Temperature-compensated attenuator circuit, radio frequency device, and temperature-compensated attenuation method

Abstract

The present invention relates to the technical field of attenuators, and discloses a temperature-compensated attenuator circuit, a radio frequency device, and a temperature-compensated attenuation method. The temperature-compensated attenuator circuit includes a control voltage generating circuit and an attenuation circuit; the control voltage generating circuit is connected to the attenuation circuit, and the attenuation circuit is used to access the output signal of a target device; the control voltage generating circuit is used to generate a first control signal and a second control signal that varies with the first control signal based on the temperature of the target device, and transmit the first control signal and the second control signal to the attenuation circuit; the attenuation circuit is used to attenuate the output signal of the target device based on the first control signal and the second control signal, and output the attenuated signal; wherein the first control signal is used to control the attenuation amount of the attenuation circuit, and the second control signal is used to maintain the impedance stability between the output signal of the target device and the attenuated signal. The temperature-compensated attenuator circuit provided by the present invention effectively solves the problem of unstable impedance matching of existing temperature-compensated attenuation circuits.

Description

Technical Field

[0001] The present invention relates to the technical field of attenuators, and in particular to a temperature-compensated attenuator circuit, a radio frequency device, and a temperature-compensated attenuation method. Background Art

[0002] With the rapid development of wireless communication technology, RF microwave amplifiers are increasingly used. The output power and gain of RF microwave amplifiers vary with temperature, significantly impacting their performance. Therefore, for operating scenarios with high temperature requirements, it is necessary to incorporate temperature drift control components into RF microwave amplifiers to ensure stable performance.

[0003] Currently, there are three commonly used methods for stabilizing amplifier level and gain. The first is automatic level control (ALC) / automatic gain control (AGC). This method samples the level and power at the output and generates a corresponding control signal, which then adjusts the gain at the input, forming a closed-loop feedback control. In principle, ALC / AGC can be used to adjust for level and gain changes caused by any factor, including temperature drift. However, this circuit structure is relatively complex, and the design and implementation costs are high. Furthermore, its response to temperature changes is slow. In this closed-loop circuit, a failure in any link could lead to abnormal reflections, poor reliability, and compromise the safety of the amplifier system.

[0004] The second method is bias compensation. This approach typically leverages the temperature characteristics of a diode, transistor, or thermistor to adjust the transistor's bias voltage accordingly, stabilizing the quiescent operating current and gain. This method requires individual analysis and design for the specific amplifier circuit. Furthermore, the diodes, transistors, and thermistors used as compensation components typically exhibit temperature nonlinearity, resulting in ideal compensation only within a relatively narrow temperature range.

[0005] The third method is to use a temperature-compensated attenuator, which is a type of attenuator whose attenuation changes linearly with temperature at a certain slope. The temperature-compensated attenuator is usually connected in series with the amplifier to match the temperature characteristics of the two to achieve temperature compensation of the total output power or stabilize the output gain of the amplifier. Temperature-compensated attenuators can be divided into two categories according to their implementation method: active (diode, transistor) and passive (thermistor). However, the passive temperature-compensated attenuator has a narrow attenuation range and poor stability, making it difficult to adapt to various working environments. Although the active temperature-compensated attenuator has a simple structure and is easy to integrate, the existing active temperature-compensated attenuator still has disadvantages such as unstable impedance matching and poor attenuation range adjustment capability. Summary of the Invention

[0006] The embodiments of the present invention provide a temperature-compensated attenuator circuit, a radio frequency device, and a temperature-compensated attenuation method, which solve the problems of unstable impedance matching and poor adjustability of the attenuation range in existing temperature-compensated attenuation circuits.

[0007] In the first aspect, an embodiment of the present invention provides a temperature-compensated attenuator circuit, comprising a control voltage generating circuit and an attenuation circuit; the control voltage generating circuit is connected to the attenuation circuit, and the attenuation circuit is used to access the output signal of a target device; the control voltage generating circuit is used to generate a first control signal and a second control signal that varies with the first control signal based on the temperature of the target device, and transmit the first control signal and the second control signal to the attenuation circuit; the attenuation circuit is used to attenuate the output signal of the target device based on the first control signal and the second control signal, and output the attenuated signal; wherein the first control signal is used to control the attenuation amount of the attenuation circuit, and the second control signal is used to maintain the impedance between the output signal of the target device and the attenuated signal stable.

