Voltage controlled oscillator with temperature compensation and method of controlling the same

Abstract

The application provides a voltage-controlled oscillator with temperature compensation and a control method thereof, the voltage-controlled oscillator comprising: a resonance unit for adjusting and controlling an oscillation frequency; a cross negative resistance unit for providing negative resistance for the resonance unit to compensate for energy loss generated by the oscillation frequency; a tail current unit for providing a tail current; a temperature compensation unit for receiving a control signal representing temperature change, generating a compensation current based on the control signal, and injecting the compensation current into the tail current unit to compensate for the tail current, thereby stabilizing the output swing of the voltage-controlled oscillator. The application realizes the starting and tuning of the voltage-controlled oscillator through the synergistic cooperation of the resonance unit, the cross negative resistance unit and the tail current unit. Meanwhile, the temperature compensation unit is introduced to inject a compensation current into the tail current, so as to maintain the relatively stable output swing of the voltage-controlled oscillator when the temperature changes, thereby providing more excellent performance for a frequency synthesizer and other systems.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and in particular to a temperature-compensated voltage-controlled oscillator and its control method. Background Technology

[0002] With the rapid development of wireless communication technology, integrated circuits are increasingly widely used in satellite communication, satellite internet, phased array radar, and cellular base station communication systems. In the field of radio frequency chips, the frequency synthesizer system is an indispensable part of wireless communication, and its performance directly affects the overall performance of the circuit system. The voltage-controlled oscillator (VCO), as the core component of the frequency synthesizer system, determines whether the frequency synthesizer system can function properly due to the stability of its output swing.

[0003] In existing technologies, traditional voltage-controlled oscillators (VCOs) lack a corresponding swing temperature compensation mechanism, causing the output swing of the VCO to change drastically with temperature variations, directly affecting the performance of the VCO. The circuit structure of traditional VCOs is relatively simple and cannot output a stable output swing under temperature changes. Summary of the Invention

[0004] This invention provides a temperature-compensated voltage-controlled oscillator and its control method to solve the technical problems such as unstable output swing of the voltage-controlled oscillator when the temperature changes.

[0005] In a first aspect, the present invention provides a temperature-compensated voltage-controlled oscillator, comprising:

[0006] A resonant unit, whose control terminal is connected to a modulation voltage, is used to control the oscillation frequency according to the modulation voltage; A cross-negative resistance unit, which is connected to the resonant unit, is used to provide negative resistance to the resonant unit to compensate for the energy loss that generates the oscillation frequency; Tail current unit, which is connected to the cross negative resistance unit, is used to provide tail current; A temperature compensation unit, connected to the tail current unit, is used to receive a control signal characterizing temperature changes, generate a compensation current in response to the control signal, and inject the compensation current into the tail current unit to compensate the tail current, thereby stabilizing the output swing of the voltage-controlled oscillator.

[0007] In one embodiment of the present invention, the resonant unit includes a first inductor, a second inductor, and a variable capacitor. A first terminal of the first inductor is connected to a power supply voltage, and a first terminal of the first inductor is also connected to a first terminal of the second inductor. A second terminal of the first inductor is connected to a first terminal of the variable capacitor, and a second terminal of the second inductor is connected to a second terminal of the variable capacitor. The control terminal of the variable capacitor is connected to the modulation voltage. The second terminal of the first inductor is a first output terminal of the resonant unit, and the second terminal of the second inductor is a second output terminal of the resonant unit.

[0008] In one embodiment of the present invention, the cross-negative resistance unit includes a first NMOS transistor and a second NMOS transistor. The drain of the first NMOS transistor is connected to the gate of the second NMOS transistor, the drain of the second NMOS transistor is connected to the gate of the first NMOS transistor, and the source of the first NMOS transistor is connected to the source of the second NMOS transistor. The drain of the first NMOS transistor is the first input terminal of the cross-negative resistance unit, the drain of the second NMOS transistor is the second input terminal of the cross-negative resistance unit, and the source of the first NMOS transistor is the output terminal of the cross-negative resistance unit.

[0009] In one embodiment of the present invention, the tail current unit includes a third NMOS transistor and a fourth NMOS transistor. The source of the third NMOS transistor is connected to the drain of the fourth NMOS transistor, the source of the fourth NMOS transistor is grounded, and the gate of the fourth NMOS transistor is connected to a bias voltage. The drain of the third NMOS transistor is the input terminal of the tail current unit, and the gate of the third NMOS transistor is the control terminal of the tail current unit.

