A voltage-controlled oscillator, chip and electronic device

Abstract

The embodiment of the application provides a voltage-controlled oscillator, an oscillator circuit, a chip and an electronic device, relates to the technical field of communication or radar detection, and can improve the linearity of the voltage-controlled oscillator. The voltage-controlled oscillator comprises a voltage-controlled oscillator resonant cavity, an even harmonic generator circuit and a self-mixing tripler circuit. The voltage-controlled oscillator resonant cavity comprises a voltage change diode array and a first mode switching capacitor. The even harmonic generator circuit comprises a group of cross-coupled tubes, one end of the group of cross-coupled tubes is electrically connected to differential two ends of the voltage-controlled oscillator, and the group of cross-coupled tubes simultaneously serves as an even harmonic generator and is electrically connected to the self-mixing tripler circuit. The self-mixing tripler circuit comprises a differential unit and a resonant cavity, and one end of the self-mixing tripler circuit is electrically connected to the even harmonic generator circuit. The low-frequency voltage-controlled oscillator and the self-mixing tripler circuit realize current multiplexing, the even harmonic generator circuit serves as an even harmonic generator of the self-mixing tripler in addition to serving as negative resistance of the oscillator, and the linearity of the millimeter wave frequency source is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication or radar detection, and in particular to a voltage-controlled oscillator, a chip and an electronic device. BACKGROUND

[0002] In the field of radar ranging and speed measurement, the linearity of the frequency source is required. In the related art, a third-order coupled inductance-capacitance resonance structure is proposed in the scheme for realizing the linearity of the frequency source. By mutual coupling of three inductances, high linearity variation of the capacitance is realized, and a linearity variation of less than 18.8% at a 20 GHz frequency band is realized. Another scheme combines a digitally controlled varactor diode array coarse adjustment with an analog bias diode array fine adjustment, and realizes high linearity of the overall system, and a linearity variation of less than 3% at a 4 GHz frequency band is realized. However, for the millimeter wave radar field, the design of the high linearity frequency source has the following problems: one is that the linearity of the capacitance voltage curve of the varactor diode is poor, and the other is that the internal wiring and the transistor itself contain parasitic capacitance, and the existence of the parasitic capacitance makes it difficult to maintain the linearity. Therefore, there are still technical problems to be solved in the related art. SUMMARY

[0003] The present application aims to at least partly solve one of the problems in the prior art.

[0004] To this end, one purpose of the embodiments of the present application is to provide a voltage-controlled oscillator, a chip and an electronic device, which can improve the linearity of the voltage-controlled oscillator.

[0005] The first technical solution adopted by the present application is:

[0006] A high linearity resonant cavity module, comprising a wide bandwidth resonant circuit, a low bandwidth resonant circuit, an inductive circuit and a switched capacitor module.

[0007] The wide bandwidth resonant circuit comprises a first varactor diode array and a first voltage biasing module; the first varactor diode array is connected with the first voltage biasing module; the low bandwidth resonant circuit comprises a second varactor diode array and a second voltage biasing module; the second varactor diode array is connected with the second voltage biasing module;

[0008] The wide bandwidth resonant circuit is configured to generate a first signal by resonating according to a high bit tuning voltage input to the first varactor diode array and a first bias signal input to the first voltage biasing module, in combination with the inductive circuit and the switched capacitor module; the first signal is a signal at a first preset frequency band;

[0009] The low-bandwidth resonant circuit is used for resonating to generate a second signal according to a low-bit tuning voltage inputted into the second variable capacitance diode array and a second bias signal inputted into the second voltage bias module, in combination with the inductive circuit and the switched capacitor module; the second signal is a signal in a second preset frequency band;

[0010] The switched capacitor module is used for adjusting the first signal or the second signal outputted by the voltage-controlled resonant cavity; the even harmonic generator generates a first even harmonic signal and a second even harmonic signal according to the first signal or the second signal; the frequency mixer generates a first tripler signal according to the first signal and the first even harmonic signal, or generates a second tripler signal according to the second signal and the second even harmonic signal.

[0011] Further, in the embodiment of the application, the first voltage bias module and the second voltage bias module are of the same structure, the first voltage bias module comprises a plurality of first sub-bias modules; the first sub-bias module comprises a first resistor and a second resistor; one end of the first resistor and one end of the second resistor are connected in parallel and then connected to the first bias signal, and the other end of the first resistor is connected to the first variable capacitance diode array; and the other end of the second resistor is connected to the first variable capacitance diode array.