[0008] Based on the first aspect, in some embodiments, the control voltage generating circuit includes a first control signal generating module and a second control signal generating module, and the control voltage generating circuit is also used to access the first signal, wherein the first signal is used to characterize the temperature of the target device; the input end of the first control signal generating module is connected to the first signal and the second signal, and the output end of the first control signal generating module is connected to the first control end of the attenuation circuit, and the first control signal generating module is used to output the first control signal according to the first signal and the second signal, wherein the second signal is used to adjust the output range of the first control signal; the second control signal generating module is connected to the first control signal generating module, and the output end of the second control signal generating module is connected to the second control end of the attenuation circuit, and the second control signal generating module is used to generate the second control signal according to the first control signal.

[0009] Based on the first aspect, in some embodiments, the first control signal generating module includes a digitally controlled current mirror module, a current mirror module, a first operational amplifier and a first RF transistor, the input end of the digitally controlled current mirror module is connected to the first signal and the second signal, the output end of the digitally controlled current mirror module is connected to the input end of the current mirror module, the output end of the current mirror module is connected to the drain of the first RF transistor and the non-inverting input end of the first operational amplifier, the reverse input end of the first operational amplifier is connected to a first reference voltage, and the output end of the first operational amplifier is connected to the attenuation circuit; the digitally controlled current mirror module is used to control the current replication ratio of the first signal according to the second signal, and output the current after proportional replication, and the current mirror module is used to replicate the current output by the digitally controlled current mirror module.

[0010] Based on the first aspect, in some embodiments, the digitally controlled current mirror module includes M transistors and N switching tubes, wherein M and N are both integers, M>N>0, and the difference between M and N is 2; the X transistors and the X-2 switching tubes form a multi-channel current mirror, the reference current input end of the multi-channel current mirror is connected to the first signal, and the output end is connected to the input end of the current mirror module; the sources of the X-2 switching tubes are respectively connected to X-2 corresponding transistors, the gates of the X-2 switching tubes are connected to the second signal, and the drains of the X-2 switching tubes are connected to the output end of the multi-channel current mirror.

[0011] Based on the first aspect, in some embodiments, the current mirror module includes a first transistor and a second transistor, the first transistor and the second transistor constitute a current mirror, the source of the second transistor is the input end of the current mirror, the source of the first transistor is connected to the drain of the second transistor and is connected to a high level, the common node after the source and gate of the second transistor are connected to each other is connected to the gate of the first transistor, the drain of the first transistor is connected to the first end of the first resistor, and the second end of the first resistor is the output end of the current mirror.

[0012] Based on the first aspect, in some embodiments, the first operational amplifier, the first RF transistor, the digitally controlled current mirror module and the current mirror module form a first feedback loop, and the first feedback loop is used to output the first control signal according to a first feedback quantity, and the first feedback quantity changes with the first signal and the second signal.

[0013] Based on the first aspect, in some embodiments, the second control signal generating module includes a second operational amplifier, a second RF transistor, a third RF transistor, a fourth RF transistor, a second resistor, and a third resistor; the non-inverting input terminal of the second operational amplifier is connected to the first terminal of the second resistor, the inverting input terminal of the second operational amplifier is connected to the second reference voltage, and the output terminal of the second operational amplifier is connected to the gate of the fourth RF transistor; the drain of the second RF transistor is connected to the drain of the fourth RF transistor, the gate of the second RF transistor and the gate of the third RF transistor are connected to the output terminal of the first control signal generating module, the source of the second RF transistor is connected to the source of the third RF transistor, the drain of the fourth RF transistor is connected to the first terminal of the second resistor, the second terminal of the second resistor is connected to a high level, the source of the fourth RF transistor is connected to the drain of the third RF transistor, the first terminal of the third resistor is connected to the source of the third RF transistor, and the second terminal of the third resistor is connected to the drain of the third RF transistor; the second operational amplifier, the second RF transistor, the third RF transistor, and the fourth RF transistor form a second feedback loop, and the second feedback loop is used to output the second control signal according to a second feedback amount, and the second feedback amount changes with the first control signal.

