阅读说明：本技术 一种基于线性高q值可调谐电感及高频压控振荡器 (Tunable inductor based on linear high Q value and high-frequency voltage-controlled oscillator ) 是由 刘术彬 常军 梁鸿志 丁瑞雪 刘晓娴 朱樟明 于 2021-06-08 设计创作，主要内容包括：本发明提供的一种基于线性高Q值可调谐电感及高频压控振荡器,调整可调谐电感不同端口之间耦合电容C1,C2大小,可对电感感值进行粗调与细调,粗调变化范围可达10pH,细调精度达0.03pH/f,使得压控振荡器具有较宽的调频范围。并且本发明由于采用电容调节电感,与现有技术电阻调节感值的压控振荡器相比,并未引入其他多余的电阻,且能使得压控振荡器保持较高品质因子Q值。(According to the tunable inductor based on the linear high Q value and the high-frequency voltage-controlled oscillator, the sizes of coupling capacitors C1 and C2 between different ports of the tunable inductor are adjusted, the inductance value of the inductor can be coarsely adjusted and finely adjusted, the coarse adjustment range can reach 10pH, the fine adjustment precision can reach 0.03pH/f, and the voltage-controlled oscillator has a wider frequency adjustment range. In addition, because the capacitor is adopted to adjust the inductance, compared with the voltage-controlled oscillator for adjusting the inductance value by the resistor in the prior art, other redundant resistors are not introduced, and the voltage-controlled oscillator can keep a higher quality factor Q value.)

1. A tunable inductor based on linear high Q value, comprising: outer inductive material, intermediate level inductive material and inlayer inductive material that are regular octagon structure and bilateral symmetry, inlayer inductive material nestification is in the intermediate level inductive material, intermediate level inductive material nestification is in the outer inductive material, intermediate level inductive material and inlayer inductive material are parallel at the limit of equidirectional, follow the outer border of inlayer inductive material and begin, take a tap MID port in the middle of taking a percentage on the symmetry axis, the lower direction of symmetry axis intermediate level inductive material, outer inductive material and inlayer inductive material have seted up the port passageway, the port passageway of outer inductive material is greater than the port passageway of intermediate level inductive material, the port passageway of intermediate level inductive material is greater than inlayer inductive port passageway.

2. The tunable resonant inductor of claim 1, wherein the outer inductor material, the middle inductor material, and the inner inductor material comprise copper and a magnetic core.

3. The tunable resonant inductor according to claim 1, wherein a fine tuning capacitor (C1) is connected between the port channels of the outer layer inductor material and the middle layer inductor material when the outer layer inductor material and the middle layer inductor material are applied to the voltage controlled oscillator, and a coarse tuning capacitor (C2) is connected between the port channels of the middle layer inductor material and the inner layer inductor material when the middle layer inductor material and the inner layer inductor material are applied to the voltage controlled oscillator.

4. A high frequency voltage controlled oscillator based on a linear high Q tunable inductor, characterized in that, using the tunable inductor of any of claims 1 to 3, the high frequency voltage controlled oscillator comprises:

a voltage controlled oscillator circuit comprising an adjustable inductive circuit portion and a non-inductive circuit portion,

wherein the adjustable inductance part in the voltage-controlled oscillator circuit comprises: the tunable inductance equivalent circuit comprises an outer layer inductance material, a middle layer inductance material and an inner layer inductance material, wherein the outer layer inductance material, the middle layer inductance material and the inner layer inductance material are respectively equivalent to a tunable inductance equivalent circuit of a first inductance (L1), a second inductance (L2) and a third inductance (L3), and a fine tuning capacitor (C1) and a coarse tuning capacitor (C2) for adjusting the first inductance (L1), the second inductance (L2) and the third inductance (L3);

