Low-power-consumption voltage-controlled oscillator based on SOI (Silicon On Insulator) process

Abstract

The invention discloses a low-power-consumption voltage-controlled oscillator based on an SOI (Silicon On Insulator) process, relates to the technical field of integrated circuit design, and is used for solving the technical problem that an existing Colpitts oscillator is too high in power consumption and cannot be applied to a low-power-consumption integrated circuit. The invention discloses a low-power-consumption voltage-controlled oscillator based on an SOI (Silicon On Insulator) process. The low-power-consumption voltage-controlled oscillator comprises a Colpitts resonance circuit, a negative resistance unit and an LC filter network, the negative resistance unit is at least provided with a pair of RC network bias NMOS transistors and a pair of cross-coupled NMOS transistors, and the drain electrodes of the RC network bias NMOS transistors are connected with the Colpitts resonance circuit; the input end of the LC filter network is connected with the source electrodes of the cross-coupled NMOS transistors; the negative resistance unit biases the NMOS transistor through the RC network to introduce a feedback path to form a C-class oscillator structure, the Colpitts resonance circuit generates a first signal, and the first signal passes through the negative resistance unit and is output after common-mode noise is filtered by the LC filter network.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of integrated circuit design, and more particularly, to a low-power voltage-controlled oscillator based on SOI technology. BACKGROUND

[0002] With the development of microelectronics technology, various electronic systems have an increasing demand for low power. In scenarios such as medical implant devices (e.g., cardiac pacemakers), Internet of Things sensor nodes, and the like, devices need to rely on limited-capacity batteries to maintain a working life of several years or even decades. The core path to prolong the battery life is to reduce system power consumption, and the power consumption control of the oscillator as the system clock source is particularly critical.

[0003] Colpitts oscillators are widely used in radio frequency and communication systems due to their high frequency stability, low phase noise, and simple circuit structure. However, due to the single-ended nature and high start-up current requirement of Colpitts oscillators, more power is needed to meet stability, making it difficult to apply to low-power integrated circuits. SUMMARY

[0004] The present application aims to provide a low-power voltage-controlled oscillator based on SOI technology to solve the technical problem of excessive power consumption of existing Colpitts oscillators, which cannot be applied to low-power integrated circuits. In view of this, the present application is implemented through the following scheme.

[0005] The present application provides a low-power voltage-controlled oscillator based on SOI technology, comprising: a Colpitts resonant circuit; a negative resistance unit, at least one pair of RC network biased NMOS transistors and one pair of cross-coupled NMOS transistors are provided, the drain of the RC network biased NMOS transistor is connected with the Colpitts resonant circuit; an LC filter network, the input end is connected with the source of the cross-coupled NMOS transistor; The negative resistance unit introduces a feedback path through the RC network biased NMOS transistor, forming a class C oscillator structure, the Colpitts resonant circuit generates a first signal, the first signal passes through the negative resistance unit and is output after filtering common-mode noise by the LC filter network.

[0006] Compared with the prior art, in the low-power voltage-controlled oscillator based on the SOI process, the Colpitts resonant circuit generates a first signal, the negative resistance unit is used for amplifying the first signal generated by the Colpitts resonant circuit, and the consumption of voltage and current of the oscillator is reduced, and the LC filter network is used for filtering common-mode noise of the first signal to improve the phase noise of the oscillator; specifically, the parasitic capacitance of the circuit using the SOI process is smaller than that of the conventional CMOS process, and the dynamic power consumption caused thereby is smaller; in addition, the buried oxygen layer of the SOI process effectively suppresses the parasitic leakage current path between the source and the drain, and therefore the static power consumption of the circuit using the SOI process is smaller; the negative resistance unit introduces a feedback path by biasing the NMOS transistor through the RC network, and constitutes a class-C oscillator structure; in the class-C oscillator structure, under the condition that the source voltage of the RC network biasing NMOS transistor is unchanged, the feedback constituted by the RC network reduces the gate-source voltage difference of the pair of RC network biasing NMOS transistors, so that the pair of RC network biasing NMOS transistors is more difficult to turn on; further, the feedback constituted by the RC network greatly reduces the conduction angle of the pair of RC network biasing NMOS transistors, the fundamental frequency current is increased, the fundamental frequency voltage amplitude is increased, and the noise injection time is reduced, which is beneficial to noise optimization; further, the quality factor of the class-C oscillator structure constituted by the above technical solution is higher, so that the circuit can significantly reduce the consumption of voltage and current under the condition that the oscillation amplitude and the phase noise level are basically unchanged, thereby achieving the purpose of reducing power consumption. The above LC filter network represents a network composed of an inductor (L) and a capacitor (C), which uses the impedance characteristic difference of the inductor and the capacitor for different frequency signals to realize selective filtering of the signal frequency; the RC network represents a circuit network composed of a resistor (R) and a capacitor (C) to realize signal phase change; through the above technical solution of the present application, the technical problem that the power consumption of the existing Colpitts oscillator is too large and cannot be applied to low-power integrated circuits is solved.