[0014] Based on the first aspect, in some embodiments, the attenuation circuit includes a fifth RF transistor, a sixth RF transistor, a seventh RF transistor and an eighth RF transistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor and an eleventh resistor, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, a seventh transistor and an eighth transistor; the gate of the fifth RF transistor is connected to the first control signal through the fifth resistor, the source is connected to the first end of the first capacitor, and the drain is connected to the drain of the seventh transistor; the gate of the sixth RF transistor is connected to the first control signal through the sixth resistor, the source is connected to the second end of the first capacitor, and the drain is connected to the drain of the eighth transistor; the gate of the seventh RF transistor is connected to the first control signal through the seventh resistor, the source is connected to the first end of the first capacitor, and the drain is connected to the source of the seventh transistor; the gate of the eighth RF transistor is connected to the first control signal through the seventh resistor, the source is connected to the first end of the first capacitor, and the drain is connected to the source of the seventh transistor; The eighth resistor is connected to the first control signal, the source is connected to the second end of the first capacitor, and the drain is connected to the source of the eighth transistor; the gate of the seventh transistor is connected to the second control signal through the fourth resistor, and the gate of the eighth transistor is connected to the second control signal through the eleventh resistor; the second capacitor, the third capacitor and the fourth capacitor are connected in parallel with the first capacitor, the first end of the ninth resistor is connected to the first end of the first capacitor, the second end of the ninth resistor is grounded, the first end of the tenth resistor is connected to the second end of the first capacitor, and the second end of the tenth resistor is grounded; the drain of the fifth RF transistor is connected to the output signal RFIN+ of the target device, the drain of the sixth RF transistor is connected to the output signal RFIN- of the target device, the drain of the seventh RF transistor outputs the attenuated signal RFOUT+, and the drain of the eighth RF transistor outputs the attenuated signal RFOUT-.

[0015] In a second aspect, an embodiment of the present invention provides a radio frequency device, comprising a temperature-compensated attenuator circuit as described in any one of claims 1 to 8 and the target device; the temperature-compensated attenuator circuit is connected to the target device, and the target device outputs a signal to the attenuation circuit in the temperature-compensated attenuator.

[0016] In a third aspect, an embodiment of the present invention provides a temperature-compensated attenuation method, which is applicable to a temperature-compensated attenuator circuit as described in any one of the first aspects above, and is characterized in that it includes: the control voltage generating circuit obtains the temperature of the target device, and generates the first control signal and the second control signal based on the temperature of the target device; the attenuation circuit adjusts the attenuation amount and impedance matching of the temperature-compensated attenuator circuit according to the first control signal and the second control signal.

[0017] In an embodiment of the present application, a control voltage generation circuit receives a first signal that varies with the temperature of a target device and outputs a first control signal based on the first signal, enabling the temperature-compensated attenuator to automatically adjust its attenuation according to temperature. A second signal, digital control information, is used to adjust the output range of the first control signal and ultimately alter the attenuation range of the attenuation circuit, thereby enhancing the adjustability of the attenuation range of the temperature-compensated attenuation circuit. The second control signal output by the control voltage generation circuit, which varies with the first control signal, effectively maintains the stability of the attenuation circuit's output impedance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 1 is a circuit diagram of a temperature-compensated attenuator provided by an embodiment of the present invention;

[0020] Figure 2 is a structural diagram of a control voltage generating circuit provided by an embodiment of the present invention;

[0021] Figure 3 is a structural diagram of a first control signal generating module provided by an embodiment of the present invention;

[0022] Figure 4 1 is an internal structure diagram of a first control signal generating module and a second control signal generating module provided in an embodiment of the present invention;

[0023] Figure 5 is a schematic diagram of an embodiment of a control voltage generating circuit provided by an embodiment of the present invention;

[0024] Figure 6 is a schematic diagram of an attenuation circuit provided by an embodiment of the present invention;

[0025] Figure 7 is a schematic structural diagram of a radio frequency device provided by an embodiment of the present invention;

[0026] Figure 8 This is a flow chart of a temperature-compensated attenuator circuit control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0028] Throughout the present specification, claims, and accompanying drawings, the term "including" and any variations thereof mean "including, but not limited to," and is intended to cover a non-exclusive inclusion and is not limited to the examples recited herein. Furthermore, the terms "first" and "second," etc., are used to distinguish between different items, not to describe a specific order.

[0029] The following is a detailed description of the implementation of the present invention with reference to the accompanying drawings:

[0030] A temperature-compensated attenuator circuit 100 includes a control voltage generating circuit 120 and an attenuation circuit 110. Figure 1 The figure shows a circuit structure diagram of a temperature-compensated attenuator provided by an embodiment of the present invention.

[0031] like Figure 1 As shown, the control voltage generating circuit 120 is connected to the attenuation circuit 110 , and the attenuation circuit 110 is used to access the output signal of the target device 200 .