[0012] The second technical solution adopted by the application is:

[0013] Current-reused frequency multiplier-oscillator architecture. Which contains even harmonic generator and self-mixer. Wherein the even harmonic generator is used as the negative resistance circuit of the oscillator at the same time.

[0014] In the embodiment of the application, the even harmonic generator comprises a third resistor, a fourth resistor, a first field effect transistor, a second field effect transistor, a third capacitor, a fourth capacitor and a first external potential; one end of the third capacitor and one end of the third resistor are connected to the gate of the first field effect transistor; one end of the fourth capacitor and one end of the fourth resistor are connected to the gate of the second field effect transistor; the other end of the fifth resistor and the other end of the fourth resistor are connected to the first external potential; the other end of the third capacitor is connected to the drain of the second field effect transistor; and the other end of the fourth capacitor is connected to the drain of the first field effect transistor.

[0015] Further, in the embodiment of the present application, the self-mixer comprises a third field effect tube, a fourth field effect tube, a second external potential, a fifth resistor, a sixth resistor and a third varactor array; one end of the fifth resistor and one end of the sixth resistor are connected with the second external potential; the other end of the fifth resistor is connected with the gate of the third field effect tube; the other end of the sixth resistor is connected with the gate of the fourth field effect tube; the source of the third field effect tube is connected with the source of the first field effect tube; the drain of the third field effect tube and one end of the third varactor array are connected with a high-frequency output end; the drain of the fourth field effect tube and the other end of the third varactor array are connected with a low-frequency output end.

[0016] Further, in the embodiment of the present application, the sixth capacitor and the seventh capacitor are arranged between the self-mixer and the even harmonic generator; one end of the sixth capacitor is connected with the gate of the third field effect tube; the other end of the sixth capacitor is connected with the drain of the first field effect tube; one end of the seventh capacitor is connected with the gate of the fourth field effect tube; the other end of the seventh capacitor is connected with the drain of the second field effect tube.

[0017] Further, in the embodiment of the present application, the voltage-controlled oscillator further comprises a switching module; the switching module is connected with an external signal; the wide-bandwidth resonant circuit and the low-bandwidth resonant circuit are connected with the switching module; the switching module is used for switching the external signal input into the wide-bandwidth resonant circuit or the low-bandwidth resonant circuit.

[0018] The third technical solution adopted by the present application is:

[0019] A chip comprising the high-linearity resonant cavity or the frequency doubler-oscillator architecture as described above.

[0020] Further, a communication device comprises a housing, a peripheral circuit board, and the chip as described above.

[0021] The present application has the following advantages and beneficial effects:

[0022] 1. In the millimeter wave frequency band, it is difficult to achieve high linearity design due to the influence of parasitic capacitance. The present application designs a high linearity millimeter wave frequency source through the current multiplexing frequency doubler-oscillator new structure, which can improve the linearity of the millimeter wave frequency source.

[0023] 2. In the conventional design, the introduction of the frequency doubler will significantly increase the overall system power consumption. In the present application, the current multiplexing new structure of the frequency doubler and the oscillator is realized, the power consumption is reduced, and the low-power design of the chip is realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A circuit module schematic diagram of a voltage-controlled oscillator in one specific embodiment of the present application;

[0025] Figure 2 A specific circuit structure schematic diagram of a voltage-controlled resonant cavity in one specific embodiment of the present application;

[0026] Figure 3 A specific circuit structure schematic diagram of a self-mixer in one specific embodiment of the present application;

[0027] Figure 4 A specific circuit structure schematic diagram of a voltage-controlled oscillator in one specific embodiment of the present application;

[0028] Figure 5 A core circuit structure schematic diagram of a voltage-controlled oscillator in another specific embodiment of the present application;

[0029] Figure 6 A frequency and Kvco variation curve diagram with tuning voltage of a millimeter wave frequency band frequency source in one specific embodiment of the present application;

[0030] Figure 7 A phase noise test diagram of a voltage-controlled oscillator in one specific embodiment of the present application. DETAILED DESCRIPTION

[0031] The following describes the principle and process of the voltage-controlled oscillator in the embodiments of the present application in detail in combination with the accompanying drawings.

