Amplification circuit with self-adaptive phase modulation function and reference frequency source

Abstract

The invention provides an amplifying circuit with a self-adaptive phase modulation function and a reference frequency source. The amplifying circuit with the self-adaptive phase modulation function comprises a first branch, a second branch and a third branch, wherein the first branch is used for amplifying an input signal and then generating a first voltage; the second branch is used for amplifying the input signal and then generating a second voltage, and the second voltage and the input signal are in phase synchronization; the phase shifter comprises a first capacitor and a transistor, the first end of the first capacitor is connected with the first branch, and the second end of the first capacitor is connected with the drain electrode of the transistor; the phase-locked loop comprises a first input end and a second input end, the first input end is connected with the drain electrode of the transistor, the second input end is connected with the second branch circuit, the output end of the phase-locked loop is connected with the grid electrode of the transistor, and the phase-locked loop is used for adjusting the conduction resistance value of the transistor in the phase shifter according to the phase difference value of the second voltage and the drain electrode voltage of the transistor. The drain voltage of the transistor is in phase synchronization with the second voltage.

Description

Technical Field

[0001] The invention relates to the technical field of high-frequency driving circuits, and in particular to an amplifier circuit and a reference frequency source with an adaptive phase modulation function. Background Art

[0002] In the measurement and control circuits of superconducting and silicon spin quantum computers, high-performance C-band and even millimeter-wave frequency synthesizers are required. In order to reduce the in-band phase noise of the frequency synthesizer, the smaller the division ratio of the phase-locked loop, the better, which requires a high-frequency reference frequency source. The frequency of traditional quartz crystal oscillators is generally below 100MHz, which cannot effectively meet the urgent needs of high-performance measurement and control circuits for quantum computers. Fortunately, the radiating contour MEMS disk resonator with high-frequency and high-Q value characteristics is expected to meet this demand. However, due to the use of a capacitive transduction mechanism, this type of resonator has a large modal resistance, which is in the order of hundreds of KΩ or even MΩ. In order to compensate for the huge insertion loss of the resonator, the peripheral drive circuit requires a very high transimpedance gain, and the phase shift of the circuit at the resonant frequency is required to be about 0 degrees to meet the positive feedback conditions of the oscillator. Generally, the goal of a phase shift of 0 degrees is achieved by setting the bandwidth of the drive circuit to 10 times or more of the resonant frequency. This method is relatively easy to implement for low-frequency (<20MHz) MEMS resonators, but it is difficult to implement for high-frequency (>100MHz) resonators. This is because achieving ultra-high gain and high bandwidth at the same time violates the basic circuit rules. Even if it is achieved, the circuit is very prone to self-excitation. Therefore, facing this design problem, it is urgent to find a high-performance driving circuit solution that can work stably. Summary of the invention

[0003] In view of this, the present invention provides an amplifier circuit and a reference frequency source with an adaptive phase modulation function.

[0004] On the one hand, the present invention provides an amplifier circuit with an adaptive phase modulation function, comprising: a first branch, used to generate a first voltage after amplifying an input signal; a second branch, used to generate a second voltage after amplifying the input signal, and the second voltage is synchronized with the input signal in phase; a phase shifter, comprising a first capacitor and a transistor, the first end of the first capacitor is connected to the first branch, and the second end of the first capacitor is connected to the drain of the transistor; a phase-locked loop, comprising a first input end and a second input end, the first input end is connected to the drain of the transistor, the second input end is connected to the second branch, and the output end of the phase-locked loop is connected to the gate of the transistor, wherein the phase-locked loop is used to: adjust the on-resistance value of the transistor in the phase shifter according to the phase difference between the second voltage and the drain voltage of the transistor, so that the drain voltage of the transistor is synchronized with the second voltage in phase.

[0005] According to an embodiment of the present invention, the input signal is a current signal, and the first branch includes: a first amplifier, used to amplify the current signal to obtain a first voltage; an isolation circuit, connected to the first amplifier and the phase shifter, and the isolation circuit is used to isolate the parasitic capacitance in the phase shifter.