[0032] The control voltage generation circuit 120 is configured to generate a first control signal and a second control signal that varies with the first control signal based on the temperature of the target device 200, and transmit the first and second control signals to the attenuation circuit 110. The attenuation circuit 110 is configured to attenuate the output signal of the target device 200 based on the first and second control signals, and output the attenuated signal. The first control signal is used to control the attenuation amount of the attenuation circuit 110, and the second control signal is used to maintain a stable impedance between the output signal of the target device 200 and the attenuated signal.

[0033] In some embodiments, as Figure 2 As shown, the control voltage generating circuit 120 includes a first control signal generating module 121 and a second control signal generating module 122. The control voltage generating circuit 120 is further configured to receive a first signal, wherein the first signal is configured to represent the temperature of the target device 200.

[0034] The first control signal generating module 121 receives the first signal and the second signal at its input, and its output is connected to the first control terminal of the attenuation circuit 110. The first control signal generating module 121 is configured to output a first control signal based on the first signal and the second signal, wherein the second signal is used to adjust the output range of the first control signal.

[0035] The second control signal generating module 122 is connected to the first control signal generating module 121, and the output terminal of the second control signal generating module 122 is connected to the second control terminal of the attenuation circuit 110. The second control signal generating module is used to generate a second control signal according to the first control signal.

[0036] In some embodiments, as Figure 3 As shown, the first control signal generating module 121 includes a digitally controlled current mirror module, a current mirror module, a first operational amplifier AMP1 and a first radio frequency transistor MOS_RF1. The input end of the digitally controlled current mirror module is connected to the first signal and the second signal, the output end of the digitally controlled current mirror module is connected to the input end of the current mirror module, the output end of the current mirror module is connected to the drain of the first radio frequency transistor MOS_RF1 and the non-inverting input end of the first operational amplifier AMP1, the inverting input end of the first operational amplifier AMP1 is connected to the first reference voltage Vref1, and the output end of the first operational amplifier AMP1 is connected to the attenuation circuit 110.

[0037] The digitally controlled current mirror module is used to control the current replication ratio of the first signal according to the second signal, and output the current after proportional replication. The current mirror module is used to replicate the current output by the digitally controlled current mirror module.

[0038] Furthermore, the digitally controlled current mirror module includes M transistors and N switch tubes, wherein M and N are both integers, M>N>0, and the difference between M and N is 2.

[0039] X transistors and X-2 switch tubes form a multi-channel current mirror, a reference current input end of the multi-channel current mirror is connected to the first signal, and an output end is connected to the input end of the current mirror module.

[0040] The sources of the X-2 switching tubes are respectively connected to the X-2 corresponding transistors, the gates of the X-2 switching tubes are connected to the second signal, and the drains of the X-2 switching tubes are connected to the output end of the multi-channel current mirror.

[0041] like Figure 4 As shown, in some embodiments, the digitally controlled current mirror module includes a first switch tube MOS_SW1 and a second switch tube MOS_SW2, a third transistor M3, a fourth transistor M4, a fifth transistor M5 and a sixth transistor M6.

[0042] The drain of the first switching transistor MOS_SW1 is connected to the input terminal of the current mirror module, the gate of the first switching transistor MOS_SW1 is connected to the CON1 signal terminal, the source of the first switching transistor MOS_SW1 is connected to the drain of the third transistor M3, the drain of the second switching transistor MOS_SW2 is connected to the drain of the first switching transistor MOS_SW1, the gate of the second switching transistor MOS_SW2 is connected to the CON2 signal terminal, and the source of the second switching transistor MOS_SW2 is connected to the drain of the fourth transistor M4. The sources of the third transistor M3, the fourth transistor M4, the fifth transistor M5, and the sixth transistor M6 are grounded. The common node of the gates of the third transistor M3, the fourth transistor M4, the fifth transistor M5, and the sixth transistor M6 is connected to the drain of the sixth transistor M6. The drain of the fifth transistor M5 is connected to the input terminal of the current mirror module.

[0043] Figure 4 The digitally controlled current mirror module uses the CON1 and CON2 signals as control bits to control the opening and closing of the first switch tube MOS_SW1 and the second switch tube MOS_SW2. Various combinations of the CON1 and CON2 signal control potentials enable the digitally controlled current mirror to have different current replication ratios.

