Voltage-controlled oscillator and wireless sensor

Abstract

The invention relates to the technical field of communication, and provides a voltage-controlled oscillator, a wireless sensor and a voltage-controlled oscillator, the voltage-controlled oscillator comprises an oscillation module, the oscillation module comprises a temperature change compensation sub-module and an oscillation sub-module, and the temperature change compensation sub-module is connected with the oscillation sub-module; the temperature change compensation sub-module is used for adjusting the voltage input to the oscillation sub-module based on temperature feedback; and the oscillation sub-module is used for generating a signal with a target frequency based on a target analog signal and a corresponding relation between the target analog signal and a preset analog signal amplitude and frequency. The temperature change compensation sub-module is introduced into the voltage-controlled oscillator, and the temperature change compensation sub-module compensates the temperature drift by using the frequency temperature characteristics of the inductance-capacitance voltage-controlled oscillator and temperature feedback, that is, the voltage input to the oscillation sub-module is adjusted based on the temperature feedback, and the temperature compensation can be realized without introducing extra power consumption.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular, to a voltage-controlled oscillator and a wireless sensor. Background Art

[0002] Since the energy of a self-powered wireless sensor network comes from the environment and is thus very weak, the power consumption requirements for wireless sensor nodes are extremely stringent, for example, less than 1 mW. A traditional wireless sensor node consists of a power generation device, an energy harvesting and management circuit, an energy storage unit, an MCU, a wireless transceiver, an ADC, and an antenna. Among them, the current of the wireless sensor network transmitter is more than a dozen mA, and at the same time, the modulation method of frequency shift keying (FSK) is adopted, which requires digitizing the signal, that is, performing ADC sampling on the sensor signal. Since wireless sensors are used for data acquisition of temperature sensors, the ambient temperature changes greatly, and the temperature drift of an inductor-capacitor voltage-controlled oscillator will introduce test errors. In order to reduce the temperature drift, temperature compensation is adopted. In traditional temperature compensation schemes, digital-method temperature compensation requires an additional clock signal, and temperature compensation using a comparator and charge and discharge also requires more power consumption. Summary of the Invention

[0003] The present invention provides a voltage-controlled oscillator and a wireless sensor to solve the defect that the temperature drift of an inductor-capacitor voltage-controlled oscillator in the prior art will introduce test errors.

[0004] The present invention provides a voltage-controlled oscillator, including an oscillation module, where the oscillation module includes a temperature-variation compensation sub-module and an oscillation sub-module, and the temperature-variation compensation sub-module is connected to the oscillation sub-module; The temperature-variation compensation sub-module is configured to adjust the voltage input to the oscillation sub-module based on temperature feedback; The oscillation sub-module is configured to generate a signal with a target frequency based on a target analog signal and the corresponding relationship between the target analog signal and the preset analog signal amplitude and frequency.

[0005] According to the voltage-controlled oscillator provided by the present invention, the temperature-variation compensation sub-module includes a negative temperature coefficient resistor and a positive temperature coefficient resistor. One end of the negative temperature coefficient resistor is connected to the input end, the other end of the negative temperature coefficient resistor is respectively connected to one end of the positive temperature coefficient resistor and the oscillation sub-module, and the other end of the positive temperature coefficient resistor is grounded.

[0006] According to the voltage-controlled oscillator provided by the present invention, the oscillation sub-module includes an oscillation unit and a selection unit. The temperature-variation compensation sub-module is respectively connected to the oscillation unit and the selection unit, and the oscillation unit is connected to the selection unit; The selection unit is configured to obtain and respond to a selection instruction, and determine a target relationship corresponding to the selection instruction from the corresponding relationship between the analog signal amplitude and frequency; The oscillation unit is configured to output a signal with a target frequency based on the target relationship.