[0010] In one embodiment of the present invention, the temperature compensation unit includes a zero temperature coefficient reference subunit and a positive temperature coefficient compensation subunit. The control signal includes a first control signal and a second control signal. The zero temperature coefficient reference subunit is connected to the first control signal and a first current source, and generates a zero temperature coefficient compensation current under the control of the first control signal. The positive temperature coefficient compensation subunit is connected to the second control signal and a second current source, and generates a positive temperature coefficient compensation current under the control of the second control signal. The output terminal of the zero temperature coefficient reference subunit is connected to the output terminal of the positive temperature coefficient compensation subunit. The compensation current is determined based on the zero temperature coefficient compensation current and the positive temperature coefficient compensation current, wherein the first control signal and the second control signal are out of phase.

[0011] In one embodiment of the present invention, the zero temperature coefficient reference subunit includes a fifth NMOS transistor, a sixth NMOS transistor, a seventh NMOS transistor, an eighth NMOS transistor, and a first current source. A first terminal of the first current source is connected to a power supply voltage, and a second terminal of the first current source is connected to the drain of the eighth NMOS transistor. The drain of the eighth NMOS transistor is connected to its gate. The gate of the eighth NMOS transistor is connected to the gates of the seventh, sixth, and fifth NMOS transistors. The source of the eighth NMOS transistor is grounded. The drain of the seventh NMOS transistor is connected to the drain of the sixth NMOS transistor and also to the drain of the fifth NMOS transistor. The source of the seventh NMOS transistor is grounded, the source of the sixth NMOS transistor is grounded, and the source of the fifth NMOS transistor is grounded. The drain of the seventh NMOS transistor is the output terminal of the zero temperature coefficient reference subunit, and the gates of the fifth, sixth, and seventh NMOS transistors are connected to the first control signal.

[0012] In one embodiment of the present invention, the positive temperature coefficient compensation subunit includes a ninth NMOS transistor, a tenth NMOS transistor, an eleventh NMOS transistor, a twelfth NMOS transistor, a second current source, and a first switch. The first terminal of the second current source is connected to the power supply voltage, and the second terminal of the second current source is connected to the drain of the ninth NMOS transistor via the first switch. The drain of the ninth NMOS transistor is connected to the gate of the ninth NMOS transistor. The gate of the ninth NMOS transistor is also connected to the gates of the tenth NMOS transistor, the eleventh NMOS transistor, and the twelfth NMOS transistor. The drain of the tenth NMOS transistor is connected to the drains of the eleventh NMOS transistor and the twelfth NMOS transistor. The source of the ninth NMOS transistor is grounded, the source of the tenth NMOS transistor is grounded, the source of the eleventh NMOS transistor is grounded, and the source of the twelfth NMOS transistor is grounded. The drain of the tenth NMOS transistor is the output terminal of the positive temperature coefficient compensation subunit, and the gates of the tenth NMOS transistor, the eleventh NMOS transistor, and the twelfth NMOS transistor are connected to the second control signal.

[0013] Secondly, this application provides a control method for a temperature-compensated voltage-controlled oscillator, the method comprising: Acquire the modulation voltage and the control signal associated with temperature changes; The oscillation frequency is controlled according to the modulation voltage; Provide negative resistance to compensate for the energy loss that causes the loss of the oscillation frequency; A tail current is provided, and a compensation current is generated based on the control signal to compensate the tail current, thereby stabilizing the output swing of the voltage-controlled oscillator.

