101. In response to this signal, the gain control circuit 101 reduces the power of the radio frequency signal received by the power transistor 300, thereby reducing the voltage input to the power transistor 300. This brings the drain voltage of the power transistor 300 back within the threshold range, thus protecting the power transistor 300.

[0092] The gain control circuit 101 can protect the power transistor 300 without interrupting its operation. Once it detects that the drain voltage of the power transistor 300 exceeds the safety threshold, it can quickly and automatically adjust the gain coefficient of the power transistor 300. This dynamic adjustment process is smooth and does not cause abrupt changes in the operating state of the power transistor 300, thus ensuring continuous and stable operation while effectively avoiding the risk of damage caused by abnormal voltage, extending the service life of the power transistor 300, and improving the reliability and stability of the entire power amplifier system. Furthermore, through precise control signals and feedback mechanisms, the gain control circuit 101 can control the drain output voltage of the power transistor 300 within a very precise range to ensure the stable performance of the power transistor 300.

[0093] Specifically, the gain control circuit 101 can precisely control the drain voltage of the power transistor 300 by adjusting the attenuation factor of the RF signal received by the power transistor 300 according to the input control signal. Based on subsequent feedback from the detection of the power transistor 300's drain voltage, the output voltage of the gain control circuit 101 is continuously reduced until the drain voltage of the power transistor 300 falls back within a safe threshold. In practical applications, the output power intensity may vary. The gain control circuit 101 can automatically adjust the gain according to the strength of the output power to ensure that the drain voltage of the power transistor 300 remains stable, thus exhibiting good applicability.

[0094] Specifically, the output of the gain control circuit 101 is connected to the gate of the power transistor 300.

[0095] Optionally, the gain control circuit 101 can be a digitally controlled attenuator or an analog attenuator.

[0096] Among them, the digitally controlled attenuator achieves high-precision, programmable gain adjustment through digital control, significantly improving the stability of gain control; while the analog attenuator provides flexible and reliable gain control with low power consumption and continuous smooth adjustment characteristics.

[0097] Specifically, digitally controlled attenuators adjust discrete attenuation by controlling a resistor network or switch array with digital signals. For example, binary codes can be used to control switches to switch between fixed attenuators with different resistance values, or digital signals can be used to adjust the current to change the junction resistance of a PIN diode.

[0098] Specifically, analog attenuators control the attenuation amount by continuously varying an analog voltage. For example, they can utilize the characteristic that the junction resistance of a PIN diode varies with current, or the resistance characteristics of a FET in the nonlinear resistive region.

[0099] See Figure 4 Optionally, the control circuit 100 is a switch control circuit 102; the input terminal of the switch control circuit 102 is connected to the output terminal of the comparator circuit 600, and the output terminal of the switch control circuit 102 is connected to the power transistor 300; the switch control circuit 102 is used to control the on / off state of the RF link.

[0100] The control circuit 100 is a switch control circuit 102, which can control the connection and disconnection of the RF link of the power transistor 300. When the drain voltage of the power transistor 300 is too high and exceeds the safe value, the switch control circuit 102 protects the power transistor 300 by disconnecting the connection between the RF signal received by the power transistor 300 and the power transistor 300.

[0101] The switch control circuit 102 can quickly connect or disconnect the transmission path of the radio frequency signal. When the drain voltage of the power transistor 300 is detected to exceed the safety threshold, the switch control circuit 102 can immediately cut off the signal, causing the power amplifier to stop working, thereby quickly protecting the power transistor 300 from damage due to excessive voltage.

[0102] Compared to the gain control circuit 101, which requires continuous adjustment of the signal gain to achieve power adjustment, the switch control circuit 102 only has two states: "on" and "off". The control logic is simpler and more direct. Although this cannot keep the power transistor 300 working continuously, it helps to reduce the complexity of the circuit design and reduce the number of control signal processing steps.

[0103] Furthermore, the gain control circuit 101 typically requires adjusting the parameters of a variable gain element (such as a variable attenuator) to change the voltage output at the drain of the power transistor 300, a process that may take some time to achieve stable gain adjustment. In contrast, the switch control circuit 102 only needs to change the state of the switch, and its response time can reach the nanosecond or even picosecond level, enabling it to react to overvoltage situations more promptly and provide faster protection.

[0104] Because the switch control circuit 102 has a relatively simple structure and fewer components, the probability of failure is reduced, and reliability is improved. At the same time, its simple control logic also reduces the possibility of circuit abnormalities caused by control signal errors or software faults, thereby improving the overall reliability of the circuit.