[0007] According to a voltage-controlled oscillator provided by the present invention, the selection unit includes at least two capacitor sets and at least two inductor sets connected in parallel. Each capacitor set includes a capacitor and two capacitor switches, and the capacitor switches are respectively connected to the capacitor and the oscillation unit. Each inductor set includes an inductor switch and two inductors, and the inductors are respectively connected to the inductor switch and the oscillation unit; The selection unit is configured to determine a target capacitor set and a target inductor set from the capacitor sets and the inductor sets, and control the capacitor switches in the target capacitor set and the inductor switches in the target inductor set to conduct, so as to connect the capacitors in the target capacitor set, the inductors in the target inductor set, and the oscillation unit to form the target relationship.

[0008] According to a voltage-controlled oscillator provided by the present invention, the oscillation unit includes an oscillator and a frequency modulator, and the frequency modulator is connected in parallel with the oscillator; The oscillator is configured to output a signal with a first frequency based on the target relationship; The frequency modulator is configured to adjust the first frequency according to a preset frequency modulation parameter, so that the oscillation unit outputs the signal with the target frequency.

[0009] According to a voltage-controlled oscillator provided by the present invention, the frequency modulator includes at least two varactor diodes connected in parallel, and the bias voltages of different varactor diodes are different; The varactor diode is configured to, when receiving a target bias voltage, adjust its capacitance value from an initial capacitance value to a target capacitance value corresponding to the target bias voltage, so as to adjust the first frequency to the target frequency.

[0010] According to a voltage-controlled oscillator provided by the present invention, the oscillator includes two flying capacitors, two bias resistors, and two control switches. The two flying capacitors are respectively connected in parallel with the selection unit, the two control switches are connected, the two control switches are respectively connected to one of the flying capacitors, and the two bias resistors are respectively connected to a bias voltage terminal and the two flying capacitors.

[0011] According to a voltage-controlled oscillator provided by the present invention, the oscillation module further includes a power supply module, and the power supply module is connected to the oscillation sub-module.

[0012] A voltage-controlled oscillator provided by the present invention, the energy supply module includes a first current tube and a second current tube, and the first current tube and the second current tube are respectively connected to one end of the oscillator sub-module.

[0013] The present invention also provides a wireless sensor, including the voltage-controlled oscillator described in any one of the foregoing items.

[0014] The voltage-controlled oscillator and the wireless sensor provided by the present invention. The voltage-controlled oscillator includes an oscillation module, and the oscillation module includes an oscillator sub-module and a temperature change compensation sub-module. The oscillator sub-module converts a target analog signal into a signal with a target frequency based on the target analog signal and the corresponding relationship between the preset analog signal amplitude and frequency. A temperature change compensation sub-module is introduced into the voltage-controlled oscillator. The temperature change compensation sub-module utilizes the frequency-temperature characteristic of the LC voltage-controlled oscillator and uses temperature feedback to compensate for the temperature drift, that is, based on the temperature feedback, the voltage input to the oscillator sub-module is adjusted, and temperature compensation can be achieved without introducing additional power consumption. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a schematic structural diagram of the voltage-controlled oscillator provided by the present invention.

[0017] Figure 2 It is a schematic diagram showing the change of the frequency of the voltage-controlled oscillator provided by the present invention with temperature before and after temperature compensation.

[0018] Figure 3 It is the control voltage-frequency curve in the voltage-controlled oscillator provided by the present invention.

[0019] Figure 4 It is a schematic structural diagram of the oscillation module provided by the present invention.

[0020] Figure 5 It is the curve of the voltage input to the oscillator sub-module changing with temperature in the embodiment provided by the present invention.

[0021] Marking Explanation: Temperature change compensation sub-module: 1; Oscillator sub-module: 2; Oscillator: 211; Frequency modulator: 212; Capacitor set: 221; Inductor set: 222; Energy supply module: 3; Detailed Embodiments

[0022] To make the objectives, technical solutions and advantages of the present invention more clear, the following will, in conjunction with the accompanying drawings in the present invention, clearly and completely describe the technical solutions in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without any creative efforts shall fall within the scope of protection of the present invention.

[0023] The following will, in conjunction with Figures 1-5 describe the voltage-controlled oscillator of the present invention.

