CN108768303B - Application of molybdenum disulfide in manufacturing odd harmonic microwave frequency multiplier - Google Patents

Abstract

The invention discloses an application of molybdenum disulfide in preparation of an odd harmonic microwave frequency multiplier, wherein the odd harmonic microwave frequency multiplier comprises a cavity, an input coaxial connector and an output coaxial connector which are respectively positioned at two ends of the cavity, and a cover plate matched with the cavity, a molybdenum disulfide frequency multiplier high-frequency substrate is arranged in the cavity, the molybdenum disulfide frequency multiplier high-frequency substrate comprises a high-frequency substrate and microstrip lines which are arranged on the high-frequency substrate and respectively connected with the microstrip line input coaxial connector and the microstrip line output coaxial connector, gaps are arranged among the microstrip lines, and molybdenum disulfide is arranged among the gaps. The invention utilizes the good nonlinear microwave characteristic of molybdenum disulfide, is suitable for nonlinear devices such as frequency multipliers, and the like, adopts the frequency multipliers made of molybdenum disulfide, has good nonlinear performance, can not generate echo signals, has very simple circuit design and good frequency doubling effect, and has the third frequency doubling loss equivalent to fundamental wave.

Description

Application of molybdenum disulfide in making odd harmonic microwave frequency multiplier

technical field

The invention relates to the field of microwaves, in particular to the application of molybdenum disulfide in the preparation of odd-order harmonic microwave frequency multipliers.

Background technique

Microwave and millimeter-wave frequency sources are widely used in systems such as radar, communication, guidance, and test instruments. The frequency multiplier is one of the important components of the frequency source. In microwave and millimeter wave frequency bands, two-port passive frequency multipliers are widely used in the design of frequency multiplier sources. In terms of stability and noise, high-frequency two-port passive frequency multipliers have better performance than active oscillators. . In the prior art, nonlinear resistance, nonlinear reactance frequency doubling, and graphene frequency doubling are mainly used.

The frequency doubling efficiency of the nonlinear resistor is low, and the highest efficiency that can be achieved is 1/N ^2, which causes the fundamental wave loss to be much greater than the third frequency doubling loss.

Non-linear reactance is often used for low-order frequency multiplication. In actual circuits, due to poor matching and advanced loss of diodes, frequency multiplication losses always exist, resulting in complex design structures.

In recent years, graphene has been considered as a next-generation electronic material due to its high electronic traction rate and good thermal conductivity, and has become a hot research direction. The disadvantage of graphene is that it will generate echo signals, so we need to The fundamental wave and the harmonic components to be recovered are in the state of total reflection, and the total reflection is to reflect the fundamental wave and the harmonic components to be recovered back to the input reflection network through graphene, resulting in a complicated structure design of the frequency multiplier. Therefore, the frequency doubling loss of the graphene frequency doubler is high, and the working efficiency is not high, which greatly limits the usage scenarios of the graphene frequency doubler.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of solution that solves the above problems, makes full use of the nonlinear microwave characteristics of molybdenum disulfide, and is suitable for the use of molybdenum disulfide for nonlinear devices such as frequency multipliers in making odd harmonic microwave frequency multipliers. application.

In order to achieve the above object, the technical solution adopted in the present invention is as follows: the application of molybdenum disulfide in the manufacture of odd-order harmonic microwave frequency multipliers.

Molybdenum disulfide has good optical nonlinearity and is mainly used in diodes, field effect transistors and other fields. For example, the document Observation of Intense Second Harmonic Generation from MoS2Atomic Crystals describes the optical nonlinearity of molybdenum disulfide, which provides new applications in optoelectronic devices. There is an opportunity; the literature Ultra-strongnonlinear optical processes and trigonal warping in MoS2layers reports that 1L-MoS2 has very strong optical nonlinearity. At the same time, there is no public report on the nonlinear microwave properties of MoS2 _two -dimensional materials, whether it is suitable for non-linear microwave characteristics such as frequency doublers. Linear devices, no conclusion has been drawn. Therefore, the present invention uses a single-layer MoS2 loading microstrip gap to study the odd-order harmonic microwave frequency multiplier. Molybdenum disulfide will output the fundamental wave and its multiplied frequency component under the excitation of the electromagnetic field. Molybdenum disulfide two-port frequency multiplier circuit has a natural even-order harmonic suppression function, and the output frequency component only contains fundamental and odd-order harmonics, which is suitable for nonlinear frequency devices, such as frequency multipliers.