[0044] In some embodiments, a 0 in the CON1 and CON2 signals represents the corresponding switch being off, while a 1 represents the corresponding switch being on. A digital potential of 00 corresponds to the first switch MOS-SW1 being off and the second switch MOS-SW2 being off; a digital potential of 01 corresponds to MOS-SW1 being off and MOS-SW2 being on; a digital potential of 10 corresponds to MOS-SW1 being on and MOS-SW2 being off; and a digital potential of 11 corresponds to MOS-SW1 being on and MOS-SW2 being on. Different digital potentials correspond to different output ranges of the digitally controlled current mirror module. When the same current is input to the input of the digitally controlled current mirror module, the output current of the digitally controlled current mirror is minimum at a digital potential of 00. The output current of the digitally controlled current mirror increases by the same amount at digital potentials of 01 and 10; and the output current of the digitally controlled current mirror is maximum at a digital potential of 11. The range change in the output current of the digitally controlled current mirror causes the output range of the first control signal to change accordingly, ultimately affecting the attenuation range of the attenuation circuit. The attenuation range of the attenuation circuit is positively correlated with the range change in the output current of the digitally controlled current mirror; the larger the output current range, the larger the attenuation range.

[0045] For example, within the TT process angle, Ku-band frequency range, and -55 to 85°C temperature range, when the digital potential of the CON1 and CON2 signals is 00, the attenuation range is 3dB; when the digital potential is 01 or 10, the attenuation range is 4dB; and when the digital potential is 11, the attenuation range is 5dB. Furthermore, at all control potentials, the input and output signal standing waves remain below -17dB, demonstrating the stability of the temperature-compensated attenuator provided by the present invention and its broad application scenarios.

[0046] The current mirror module includes a first transistor M1 and a second transistor M2. The first transistor M1 and the second transistor M2 form a current mirror. The source of the second transistor M2 is the input end of the current mirror. The source of the first transistor M1 is connected to the drain of the second transistor M2 and is connected to a high level. The common node after the source and gate of the second transistor M2 are connected to each other is connected to the gate of the first transistor M1. The drain of the first transistor M1 is connected to the first end of the first resistor R1. The second end of the first resistor R1 is the output end of the current mirror.

[0047] The first operational amplifier AMP1, the first radio frequency transistor M1, the digitally controlled current mirror module and the current mirror module form a first feedback loop. The first feedback loop is used to output a first control signal according to a first feedback amount. The first feedback amount varies with the first signal and the second signal. Figure 4 The signal output from the Vcont voltage terminal is the first control signal. Due to the clamping action of the first operational amplifier AMP1, the drain terminal of the first RF transistor MOS_RF1 is fixed to a constant voltage Vref1. When the output current of the current mirror, i.e., the drain current of the first RF transistor MOS_RF1, changes, the output voltage Vcont of the first operational amplifier AMP1 changes accordingly, based on the volt-ampere characteristic of the MOS transistor.

[0048] In some embodiments, as Figure 4 As shown, the second control signal generating module 122 includes a second operational amplifier AMP2, a second radio frequency transistor MOS_RF2, a third radio frequency transistor MOS_RF3, a fourth radio frequency transistor MOS_RF4, a second resistor R2 and a third resistor R3.

[0049] The non-inverting input terminal of the second operational amplifier AMP2 is connected to the first end of the second resistor R2 , the inverting input terminal of the second operational amplifier AMP2 is connected to the second reference voltage Vref2 , and the output terminal of the second operational amplifier AMP2 is connected to the gate of the fourth RF transistor MOS_RF4 .

[0050] The drain of the second RF transistor MOS_RF2 is connected to the drain of the fourth RF transistor MOS_RF4. The gates of the second RF transistor MOS_RF2 and the third RF transistor MOS_RF3 are connected to the output of the first control signal generating module 121. The source of the second RF transistor MOS_RF2 is connected to the source of the third RF transistor MOS_RF3. The drain of the fourth RF transistor MOS_RF4 is connected to the first end of the second resistor R2. The second end of the second resistor R2 is connected to a high level. The source of the fourth RF transistor MOS_RF4 is connected to the drain of the third RF transistor MOS_RF3. The first end of the third resistor R3 is connected to the source of the third RF transistor MOS_RF3. The second end of the third resistor R3 is connected to the drain of the third RF transistor MOS_RF3. When the size of the third resistor R3 is close to the impedance value of the attenuation circuit, a better matching effect can be achieved. For example, when the size of the third resistor R3 is approximately 50 ohms, the impedance matching value of the attenuation circuit is also stable at approximately 50 ohms.