[0024] Figure 1 is a schematic diagram of a voltage-controlled oscillator shown according to an exemplary embodiment. As Figure 1 shown, in an exemplary embodiment, the voltage-controlled oscillator includes an oscillation module. The oscillation module includes a temperature-variation compensation sub-module 1 and an oscillation sub-module 2. The temperature-variation compensation sub-module 1 is connected to the oscillation sub-module 2; The temperature-variation compensation sub-module 1 is configured to adjust the voltage input to the oscillation sub-module 2 based on temperature feedback; The oscillation sub-module 2 is configured to generate a signal with a target frequency based on a target analog signal and the corresponding relationship between the target analog signal and the preset analog signal amplitude and frequency.

[0025] In the embodiments of the present invention, by using the frequency-temperature characteristic of an LC VCO (Inductor-Capacitor Voltage Controlled Oscillator), the temperature-variation compensation sub-module 1 is introduced, and temperature negative feedback is used to compensate for temperature drift, that is, the voltage input to the oscillation sub-module 2 is adjusted based on temperature feedback, without the need to introduce additional power consumption.

[0026] The oscillation sub-module 2 converts the target analog signal into a signal with a target frequency based on the target analog signal and the corresponding relationship between the preset analog signal amplitude and frequency.

[0027] In an exemplary embodiment of the present invention, the temperature-variation compensation sub-module 1 includes a negative temperature coefficient resistor and a positive temperature coefficient resistor. One end of the negative temperature coefficient resistor is connected to the input end. The other end of the negative temperature coefficient resistor is respectively connected to one end of the positive temperature coefficient resistor and the oscillation sub-module 2. The other end of the positive temperature coefficient resistor is grounded.

[0028] In the embodiments of the present invention, since the sensor network tests the temperature sensor data, the temperature of the environment changes greatly, which requires that the frequency of the voltage-controlled oscillator does not change with temperature. An actual voltage-controlled oscillator such as Figure 2As shown by the solid line (uncompensated), as the temperature increases, the frequency decreases, resulting in a frequency error and causing inaccurate test results. For example, Figure 3 shown, Figure 3 is the control voltage-frequency curve provided by the present invention in the voltage-controlled oscillator. It can be seen that the frequency increases as the control voltage increases.

[0029] Therefore, the present invention provides a compensation scheme. As Figure 4 shown, a temperature variation compensation sub-module 1 is provided. The temperature variation compensation sub-module 1 is composed of a negative temperature coefficient resistor R01 and a positive temperature coefficient resistor R02. The voltage Vctrlin is divided by the negative temperature coefficient resistor R01 and the positive temperature coefficient resistor R02 and then outputs the voltage Vctrl to the oscillation sub-module 2. Vctrl is the voltage amplitude of the input signal of the oscillation sub-module 2. The calculation of the voltage Vctrl input to the oscillation sub-module 2 is as follows: Vctrl = Vctrlin * R02 / (R01 + R02) = Vctrlin / (R01 / R02 + 1).

[0030] As the temperature increases, the negative temperature coefficient resistor becomes smaller and the positive temperature coefficient resistor becomes larger. It can be seen that Vctrl becomes larger. The control voltage-temperature curve is as Figure 5 shown. The increase in temperature increases the divided voltage Vctrl, increases the operating frequency, and compensates for the frequency decrease caused by the original temperature. The compensated frequency-temperature curve is as Figure 2 shown by the dashed line in. The negative temperature coefficient resistor can be an HR high-resistance resistor, and the positive temperature coefficient resistor can be a poly resistor.

[0031] In an exemplary embodiment of the present invention, the oscillation sub-module 2 includes an oscillation unit and a selection unit. The temperature variation compensation sub-module 1 is respectively connected to the oscillation unit and the selection unit, and the oscillation unit is connected to the selection unit; The selection unit is configured to obtain and respond to a selection instruction, and determine a target relationship corresponding to the selection instruction from the correspondence between the analog signal amplitude and the frequency; The oscillation unit is configured to output a signal with a target frequency based on the target relationship.

[0032] In an embodiment of the present invention, the selection instruction may be generated by the electronic device after the user determines the target relationship at the electronic device and then sent to the voltage-controlled oscillator, or may be generated by the user after determining the target relationship at the wireless sensor. After the selection unit determines the target relationship, the oscillation unit will determine the corresponding target frequency in the target relationship. In different target relationships, the output frequencies corresponding to the same input signal amplitude are different. That is, in the oscillator sub-module 2, the target frequency range corresponding to the output frequency is determined by the selection unit, and the corresponding target frequency is determined by the oscillation unit within the target frequency range.