[0006] According to an embodiment of the present invention, the first amplifier includes a circuit structure with gate voltage feedback, and the circuit structure with gate voltage feedback is used to reduce the resistance value of the current signal.

[0007] According to an embodiment of the present invention, the isolation circuit includes a source follower, an input end of the source follower is connected to an output end of the first amplifier, and an output end of the source follower is connected to a first end of the first capacitor.

[0008] According to an embodiment of the present invention, the second branch includes: a second amplifier, used to perform a first-stage amplification of the current signal to obtain a third voltage, the second amplifier has the same circuit structure as the first amplifier, and the gain of the third voltage is less than the first voltage; a third amplifier, used to perform a second-stage amplification of the third voltage to obtain a second voltage, and the third amplifier has a different circuit structure from the second amplifier.

[0009] According to an embodiment of the present invention, the third amplifier includes an amplifier with a current multiplexing structure.

[0010] According to an embodiment of the present invention, a phase-locked loop includes a phase frequency detector, a charge pump and a loop filter, wherein the phase frequency detector includes a first input terminal and a second input terminal, the charge pump is connected to the phase frequency detector and the loop filter, the loop filter is also connected to the gate of the transistor, and the phase frequency detector, the charge pump, the loop filter and the transistor form a negative feedback closed loop.

[0011] According to an embodiment of the present invention, the loop filter is a three-order loop filter, each order loop has a second capacitor, and the capacitance of the second capacitor decreases or increases by one order of magnitude in sequence.

[0012] Another aspect of the present invention provides a reference frequency source, comprising: a resonator for generating a frequency signal; and an amplifier circuit according to any one of the above embodiments, the amplifier circuit being used to amplify the frequency signal and then output it.

[0013] According to an embodiment of the present invention, the output mode of the reference frequency source includes any one of single-ended output and differential output.

[0014] According to the amplifier circuit and reference frequency source with adaptive phase modulation function of the embodiment of the present invention, the tunable phase shifter is composed of a transistor and a capacitor biased in the deep linear region, the on-resistance of the transistor changes with the control voltage output by the phase-locked loop, and the time constant of the phase shifter is adjusted accordingly, so that the leading phase compensation amount introduced by the phase shifter also changes accordingly, thereby realizing the adaptive phase modulation function of the circuit. The phase shift network in the amplifier circuit of the present invention is more streamlined, and can well complete the compensation of the lagging phase shift of the high-gain transimpedance amplifier. The circuit structure is simple, and the introduced noise is lower and the parasitic is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0016] Figure 1 The existing ultra-high gain broadband circuit with adaptive phase compensation is schematically shown;

[0017] Figure 2 Schematically shows Figure 1 Phase shifter circuit in ultra-high gain broadband circuit;

[0018] Figure 3 A system framework diagram of an amplifier circuit with adaptive phase modulation function according to an embodiment of the present invention is schematically shown;

[0019] Figure 4 Schematically illustrates an amplifier circuit with adaptive phase modulation function according to some embodiments of the present invention;

[0020] Figure 5 A schematic diagram shows an RGC transimpedance amplifier circuit according to an embodiment of the present invention;

[0021] Figure 6 A Cherry-Hooper broadband amplifier circuit according to an embodiment of the present invention is schematically shown;

[0022] Figure 7 A phase-locked loop circuit according to an embodiment of the present invention is schematically shown;

[0023] Figure 8 A time domain diagram schematically showing the effect of adjusting the voltage phase of a key node according to an embodiment of the present invention;

[0024] Fig. 9 A frequency domain diagram schematically shows the effect of adjusting the voltage phase of a key node according to an embodiment of the present invention;

[0025] Fig.10 A system framework diagram of a reference frequency source according to an embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0026] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0027] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0028] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0029] Figure 1 The schematic diagram shows an existing ultra-high gain broadband circuit with adaptive phase compensation. Figure 2 Schematically shows Figure 1 Phase shifter circuit in ultra-high gain broadband circuit.