[0032] In related technologies, frequency sources also have very wide application scenarios in measurement problems. Distance and speed of an object can be measured through electromagnetic waves. The signal emitted by a radar transmitter contacts an object and is reflected back to the receiver. After being processed by the receiver and a digital processor, the distance and speed information of the target object can be obtained. The most common radar used for measurement is a frequency-modulated continuous wave (FMCW) radar. The FMCW radar transmits a triangular wave modulated signal through the transmitter. By processing the return signal received by the receiver, the information of the measured target can be obtained. By comparing the frequency difference between the return signal and the transmitted signal, the distance information of the target signal and the radar can be obtained. Therefore, the higher the linearity of the triangular wave modulated signal, the higher the detection information accuracy. The high linearity signal source applied to the detection radar is the core of the detection radar technology.

[0033] In recent years, many technologies for optimizing the high linearity of the frequency source have appeared. Among the existing schemes, in one scheme, a three-coupled inductance-capacitance resonant structure is proposed, the high linearity of the capacitance is realized through the mutual coupling of the three inductances, and the linear change of less than 18.8% is realized at the 20GHz frequency band. In another scheme, a combination of digitally controlled varactor diode array coarse tuning and analog bias diode array fine tuning is adopted, and the high linearity of the overall system is realized, and the linearity change of less than 3% is realized at the 4GHz frequency band.

[0034] In the field of millimeter wave radio frequency radar, the design of high linearity frequency source has the following problems. First, the linearity of the capacitance voltage curve of the varactor diode is poor. Second, due to the internal connection and the parasitic capacitance of the transistor itself, the existence of the parasitic capacitance makes it difficult to maintain the linearity. In the first scheme, a three-stage inductance coupling method is adopted to couple the capacitance values of multiple varactor diodes to obtain a relatively linear capacitance voltage curve. On the one hand, the design is difficult, and the three-stage coupled inductance structure is complex. On the other hand, the complex inductance coupling relationship is difficult to simulate and design accurately, resulting in poor actual design results. The second scheme adopts a combination of digital control and analog to design a high linearity voltage controlled oscillator, but the capacitance structure is too large, which makes it only available at low frequencies, and it is difficult to apply in the mainstream millimeter wave radar field. Therefore, there are still technical problems to be solved in the related art. In view of the above problems, the technical scheme adopted by the present application includes: providing a varactor diode array and an oscillator-frequency multiplier current multiplexing new architecture circuit that can be used for high linearity resonant cavity. A high linearity frequency multiplier is designed by combining multiple varactor diodes. A new architecture voltage controlled oscillator circuit of oscillator-frequency multiplier is adopted, which solves the problem of designing a high linearity voltage controlled oscillator in the millimeter wave frequency band without additional power consumption.

[0035] Embodiment 1:

[0036] Further, in the embodiments of the present application, the varactor diode array structure in the wide bandwidth resonant circuit and the low bandwidth resonant circuit can refer to Figure 2 , in Figure 2The first varactor diode array and the second varactor diode array have the same structure, the first varactor diode array can include a plurality of diode sub-arrays having the same structure and connected in parallel with each other; the diode sub-array includes a first varactor diode var7, a second varactor diode var8, a first capacitor C7 and a second capacitor C8; the first varactor diode var7, the second varactor diode var8, the first capacitor C7 and the second capacitor C8 are connected in series; the first varactor diode array of the wide-bandwidth resonant circuit and the second varactor diode array of the low-bandwidth resonant circuit are connected in parallel, one of the parallel nodes after the connection can be used as a low-frequency positive signal LOW FREQ VOUTP output, and the other parallel node after the connection can be used as a low-frequency negative signal LOW FREQ VOUTN output. The first varactor diode var7 and the second varactor diode var8 form a series node in series, and the series node is connected with the tuning voltage VTH or VTL. Specifically, the series node formed by the first varactor diode and the second varactor diode of the first varactor diode array is connected with the high tuning voltage VTH, and the series node formed by the first varactor diode and the second varactor diode of the first varactor diode array is connected with the low tuning voltage VTL.

[0037] Further, in the embodiments of the present application, referring to Figure 2 , the first voltage biasing module and the second voltage biasing module have the same structure, the first voltage biasing module includes a plurality of first sub-biasing modules; the first sub-biasing module includes a first resistor R11 and a second resistor R12; one end of the first resistor R11 and one end of the second resistor R12 are connected in parallel and then connected to one, two combinations or multiple combinations of the first biasing signals VBL1, VBL2 and VBL3, one end of the first resistor R11 is connected with the first varactor diode array; one end of the second resistor R12 is connected with the first varactor diode array.