[0014] The beneficial effects of this invention are as follows: This invention provides a temperature-compensated voltage-controlled oscillator (VCO) and its control method. The VCO includes: adjusting and controlling the oscillation frequency through a resonant unit; providing negative resistance to the resonant unit through a cross-resistance unit to compensate for energy loss in generating the oscillation frequency through a cross-resistance unit; providing a tail current through a tail current unit; receiving a control signal characterizing temperature changes through a temperature compensation unit; generating a compensation current based on the control signal; and injecting the compensation current into the tail current unit to compensate for the tail current, thereby stabilizing the output swing of the VCO. This invention achieves the start-up and tuning of the VCO through the coordinated operation of the resonant unit, the cross-resistance unit, and the tail current unit. Simultaneously, the introduction of the temperature compensation unit to provide compensation current to the tail current maintains a relatively stable output swing of the VCO when the temperature changes, thus providing superior performance for systems such as frequency synthesizers. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0016] In the attached diagram: Figure 1 This is a block diagram of a temperature-compensated voltage-controlled oscillator provided in an embodiment of the present invention; Figure 2 This is a circuit diagram of a temperature-compensated voltage-controlled oscillator provided in an embodiment of the present invention; Figure 3 The above is an equivalent RLC topology diagram of the voltage-controlled oscillator resonant cavity provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the start-up waveform of the voltage-controlled oscillator provided in an embodiment of the present invention; Figure 5 This is a schematic diagram showing the curve changes of the tail current of the voltage-controlled oscillator with and without temperature compensation enabled in an embodiment of the present invention. Figure 6 This is a schematic diagram showing the curve changes of the output swing of the voltage-controlled oscillator with and without temperature compensation enabled in an embodiment of the present invention.

[0017] Figure reference numerals: 110 - Resonant unit; 120 - Cross negative resistance unit; 130 - Tail current unit; 140 - Temperature compensation unit; Vtune - Modulation voltage; I tial - Tail current; Ip - Compensation current; CS - Control signal; CS1_tcl<2:0> - First control signal; CS2_tcl<2:0> - Second control signal; I S1 - First current source; I S2 -Second current source; V B1 - Bias voltage. Detailed Implementation

[0018] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0021] With the rapid development of wireless communication technology, integrated circuits are increasingly widely used in satellite communication, satellite internet, phased array radar, and cellular base station communication systems. In the field of radio frequency chips, the frequency synthesizer system is an indispensable part of wireless communication, and its performance directly affects the overall performance of the circuit system. The voltage-controlled oscillator (VCO), as the core component of the frequency synthesizer system, determines whether the frequency synthesizer system can function properly due to the stability of its output swing.

[0022] In existing technologies, traditional voltage-controlled oscillators (VCOs) lack a corresponding swing temperature compensation mechanism, causing the output swing of the VCO to fluctuate drastically with temperature changes, directly affecting the performance of the VCO. The relatively simple circuit structure of traditional VCOs makes it difficult to achieve a stable output swing under temperature variations, thus impacting the overall circuit performance.

[0023] To solve the above problems, such as Figure 1 As shown, this application provides a temperature-compensated voltage-controlled oscillator, comprising: The resonant unit 110 has its control terminal connected to the modulation voltage V. tune Used according to the modulation voltage V tune Control the oscillation frequency; The cross negative resistance unit 120 is connected to the resonant unit 110 and is used to provide negative resistance to the resonant unit 110 to compensate for the energy loss that generates the oscillation frequency. Tail current unit 130, which is connected to cross negative resistance unit 120, is used to provide tail current I. tial ; Temperature compensation unit 140, connected to tail current unit 130, receives control signal CS characterizing temperature change, generates compensation current Ip in response to control signal CS, and injects compensation current Ip into tail current unit 130 to compensate tail current I. tial This stabilizes the output swing of the voltage-controlled oscillator.

[0024] In detail, such as Figure 2 As shown, the resonant unit 110 includes a first inductor L1, a second inductor L2, and a variable capacitor C. VAR The first terminal of the first inductor L1 is connected to the power supply voltage VDD, and the first terminal of the first inductor L1 is also connected to the first terminal of the second inductor L2. The second terminal of the first inductor L1 is connected to the variable capacitor C. VAR The first terminal of the second inductor L2 is connected to the second terminal of the variable capacitor C. VAR The second terminal, where the variable capacitor C VAR The control terminal is connected to the modulation voltage V tune The second end of the first inductor L1 is the first output terminal of the resonant unit 110, and the first output terminal of the resonant unit 110 is the negative output terminal LOP of the voltage-controlled oscillator. The second end of the second inductor L2 is the second output terminal of the resonant unit 110, and the second output terminal of the resonant unit 110 is the positive output terminal LON of the voltage-controlled oscillator.