[0030] like Figure 1 As shown, a disclosed ultra-high gain broadband circuit with adaptive phase compensation includes: a transimpedance amplifier 211, a Cherry-Hooper broadband amplifier 212, a tunable phase shifter 224 and an adaptive phase control circuit 220. The transimpedance amplifier 211 uses a method of sacrificing bandwidth in exchange for gain, and sets the upper cutoff frequency at the resonant frequency of the MEMS device, thereby obtaining a 10-fold gain increase. The approximately -45-degree lagging phase shift introduced by the transimpedance amplifier 211 is compensated by the third-stage tunable phase shifter 224. The phase shift amount of the phase shifter 224 is determined by an adaptive control branch output signal V CTRL The broadband transimpedance amplifier 221 and the Cherry-Hooper broadband amplifier 222 in the adaptive control branch jointly generate a voltage signal with no phase lag, which is used as a reference signal for the phase-locked loop. The phase-locked loop locks the output voltage phase of the phase shifter to the reference signal, thereby achieving accurate phase compensation. The specific structure of the phase shifter 224 is as follows: Figure 2As shown in the figure, the leading phase shift is realized by the capacitor / resistor array controlled by the digital code and the MOS tube working in the deep linear region. The gate voltage V of the MOS tube is adjusted in real time through the closed loop. CTRL , the drain-source resistance of the MOS tube will change, and then the phase-locked loop will be used to perform closed-loop, real-time phase shift compensation.

[0031] In the process of implementing the present invention, the inventors found that the above-mentioned prior art solutions have the following technical defects:

[0032] (1) The in-phase proportional amplifier in the tunable phase shifter needs to have a wide bandwidth, such as 1.5 GHz (without introducing phase shift), while providing a large voltage gain, which is difficult to achieve in engineering.

[0033] (2) Digitally controlled capacitor / resistor arrays in tunable phase shifters are difficult to implement, especially capacitor arrays, which have large parasitic capacitances. This can cause the MOS tube of the adjustable resistor to exceed the range during regulation, causing the phase-locked loop to lose lock.

[0034] (3) The specific implementation details of the phase-locked loop circuit are not disclosed. This will not only greatly reduce the practical value of the technical solution, but may also cause many other engineering problems, such as the interface problem between the phase-locked loop and other modules. Therefore, the above technical solution is still far from practical use.

[0035] In order to solve the above technical defects, the present invention proposes a more specific and feasible implementation scheme. Figure 3~Figure 10 Provide explanation.

[0036] Figure 3 A system framework diagram of an amplifier circuit with adaptive phase modulation function according to an embodiment of the present invention is schematically shown; Figure 4 An amplifier circuit with an adaptive phase modulation function according to some embodiments of the present invention is schematically shown.

[0037] like Figure 3 As shown, the amplifier circuit with adaptive phase modulation function may include a first branch 310 , a second branch 320 , and an adaptive loop 330 . The adaptive loop 330 may be composed of a phase shifter 331 and a phase-locked loop 332 .

[0038] The first branch 310 can be used as a gain branch of the amplifier circuit to increase the input signal I IN After amplification, a first voltage V is generated O1 The second branch 320 can be used as a reference branch of the amplifier circuit for the same input signal I IN After amplification, a second voltage V is generated REF , the second voltage V REF With input signal I INPhase synchronization. The second voltage V REF Can be regarded as the first voltage V O1 The phase shifter 331 may include a first capacitor C1 (eg Figure 4 as shown) and transistor M4 (as Figure 4 As shown in FIG. 1 ), the first end of the first capacitor C1 is connected to the first branch 310, and the second end of the first capacitor C1 is connected to the drain of the transistor. The phase-locked loop 332 includes a first input end and a second input end, the first input end is connected to the drain of the transistor M4, the second input end is connected to the second branch 320, and the output end of the phase-locked loop 332 is connected to the gate of the transistor M4. In the amplifier circuit, the phase-locked loop 332 can be configured to generate a voltage according to the second voltage V REF and the drain voltage V OUT The phase difference is adjusted to adjust the on-resistance of transistor M4 in phase shifter 331 so that the drain voltage V OUT and the second voltage V REF Phase synchronization. Drain voltage V OUT This is equivalent to the output voltage of the amplifier circuit. In other words, the output voltage of the entire amplifier circuit can be synchronized with the input signal phase.