[0038] Further, in the embodiments of the present application, referring to Figure 2 , the second voltage biasing module includes a plurality of second sub-biasing modules; the second sub-biasing module includes a third resistor R13 and a fourth resistor R14; one end of the third resistor R13 and one end of the fourth resistor R14 are connected in parallel and then connected to one, two combinations or multiple combinations of the second biasing signals VBH1, VBH2 or VBH3, one end of the third resistor R13 is connected with the second varactor diode array; one end of the fourth resistor R14 is connected with the second varactor diode array.

[0039] Further, in the embodiments of the present application, the sum of the number of the first sub-biasing modules and the number of the second sub-biasing modules is the same as the number of the diode sub-arrays, specifically, it can be seen from Figure 2 that each diode sub-array can correspond to a first sub-biasing module or a second sub-biasing module.

[0040] In this embodiment, the varactor array can be applied to various circuit structures, and is not limited to an oscillator.

[0041] Embodiment 2

[0042] This embodiment provides a high-linearity voltage-controlled oscillator circuit. It contains, for example, a high-linearity varactor array, a switched-capacitor array, an inductive circuit, and a negative resistance circuit.

[0043] The switched-capacitor module is used to adjust the first signal or the second signal output by the voltage-controlled resonant cavity; the even harmonic generator circuit generates a first even harmonic signal and a second even harmonic signal according to the first signal or the second signal; the self-mixing frequency multiplier generates a first tripler signal according to the first signal and the first even harmonic signal, or generates a second tripler signal according to the second signal and the second even harmonic signal. The self-mixing frequency multiplier resonant cavity adjusts the output gain of the first tripler signal and the second tripler signal according to the frequency of the first signal.

[0044] The inductive circuit is used to resonate with the capacitive module to generate a low-frequency oscillation signal, which contains an inductor connected across the output of the wideband card operating mode varactor array.

[0045] The negative resistance circuit is composed of a pair of cross-coupled tubes, which can compensate for the power loss caused by the non-ideal parasitic of passive devices.

[0046] The inductive circuit is connected to the high-linearity varactor array, and the high-linearity varactor is connected to the negative resistance circuit. The combination of the aforementioned high-linearity varactor array, switched-capacitor array, inductive circuit, and negative resistance circuit can realize a low-frequency high-linearity voltage-controlled oscillator.

[0047] In this embodiment, the voltage-controlled oscillator can be applied to various use scenarios, and is not limited to the high-linearity use field and the radar ranging field.

[0048] Embodiment 3

[0049] This embodiment provides a self-mixing circuit based on cross-coupled tubes, as shown in Figure 3 which contains an even harmonic generator and a self-mixer composed of a combination of cross-coupled tubes

[0050] Further, in the embodiments of the present application, reference is made to Figure 3The cross-coupled tube comprises a fifth resistor R1, a sixth resistor R2, a first field effect transistor M1, a second field effect transistor M2, a third capacitor C1, and a fourth capacitor C2, and a first external potential VB2; one end of the third capacitor C1 and one end of the fifth resistor R1 are connected with a gate of the first field effect transistor M1; one end of the fourth capacitor C2 and one end of the sixth resistor R2 are connected with a gate of the second field effect transistor M2; the other end of the fifth resistor R1 and the other end of the sixth resistor R2 are connected with the first external potential VB2; the other end of the third capacitor C1 is connected with a drain of the second field effect transistor M2; and the other end of the fourth capacitor C2 is connected with a drain of the first field effect transistor M1.

[0051] Further, in the embodiments of the present application, referring to Figure 3 The mixer can comprise a third field effect transistor M3, a fourth field effect transistor M4, a second external potential VB1, a seventh resistor R3, an eighth resistor R4, and a third varactor diode array. The third varactor diode array has the same structure as the first varactor diode array. Optionally, the mixer can comprise a third voltage biasing module and the third varactor diode array. The third varactor diode array is connected with the third voltage biasing module, and the third varactor diode array comprises a plurality of diode sub-arrays which are connected in parallel and have the same structure; each diode sub-array comprises a third varactor diode, a fourth varactor diode, an eighth capacitor, and a ninth capacitor; the third varactor diode, the fourth varactor diode, the eighth capacitor, and the ninth capacitor are connected in series; and the connection between the third varactor diode and the fourth varactor diode is controlled by the high-tuning voltage of the first varactor diode of the low-frequency voltage-controlled resonant cavity.