the tunable inductance equivalent circuit is of a symmetrical structure, the symmetrical structure comprises a first symmetrical part and a second symmetrical part, and each symmetrical part comprises a first inductor (L1), a second inductor (L2) and a third inductor (L3); the third inductance (L3) of each symmetrical part is coupled with the second inductance (L2) of the other symmetrical part, and the coupling coefficient is K2; each symmetrical portion has a respective first inductance (L1) coupled to a respective second inductance (L2) with a coupling coefficient K1; one end of the first inductor (L1) and one end of the second inductor (L2) of each symmetrical part are simultaneously connected with a power supply Voltage (VDD), a fine tuning capacitor (C1) is connected between the two ends of the first inductor, one end of the third inductor (L3) of each symmetrical part and one end of the second inductor (L2) coupled with the third inductor are simultaneously connected with the power supply (VDD), and a coarse tuning capacitor (C2) is connected between the two ends of the third inductor.

5. The high frequency voltage controlled oscillator of claim 1, wherein the non-inductive circuit portion comprises: a first transistor (N1), a second transistor (N2), a third transistor (N3), a fourth transistor (N4), a first capacitor (Ca) and a second capacitor (Cb), wherein the gate of the first transistor (N1) is connected to the drain of the second transistor (N2), one end of the adjustable inductor circuit portion, the positive end of the second capacitor (Cb), the gate of the third transistor (N3) and the drain of the fourth transistor (N4), the gate of the second transistor (N2) is connected to the drain of the first transistor (N1), the other end of the adjustable inductor circuit portion, the positive end of the first capacitor (Ca), the gate of the fourth transistor (N4) and the drain of the third transistor (N3), the sources of the first transistor (N1) and the second transistor (N2) are connected to a power supply (GND), the sources of the third transistor (N3) and the fourth transistor (N4) are connected to ground (VDD), the other end of the first capacitor (Ca) is connected to the other end of the second capacitor (Cb).

Technical Field

The invention belongs to the technical field of voltage-controlled oscillators, and particularly relates to a tunable inductor based on linear high Q value and a high-frequency voltage-controlled oscillator.

Background

The phase-locked loop frequency synthesizer circuit directly influences the performance of the wireless transceiver, the VCO is a core module in the frequency synthesizer, the tuning range of the VCO determines the output frequency band, the phase noise and the power consumption performance of the phase-locked loop system, and the phase-locked loop frequency synthesizer circuit is of great importance to the phase-locked loop and even the whole wireless transceiver system.

The oscillator realizes stable oscillation when receiving an excitation signal outside the oscillator, and the LC VCO is applied to a frequency band above GHz and has better phase noise. Referring to fig. 1a, fig. 1a is a conventional LC VCO structure. In fig. 1a, L is a high quality factor three-terminal inductor, Csw is a switch capacitor in a resonant cavity, Cvar is a continuously adjustable capacitor in the resonant cavity, and in order to implement a broadband tuning range, the size or dimension of Csw is generally increased, so that a VCO implements a wider tunable range. From a physical implementation, a larger parasitic capacitance is introduced due to the increase of Csw, which leads to a frequency drop and attenuation of the starting stability. It is difficult to achieve a high frequency, wide tuning range with the conventional use of fixed inductors.

The prior art proposes to change the inductance value of the inductor by adjusting the resistance, as shown in fig. 1b, but the introduced large resistance seriously affects the quality factor (Q value) of the inductor, and degrades the performance of phase noise, stable oscillation starting and the like.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a tunable inductor based on linear high-Q value and a high-frequency voltage-controlled oscillator. The technical problem to be solved by the invention is realized by the following technical scheme:

in a first aspect, the present invention provides a tunable inductor based on linear high Q value, including: the inductor comprises an outer layer inductor material, a middle layer inductor material and an inner layer inductor material which are in a regular octagonal structure and are symmetrical in a left-right axis mode, the inner layer inductor material is nested in the middle layer inductor material, the middle layer inductor material is nested in the outer layer inductor material, the middle layer inductor material and the inner layer inductor material are parallel to each other in the same direction, an MID port is tapped on a symmetrical axis from the outer edge of the inner layer inductor material, port channels are formed in the middle layer inductor material, the outer layer inductor material and the inner layer inductor material in the lower direction of the symmetrical axis, the port channels of the outer layer inductor material are larger than those of the middle layer inductor material, and the port channels of the middle layer inductor material are larger than those of the inner layer inductor material.