[0039] The voltage V generated by the phase-locked loop 332 can be CTRL The gate of the transistor M4 of the control phase shifter 331 is biased in the deep linear region. The on-resistance of the transistor M4 changes with the voltage V CTRL When the output voltage V OUT When the phase of V changes, for example, if the circuit bandwidth is insufficient or the power supply / process / temperature changes, the phase-locked loop 332 senses this change and adjusts the voltage V in real time. CTRL , the time constant of the phase shifter 331 is adjusted accordingly, and thus the leading phase compensation amount introduced by the phase shifter 331 is also changed accordingly, thereby realizing the adaptive phase modulation function of the amplifier circuit. Compared with the disclosed technical solutions, the phase shift network of the embodiment of the present invention is more streamlined, and can well complete the compensation of the lagging phase shift of the high-gain transimpedance amplifier. The circuit structure of the embodiment of the present invention is simple, and the introduced noise is lower and the parasitic is lower.

[0040] like Figure 3 As shown, in an embodiment of the present invention, the first branch 310 may include: a first amplifier 311 and an isolation circuit ( Figure 3 (not shown). The first amplifier 311 can be used to IN Amplify to obtain the first voltage V O1 The first amplifier 311 may be a high-gain cross-group amplifier. The isolation circuit connects the first amplifier 311 and the phase shifter 331, and the isolation circuit is used to isolate the parasitic capacitance in the phase shifter 331. Figure 1The disclosed technical solution, the embodiment of the present invention reduces the Cherry-Hooper amplifier of the gain branch. This is because first, the gain of the reference branch is not large enough, and for the sake of balance, the gain of the gain branch is reduced; second, the high-gain transimpedance amplifier of the gain branch can already provide a large gain, and there is no need for a subsequent Cherry-Hooper amplifier; third, the Cherry-Hooper amplifier is omitted, the circuit is more streamlined, and the noise caused is lower. In addition, an isolation circuit is cascaded at the output of the first amplifier, which can isolate the parasitic capacitance introduced by the subsequent circuit and improve the circuit bandwidth.

[0041] Figure 5 The RGC transimpedance amplifier circuit according to an embodiment of the present invention is schematically shown.

[0042] In some embodiments, the first amplifier 311 may adopt a circuit structure with gate voltage feedback (Regulated Cascode, RGC). In other words, the first amplifier 311 may be an RGC transimpedance amplifier. The RGC circuit structure can effectively reduce the input current signal I IN The resistance value of the circuit is set to achieve broadband. Figure 4 and Figure 5 As shown, the RGC transimpedance amplifier can be composed of transistors M1 and M2 and bias resistors R1, R2 and R3. Through the signal amplification function of the NMOS tube and the load resistor R1, the RGC transimpedance amplifier achieves high gain and broadband. The input current signal I IN The voltage is input at the source of transistor M1, flows through transistor M1 to the load end, and is converted into an output voltage V through load resistor R1. OUT .

[0043] In some embodiments, the isolation circuit may include a source follower, an input end of the source follower is connected to an output end of the first amplifier, and an output end of the source follower is connected to a first end of the first capacitor. Figure 4 As shown, the source follower may be composed of a transistor M3 and a resistor R4 to isolate the parasitics of the subsequent phase shifter 331 .