[0051] The second operational amplifier AMP2, the second RF transistor MOS_RF2, the third RF transistor MOS_RF3 and the fourth RF transistor MOS_RF4 form a second feedback loop, which is used to output a second control signal according to a second feedback amount, and the second feedback amount varies with the first control signal. Figure 5 The signal output from the Vmatch voltage terminal is the second control signal. Due to the clamping effect of the second operational amplifier AMP2, the inverting terminal of the second operational amplifier AMP2 is fixed to a constant voltage Vref2. Resistor R2, the second RF transistor MOS_RF2, the third RF transistor MOS_RF3, the fourth RF transistor MOS_RF4, and resistor R3 form a voltage divider network. The second RF transistor MOS_RF2, the third RF transistor MOS_RF3, and the fourth RF transistor MOS_RF4 can be equivalent to a voltage-controlled channel variable resistor. When the voltage Vcont changes, the channel resistance of the second RF transistor MOS_RF2 and the third RF transistor MOS_RF3 changes accordingly, and the output voltage Vmatch of the second operational amplifier AMP2 changes accordingly. The channel resistance of the fourth RF transistor MOS_RF4 also changes accordingly, maintaining the constant voltage at the non-inverting input terminal of AMP2.

[0052] For example, Figure 5As shown, the current input terminal Ictat is a negative temperature coefficient current input terminal, and Vref1 and Vref2 are reference voltages. The first N-type transistor NMOS1, the second N-type transistor NMOS2, the third N-type transistor NMOS3, and the fourth N-type transistor NMOS4 form a current mirror, which proportionally replicates the input negative temperature coefficient current. The branch where the first N-type transistor NMOS1 and the second N-type transistor NMOS2 are located can be turned on and off by the first switch tube NMOS_SW1 and the second switch tube NMOS_SW2 to achieve different current replication ratios, thereby controlling the temperature-compensated attenuator to achieve different attenuation amounts. The first transistor PMOS1 and the second transistor PMOS2 also form a current mirror, and the output current flows into the drain of the first RF transistor NMOS_RF1 through the first resistor R1. The first resistor R1 can provide a certain voltage drop to ensure that the first transistor PMOS1 operates in the saturation region.

[0053] like Figure 6 As shown, the attenuation circuit 110 includes a fifth RF transistor MOS_RF5, a sixth RF transistor MOS_RF6, a seventh RF transistor MOS_RF7 and an eighth RF transistor MOS_RF8, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and an eleventh resistor R11, a first capacitor C1, a second capacitor C2, a third capacitor C3 and a fourth capacitor C4, a seventh transistor M7 and an eighth transistor M8.

[0054] The gate of the fifth RF transistor MOS_RF5 is connected to the first control signal via a fifth resistor R5, its source is connected to the first end of the first capacitor C1, and its drain is connected to the drain of the seventh transistor M7. The gate of the sixth RF transistor MOS_RF6 is connected to the first control signal via a sixth resistor R6, its source is connected to the second end of the first capacitor C1, and its drain is connected to the drain of the eighth transistor M8. The gate of the seventh RF transistor MOS_RF7 is connected to the first control signal via a seventh resistor R7, its source is connected to the first end of the first capacitor C1, and its drain is connected to the source of the seventh transistor M7. The gate of the eighth RF transistor MOS_RF8 is connected to the first control signal via an eighth resistor R8, its source is connected to the second end of the first capacitor C1, and its drain is connected to the source of the eighth transistor M8.

[0055] The gate of the seventh transistor M7 is connected to the second control signal via the fourth resistor R4, and the gate of the eighth transistor M8 is connected to the second control signal via the eleventh resistor R11. The second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are connected in parallel with the first capacitor C1. A first end of the ninth resistor R9 is connected to the first end of the first capacitor C1, and a second end of the ninth resistor R9 is grounded. A first end of the tenth resistor R10 is connected to the second end of the first capacitor C1, and a second end of the tenth resistor R10 is grounded.

[0056] The drain of the fifth RF transistor MOS_RF5 is connected to the output signal RFIN+ of the target device. The drain of the sixth RF transistor MOS_RF6 is connected to the output signal RFIN- of the target device. The drain of the seventh RF transistor MOS_RF7 outputs the attenuated signal RFOUT+. The drain of the eighth RF transistor MOS_RF8 outputs the attenuated signal RFOUT-. RFIN+ and RFIN-, as well as RFOUT+ and RFOUT-, are differential signals, improving the common-mode rejection ratio of the circuit. The fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are bias resistors used to reduce power loss caused by parasitic capacitance of the MOS transistors at high frequencies.