[0007] Further, in the low-power voltage-controlled oscillator based on the SOI process, the RC network biasing NMOS transistor includes a first NMOS transistor and a second NMOS transistor; the cross-coupled NMOS transistor includes a third NMOS transistor and a fourth NMOS transistor. The drains of the first NMOS transistor and the second NMOS transistor are connected to the Colpitts resonant circuit, and the sources of the third NMOS transistor and the fourth NMOS transistor are connected to the input end of the LC filter network.

[0008] Further, in the low-power voltage-controlled oscillator based on the SOI process, the Colpitts resonant circuit includes a first inductor, a first capacitor and a second capacitor; The center tap of the first inductor is connected to a power supply end; The first capacitor and the second capacitor are connected in parallel with the first inductor, and the parallel ports are connected with the drain of the first NMOS transistor and the drain of the second NMOS transistor respectively.

[0009] Further, in the low-power voltage-controlled oscillator based on the SOI process, the first end of the first inductor is connected with the first end of the first capacitor, the second end of the first capacitor is connected with the second end of the second capacitor, and the first end of the second capacitor is connected with the second end of the first inductor. The first end of the first capacitor is connected with the drain of the first NMOS transistor. The first end of the second capacitor is connected with the drain of the second NMOS transistor.

[0010] Further, in the low-power voltage-controlled oscillator based on the SOI process, the negative resistance unit further comprises a third capacitor and a fourth capacitor. The first end of the third capacitor is connected with the drain of the first NMOS transistor, the second end of the third capacitor is connected with the gate of the second NMOS transistor, the first end of the fourth capacitor is connected with the drain of the second NMOS transistor, and the second end of the fourth capacitor is connected with the gate of the first NMOS transistor. The first end of the third capacitor is connected with the first end of the first capacitor and the first end of the first inductor, and the first end of the fourth capacitor is connected with the first end of the second capacitor and the second end of the first inductor.

[0011] Further, in the low-power voltage-controlled oscillator based on the SOI process, the negative resistance unit further comprises a first resistor and a second resistor. The second ends of the first resistor and the second resistor are connected with a bias voltage. The first end of the first resistor is connected with the gate of the first NMOS transistor, and the first end of the first resistor is connected with the second end of the fourth capacitor. The first end of the second resistor is connected with the gate of the second NMOS transistor, and the first end of the second resistor is connected with the second end of the third capacitor.

[0012] Further, in the low-power voltage-controlled oscillator based on the SOI process, the source of the first NMOS transistor is connected with the drain of a third NMOS transistor, and the source of the second NMOS transistor is connected with the drain of a fourth NMOS transistor. The drain of the third NMOS transistor is connected with the gate of the fourth NMOS transistor, and the drain of the fourth NMOS transistor is connected with the gate of the third NMOS transistor.

[0013] Further, in the low-power voltage-controlled oscillator based on SOI process, the body terminal of the first NMOS transistor is connected to the source terminal of the second NMOS transistor, and the body terminal of the second NMOS transistor is connected to the source terminal of the first NMOS transistor; the body terminal of the third NMOS transistor is connected to the drain terminal of the fourth NMOS transistor, and the body terminal of the fourth NMOS transistor is connected to the drain terminal of the third NMOS transistor. The body terminal of the first NMOS transistor is connected to the body terminal of the third NMOS transistor, and the body terminal of the second NMOS transistor is connected to the body terminal of the fourth NMOS transistor; the source terminals of the third NMOS transistor and the fourth NMOS transistor are connected to the input terminal of the LC filter network.

[0014] Further, in the low-power voltage-controlled oscillator based on SOI process, the LC filter network comprises a second inductor and a fifth capacitor. The first terminal of the second inductor is connected to the source terminals of the third NMOS transistor and the fourth NMOS transistor; the second terminal of the second inductor is grounded; the first terminal of the fifth capacitor is connected to the source terminals of the third NMOS transistor and the fourth NMOS transistor; and the second terminal of the fifth capacitor is grounded.