[0025] In detail, such as Figure 2As shown, the cross-negative resistance unit 120 includes a first NMOS transistor M1 and a second NMOS transistor M2. The drain of the first NMOS transistor M1 is connected to the gate of the second NMOS transistor M2, the drain of the second NMOS transistor M2 is connected to the gate of the first NMOS transistor M1, and the source of the first NMOS transistor M1 is connected to the source of the second NMOS transistor M2. The drain of the first NMOS transistor M1 is the first input terminal of the cross-negative resistance unit 120, which is connected to the second terminal of the first inductor L1. The drain of the second NMOS transistor M2 is the second input terminal of the cross-negative resistance unit 120, which is connected to the second terminal of the second inductor L2. The source of the first NMOS transistor M1 is the output terminal of the cross-negative resistance unit 120.

[0026] In detail, such as Figure 2 As shown, the tail current unit 130 includes a third NMOS transistor M3 and a fourth NMOS transistor M4. The source of the third NMOS transistor M3 is connected to the drain of the fourth NMOS transistor M4, the source of the fourth NMOS transistor M4 is grounded, and the gate of the fourth NMOS transistor M4 is connected to a bias voltage V. B1 The drain of the third NMOS transistor M3 is the input terminal of the tail current unit 130, the input terminal of the tail current unit 130 is connected to the source of the first NMOS transistor M1, and the gate of the third NMOS transistor M3 is the control terminal of the tail current unit 130.

[0027] In detail, the temperature compensation unit 140 includes a zero temperature coefficient reference subunit and a positive temperature coefficient compensation subunit. The control signal CS includes a first control signal CS1 and a second control signal CS2_tcl<2:0>. The zero temperature coefficient reference subunit is connected to the first control signal CS1_tcl<2:0> and the first current source I. S1 Under the control of the first control signal CS1_tcl<2:0>, a zero temperature coefficient compensation current In is generated; the positive temperature coefficient compensation subunit is connected to the second control signal CS2_tcl<2:0> and the second current source I. S2 Under the control of the second control signal CS2_tcl<2:0>, a positive temperature coefficient compensation current Im is generated. The output terminal of the zero temperature coefficient reference subunit is connected to the output terminal of the positive temperature coefficient compensation subunit. The compensation current Ip is determined based on the zero temperature coefficient compensation current In and the positive temperature coefficient compensation current Im. The first control signal CS1_tcl<2:0> is inversely related to the second control signal CS2_tcl<2:0>. The first current source I... S1 The current generated by the zero temperature coefficient, the second current source I S2 The current generated by a positive temperature coefficient.

[0028] More in detail, such as Figure 2As shown, the zero temperature coefficient reference subunit includes the fifth NMOS transistor M5, the sixth NMOS transistor M6, the seventh NMOS transistor M7, the eighth NMOS transistor M8, and the first current source I. S1 First current source I S1 The first terminal is connected to the power supply voltage VDD, and the first current source I. S1 The second terminal is connected to the drain of the eighth NMOS transistor M8. The drain of the eighth NMOS transistor M8 is connected to its gate. The gate of the eighth NMOS transistor M8 is connected to the gates of the seventh NMOS transistor M7, the sixth NMOS transistor M6, and the fifth NMOS transistor M5. The source of the eighth NMOS transistor M8 is grounded. The drain of the seventh NMOS transistor M7 is connected to the drain of the sixth NMOS transistor M6. The drain of the seventh NMOS transistor M7 is also connected to the drain of the fifth NMOS transistor M5. The source of the seventh NMOS transistor M7 is grounded. The source of the sixth NMOS transistor M6 is grounded, and the source of the fifth NMOS transistor M5 is also grounded. The drain of the seventh NMOS transistor M7 is the output terminal of the zero-temperature coefficient reference sub-unit, which outputs a zero-temperature coefficient compensation current In. The gates of the fifth NMOS transistor M5, the sixth NMOS transistor M6, and the seventh NMOS transistor M7 are connected to the first control signal CS1_tcl<2:0>. The gate of the fifth NMOS transistor M5 is connected to the first bit of the first control signal CS1_tcl. <0> The gate of the sixth NMOS transistor M6 is connected to the second bit CS1_tcl of the first control signal. <1> The gate of the seventh NMOS transistor M7 is connected to the third bit of the first control signal, CS1_tcl. <2> .