[0052] One end of the seventh resistor R3 and one end of the eighth resistor R4 are connected with the second external potential VB1; the other end of the seventh resistor R3 is connected with a gate of the third field effect transistor M3; the other end of the eighth resistor R4 is connected with a gate of the fourth field effect transistor M4; a source of the third field effect transistor M3 is connected with a source of the first field effect transistor M1; a drain of the third field effect transistor M3 and one end of the third varactor diode array are connected with a high-frequency output terminal; and a drain of the fourth field effect transistor M4 and the other end of the third varactor diode array are connected with a low-frequency output terminal.

[0053] Further, in the embodiments of the present application, referring to Figure 3 The mixer and the even harmonic generator are connected with a sixth capacitor C3 and a seventh capacitor C4; one end of the sixth capacitor C3 is connected with a gate of the third field effect transistor M3; the other end of the sixth capacitor C3 is connected with a drain of the first field effect transistor M1; one end of the seventh capacitor C4 is connected with a gate of the fourth field effect transistor M4; and the other end of the seventh capacitor C4 is connected with a drain of the second field effect transistor M2.

[0054] In the embodiments, the self-mixer can be used in multiple fields, and is not limited to frequency multipliers.

[0055] Embodiment 4:

[0056] The embodiment provides an oscillator-voltage-controlled oscillator circuit of a new architecture of an oscillator-multiplier. Wherein, referring to Figure 4 , Figure 4 is a structural schematic diagram of the oscillator. In Figure 4 , the oscillator comprises a voltage-controlled resonant cavity, an even harmonic generator and a frequency mixer; the voltage-controlled resonant cavity is connected with the even harmonic generator; the even harmonic generator is connected with the frequency mixer; the voltage-controlled resonant cavity comprises a wide-bandwidth resonant circuit, a low-bandwidth resonant circuit, an inductive circuit and a switched-capacitor module; the wide-bandwidth resonant circuit, the low-bandwidth resonant circuit, the inductive circuit and the switched-capacitor module are connected in parallel; the wide-bandwidth resonant circuit comprises a first varactor array and a first voltage biasing module; the first varactor array is connected with the first voltage biasing module; the low-bandwidth resonant circuit comprises a second varactor array and a second voltage biasing module; the second varactor array is connected with the second voltage biasing module;

[0057] The wide-bandwidth resonant circuit is configured to generate a first signal by resonating in combination with the inductive circuit and the switched-capacitor module according to a high-bit tuning voltage input into the first varactor array and a first biasing signal input into the first voltage biasing module; the first signal is a signal in a first preset frequency band;

[0058] The low-bandwidth resonant circuit is configured to generate a second signal by resonating in combination with the inductive circuit and the switched-capacitor module according to a low-bit tuning voltage input into the second varactor array and a second biasing signal input into the second voltage biasing module; the second signal is a signal in a second preset frequency band;

[0059] The switched-capacitor module is configured to adjust the voltage-controlled resonant cavity to output the first signal or the second signal; the even harmonic generator generates a first even harmonic signal and a second even harmonic signal according to the first signal or the second signal; the frequency mixer generates a first tripler signal according to the first signal and the first even harmonic signal, or generates a second tripler signal according to the second signal and the second even harmonic signal. The frequency mixer can internally comprise a self-mixing frequency multiplier resonant cavity, which can adjust the output gain of the first tripler signal and the second tripler signal according to the frequency of the first signal.

[0060] It can be understood that the "first" and "second" in the above embodiment are only used as names for distinction, and do not represent any specific order between each other.

[0061] Further, in the embodiment of the present application, referring to Figure 4The voltage-controlled oscillator further comprises a switching module SW1; the switching module SW1 is connected with the external signal; the wide-bandwidth resonant circuit and the low-bandwidth resonant circuit are connected with the switching module SW1; and the switching module SW1 is used for switching the external signal input into the wide-bandwidth resonant circuit or the low-bandwidth resonant circuit.