[0015] Further, in the low-power voltage-controlled oscillator based on SOI process, the LC filter network is used to filter common-mode noise of the first signal to improve the phase noise of the oscillator. The negative resistance unit is used to amplify the first signal generated by the Colpitts resonance circuit and reduce the consumption of voltage and current of the oscillator. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings: Figure 1 The structure schematic diagram of the low-power voltage-controlled oscillator based on SOI process; Figure 2 The phase noise schematic diagram in the simulation experiment of the voltage-controlled oscillator.

[0017] Reference signs: Figure 1L1, first inductor; L2, second inductor; M1, first NMOS transistor; M2, second NMOS transistor; M3, third NMOS transistor; M4, fourth NMOS transistor; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; R1, first resistor; R2, second resistor; V B , bias voltage. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0019] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0020] In addition, the terms "first", "second" are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited. The meaning of "several" is one or more, unless otherwise explicitly and specifically limited.

[0021] Colpitts oscillator is widely used in radio frequency and communication system for its high frequency stability, low phase noise and simple circuit structure; however, due to the single-ended characteristic and high starting current requirement of the Colpitts oscillator, more power consumption is needed to meet the stability, which makes it difficult to be applied in low-power integrated circuits.

[0022] In order to solve the above technical problems, the present application provides a low-power voltage-controlled oscillator based on SOI process, comprising a Colpitts resonant circuit, a negative resistance unit and an LC filter network; wherein: The negative resistance unit is provided with at least a pair of RC network biased NMOS transistors and a pair of cross-coupled NMOS transistors, the drain of the RC network biased NMOS transistor is connected with the Colpitts resonant circuit; the input end of the LC filter network is connected with the source of the cross-coupled NMOS transistor; the negative resistance unit introduces a feedback path through the RC network biased NMOS transistor, forming a class C oscillator structure, the Colpitts resonant circuit generates a first signal, the first signal passes through the negative resistance unit and is output after filtering common mode noise by the LC filter network.

[0023] In the low-power voltage-controlled oscillator based on SOI process, the Colpitts resonant circuit generates a first signal, the negative resistance unit is used for amplifying the first signal generated by the Colpitts resonant circuit, and the consumption of voltage and current of the oscillator is reduced, and the LC filter network is used for filtering common-mode noise of the first signal to improve the phase noise of the oscillator. Specifically, the negative resistance unit introduces a feedback path for a pair of RC network bias NMOS transistors through an RC network, and constitutes a class-C oscillator structure. In the class-C oscillator structure, under the condition that the source voltage of the RC network bias NMOS transistor is unchanged, the feedback formed by the RC network reduces the gate-source voltage difference of the pair of RC network bias NMOS transistors, so that the pair of RC network bias NMOS transistors is more difficult to turn on. Further, the feedback formed by the RC network makes the conduction angle of the pair of RC network bias NMOS transistors decrease significantly, the fundamental frequency current increases, the fundamental frequency voltage amplitude increases, and the noise injection time decreases, which is beneficial to noise optimization. Further, since the quality factor of the class-C oscillator structure formed by the above technical solution is higher, the consumption of voltage and current can be significantly reduced under the condition that the oscillation amplitude and the phase noise level are basically unchanged, so as to realize the purpose of reducing power consumption. Through the above technical solution of the present application, the technical problem that the power consumption of the existing Colpitts oscillator is too large and cannot be applied to low-power integrated circuits is solved.

[0024] As a possible implementation, in the low-power voltage-controlled oscillator based on the SOI process of the present application, the RC network biasing NMOS transistor includes a first NMOS transistor M1 and a second NMOS transistor M2; the cross-coupled NMOS transistor includes a third NMOS transistor M3 and a fourth NMOS transistor M4; the drains of the first NMOS transistor M1 and the second NMOS transistor M2 are connected to the Colpitts resonant circuit, and the sources of the third NMOS transistor M3 and the fourth NMOS transistor M4 are connected to the input end of the LC filter network. In the case of using the technical solution, the negative resistance unit includes the first NMOS transistor M1, the second NMOS transistor M2, the third NMOS transistor M3, and the fourth NMOS transistor M4; based on the structure of the negative resistance unit, the negative resistance unit introduces a feedback path for the first NMOS transistor M1 and the second NMOS transistor M2 through the RC network, and constitutes a class-C oscillator structure; in the class-C oscillator structure, under the condition that the source voltage of the first NMOS transistor M1 and the second NMOS transistor M2 is unchanged, the feedback constituted by the RC network reduces the gate-source voltage difference of the first NMOS transistor M1 and the second NMOS transistor M2, so that the first NMOS transistor M1 and the second NMOS transistor M2 are more difficult to turn on; further, the feedback constituted by the RC network greatly reduces the conduction angle of the first NMOS transistor M1 and the second NMOS transistor M2, the fundamental frequency current becomes larger, the fundamental frequency voltage amplitude becomes larger, and the noise injection time decreases, which is conducive to noise optimization; further, the cross-coupled third NMOS transistor M3 and the fourth NMOS transistor M4 function as a negative resistance in the circuit, and provide energy for the oscillation signal of the oscillator circuit, and continuously amplify the oscillation signal; further, the first NMOS transistor M1, the second NMOS transistor M2, the third NMOS transistor M3, and the fourth NMOS transistor M4 can use the adaptive body biasing technology, and dynamically adjust the body bias voltage V B The corresponding transistor threshold voltage is periodically reduced, so as to realize the reduction of the power supply voltage.