The outer layer inductance material, the middle layer inductance material and the inner layer inductance material comprise copper and a magnetic core.

Optionally, when the outer layer inductance material and the middle layer inductance material are applied to the voltage-controlled oscillator, a fine tuning capacitor C1 is connected between port channels of the outer layer inductance material and the middle layer inductance material, and when the middle layer inductance material and the inner layer inductance material are applied to the voltage-controlled oscillator, a coarse tuning capacitor C2 is connected between port channels of the middle layer inductance material and the inner layer inductance material.

In a second aspect, the present invention provides a high-frequency voltage-controlled oscillator based on a linear high-Q tunable inductor, where the tunable inductor in the first aspect is used, and the high-frequency voltage-controlled oscillator includes:

a voltage controlled oscillator circuit comprising an adjustable inductive circuit portion and a non-inductive circuit portion,

wherein, the adjustable inductance part in the voltage-controlled oscillator circuit includes: the outer layer inductance material, the middle layer inductance material and the inner layer inductance material are respectively equivalent to a tunable inductance equivalent circuit of a first inductance L1, a second inductance L2 and a third inductance L3, and are used for adjusting a fine tuning capacitance C1 and a coarse tuning capacitance C2 of the first inductance L1, the second inductance L2 and the third inductance L3;

the tunable inductor equivalent circuit is of a symmetrical structure, the symmetrical structure comprises a first symmetrical part and a second symmetrical part, and each symmetrical part comprises a first inductor L1, a second inductor L2 and a third inductor L3; the third inductor L3 of each symmetrical part is coupled with the second inductor L2 of the other symmetrical part, and the coupling coefficient is K2; the respective first inductor L1 of each symmetric part is coupled with the respective second inductor L2, and the coupling coefficient is K1; the respective first inductor L1 and the respective second inductor L2 of each symmetric part have one end connected to the power supply voltage VDD at the same time, and the fine tuning capacitor C1 is connected between the one ends, and the respective third inductor L3 of each symmetric part and one end of the coupled second inductor L2 of each symmetric part are connected to the power supply VDD at the same time, and the coarse tuning capacitor C2 is connected between the other ends.

Optionally, the non-inductive circuit part includes: a first transistor N1, a second transistor N2, a third transistor N3, a fourth transistor N4, a first capacitor Ca, and a second capacitor Cb, wherein a gate of the first transistor N1 is connected to a drain of the second transistor N2, one end of the adjustable inductor circuit portion, a positive terminal of the second capacitor Cb, a gate of the third transistor N3, and a drain of the fourth transistor N4, a gate of the second transistor N2 is connected to a drain of the first transistor N1, the other end of the adjustable inductor circuit portion, a positive terminal of the first capacitor Ca, a gate of the fourth transistor N4, and a drain of the third transistor N3, sources of the first transistor N1 and the second transistor N2 are connected to the power supply VDD, sources of the third transistor N3 and the fourth transistor N4 are connected to the power supply ground GND, and the other end of the first capacitor Ca is connected to the other end of the second capacitor Cb.

The invention provides a tunable inductor based on a linear high Q value and a high-frequency voltage-controlled oscillator, which can adjust the sizes of coupling capacitors C1 and C2 between different ports of the tunable inductor, can perform coarse adjustment and fine adjustment on the inductance value of the inductor, and can ensure that the coarse adjustment change range can reach 10pH and the fine adjustment precision reaches 0.03pH/f, so that the voltage-controlled oscillator has a wider frequency adjustment range. In addition, because the capacitor is adopted to adjust the inductance, compared with the voltage-controlled oscillator for adjusting the inductance value by the resistor in the prior art, other redundant resistors are not introduced, and the voltage-controlled oscillator can keep a higher quality factor Q value.