[0033] In an exemplary embodiment of the present invention, the selection unit includes at least two capacitor sets 221 connected in parallel and at least two inductor sets 222 connected in parallel. The capacitor set 221 includes a capacitor and two capacitor switches, and the capacitor switches are respectively connected to the capacitor and the oscillation unit. The inductor set 222 includes an inductor switch and two inductors, and the inductors are respectively connected to the inductor switch and the oscillation unit. The selection unit is configured to determine a target capacitor set and a target inductor set from the capacitor set 221 and the inductor set 222, and control the capacitor switches in the target capacitor set and the inductor switches in the target inductor set to conduct, so as to connect the capacitor in the target capacitor set, the inductor in the target inductor set, and the oscillation unit to form the target relationship.

[0034] In an embodiment of the present invention, the capacitor set 221 and the inductor set 222 resonate to generate an oscillation frequency. By setting the capacitor set 221 and the inductor set 222, and by controlling the conduction of the capacitor switches and the inductor switches to connect the capacitor to the oscillation unit and the inductor to the oscillation unit, the selection of the target relationship is controlled by controlling the magnitudes of the total capacitance and the total inductance connected to the oscillator sub-module 2. Since the capacitor stores part of the charge, the larger the total capacitance connected in parallel to the oscillation unit, the lower the target frequency range corresponding to the target relationship presented by the selection unit, thereby realizing the determination of the target relationship.

[0035] As Figure 4 shown, the selection unit includes n capacitor sets 221 composed of n capacitors and 2n capacitor switches. The 2n capacitor switches are respectively S11, S12... Sn1 and Sn2, the n capacitors are respectively C1... and Cn, and the n capacitors are respectively connected in parallel to the oscillator 211 through 2n capacitor switches. The selection unit further includes n inductor sets 222 composed of 2n inductors and n inductor switches. The n inductor switches are respectively S1, S2... Sn, the 2n inductors are respectively L11, L12... Ln1 and Ln2, and the 2n inductors are respectively connected to the inductor switches and the oscillator 211.

[0036] The frequency of the voltage-controlled oscillator is determined by the product of the inductor and the capacitor, i.e., f = 1 / √LC. When the number of frequencies remains unchanged, if the number of inductors increases, the number of capacitors decreases. To achieve wideband coverage, adjusting only the capacitors will introduce a very large number of switch groups.

[0037] Therefore, to reduce the number of switch groups, at least two inductor sets 222 are introduced. For example, previously 16 capacitor sets 221 were set. By adding the inductor sets 222 in the present invention, setting two inductor sets 222 and eight capacitor sets 221 can achieve the same effect as the previous 16 capacitor sets 221, reducing six groups of switches.

[0038] In some embodiments, the target capacitor set may include multiple capacitors. The multiple capacitors may be the capacitors in one capacitor set 221 or the capacitors in multiple capacitor sets 221. Each of the above capacitor sets 221 may include only one capacitor or at least two capacitors, which are specifically set by those skilled in the art according to the actual situation, and the present invention does not make any limitations. Similarly, the setting of the inductors in the target inductor set is set by those skilled in the art according to the actual situation, and the present invention does not make any limitations.

[0039] In an embodiment of the present invention, the oscillation unit includes an oscillator 211 and a frequency modulator 212, and the frequency modulator 212 is connected in parallel with the oscillator 211; The oscillator 211 is configured to output a signal with a first frequency based on the target relationship; The frequency modulator 212 is configured to adjust the first frequency according to a preset frequency modulation parameter so that the oscillation unit outputs the signal with the target frequency.

[0040] In an embodiment of the present invention, the above frequency modulator 212 can adjust the resonance parameters of the internal resonance circuit according to the input voltage, such as capacitance value, inductance value, etc., and then change the frequency of the output signal generated by the oscillator 211 in real time, thereby realizing continuous adjustment of the oscillator sub-module 2.