[0062] The overall circuit of the present application is shown in Figure 5 The specific circuit is divided into three parts, the first part is a voltage-controlled oscillation resonant cavity with a frequency of about 8GHz, which comprises a wide-bandwidth resonant circuit, a low-bandwidth resonant circuit, an inductive circuit and a switched capacitor module. The wide-bandwidth resonant circuit and the low-bandwidth resonant circuit each comprise a varactor diode array. The varactor diode array of the wide-bandwidth resonant circuit comprises a plurality of sub-arrays, and the number of the sub-arrays is the same as the number of the sub-bias modules of the voltage bias module. Similarly, the varactor diode array of the low-bandwidth resonant circuit comprises a plurality of sub-arrays, and the number of the sub-arrays is the same as the number of the sub-bias modules of the voltage bias module. The second part is an even harmonic generator, and the third part is a self-mixer to realize the function of tripling frequency.

[0063] In the highest linearity mode, the value of ΔK VCO is less than 5.35%, the high linearity coverage range is greater than 2.64GHz, the frequency band range greater than 10% can cover 23.245G-26.89G. The frequency and Kvco change curve with the tuning voltage is shown in Figure 6 The high linearity voltage-controlled oscillator designed in the present application realizes a higher linearity capability. The maximum tuning range of the oscillator reaches 21.758G-27.4617GHz, and the tuning range greater than 5.7GHz (23%) is greater than 5.7GHz. The phase noise of the low-frequency oscillator at the highest working frequency is -108.96dBc / Hz (@1MHz), as shown in Figure 7 The quality factor FoM of the oscillator is -175.1.

[0064] II. Circuit working principle

[0065] The frequency of the voltage-controlled oscillator can be expressed in the form of (1)

[0066]

[0067] Therefore, if a linear frequency-voltage curve is to be realized, it can be required that K VCO is basically constant, and the frequency is expressed as f=k·V+n, where k and n are coefficients, and the capacitance array can be expressed as

[0068]

[0069] And the capacitance, in addition to the varactor, the parasitic capacitance in the circuit also as a part of the capacitance into the resonant circuit. Therefore, for the millimeter wave frequency band, its capacitance array size can not be too large, while the parasitic capacitance is not reduced, so for the millimeter wave frequency band, it is more difficult to realize the high linearity of the oscillator.

[0070] Therefore, based on the low frequency band high linearity voltage controlled oscillator, it is a feasible idea to design a voltage controlled oscillator that can work in the millimeter wave frequency band. At the same time, in the low frequency band voltage controlled oscillator, the capacitance array can be large, which is more conducive to obtaining high linearity. However, the traditional idea of using VCO and frequency multiplier combination, its power consumption is equivalent to the superposition of the two, its high power consumption makes it difficult to meet the demand of modern communication system for low power consumption.

[0071] The negative resistance of the oscillator composed of cross-coupled tubes can also be regarded as a differential common-drain amplifier. Due to the nonlinearity of the transistor, the output current contains other harmonic components. The differential single-ended source current can be expressed as:

[0072]

[0073] Where α0, α1, α2 represent the harmonic coefficients. For the other end, the input can be represented as -cosωt. Then the output current of the other end can be expressed as

[0074]

[0075] Then, in the output of the differential combination, the odd harmonic components are cancelled, and the even harmonic components are doubled. The combined output is:

[0076] I S =2α0+α2A 2 +α2A 2 cos2ωt+…

[0077] Therefore, the cross-coupled tube of the voltage controlled oscillator can be used as an even harmonic generator. Its output current contains the second harmonic component. For the application scenario of the present application, a DC blocking capacitor is added to the input end of the cross-coupled tube / even harmonic generator, which can provide an independent bias voltage to maximize the second harmonic. At the same time, since the DC blocking capacitor and the parasitic capacitance of the later cross-coupled tube are divided, the capacitance value in the present application should not be too large.

[0078] The output of the voltage-controlled oscillator can be mixed with the output of the even harmonic generator to realize the function of tripling frequency. The self-mixing frequency multiplier can realize current multiplexing with the voltage-controlled oscillator and the even harmonic generator, thereby saving power consumption. Meanwhile, the mixer also plays the function of isolating the voltage-controlled oscillator from external circuits. The connection between the voltage-controlled oscillator and the external circuits is difficult, and it is difficult to accurately measure the output capacitance introduced by the external circuits, thereby causing the decrease of linearity. The frequency multiplier plays the function of output buffer, and simultaneously reduces the design difficulty of high linearity.