[0025] As a possible implementation, in the low-power voltage-controlled oscillator based on the SOI process, the Colpitts resonant circuit comprises a first inductor L1, a first capacitor C1 and a second capacitor C2; a center tap of the first inductor L1 is connected to a power supply end; the first capacitor C1 and the second capacitor C2 are connected in parallel with the first inductor L1, and parallel ports are respectively connected to a drain of a first NMOS transistor M1 and a drain of a second NMOS transistor M2. In the case of adopting the technical solution, the above elements form a parallel LC resonant tank, two capacitors (the first capacitor C1 and the second capacitor C2) form a feedback by voltage division, a part of a signal is fed back to the NMOS transistor, and a 180° phase shift is generated by the two capacitors in series. The phase-shifted signal generates a 180° phase shift again through the voltage division of the capacitors, thereby generating the required positive feedback, so that the resonator can generate an oscillation signal of a certain frequency.

[0026] As a possible implementation, in the low-power voltage-controlled oscillator based on the SOI process, the negative resistance unit further comprises a third capacitor C3, a fourth capacitor C4, a first resistor R1 and a second resistor R2; a first end of the third capacitor C3 is connected to a drain of the first NMOS transistor M1; a second end of the third capacitor C3 is connected to a gate of the second NMOS transistor M2; a first end of the fourth capacitor C4 is connected to a drain of the second NMOS transistor M2; a second end of the fourth capacitor C4 is connected to a gate of the first NMOS transistor M1; the first end of the third capacitor C3 is connected to a first end of the first capacitor C1 and a first end of the first inductor L1; the first end of the fourth capacitor C4 is connected to a first end of the second capacitor C2 and a second end of the first inductor L1; a second end of the first resistor R1 and a second end of the second resistor R2 are connected to a bias voltage V B ; a first end of the first resistor R1 is connected to a gate of the first NMOS transistor M1; the first end of the first resistor R1 is connected to the second end of the fourth capacitor C4; a first end of the second resistor R2 is connected to a gate of the second NMOS transistor M2; the first end of the second resistor R2 is connected to the second end of the third capacitor C3. In the case of adopting the technical solution, the third capacitor C3 and the first resistor R1, and the fourth capacitor C4 and the second resistor R2 form an RC network respectively, a feedback path is introduced for a pair of RC network biased NMOS transistors through the RC network, and a class C oscillator structure is constituted; in the class C oscillator structure, under the condition that a source voltage of the RC network biased NMOS transistor is unchanged, the feedback constituted by the RC network reduces a gate-source voltage difference of the pair of RC network biased NMOS transistors, so that the pair of RC network biased NMOS transistors is more difficult to turn on; further, the feedback constituted by the RC network greatly reduces a conduction angle of the pair of RC network biased NMOS transistors, a fundamental frequency current is increased, a fundamental frequency voltage amplitude is increased, and a noise injection time is reduced, which is conducive to noise optimization.

[0027] As a possible implementation, in the low-power voltage-controlled oscillator based on SOI process of the present application, the source of the first NMOS transistor M1 is connected to the drain of the third NMOS transistor M3; the source of the second NMOS transistor M2 is connected to the drain of the fourth NMOS transistor M4; the drain of the third NMOS transistor M3 is connected to the gate of the fourth NMOS transistor M4; and the drain of the fourth NMOS transistor M4 is connected to the gate of the third NMOS transistor M3. In this case, the third NMOS transistor M3 and the fourth NMOS transistor M4 form a cross-coupled structure, and the cross-coupled third NMOS transistor M3 and fourth NMOS transistor M4 function as a negative resistance in the circuit, providing energy for the oscillation signal of the oscillator circuit and continuously amplifying the oscillation signal.