[0029] More in detail, such as Figure 2 As shown, the positive temperature coefficient compensation subunit includes the ninth NMOS transistor M9, the tenth NMOS transistor M10, the eleventh NMOS transistor M11, the twelfth NMOS transistor M12, and the second current source I. S2 and the first switch SW, the second current source I S2 The first terminal is connected to the power supply voltage VDD, and the second current source I. S2The second terminal is connected to the drain of the ninth NMOS transistor M9 after passing through the first switch SW. The drain of the ninth NMOS transistor M9 is connected to the gate of the ninth NMOS transistor M9. The gate of the ninth NMOS transistor M9 is also connected to the gate of the tenth NMOS transistor M10, the gate of the eleventh NMOS transistor M11, and the gate of the twelfth NMOS transistor M12. The drain of the tenth NMOS transistor M10 is connected to the drain of the eleventh NMOS transistor M11 and the drain of the twelfth NMOS transistor M12. The source of the ninth NMOS transistor M9 is grounded, and the source of the tenth NMOS transistor M10 is grounded. The source of NMOS transistor M11 is grounded, and the source of NMOS transistor M12 is grounded. The drain of NMOS transistor M10 is the output terminal of the positive temperature coefficient compensation subunit, which outputs a positive temperature coefficient compensation current Im. The gates of NMOS transistors M10, M11, and M12 are connected to the second control signal CS2_tcl<2:0>. The gate of NMOS transistor M10 is connected to the third bit of the second control signal CS2_tcl. <2> The gate of the eleventh NMOS transistor M11 is connected to the second bit of the second control signal, CS2_tcl. <1> The gate of the twelfth NMOS transistor M12 is connected to the first bit of the second control signal, CS2_tcl. <0> .

[0030] Please refer to Figures 1 to 6 As shown, the working principle of the temperature-compensated voltage-controlled oscillator provided in this application is as follows: like Figure 1-2 As shown, the resonant unit 110 achieves resonant operation through a combination of inductors, capacitors, and a variable capacitor, and can be controlled by the variable capacitor C. VAR The modulation voltage V input to the control terminal tune The oscillation frequency of the voltage-controlled oscillator is adjusted; the cross-negative resistance unit 120 is connected to the resonant unit 110, providing energy loss compensation to the resonant unit 110 through negative resistance; the tail current unit 130 is connected to the cross-negative resistance unit 120, providing power consumption energy to the voltage-controlled oscillator and providing tail current I. tial To maintain the oscillation state of the voltage-controlled oscillator; the temperature compensation unit 140 is connected to the control terminal of the tail current unit 130, and after the temperature changes, it closes the first switch SW and connects the second current source I. S2When the second control signal CS2_tcl<2:0> is high, it controls the ninth NMOS transistor M9, the tenth NMOS transistor M10, the eleventh NMOS transistor M11, and the twelfth NMOS transistor M12 to conduct, thereby adjusting the magnitude of the positive temperature coefficient compensation current Im. At this time, the first control signal CS1_tcl<2:0> is low, the fifth NMOS transistor M5, the sixth NMOS transistor M6, the seventh NMOS transistor M7, and the eighth NMOS transistor M8 are cut off, and the zero temperature coefficient compensation current In is zero. The positive temperature coefficient compensation current Im and the zero temperature coefficient compensation current In are added together to obtain the compensation current Ip, thereby compensating for the drift of the output swing of the voltage-controlled oscillator with temperature.

[0031] like Figure 3 As shown, Figure 3 The above is the equivalent topology of the resonant cavity of the voltage-controlled oscillator in this invention. The output swing formula of the voltage-controlled oscillator is V. tank =(4 / π) I tial / g m As the temperature increases, the tail current I tial The equivalent transconductance g of inductor L and capacitor C remains unchanged. m It will increase with rising temperature, causing the output swing V to increase. tank The current decreases, therefore the tail current I needs to be adjusted. tial Temperature compensation is performed to stabilize the output swing.