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Drawings

FIG. 1a is a block diagram of a conventional LC VCO;

FIG. 1b is a block diagram of an LC VCO with resistors adjusted to change inductance values;

fig. 2 is a structural diagram of a tunable inductor based on a linear high Q value according to an embodiment of the present invention;

fig. 3 is a structural diagram of a high-frequency voltage-controlled oscillator based on a linear high-Q tunable inductor according to an embodiment of the present invention;

fig. 4 is a structural diagram of an equivalent circuit of a variable inductor structure according to an embodiment of the present invention;

fig. 5 is a circuit structure diagram after the equivalent circuit of the variable inductor structure is decoupled according to the embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

Example one

As shown in fig. 2, the tunable inductor based on linear high Q value provided by the present invention is applied to a voltage controlled oscillator, and includes: the inductor comprises an outer layer inductor material, an intermediate layer inductor material and an inner layer inductor material which are in a regular octagonal structure and are in bilateral symmetry, wherein the inner layer inductor material is nested in the intermediate layer inductor material, the intermediate layer inductor material is nested in the outer layer inductor material, the edges of the outer layer inductor material, the intermediate layer inductor material and the inner layer inductor material in the same direction are parallel, MID middle is tapped on a symmetry axis from the outer edge of the inner layer inductor material, a middle tapping port is tapped in the middle of the symmetry axis, port channels are formed in the intermediate layer inductor material, the outer layer inductor material and the inner layer inductor material in the lower direction of the symmetry axis, the port channels of the outer layer inductor material are larger than the port channels of the intermediate layer inductor material, and the port channels of the intermediate layer inductor material are larger than the port channels of the inner layer inductor material.

The outer layer inductance material, the middle layer inductance material and the inner layer inductance material comprise copper and a magnetic core. When the outer layer inductance material and the middle layer inductance material are applied to the voltage-controlled oscillator, a fine tuning capacitor C1 is connected between port channels of the outer layer inductance material and the middle layer inductance material, and when the middle layer inductance material and the inner layer inductance material are applied to the voltage-controlled oscillator, a coarse tuning capacitor C2 is connected between the port channels of the middle layer inductance material and the inner layer inductance material.

The invention provides a tunable inductor based on a linear high Q value, which can adjust the sizes of coupling capacitors C1 and C2 between different ports, can perform coarse adjustment and fine adjustment on the inductance value of the inductor, wherein the coarse adjustment range can reach 10pH, and the fine adjustment precision can reach 0.03pH/f, so that a voltage-controlled oscillator has a wider frequency adjustment range. In addition, because the capacitance is adopted to adjust the inductance, compared with the prior art that the inductance is adjusted through the resistance, other redundant resistance is not introduced, and the Q value of a high quality factor can be kept.

As shown in fig. 3, the high-frequency voltage-controlled oscillator based on the linear high-Q tunable inductor provided by the present invention uses the tunable inductor shown in fig. 2, and includes:

a voltage controlled oscillator circuit comprising an adjustable inductive circuit portion and a non-inductive circuit portion,

wherein, the adjustable inductance part in the voltage-controlled oscillator circuit includes: the outer layer inductance material, the middle layer inductance material and the inner layer inductance material are respectively equivalent to a tunable inductance equivalent circuit of a first inductance L1, a second inductance L2 and a third inductance L3, and are used for adjusting a fine tuning capacitance C1 and a coarse tuning capacitance C2 of the first inductance L1, the second inductance L2 and the third inductance L3;

the tunable inductor equivalent circuit is of a symmetrical structure, the symmetrical structure comprises a first symmetrical part and a second symmetrical part, and each symmetrical part comprises a first inductor L1, a second inductor L2 and a third inductor L3; the third inductor L3 of each symmetrical part is coupled with the second inductor L2 of the other symmetrical part, and the coupling coefficient is K2; the respective first inductor L1 of each symmetric part is coupled with the respective second inductor L2, and the coupling coefficient is K1; the respective first inductor L1 and the respective second inductor L2 of each symmetric part have one end connected to the power supply voltage VDD at the same time, and the fine tuning capacitor C1 is connected between the one ends, and the respective third inductor L3 of each symmetric part and one end of the coupled second inductor L2 of each symmetric part are connected to the power supply VDD at the same time, and the coarse tuning capacitor C2 is connected between the other ends.