[0028] As a possible implementation, in the low-power voltage-controlled oscillator based on SOI process of the present application, the body terminal of the first NMOS transistor M1 is connected to the source of the second NMOS transistor M2, and the body terminal of the second NMOS transistor M2 is connected to the source of the first NMOS transistor M1; the body terminal of the third NMOS transistor M3 is connected to the drain of the fourth NMOS transistor M4, and the body terminal of the fourth NMOS transistor M4 is connected to the drain of the third NMOS transistor M3; the body terminal of the first NMOS transistor M1 is connected to the body terminal of the third NMOS transistor M3, and the body terminal of the second NMOS transistor M2 is connected to the body terminal of the fourth NMOS transistor M4; and the sources of the third NMOS transistor M3 and the fourth NMOS transistor M4 are commonly connected to the input end of the LC filter network. In this case, the periodic forward bias voltage V B of the third NMOS transistor M3 and the fourth NMOS transistor M4 can be realized, and the threshold voltage of the third NMOS transistor M3 and the fourth NMOS transistor M4 is reduced. B In this case, the threshold voltage of the third NMOS transistor M3 and the fourth NMOS transistor M4 is reduced, and the transconductance of the third NMOS transistor M3 and the fourth NMOS transistor M4 is improved; and the reduced threshold voltage of the third NMOS transistor M3 and the fourth NMOS transistor M4 enables the overall circuit to work normally under a lower power supply voltage.

[0029] As a possible implementation, in the low-power voltage-controlled oscillator based on an SOI process of the present invention, an LC filter network includes a second inductor L2 and a fifth capacitor C5; the first end of the second inductor L2 is connected to the source of the third NMOS transistor M3 and the fourth NMOS transistor M4; the second end of the second inductor L2 is grounded; the first end of the fifth capacitor C5 is connected to the source of the third NMOS transistor M3 and the fourth NMOS transistor M4; and the second end of the fifth capacitor C5 is grounded. When this technical solution is adopted, the impedance of the parallel LC network tends to infinity (ideal open circuit) at the designed resonant frequency and presents a finite impedance at other frequencies. Therefore, the network can effectively suppress tail current source noise and blocking common-mode noise of the power supply, reducing the phase noise of the oscillator.

[0030] Furthermore, a simulation experiment was conducted on the low-power voltage-controlled oscillator based on SOI process of the present invention. Specifically, the simulation experiment components of the present invention adopt XMC_55nm_RFSOI process, and a complete orthogonal voltage-controlled oscillator circuit is built based on CadenceIC617 simulation platform under Linux system environment. The simulation experiment uses Spectre RF simulation tool, and sets the power supply voltage VDD to 0.7V, the operating temperature to 27℃, and the bias voltage V B is 0.5V.

[0031] Simulation process: Under the above working conditions, the Spectre RF simulation tool is used to set the corresponding output port at the differential output end of each voltage-controlled oscillator (i.e., the low-power voltage-controlled oscillator based on SOI process of the present invention) and perform PSS+PNOISE simulation. The results are as follows: Figure 2 As shown, Figure 2 The horizontal axis is the offset frequency in Hz, and the vertical axis is the phase noise of the output signal in dBc / Hz. Figure 2 As can be seen, the SOI-based low-power voltage-controlled oscillator of the present invention has a phase noise of -118.2281 dBc / Hz at a 1 MHz frequency offset, with a power consumption of 2.134 mW and an operating frequency of 25 GHz. Simulation results demonstrate that the SOI-based low-power voltage-controlled oscillator of the present invention, by employing adaptive body biasing technology and a Class C oscillator structure, reduces the supply voltage and operating current while maintaining essentially unchanged performance, thereby achieving the goal of reducing power consumption. This makes the SOI-based low-power voltage-controlled oscillator of the present invention suitable for use in low-power integrated circuits.

[0032] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0033] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A low-power voltage-controlled oscillator based on SOI technology, characterized in that: include: Colpitts resonant circuit; a negative resistance unit, comprising at least a pair of RC network biased NMOS transistors and a pair of cross-coupled NMOS transistors, wherein the drains of the RC network biased NMOS transistors are connected to the Colpitts resonant circuit; an LC filter network, an input end of which is connected to the source of the cross-coupled NMOS transistor; The negative resistance unit introduces a feedback path by biasing the NMOS transistor through an RC network to form a class C oscillator structure. The Colpitts resonant circuit generates a first signal, which passes through the negative resistance unit and is output after filtering common-mode noise by the LC filter network.