[0032] like Figure 4 As shown, Figure 4 This is the starting waveform of the voltage-controlled oscillator in this invention; for example... Figure 5 As shown, when the first control signal CS1_tcl<2:0> is 111 (green curve) and the second control signal CS2_tcl<2:0> is 000, the temperature compensation unit 140 outputs a compensation current Ip with zero temperature coefficient. As the temperature increases, the tail current I... tial The current remains unchanged. When the first control signal CS1_tcl<2:0> is 000 (red curve) and the second control signal CS2_tcl<2:0> is 111, the tail current I is adjusted by the temperature compensation unit 140. tial Provides a compensation current Ip with a positive temperature coefficient, and a tail current I tial Exhibiting a positive temperature coefficient, the equivalent transconductance g of inductance L and capacitance C increases with increasing temperature. m The amplitude increases with increasing temperature, causing the output swing to decrease, which can reduce the tail current I. tial It increases with increasing temperature to provide a more stable output swing.

[0033] like Figure 6As shown, when the temperature compensation unit 140 provides a zero-temperature-coefficient compensation current Ip (red curve), and temperature compensation is not enabled, the peak value of the voltage-controlled oscillator's output swing decreases from 1.49V to 1.21V (red curve) as the temperature rises, exhibiting a significant fluctuation of approximately 18.7%, indicating output swing instability. When the temperature compensation unit 140 provides a positive temperature coefficient compensation current Ip (black curve), the temperature compensation unit 140 adjusts the tail current I... tial With temperature compensation, the peak value of the output swing of the voltage-controlled oscillator varies between 1.376V and 1.463V, with a fluctuation range of only 6.3%, making the output swing of the voltage-controlled oscillator relatively stable.

[0034] This application also provides a control method for a temperature-compensated voltage-controlled oscillator, including: Obtain the modulation voltage V tune and the control signal CS associated with temperature changes; According to the modulation voltage V tune Control the oscillation frequency; Provide negative resistance to compensate for energy loss that causes the oscillation frequency to be lost; Provide tail current I tial A compensation current Ip is generated based on the control signal CS, and the tail current I is compensated based on the compensation current Ip. tial This stabilizes the output swing of the voltage-controlled oscillator.

[0035] This invention provides a temperature-compensated voltage-controlled oscillator (VCO) and its control method. The VCO includes: adjusting and controlling the oscillation frequency through a resonant unit; providing negative resistance to the resonant unit through a cross-resistance unit to compensate for energy loss in generating the oscillation frequency through a cross-resistance unit; providing a tail current through a tail current unit; receiving a control signal characterizing temperature changes through a temperature compensation unit; generating a compensation current based on the control signal; and injecting the compensation current into the tail current unit to compensate for the tail current, thereby stabilizing the output swing of the VCO. This invention achieves the start-up and tuning of the VCO through the coordinated operation of the resonant unit, the cross-resistance unit, and the tail current unit. Simultaneously, the introduction of the temperature compensation unit to provide compensation current to the tail current maintains a relatively stable output swing of the VCO during temperature changes, thus providing superior performance for systems such as frequency synthesizers.

[0036] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A voltage-controlled oscillator with temperature compensation, characterized in that, include: A resonant unit, whose control terminal is connected to a modulation voltage, is used to control the oscillation frequency according to the modulation voltage; A cross-negative resistance unit, which is connected to the resonant unit, is used to provide negative resistance to the resonant unit to compensate for the energy loss that generates the oscillation frequency; Tail current unit, which is connected to the cross negative resistance unit, is used to provide tail current; A temperature compensation unit, connected to the tail current unit, is used to receive a control signal characterizing temperature changes, generate a compensation current in response to the control signal, and inject the compensation current into the tail current unit to compensate the tail current, thereby stabilizing the output swing of the voltage-controlled oscillator.

2. The temperature-compensated voltage-controlled oscillator according to claim 1, characterized in that, The resonant unit includes a first inductor, a second inductor, and a variable capacitor. The first terminal of the first inductor is connected to the power supply voltage, and the first terminal of the first inductor is also connected to the first terminal of the second inductor. The second terminal of the first inductor is connected to the first terminal of the variable capacitor, and the second terminal of the second inductor is connected to the second terminal of the variable capacitor. The control terminal of the variable capacitor is connected to the modulation voltage. The second terminal of the first inductor is the first output terminal of the resonant unit, and the second terminal of the second inductor is the second output terminal of the resonant unit.