Referring to fig. 3, the non-inductive circuit portion includes: a first transistor N1, a second transistor N2, a third transistor N3, a fourth transistor N4, a first capacitor Ca, and a second capacitor Cb, wherein a gate of the first transistor N1 is connected to a drain of the second transistor N2, one end of the adjustable inductor circuit portion, a positive terminal of the second capacitor Cb, a gate of the third transistor N3, and a drain of the fourth transistor N4, a gate of the second transistor N2 is connected to a drain of the first transistor N1, the other end of the adjustable inductor circuit portion, a positive terminal of the first capacitor Ca, a gate of the fourth transistor N4, and a drain of the third transistor N3, sources of the first transistor N1 and the second transistor N2 are connected to the power supply VDD, sources of the third transistor N3 and the fourth transistor N4 are connected to the power supply ground GND, and the other end of the first capacitor Ca is connected to the other end of the second capacitor Cb.

The variable inductor structure proposed in fig. 2 is equivalent, and the equivalent structure is shown in fig. 4, where L1, L2, and L3 are equivalent inductors from outer ring to inner ring, respectively, C1 and C2 are capacitors introduced for adjusting the inductor, where C1 is a fine tuning capacitor, C2 is a coarse tuning capacitor, R1 and R are sums of on-resistance and series resistance of the inductor, which are added for adjusting the capacitance values of C1 and C2, and the resistance values are relatively large, and R2 and R3 are only series resistances of the inductor, and the resistance values are relatively small, and K1 and K2 are coupling coefficients of adjacent inductors. The equivalent circuit structure is calculated as follows.

The circuit of fig. 4 is decoupled and the equivalent circuit can be changed to that shown in fig. 5. For convenience of calculation, all inductors may be equal to L, the series resistance is R, and the switch resistance is R1, and equivalent inductors LEQ and REQ may be calculated. The values of L, R, R1 taken here for simplicity of calculation are not the same as in FIG. 2. The formula is as follows:

denotes multiplication. The inductance value of the equivalent inductance is determined by the capacitors C1 and C2, and the difference between the coefficients C1 and C2 in the formula reflects the difference between the adjustable accuracies of the two capacitors, the coefficient C1 is smaller, the range of the adjusted inductance value is small, the accuracy is high, and the method can be used for fine adjustment and adjustment of the high-frequency of the VCO. The inductance value adjusted by the larger coefficient in front of the C2 has a wider range and low precision, and can be used for coarse adjustment and adjustment of the low-frequency of the VCO, so the designed novel inductance structure can realize the VCO with a wide frequency adjustment range, because the resistance except the on-resistance of the switching tube is not introduced, the equivalent resistance REQ can be seen to be slightly influenced by R from the formula of the equivalent resistance REQ, and the effects of the C1 and the C2 on the equivalent resistance REQ are almost the same as the effects of the LEQ according to the formula:

it can be analyzed that the Q value is very small and can still keep a very high Q value.

The high-frequency voltage-controlled oscillator based on the linear high-Q value tunable inductor provided by the invention can be used for performing coarse adjustment and fine adjustment on the inductance value of the inductor by adjusting the coupling capacitors C1 and C2 between different ports of the tunable inductor, the coarse adjustment range can reach 10pH, and the fine adjustment precision can reach 0.03pH/f, so that the voltage-controlled oscillator has a wider frequency adjustment range. In addition, as the capacitance is adopted to adjust the inductance, compared with the voltage-controlled oscillator for adjusting the inductance value by the resistance in the prior art, other redundant resistance is not introduced, and the voltage-controlled oscillator can keep a higher quality factor Q value.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.