[0057] The above-mentioned attenuation circuit adopts a π-type structure. In some embodiments, the attenuation circuit can be designed using a variety of structures such as a π-type structure, a T-type structure, and a bridge T-type structure to adapt to different working scenarios.

[0058] like Figure 8 As shown, the present invention also provides a radio frequency device, including the above-mentioned temperature-compensated attenuator circuit and a target device.

[0059] The temperature compensating attenuator is connected to a target device, the target device outputs a signal, and the temperature compensating attenuator attenuates the output signal of the target device based on the temperature of the target device and outputs the attenuated signal.

[0060] The target device can be a radio frequency microwave amplifier, and the temperature-compensated attenuator is used to compensate the output gain of the radio frequency microwave amplifier. The target device can also be a receiving channel or a transmitting channel, and the temperature-compensated attenuator is used to compensate the gain of the transmitting and receiving channels at high and low temperatures.

[0061] Applicable to the above temperature-compensated attenuator, the present invention also proposes a corresponding temperature-compensated attenuator circuit control method, such as Figure 7 As shown, the temperature-compensated attenuator circuit control method may include steps 101 and 102.

[0062] Step 101: a control voltage generating circuit obtains the temperature of a target device, and generates a first control signal and a second control signal based on the temperature of the target device.

[0063] Specifically, the control voltage generating circuit 120 obtains a first signal and a second signal, wherein the first signal represents the temperature of the target device and the second signal adjusts the output range of the control voltage generating circuit. Based on the first signal and the second signal, the control voltage generating circuit 120 generates a first control signal and a second control signal.

[0064] Step 102: The attenuation circuit adjusts the attenuation and impedance matching of the temperature-compensated attenuator circuit according to the first control signal and the second control signal.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A temperature-compensated attenuator circuit, characterized in that: including a control voltage generating circuit and an attenuation circuit; The control voltage generating circuit is connected to the attenuation circuit, and the attenuation circuit is used to access the output signal of the target device; The control voltage generating circuit is configured to generate a first control signal and a second control signal varying with the first control signal based on the temperature of the target device, and transmit the first control signal and the second control signal to the attenuation circuit; The attenuation circuit is configured to attenuate the output signal of the target device based on the first control signal and the second control signal, and output the attenuated signal; The first control signal is used to control the attenuation of the attenuation circuit, and the second control signal is used to maintain a stable impedance between the output signal of the target device and the attenuated signal; The control voltage generating circuit includes a first control signal generating module and a second control signal generating module. The control voltage generating circuit is further configured to receive a first signal, wherein the first signal is configured to represent the temperature of the target device. The input end of the first control signal generating module is connected to the first signal and the second signal, and the output end of the first control signal generating module is connected to the first control end of the attenuation circuit. The first control signal generating module is used to output the first control signal according to the first signal and the second signal, wherein the second signal is used to adjust the output interval of the first control signal; The second control signal generating module is connected to the first control signal generating module, the output end of the second control signal generating module is connected to the second control end of the attenuation circuit, and the second control signal generating module is used to generate the second control signal according to the first control signal; The first control signal generating module includes a digitally controlled current mirror module, a current mirror module, a first operational amplifier, and a first radio frequency transistor; the input end of the digitally controlled current mirror module is connected to the first signal and the second signal; the output end of the digitally controlled current mirror module is connected to the input end of the current mirror module; the output end of the current mirror module is connected to the drain of the first radio frequency transistor and the non-inverting input end of the first operational amplifier; the inverting input end of the first operational amplifier is connected to a first reference voltage; and the output end of the first operational amplifier is connected to the attenuation circuit; The digitally controlled current mirror module is used to control the current replication ratio of the first signal according to the second signal, and output the current after proportional replication. The current mirror module is used to replicate the current output by the digitally controlled current mirror module.

2. The temperature-compensated attenuator circuit according to claim 1, wherein: The digitally controlled current mirror module includes M transistors and N switch tubes, wherein M and N are both integers, M>N>0, and the difference between M and N is 2; The M transistors and the M-2 switch tubes form a multi-channel current mirror, a reference current input end of the multi-channel current mirror is connected to the first signal, and an output end is connected to the input end of the current mirror module; The sources of the M-2 switching tubes are respectively connected to M-2 corresponding transistors, the gates of the M-2 switching tubes are connected to the second signal, and the drains of the M-2 switching tubes are connected to the output end of the multi-channel current mirror.