[0041] By setting the frequency modulator 212 to adjust the first frequency according to a preset frequency modulation parameter, the oscillation unit can output a signal with a target frequency.

[0042] In an exemplary embodiment of the present invention, the frequency modulator 212 includes at least two varactor diodes connected in parallel, and the bias voltages of different varactor diodes are different; The varactor diode is configured to adjust its capacitance value from the initial capacitance value to the target capacitance value corresponding to the target bias voltage when receiving the target bias voltage, so as to adjust the first frequency to the target frequency.

[0043] In the embodiments of the present invention, since at least two varactor diodes are connected in parallel, and the bias voltages of different varactor diodes are different, the linearity of the variable capacitance under a single bias voltage can be improved after at least two varactor diodes are connected in parallel. It can be understood that by connecting varactor diodes with different bias reference voltages in parallel, the curve fluctuation can be reduced, the curve part with better linearity can be expanded, and the working range of the oscillator sub-module 2 can be expanded.

[0044] In the embodiments of the present invention, as Figure 4 shown, the frequency modulator 212 includes four DC-blocking capacitors, four varactor diodes, and four bias resistors. The four DC-blocking capacitors are C1, C2, C3, and C4 respectively, the four varactor diodes are D1, D2, D3, and D4 respectively, and the four bias resistors are R1, R2, R3, and R4 respectively. The negative connection ends of the four varactor diodes are respectively connected to the output end of the temperature change compensation sub-module 1, and the positive connection ends of the four varactor diodes are respectively connected to the four bias resistors and the four DC-blocking capacitors. The DC-blocking capacitors are used to ensure the independence of the first bias voltage connection end VrefL and the second bias voltage connection end VrefH.

[0045] In an exemplary embodiment of the present invention, the oscillator 211 includes two flying capacitors, two bias resistors, and two control switches. The two flying capacitors are respectively connected in parallel with the selection unit, the two control switches are connected, the two control switches are respectively connected to one of the flying capacitors, and the two bias resistors are respectively connected to the bias voltage terminal and the two flying capacitors.

[0046] In the embodiments of the present invention, as Figure 4 shown, the oscillator 211 includes two flying capacitors Cf1 and Cf2, two bias resistors Rb1 and Rb2, and two control switches M1 and M2. The two flying capacitors Cf1 and Cf2 are respectively connected in parallel with the selection unit, the two control switches M1 and M2 are respectively connected to the two flying capacitors Cf1 and Cf2 and the two control switches M1 and M2, and the two bias resistors Rb1 and Rb2 are respectively connected to the bias voltage terminal and the two flying capacitors Cf1 and Cf2.

[0047] In an exemplary embodiment of the present invention, the oscillation module further includes a power supply module 3, and the power supply module 3 is connected to the oscillator sub-module 2.

[0048] In the embodiments of the present invention, the oscillation module further includes a power supply module 3 for supplying power to the oscillator sub-module 2.

[0049] In an exemplary embodiment of the present invention, the power supply module 3 includes a first current tube and a second current tube, and the first current tube and the second current tube are respectively connected to one end of the oscillator sub-module 2.

[0050] In the embodiments of the present invention, as Figure 4 shown in the circuit, since the control switches M1 and M2 alternately operate in the linear and cut-off states, when in the linear state, it is equivalent to a low resistance, thus forming a low resistance between the power supply and the ground, which brings additional power consumption. In order to eliminate the low resistance problem between the power supply and the ground caused by the linear state of the control switches M1 and M2, the first current tube M3 and the second current tube M4 are introduced to provide current. Since the impedance of the current tube is very large, it is equivalent to introducing a high-impedance current source, eliminating the loss of impedance between the power supply and the ground.

[0051] In an exemplary embodiment of the present invention, a wireless sensor is also disclosed, including the voltage-controlled oscillator described in any one of the foregoing items.