[0079] The low-frequency high-linearity voltage-controlled oscillator provided in the application can realize 24-26GHz and 24-24.25GHz dual-band operation modes. As shown in the figure, Figure 2 The voltage-controlled oscillator has a dual-band operation mode and is composed of two groups of varactor diode arrays. Each group contains 3bit varactor diodes. One end of the varactor diodes can be independently biased at 0V or 1.2V through digital control (VBH1-VBH3, VBL1-VBL3), and the other end is a tuning voltage. Through the combination of different bias modes of the varactor diodes, a high-linearity oscillator can be realized. Meanwhile, there is a one-bit switch capacitor. The switch capacitor is turned on when the 24-26GHz operation mode is used, and is turned off when the 24-24.25GHz operation mode is used, thereby ensuring the complete coverage of the two frequency bands (1.8pF in the figure is a DC blocking capacitor, VTH is a high-bit tuning voltage, and VTL is a low-bit tuning voltage).

[0080] Meanwhile, the application considers that the output frequency range of the high-linearity voltage-controlled oscillator is wide, and the tripler also adds a varactor diode. The tuning voltage of the varactor diode is consistent with the tuning voltage of the oscillator, and the third harmonic gain curve is adjusted to maximize the output signal power.

[0081] The application provides a high-linearity frequency source with a new structure of combination of a voltage-controlled oscillator and a frequency multiplier, thereby improving the linearity of the frequency source in the millimeter wave frequency band. Meanwhile, current multiplexing avoids the increase of power consumption caused by the additional use of the frequency multiplier.

[0082] In addition, the application embodiment also provides a radio frequency circuit, which can include the voltage-controlled oscillator described above.

[0083] The contents in the voltage-controlled oscillator described above are all applicable to the radio frequency circuit embodiment. The radio frequency circuit embodiment specifically realizes the same functions as the voltage-controlled oscillator embodiment described above, and achieves the same beneficial effects as the voltage-controlled oscillator embodiment described above.

[0084] In some alternative embodiments, the functions / operations described in the block diagrams can not occur in the order described in the operational illustrations. For example, two blocks shown in succession can in fact be executed substantially concurrently or the blocks can sometimes be executed in the reverse order, depending upon the functionality / operations involved. Also, although the embodiments presented in the flow diagrams are shown as a sequence of operations, it is to be understood that the logical flow is merely illustrative of alternative embodiments. The disclosed methods can be implemented in any number of variations not depicted in the illustrations. For example, the order of the operations can be changed, or one or more operations can be changed, eliminated, or combined. Additionally, the term "operation" as used herein, refers to an operation, a process, a method, a function, a procedure, a subroutine, a subprogram, etc.

[0085] Furthermore, although the present application is described in the context of functional modules, it is to be understood that one or more of the functions and / or features can be integrated in a single physical device and / or software module, or one or more functions and / or features can be implemented in separate physical devices or software modules. It is also to be understood that detailed discussion of the actual implementation of each module is unnecessary to an understanding of the present application. Rather, the actual implementation is within the routine skill of engineers familiar with the attributes, functions, and internal relationships of the various functional modules disclosed herein. Accordingly, the present application is not limited to purely hardware or software implementations, since combinations of hardware and software embodiments are also within the scope of the present application. It is also to be understood that the specific concepts disclosed are merely illustrative and that the scope of the present application is to be determined by the entire scope of the claims, along with all equivalents of the claims, and that the claims are to be accorded their broadest interpretation under the patent statutes.

[0086] It is to be understood that the various parts of the present application can be implemented (1) as a combination of hardware and software, (2) as software, (3) as firmware, or (4) as hardware. In the above embodiments, a number of the steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable

[0087] In the above description of the present specification, the description of the terms "one embodiment", "another embodiment", or "certain embodiments" or the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner.

[0088] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

[0089] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the described embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present application, and these equivalent modifications or substitutions are included in the scope defined by the claims of the present application.