3. The temperature-compensated voltage-controlled oscillator according to claim 1, characterized in that, The cross-negative resistance unit includes a first NMOS transistor and a second NMOS transistor. The drain of the first NMOS transistor is connected to the gate of the second NMOS transistor, the drain of the second NMOS transistor is connected to the gate of the first NMOS transistor, and the source of the first NMOS transistor is connected to the source of the second NMOS transistor. The drain of the first NMOS transistor is the first input terminal of the cross-negative resistance unit, the drain of the second NMOS transistor is the second input terminal of the cross-negative resistance unit, and the source of the first NMOS transistor is the output terminal of the cross-negative resistance unit.

4. The temperature-compensated voltage-controlled oscillator according to claim 1, characterized in that, The tail current unit includes a third NMOS transistor and a fourth NMOS transistor. The source of the third NMOS transistor is connected to the drain of the fourth NMOS transistor, the source of the fourth NMOS transistor is grounded, and the gate of the fourth NMOS transistor is connected to a bias voltage. The drain of the third NMOS transistor is the input terminal of the tail current unit, and the gate of the third NMOS transistor is the control terminal of the tail current unit.

5. The temperature-compensated voltage-controlled oscillator according to claim 1, characterized in that, The temperature compensation unit includes a zero temperature coefficient reference subunit and a positive temperature coefficient compensation subunit. The control signal includes a first control signal and a second control signal. The zero temperature coefficient reference subunit is connected to the first control signal and a first current source, and generates a zero temperature coefficient compensation current under the control of the first control signal. The positive temperature coefficient compensation subunit is connected to the second control signal and a second current source, and generates a positive temperature coefficient compensation current under the control of the second control signal. The output terminal of the zero temperature coefficient reference subunit is connected to the output terminal of the positive temperature coefficient compensation subunit. The compensation current is determined based on the zero temperature coefficient compensation current and the positive temperature coefficient compensation current. The first control signal is out of phase with the second control signal.

6. The temperature-compensated voltage-controlled oscillator according to claim 5, characterized in that, The zero-temperature coefficient reference sub-unit includes a fifth NMOS transistor, a sixth NMOS transistor, a seventh NMOS transistor, an eighth NMOS transistor, and a first current source. The first terminal of the first current source is connected to the power supply voltage, and the second terminal of the first current source is connected to the drain of the eighth NMOS transistor. The drain of the eighth NMOS transistor is connected to its gate. The gate of the eighth NMOS transistor is connected to the gates of the seventh NMOS transistor, the sixth NMOS transistor, and the fifth NMOS transistor. The source of the eighth NMOS transistor is grounded. The drain of the seventh NMOS transistor is connected to the drain of the sixth NMOS transistor and also to the drain of the fifth NMOS transistor. The source of the seventh NMOS transistor is grounded, the source of the sixth NMOS transistor is grounded, and the source of the fifth NMOS transistor is grounded. The drain of the seventh NMOS transistor is the output terminal of the zero-temperature coefficient reference sub-unit. The gates of the fifth NMOS transistor, the sixth NMOS transistor, and the seventh NMOS transistor are connected to the first control signal.

7. The temperature-compensated voltage-controlled oscillator according to claim 5, characterized in that, The positive temperature coefficient compensation subunit includes a ninth NMOS transistor, a tenth NMOS transistor, an eleventh NMOS transistor, a twelfth NMOS transistor, a second current source, and a first switch. The first terminal of the second current source is connected to the power supply voltage, and the second terminal of the second current source is connected to the drain of the ninth NMOS transistor via the first switch. The drain of the ninth NMOS transistor is connected to its gate. The gate of the ninth NMOS transistor is also connected to the gates of the tenth, eleventh, and twelfth NMOS transistors. The drain of the tenth NMOS transistor is connected to the drains of the eleventh and twelfth NMOS transistors. The source of the ninth, tenth, eleventh, and twelfth NMOS transistors is grounded. The drain of the tenth NMOS transistor is the output terminal of the positive temperature coefficient compensation subunit, and the gates of the tenth, eleventh, and twelfth NMOS transistors are connected to the second control signal.

8. A control method for a temperature-compensated voltage-controlled oscillator, characterized in that, include: Acquire the modulation voltage and the control signal associated with temperature changes; The oscillation frequency is controlled according to the modulation voltage; Provide negative resistance to compensate for the energy loss that causes the loss of the oscillation frequency; A tail current is provided, and a compensation current is generated based on the control signal to compensate the tail current, thereby stabilizing the output swing of the voltage-controlled oscillator.

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