3. The temperature-compensated attenuator circuit according to claim 1, wherein: The current mirror module includes a first transistor and a second transistor, the first transistor and the second transistor form a current mirror, the source of the second transistor is the input end of the current mirror, the source of the first transistor is connected to the drain of the second transistor and is connected to a high level, the common node after the source and gate of the second transistor are connected to each other is connected to the gate of the first transistor, the drain of the first transistor is connected to the first end of the first resistor, and the second end of the first resistor is the output end of the current mirror.

4. The temperature-compensated attenuator circuit according to claim 1, wherein: The first operational amplifier, the first RF transistor, the digitally controlled current mirror module and the current mirror module form a first feedback loop, and the first feedback loop is used to output the first control signal according to a first feedback amount, and the first feedback amount changes with the first signal and the second signal.

5. The temperature-compensated attenuator circuit according to claim 1, wherein: The second control signal generating module includes a second operational amplifier, a second radio frequency transistor, a third radio frequency transistor, a fourth radio frequency transistor, a second resistor and a third resistor; A non-inverting input terminal of the second operational amplifier is connected to the first end of the second resistor, an inverting input terminal of the second operational amplifier is connected to a second reference voltage, and an output terminal of the second operational amplifier is connected to the gate of the fourth radio frequency transistor; The drain of the second RF transistor is connected to the drain of the fourth RF transistor, the gate of the second RF transistor and the gate of the third RF transistor are connected to the output end of the first control signal generating module, the source of the second RF transistor is connected to the source of the third RF transistor, the drain of the fourth RF transistor is connected to the first end of the second resistor, the second end of the second resistor is connected to a high level, the source of the fourth RF transistor is connected to the drain of the third RF transistor, the first end of the third resistor is connected to the source of the third RF transistor, and the second end of the third resistor is connected to the drain of the third RF transistor; The second operational amplifier, the second RF transistor, the third RF transistor and the fourth RF transistor form a second feedback loop, and the second feedback loop is used to output the second control signal according to a second feedback amount, and the second feedback amount changes with the first control signal.

6. The temperature-compensated attenuator circuit according to claim 1, wherein: The attenuation circuit includes a fifth radio frequency transistor, a sixth radio frequency transistor, a seventh radio frequency transistor and an eighth radio frequency transistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor and an eleventh resistor, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, a seventh transistor and an eighth transistor; The gate of the fifth RF transistor is connected to the first control signal through the fifth resistor, the source is connected to the first end of the first capacitor, and the drain is connected to the drain of the seventh transistor; the gate of the sixth RF transistor is connected to the first control signal through the sixth resistor, the source is connected to the second end of the first capacitor, and the drain is connected to the drain of the eighth transistor; the gate of the seventh RF transistor is connected to the first control signal through the seventh resistor, the source is connected to the first end of the first capacitor, and the drain is connected to the source of the seventh transistor; The gate of the eighth RF transistor is connected to the first control signal through the eighth resistor, the source is connected to the second end of the first capacitor, and the drain is connected to the source of the eighth transistor; The gate of the seventh transistor is connected to the second control signal via the fourth resistor, and the gate of the eighth transistor is connected to the second control signal via the eleventh resistor; the second capacitor, the third capacitor, and the fourth capacitor are connected in parallel with the first capacitor, a first end of the ninth resistor is connected to the first end of the first capacitor, a second end of the ninth resistor is grounded, a first end of the tenth resistor is connected to the second end of the first capacitor, and a second end of the tenth resistor is grounded; The drain of the fifth RF transistor is connected to the output signal RFIN+ of the target device, the drain of the sixth RF transistor is connected to the output signal RFIN- of the target device, the drain of the seventh RF transistor outputs the attenuated signal RFOUT+, and the drain of the eighth RF transistor outputs the attenuated signal RFOUT-.

7. A radio frequency device, characterized in that: Comprising the temperature-compensated attenuator circuit according to any one of claims 1 to 6 and the target device; The temperature-compensated attenuator circuit is connected to the target device, and the target device outputs a signal to the attenuation circuit in the temperature-compensated attenuator.

8. A temperature-compensated attenuation method, applicable to the temperature-compensated attenuator circuit according to any one of claims 1 to 6, characterized in that: include: The control voltage generating circuit acquires the temperature of the target device and generates the first control signal and the second control signal based on the temperature of the target device; The attenuation circuit adjusts the attenuation and impedance matching of the temperature-compensated attenuator circuit according to the first control signal and the second control signal.

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