[0052] For the wireless sensor provided by the present invention, the temperature change compensation sub-module 1 utilizes the frequency-temperature characteristics of the LC VCO and uses temperature negative feedback to compensate for the temperature drift, that is, based on the temperature feedback, the voltage input to the oscillation sub-module 2 is adjusted, without the need to introduce additional power consumption. The oscillation sub-module 2 converts the target analog signal into a signal with a target frequency based on the target analog signal and the corresponding relationship between the preset analog signal amplitude and frequency.

[0053] In addition, it should be noted that: in the embodiments of the present invention, the terms "first", "second", etc. are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are usually of the same type, and the number of objects is not limited. For example, the first object can be one or multiple.

[0054] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A voltage-controlled oscillator, characterized in that: It includes an oscillation module, the oscillation module includes a temperature variation compensation submodule and an oscillation submodule, and the temperature variation compensation submodule is connected to the oscillation submodule; The temperature variation compensation submodule is used to adjust the voltage input to the oscillation submodule based on temperature feedback; The oscillator module is used to generate a signal with a target frequency based on a target analog signal and a corresponding relationship between the target analog signal and a preset analog signal amplitude and frequency.

2. The voltage controlled oscillator according to claim 1, characterized in that: The temperature variation compensation submodule includes a negative temperature coefficient resistor and a positive temperature coefficient resistor, one end of the negative temperature coefficient resistor is connected to the input end, the other end of the negative temperature coefficient resistor is respectively connected to one end of the positive temperature coefficient resistor and the oscillator submodule, and the other end of the positive temperature coefficient resistor is grounded.

3. The voltage controlled oscillator according to claim 1, characterized in that: The oscillator module includes an oscillator unit and a selection unit, the temperature variation compensation submodule is connected to the oscillator unit and the selection unit respectively, and the oscillator unit is connected to the selection unit; The selection unit is used to obtain and respond to the selection instruction, and determine the target relationship corresponding to the selection instruction from the corresponding relationship between the amplitude and frequency of the analog signal; The oscillation unit is used to output the signal with the target frequency based on the target relationship.

4. The voltage controlled oscillator according to claim 3, characterized in that: The selection unit includes at least two capacitor sets and at least two inductor sets connected in parallel, the capacitor set includes a capacitor and two capacitor switches, the capacitor switches are connected to the capacitor and the oscillation unit respectively, the inductor set includes an inductor switch and two inductors, the inductors are connected to the inductor switch and the oscillation unit respectively; The selection unit is used to determine a target capacitor set and a target inductor set from the capacitor set and the inductor set, and control the capacitor switches in the target capacitor set and the inductor switches in the target inductor set to be turned on, so as to connect the capacitors in the target capacitor set, the inductors in the target inductor set and the oscillation unit to form the target relationship.

5. The voltage controlled oscillator according to claim 3, characterized in that: The oscillation unit comprises an oscillator and a frequency modulator, wherein the frequency modulator is connected in parallel with the oscillator; The oscillator is configured to output a signal having a first frequency based on the target relationship; The frequency modulator is used to adjust the first frequency according to preset frequency modulation parameters so that the oscillation unit outputs the signal with the target frequency.

6. The voltage controlled oscillator according to claim 5, characterized in that: The frequency modulator comprises at least two varactors connected in parallel, and different varactors have different bias voltages; The varactor is used to adjust its capacitance value from an initial capacitance value to a target capacitance value corresponding to the target bias voltage when receiving the target bias voltage, so as to adjust the first frequency to the target frequency.

7. The voltage controlled oscillator according to claim 5, characterized in that: The oscillator includes two flying capacitors, two bias resistors and two control switches. The two flying capacitors are respectively connected in parallel with the selection units, the two control switches are connected, the two control switches are respectively connected to one flying capacitor, and the two bias resistors are respectively connected to the bias voltage terminal and the two flying capacitors.

8. The voltage controlled oscillator according to claim 1, characterized in that: The oscillation module further includes a power supply module, and the power supply module is connected to the oscillation submodule.

9. The voltage controlled oscillator according to claim 8, characterized in that: The energy supply module includes a first current tube and a second current tube, and the first current tube and the second current tube are respectively connected to one end of the oscillator module.

10. A wireless sensor, characterized in that: A voltage controlled oscillator comprising any one of claims 1 to 9.

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