[0105] Specifically, the output terminal of the switch control circuit 102 is connected to the gate of the power transistor 300.

[0106] See Figure 2 In some embodiments, the leakage protection circuit of the power transistor 300 further includes a logic circuit 700. The input terminal of the logic circuit 700 is connected to the output terminal of the comparator circuit 600, and the output terminal of the logic circuit 700 is connected to the input terminal of the control circuit 100. The logic circuit 700 is used to detect and determine the comparison result signal, and send a control signal to the control circuit 100 according to the detection and determination result. The control signal is used to instruct the control circuit 100 to control at least one of the on / off state of the radio frequency link and the output power.

[0107] The signal output by the comparator circuit 600 may be affected by noise, transient interference, and other factors, resulting in brief abnormal pulses. The logic circuit 700 can filter and shape the signal input to the comparator circuit 600 to remove these interference signals, avoid unnecessary actions of the control circuit 100 due to misjudgment, and thus improve the stability of the circuit.

[0108] Furthermore, in some cases, drain voltage protection may require comprehensive consideration of multiple factors, not just a single voltage comparison result. Logic circuit 700 can implement more complex logical judgment functions, such as combining the output results of multiple comparators 601, considering the system's operating mode, time series, and other information, to make more accurate decisions to determine whether the control circuit 100 needs adjustment. In this scenario, logic circuit 700 can serve as an interface between the protection circuit and external systems, enabling information exchange and coordination. For example, it can receive instructions from other modules or adjust the control strategy of control circuit 100 according to the overall system requirements. Simultaneously, it can also feed back the operating status of the protection circuit to external systems, enabling system monitoring and management, and improving the scalability of the protection circuit.

[0109] Optionally, logic circuit 700 is logic chip 701.

[0110] The core function of the logic chip 701 is to perform Boolean logic operations (such as AND, OR, NOT, XOR, etc.) and to implement more complex functions through combinational logic gates, such as application-specific integrated circuits (ASICs) and programmable logic gates (FPGAs).

[0111] See Figure 1 In some embodiments, this application also provides a power amplifier circuit, including the above-described leakage protection circuit, power transistor 300 and output matching circuit 400.

[0112] In this embodiment, by setting a leakage protection circuit in the power amplifier circuit, the power transistor 300 in the power amplifier circuit can be protected, thereby improving the reliability of the power transistor 300 and extending its service life.

[0113] Specifically, an output matching circuit 400 is set at the drain output terminal of the power transistor 300. The output matching circuit 400 is responsible for transforming the output impedance of the power transistor 300 under optimal load conditions to an impedance value that matches the load, so as to achieve maximum power transmission. Through reasonable design, it can improve output power and efficiency and reduce circuit loss. At the same time, it needs to optimize the output VSWR to ensure circuit stability, prevent parasitic signals and self-oscillation, and also needs to have harmonic suppression function to further improve the linearity of the power amplifier circuit by reducing harmonic output.

[0114] See Figure 1 Optionally, the power amplifier circuit further includes an input matching circuit 200; the input terminal of the input matching circuit 200 is connected to the output terminal of the control circuit 100, and the output terminal of the input matching circuit 200 is connected to the power transistor 300, for adjusting the radio frequency signal output by the control circuit 100 so that the impedance of the radio frequency signal received by the power transistor 300 is matched with the impedance of the power transistor 300.

[0115] Specifically, an input matching circuit 200 is set at the input terminal of the power transistor 300. The input matching circuit 200 transforms the relatively small complex input impedance of the power transistor 300 into an impedance value that matches the signal source, thereby achieving conjugate matching, maximizing power transmission, reducing signal reflection, and effectively improving circuit stability, avoiding the risk of self-oscillation. At the same time, it also needs to take into account the gain characteristics of the power transistor 300, ensure flat gain within the frequency band, and minimize its own losses to improve overall efficiency. In addition, it also needs to have a certain harmonic suppression capability to improve the linearity of the power amplifier.

[0116] Specifically, the output of the input matching circuit 200 is connected to the gate of the power transistor 300.

[0117] In some embodiments, this application also provides an radio frequency power supply, including the power amplifier circuit described above.