[0044] Please continue reading Figure 3 In some embodiments, the second branch 320 may include a second amplifier 321 and a third amplifier 322. The second amplifier 321 is used to IN Perform the first stage amplification to obtain the third voltage V O2 The circuit structure of the second amplifier 321 and the first amplifier 311 may be the same, and the third voltage V O2 The gain is less than the first voltage V O1That is, the second amplifier 321 and the first amplifier 311 can use amplifiers with the same circuit structure, but the first amplifier 311 obtains an output signal with a higher gain, while the second amplifier 321 obtains an output signal with a larger bandwidth. The third amplifier 322 is used to O2 Perform the second stage amplification to obtain the second voltage V REF The circuit structure of the third amplifier 322 is different from that of the second amplifier 321. Through the two-stage amplification of the second amplifier 321 and the third amplifier 322, the current signal I IN The synchronous reference voltage, i.e. the second voltage V REF .

[0045] In some embodiments, the third amplifier 322 may include an amplifier with a current multiplexing structure. For example, the third amplifier 322 may be a Cherry-Hooper broadband amplifier. Figure 6 The Cherry-Hooper broadband amplifier circuit according to an embodiment of the present invention is schematically shown.

[0046] like Figure 4 and Figure 6 As shown, the Cherry-Hooper broadband amplifier can be composed of transistors M8~M11, resistors R11~R12 and capacitor C4. Transistors M8 and M9 form the first-stage inverting amplifier, and transistors M10 and M11 form the second-stage inverting amplifier. Resistors R9~R10 and transistor M7 are the bias circuit of the first-stage inverting amplifier, and resistors R11~R12 and capacitor C4 form the feedback circuit of the second-stage inverting amplifier, providing self-bias voltage, expanding bandwidth and increasing gain. The Cherry-Hooper broadband amplifier circuit uses current multiplexing technology to achieve low power consumption and high gain at the same time.

[0047] like Figure 4 As shown, the second branch 320 may also include a capacitor C3, which is connected to the RGC transimpedance amplifier and the Cherry-Hooper broadband amplifier and used as a DC isolation capacitor. Figure 4 As shown, the amplifier circuit may further include a capacitor C2 and a resistor R5, which may function as a potential clamp. Similarly, the capacitor C5 and the capacitor R13 may also function as a potential clamp.

[0048] Figure 7 The phase-locked loop circuit according to an embodiment of the present invention is schematically shown.

[0049] In some embodiments, the phase-locked loop 332 may include a phase frequency detector (PFD), a charge pump (CP), and a loop filter (LF). The phase frequency detector includes two input terminals, the charge pump is connected to the phase frequency detector and the loop filter, the loop filter is also connected to the gate of the transistor, and the phase frequency detector, the charge pump, the loop filter and the transistor form a negative feedback closed loop. In some embodiments, the loop filter is a third-order loop filter, each order loop has a second capacitor, and the capacitance of the second capacitor decreases or increases by one order of magnitude.

[0050] like Figure 4 and Figure 7 As shown, as an example, the frequency detector can be composed of two D flip-flops, an AND gate and a delay module (DELAY) to detect the two signals V at the input end. OUT and V REF The phase difference is 1 / 4, which generates rectangular pulse output voltages UP and DOWN. In order to match the delay, an inverter can be inserted into the UP branch and a CMOS transmission gate TG can be inserted into the DOWN branch. The charge pump can be composed of transistors M12~M17 and two DC current sources I UP and I DN The loop filter can be composed of resistors R14~R15 and capacitors C6~C8.

[0051] like Figure 4 and Figure 7 As shown in Figure 1, the filter is designed to be third order to achieve a good loop filtering effect. The capacitance of capacitors C6~C8 is reduced by one order of magnitude to ensure the stability of the loop. The filter can output a nearly DC output voltage V CTRL , is supplied to the gate of the transistor M4 in the deep linear region of the phase shifter 331, thereby forming a negative feedback closed loop. The description of the phase shifter 331 has been introduced above, and will not be repeated here.

[0052] Figure 8 The time domain diagram schematically shows the key node voltage phase adjustment effect according to an embodiment of the present invention.