Claims

1. A high linearity voltage controlled oscillator characterized by, The application relates to a voltage-controlled resonant cavity, an even harmonic generator and a frequency mixer. The voltage-controlled resonant cavity is connected with the even harmonic generator. The even harmonic generator is connected with the frequency mixer. The voltage-controlled resonant cavity is used for generating a first signal, and after the first signal passes through the even harmonic generator and the frequency mixer, a second signal with a target frequency is generated; wherein the frequency of the first signal is less than that of the second signal. The voltage-controlled resonant cavity comprises a wide-bandwidth resonant circuit, a low-bandwidth resonant circuit, an inductive circuit and a switched capacitor module; the wide-bandwidth resonant circuit comprises a first varactor diode array and a first voltage biasing module; the low-bandwidth resonant circuit comprises a second varactor diode array and a second voltage biasing module; the inductive circuit resonates with the wide-bandwidth resonant circuit and the switched capacitor module to generate the first signal; the inductive circuit resonates with the low-bandwidth resonant circuit and the switched capacitor module to generate the second signal; and the switched capacitor module is used for adjusting the first signal or the second signal. The even harmonic generator comprises a fifth resistor, a sixth resistor, a first field effect transistor, a second field effect transistor, a third capacitor, a fourth capacitor and a first external potential; the even harmonic generator is a negative resistance and self-mixing module of an oscillator; one end of the third capacitor and one end of the fifth resistor are connected with the gate of the first field effect transistor; one end of the fourth capacitor and one end of the sixth resistor are connected with the gate of the second field effect transistor; the other end of the fifth resistor and the other end of the sixth resistor are connected with the first external potential; the other end of the third capacitor is connected with the drain of the second field effect transistor; and the other end of the fourth capacitor is connected with the drain of the first field effect transistor. The frequency mixer comprises a third field effect transistor, a fourth field effect transistor, a second external potential, a seventh resistor, an eighth resistor and a third varactor diode array. One end of the seventh resistor and one end of the eighth resistor are connected with the second external potential; the other end of the seventh resistor is connected with the gate of the third field effect transistor; the other end of the eighth resistor is connected with the gate of the fourth field effect transistor; the source of the third field effect transistor is connected with the source of the first field effect transistor; the drain of the third field effect transistor and one end of the third varactor diode array are connected with a high-frequency output end; and the drain of the fourth field effect transistor and the other end of the third varactor diode array are connected with a low-frequency output end. ​ 2. The high linearity voltage controlled oscillator of claim 1, wherein, The first varactor diode array is connected with a first voltage biasing module, and the second varactor diode array is connected with a second voltage biasing module; the first varactor diode array has the same structure as the second varactor diode array, and the first varactor diode array comprises a plurality of diode sub-arrays which are connected in parallel and have the same structure; the diode sub-array comprises a first varactor diode, a second varactor diode, a first capacitor and a second capacitor; the first varactor diode, the second varactor diode, the first capacitor and the second capacitor are connected in series; one end of the diode sub-array is used as a low-frequency positive signal output, and the other end of the diode sub-array is used as a low-frequency negative signal output.

3. The high linearity voltage controlled oscillator of claim 1, wherein, The first voltage biasing module has the same structure as the second voltage biasing module, and the first voltage biasing module comprises a plurality of first sub-biasing modules; the first sub-biasing module comprises a first resistor and a second resistor; one end of the first resistor is connected with one end of the second resistor in parallel, and then connected with a first biasing signal; one end of the first resistor is connected with the first varactor diode array; one end of the second resistor is connected with the first varactor diode array.

4. The high linearity voltage controlled oscillator of claim 3, wherein, The sum of the number of the first sub-biasing modules and the number of the second sub-biasing modules is equal to the number of the diode sub-arrays.

5. The high linearity voltage controlled oscillator of claim 1, wherein, The switched capacitor module is used for adjusting the frequency of the first signal and the second signal.

6. The high linearity voltage controlled oscillator of claim 1, wherein, The sixth capacitor and the seventh capacitor are arranged between the mixer and the even harmonic generator; one end of the sixth capacitor is connected with the gate of the third field effect tube; the other end of the sixth capacitor is connected with the drain of the first field effect tube; one end of the seventh capacitor is connected with the gate of the fourth field effect tube; the other end of the seventh capacitor is connected with the drain of the second field effect tube.

7. The high linearity voltage controlled oscillator of claim 1, wherein, The voltage-controlled oscillator further comprises a switching module; the switching module is connected with an external signal; the wide-bandwidth resonant circuit and the low-bandwidth resonant circuit are connected with the switching module; the switching module is used for switching the external signal input into the wide-bandwidth resonant circuit or the low-bandwidth resonant circuit; the third varactor diode array of the mixer is connected with the switching module; when the switching module inputs the wide-bandwidth resonant circuit, the external signal is connected with the tuning voltage of the third varactor diode array of the mixer.

8. A chip, characterized by The voltage-controlled oscillator comprises the chip of any one of claims 1-7.

9. An electronic device, comprising: The voltage-controlled oscillator comprises a housing and a circuit board; wherein the circuit board comprises the chip of claim 8.

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