[0118] In this embodiment, a dedicated leakage protection circuit is set in the RF power supply. When the drain voltage of the power transistor 300 in the RF power supply is detected to exceed the set safety threshold, protective measures are quickly taken. By reducing the output power of the RF link of the power transistor 300 and shutting down the RF link, the power transistor 300 is protected from damage, thereby improving the reliability of the power transistor 300 and extending its service life.

[0119] In some embodiments, this application also provides a semiconductor device including the radio frequency power supply described above.

[0120] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application.

[0121] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0122] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0123] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0124] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0125] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the appended claims.

[0126] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A leakage voltage protection circuit, characterized in that, The power transistor and the output matching circuit are used to protect the power transistor. The power transistor and the output matching circuit form an RF link. The power transistor is used to amplify the RF signal. The output matching circuit is used to adjust the RF signal amplified by the power transistor and output the RF signal to the load so that the impedance of the RF signal output to the load is matched with the impedance of the load. The leakage protection circuit includes a voltage divider circuit, a comparator circuit, and a control circuit connected in sequence. The voltage divider circuit is connected between the power transistor and the output matching circuit, and is used to divide the drain voltage of the power transistor to obtain a divided voltage. The comparison circuit is used to compare the divided voltage with the threshold voltage, and generate a comparison result signal based on the comparison result of the divided voltage and the threshold voltage; The control circuit is used to control at least one of the on / off state of the radio frequency link and the output power according to the comparison result signal; wherein the output power of the radio frequency link is the power output by the output matching circuit.

2. The leakage protection circuit according to claim 1, characterized in that, The voltage divider circuit includes a first capacitor and a second capacitor; The first terminal of the first capacitor is connected to the drain of the power transistor, and the second terminal of the first capacitor is connected to the input terminal of the comparator circuit. The first terminal of the second capacitor is connected to the second terminal of the first capacitor, and the second terminal of the second capacitor is grounded.

3. The leakage protection circuit according to claim 1, characterized in that, The comparison circuit is a comparator; The first input terminal of the comparator is connected to the output terminal of the voltage divider circuit, the second input terminal of the comparator is connected to the threshold voltage, and the output terminal of the comparator is connected to the input terminal of the control circuit.

4. The leakage protection circuit according to claim 3, characterized in that, The comparator is a high-speed comparator.

5. The leakage protection circuit according to any one of claims 1-4, characterized in that, The control circuit is used to control at least one of the on / off state of the radio frequency link and the output power based on the comparison result signal, including: The control circuit is used to control the RF link to disconnect or control the output power of the RF link to decrease when the comparison result signal indicates that the voltage divider voltage is greater than the threshold voltage.

6. The leakage protection circuit according to any one of claims 1-4, characterized in that, The control circuit is a gain control circuit; The input terminal of the gain control circuit is connected to the output terminal of the comparator circuit, and the output terminal of the gain control circuit is connected to the power transistor. The gain control circuit is used to control the power of the radio frequency signal received by the power transistor, so as to control the output power of the radio frequency link.

7. The leakage protection circuit according to claim 6, characterized in that, The gain control circuit is a digitally controlled attenuator or an analog attenuator.

8. The leakage protection circuit according to any one of claims 1-4, characterized in that, The control circuit is a switch control circuit; The input terminal of the switch control circuit is connected to the output terminal of the comparator circuit, and the output terminal of the switch control circuit is connected to the power transistor. The switch control circuit is used to control the on / off state of the radio frequency link.

9. The leakage protection circuit according to any one of claims 1-4, characterized in that, It also includes a logic circuit, the input of which is connected to the output of the comparison circuit, and the output of which is connected to the input of the control circuit. The logic circuit is used to detect and determine the comparison result signal, and send a control signal to the control circuit according to the detection and determination result; wherein, the control signal is used to instruct the control circuit to control at least one of the on / off state of the radio frequency link and the output power.

10. A power amplifier circuit, characterized in that, It includes the leakage protection circuit as described in any one of claims 1-9, the power transistor, and the output matching circuit.

11. The power amplifier circuit according to claim 10, characterized in that, It also includes an input matching circuit; The input terminal of the input matching circuit is connected to the output terminal of the control circuit, and the output terminal of the input matching circuit is connected to the power transistor. It is used to adjust the radio frequency signal output by the control circuit so that the impedance of the radio frequency signal received by the power transistor matches the impedance of the power transistor.

12. A radio frequency power supply, characterized in that, Includes the power amplifier circuit as described in claim 10 or 11.

13. A semiconductor device, characterized in that, Includes the radio frequency power supply as described in claim 12.

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