2. The low-power voltage-controlled oscillator based on SOI technology according to claim 1, characterized in that: The RC network biased NMOS transistor includes a first NMOS transistor and a second NMOS transistor; the cross-coupled NMOS transistor includes a third NMOS transistor and a fourth NMOS transistor; The drains of the first and second NMOS transistors are connected to the Colpitts resonant circuit, and the sources of the third and fourth NMOS transistors are connected to the input end of the LC filter network.

3. The low-power voltage-controlled oscillator based on SOI technology according to claim 1 or 2, characterized in that: The Colpitts resonant circuit includes a first inductor, a first capacitor and a second capacitor; The center tap of the first inductor is connected to the power supply terminal; The first capacitor and the second capacitor are connected in parallel with the first inductor, and the parallel ports are connected to the drain of the first NMOS transistor and the drain of the second NMOS transistor respectively.

4. The low-power voltage-controlled oscillator based on SOI technology according to claim 3, characterized in that: The first end of the first inductor is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the second end of the second capacitor, and the first end of the second capacitor is connected to the second end of the first inductor; A first end of the first capacitor is connected to the drain of the first NMOS transistor; A first end of the second capacitor is connected to the drain of the second NMOS transistor.

5. The low-power voltage-controlled oscillator based on SOI technology according to claim 4, characterized in that: The negative resistance unit further includes a third capacitor and a fourth capacitor; A first end of the third capacitor is connected to the drain of the first NMOS transistor; a second end of the third capacitor is connected to the gate of the second NMOS transistor; a first end of the fourth capacitor is connected to the drain of the second NMOS transistor; a second end of the fourth capacitor is connected to the gate of the first NMOS transistor; The first end of the third capacitor is connected to the first end of the first capacitor and the first end of the first inductor; the first end of the fourth capacitor is connected to the first end of the second capacitor and the second end of the first inductor.

6. The low-power voltage-controlled oscillator based on SOI technology according to claim 5, characterized in that: The negative resistance unit further includes a first resistor and a second resistor; The second ends of the first resistor and the second resistor are connected to a bias voltage; The first end of the first resistor is connected to the gate of the first NMOS transistor; the first end of the first resistor is connected to the second end of the fourth capacitor; The first end of the second resistor is connected to the gate of the second NMOS transistor; the first end of the second resistor is connected to the second end of the third capacitor.

7. The low-power voltage-controlled oscillator based on SOI technology according to claim 6, characterized in that: The source of the first NMOS transistor is connected to the drain of the third NMOS transistor; the source of the second NMOS transistor is connected to the drain of the fourth NMOS transistor; The drain of the third NMOS transistor is connected to the gate of the fourth NMOS transistor; the drain of the fourth NMOS transistor is connected to the gate of the third NMOS transistor.

8. The low-power voltage-controlled oscillator based on SOI technology according to claim 7, characterized in that: The body terminal of the first NMOS transistor is connected to the source of the second NMOS transistor, and the body terminal of the second NMOS transistor is connected to the source of the first NMOS transistor; the body terminal of the third NMOS transistor is connected to the drain of the fourth NMOS transistor, and the body terminal of the fourth NMOS transistor is connected to the drain of the third NMOS transistor; The body terminal of the first NMOS transistor is connected to the body terminal of the third NMOS transistor, and the body terminal of the second NMOS transistor is connected to the body terminal of the fourth NMOS transistor; the sources of the third NMOS transistor and the fourth NMOS transistor are commonly connected to the input terminal of the LC filtering network.

9. The low-power voltage-controlled oscillator based on SOI technology according to claim 8, characterized in that: The LC filter network includes a second inductor and a fifth capacitor; A first end of the second inductor is connected to the source of the third NMOS transistor and the fourth NMOS transistor; a second end of the second inductor is grounded; a first end of the fifth capacitor is connected to the source of the third NMOS transistor and the fourth NMOS transistor; and a second end of the fifth capacitor is grounded.

10. The low-power voltage-controlled oscillator based on SOI technology according to claim 9, characterized in that: The LC filter network is used to filter the common mode noise of the first signal to improve the oscillator phase noise; The negative resistance unit is used to amplify the first signal generated by the Colpitts resonant circuit and reduce the voltage and current consumption of the oscillator.

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