[0053] In order to verify the implementation effect of the technical solution of the present invention, the inventor used Cadence design software to Figure 4 The specific implementation circuit of the circuit was simulated transiently. The simulation results are shown in Figure 8 As shown. From top to bottom, they are I IN The corresponding input voltage signal V IN , the output voltage signal V after being amplified by the high gain transimpedance amplifier O1 And the final output voltage signal VOUT .from Figure 8 It can be seen that as the adaptive phase adjustment is completed, the measurement result at 4.9μs shows that V O1 Relative to V IN There is a large phase lag, but V OUT Relative to V IN Phase alignment is achieved, that is, phase compensation is in place.

[0054] Fig. 9 The frequency domain diagram schematically shows the effect of adjusting the voltage phase of a key node according to an embodiment of the present invention.

[0055] In order to further clarify the phase adjustment effect, the inventors also performed simulations in the frequency domain, such as Fig. 9 shown. Fig. 9 The middle dashed line is the output voltage V after the input signal passes through the high gain transimpedance amplifier. O1 Phase frequency response diagram; the solid line is the final output voltage signal V OUT .Depend on Fig. 9 It can be seen that the output voltage V of the transimpedance amplifier O1 Relative to the input signal, it shows a lagging phase shift of about -45 degrees, which is caused by the bandwidth of the transimpedance amplifier being set to 1 times the MEMS resonant frequency. Under the action of the adaptive phase modulation circuit, the final output voltage VOUT of the circuit shows almost the same phase as the input voltage, achieving phase compensation.

[0056] In summary, the amplifier circuits with adaptive phase modulation function in the above-mentioned embodiments have at least the following beneficial effects:

[0057] (1) The phase shift network given is more concise and can effectively compensate for the lagging phase shift of the high gain transimpedance amplifier. The circuit structure is simple, and the introduced noise and parasitics are lower.

[0058] (2) The proposed transimpedance amplifier can adopt an architecture with gate voltage feedback. Compared with the classic current mirror amplifier architecture, the circuit requires lower power consumption at the same gain. In addition, a source follower is introduced at the output of the amplifier to isolate the parasitic capacitance introduced by the subsequent circuit and improve the circuit bandwidth.

[0059] (3) The specific internal design of the adaptive phase-locked loop and the interface circuit design are given, providing a useful reference for ordinary technicians in this industry.

[0060] (4) Compared with the existing technical solutions, the embodiment of the present invention provides a complete transimpedance amplifier circuit with adaptive phase modulation function. The circuit is implemented and simulated. The results show that the circuit performance meets the standard and the adaptive phase modulation function is normal.

[0061] Based on the amplifier circuit with adaptive phase modulation function in the above embodiment, the present invention further provides a reference frequency source having the same technical features and beneficial effects as the amplifier circuit with adaptive phase modulation function in the above embodiment, which will not be described in detail here. Fig.10 A system framework diagram of a reference frequency source according to an embodiment of the present invention is schematically shown.

[0062] like Fig.10 As shown, the amplifier circuit with adaptive phase modulation function provided in the embodiment of the present invention can be used in conjunction with a radio frequency MEMS resonator to form a high-frequency reference frequency source. The resonator can be used to generate a frequency signal I in The amplifier circuit with adaptive phase modulation function can be used to amplify the frequency signal and output V buf The reference frequency source can be used as a frequency synthesizer for higher frequencies such as RF / microwave / millimeter wave. The output of the frequency source can be both single-ended and differential.

[0063] Although the present invention has been shown and described with reference to specific exemplary embodiments of the present invention, it should be understood by those skilled in the art that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents, for example: (1) The RGC structure of the transimpedance amplifier can be replaced with a common source and common gate structure to adapt to different gain and bandwidth requirements while maintaining the stability and low noise characteristics of the circuit. (2) The current multiplexing structure of the Cherry-Hooper amplifier can be replaced with a traditional common source amplifier structure to simplify the design and improve the stability of the circuit, especially in applications that are not sensitive to environmental changes. (3) The source follower of the transimpedance amplifier can be replaced with a common source circuit structure to provide good isolation while providing some voltage gain. (4) The single-ended design in the circuit can be changed to a fully differential form to improve the circuit's ability to resist common mode interference and signal processing speed, which is suitable for high-speed or high-precision application scenarios. (5) The components in the circuit can be manufactured using different materials or processes to optimize performance, cost or reliability, such as using silicon-based semiconductors, gallium arsenide (GaAs) or other compound semiconductor materials. Through these changes and substitutions, the circuit design of the present invention can be more flexibly adapted to different application requirements and technical conditions while maintaining its core advantages and performance characteristics.

[0064] It should be noted that the ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not mean that the element has any ordinal number, nor do they represent the order of one element and another element, or the order of the manufacturing method. The use of these ordinal numbers is only used to make a component with a certain name clearly distinguishable from another component with the same name. Furthermore, the word "comprises" or "includes" does not exclude the existence of elements or steps not listed in the claims. The word "a" or "an" placed before an element does not exclude the existence of multiple such elements.

[0065] The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all functions of some or all components in the relevant equipment according to an embodiment of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0066] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and / or combinations fall within the scope of the present invention.

Claims

1. An amplifier circuit with adaptive phase modulation function, characterized in that: include: The first branch is used to generate a first voltage after amplifying the input signal; A second branch, used for generating a second voltage after amplifying the input signal, wherein the second voltage is synchronized in phase with the input signal; A phase shifter, comprising a first capacitor and a transistor, wherein a first end of the first capacitor is connected to the first branch, and a second end of the first capacitor is connected to a drain of the transistor; A phase-locked loop, comprising a first input terminal and a second input terminal, wherein the first input terminal is connected to the drain of the transistor, the second input terminal is connected to the second branch, and the output terminal of the phase-locked loop is connected to the gate of the transistor, wherein the phase-locked loop is used to: According to the phase difference between the second voltage and the drain voltage of the transistor, the on-resistance value of the transistor in the phase shifter is adjusted to synchronize the drain voltage of the transistor with the second voltage in phase.

2. The amplifier circuit according to claim 1, characterized in that: The input signal is a current signal, and the first branch includes: A first amplifier, used to amplify the current signal to obtain the first voltage; An isolation circuit is connected to the first amplifier and the phase shifter, and the isolation circuit is used to isolate the parasitic capacitance in the phase shifter.

3. The amplifier circuit according to claim 2, characterized in that: The first amplifier includes a circuit structure with gate voltage feedback, and the circuit structure with gate voltage feedback is used to reduce the resistance value of the current signal.

4. The amplifier circuit according to claim 2, characterized in that: The isolation circuit includes a source follower, an input end of the source follower is connected to an output end of the first amplifier, and an output end of the source follower is connected to the first end of the first capacitor.

5. The amplifier circuit according to claim 2, characterized in that: The second branch comprises: a second amplifier, configured to perform a first-stage amplification on the current signal to obtain a third voltage, wherein the second amplifier has the same circuit structure as the first amplifier, and a gain of the third voltage is smaller than the first voltage; The third amplifier is used to perform a second-stage amplification on the third voltage to obtain the second voltage. The circuit structure of the third amplifier is different from that of the second amplifier.

6. The amplifier circuit according to claim 5, characterized in that: The third amplifier includes an amplifier with a current multiplexing structure.

7. The amplifier circuit according to claim 1, characterized in that: The phase-locked loop includes a phase frequency detector, a charge pump and a loop filter, wherein the phase frequency detector includes the first input terminal and the second input terminal, the charge pump is connected to the phase frequency detector and the loop filter, the loop filter is also connected to the gate of the transistor, and the phase frequency detector, the charge pump, the loop filter and the transistor form a negative feedback closed loop.

8. The amplifier circuit according to claim 7, characterized in that: The loop filter is a three-order loop filter, each order loop has a second capacitor, and the capacitance of the second capacitor decreases or increases by one order of magnitude in sequence.

9. A reference frequency source, characterized in that: include: A resonator for generating a frequency signal; According to any one of claims 1 to 8, the amplifier circuit is used to amplify the frequency signal and then output it.

10. The reference frequency source according to claim 9, characterized in that: The output mode of the reference frequency source includes any one of single-ended output and differential output.

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