Preferably: the odd-order harmonic microwave frequency multiplier includes a cavity, an input coaxial connector and an output coaxial connector located at both ends of the cavity, and a cover plate matched with the cavity, and the cavity is provided with molybdenum disulfide. The frequency multiplier high-frequency substrate, the molybdenum disulfide frequency multiplier high-frequency substrate includes a high-frequency substrate, a microstrip line arranged on the high-frequency substrate and connected to the input coaxial connector and the output coaxial connector of the microstrip line respectively. There are gaps, and molybdenum disulfide is arranged between the gaps.

As a preference: the manufacturing method of the high-frequency substrate of the molybdenum disulfide frequency doubler is:

(1) According to the input signal and the frequency multiplication times, the output frequency is obtained;

(2) Design the microstrip line and microstrip gap according to the input frequency and output frequency;

(3) Transfer molybdenum disulfide to the microstrip gap.

Compared with the prior art, the advantages of the present invention are: compared with graphene, graphene generates echo signals, resulting in complicated design, and the third harmonic frequency doubling loss is less than the frequency doubling loss of odd harmonics, and in the present invention, The use of molybdenum disulfide has good nonlinear performance, no echo signal is generated, the circuit design is very simple, and the frequency doubling effect is good, and the third frequency doubling loss is equivalent to the fundamental wave.

Description of drawings

Fig. 1 is the structural representation of embodiment 1;

Fig. 2 is the circuit schematic diagram of Embodiment 1;

Fig. 3 is the design flow chart of embodiment 1;

4 is a circuit schematic diagram of Comparative Example 1;

Fig. 5 is the design flow chart of embodiment 1;

FIG. 6 is a schematic diagram of the ratio of the triple frequency of molybdenum disulfide to the fundamental wave loss in Example 1. FIG.

Fig. 7 is the ratio schematic diagram of graphene triple frequency and fundamental wave loss in Comparative Example 1;

Fig. 8 is comparative example 2 non-linear resistance frequency doubling derivation circuit;

FIG. 9 is a derivation circuit of nonlinear reactance frequency doubling in Comparative Example 2. FIG.

In the figure: 1, cover plate; 2, high frequency substrate; 3, cavity; 4, input coaxial connector; 5, output coaxial connector; 6, microstrip line; 7, input reflection network; 8, output reflection network; 9. Graphene; 10. Molybdenum disulfide.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings.

Embodiment 1: Referring to FIG. 1 , FIG. 2 , and FIG. 3 , this embodiment illustrates the application of molybdenum disulfide 10 in making odd-order harmonic microwave frequency multipliers. This embodiment makes full use of the nonlinear microwave characteristics of molybdenum disulfide 10 .

Wherein: the odd-order harmonic microwave frequency multiplier includes a cavity 3, an input coaxial joint 4 and an output coaxial joint 5 respectively located at both ends of the cavity 3, and a cover plate 1 matched with the cavity 3. The cavity 3 is provided with a molybdenum disulfide 10-frequency multiplier high-frequency substrate 2, and the molybdenum disulfide 10-frequency multiplier high-frequency substrate 2 includes a high-frequency substrate 2, which is arranged on the high-frequency substrate 2 and is respectively connected with the microstrip line 6 input coaxial joints 4 and 4. Microstrip lines 6 connected to the output coaxial connector 5 are provided with gaps between the microstrip lines 6, and molybdenum disulfide 10 is provided between the gaps.

The manufacturing method of the high-frequency substrate 2 of the molybdenum disulfide 10 frequency multiplier is:

(1) According to the input signal and the frequency multiplication times, the output frequency is obtained;

(2) Design the microstrip line 6 and the microstrip gap according to the input frequency and the output frequency;

(3) The molybdenum disulfide 10 is transferred to the microstrip gap.

Comparative Example 1:

Referring to FIGS. 4 and 5, a graphene 9 odd harmonic frequency multiplier includes a cavity 3 assembly and a cover plate 1, and the cavity 3 assembly includes a cavity 3 and an input same as the input at both ends of the cavity 3. Axle joint 4 and output coaxial joint 5, also include graphene 9 frequency multiplier high-frequency substrate 2; Described graphene 9 frequency multiplier high-frequency substrate 2 includes high-frequency substrate 2, the input reflection network 7 arranged on the high-frequency substrate 2, Graphene 9 and output reflection network 8, described input reflection network 7 and output reflection network 8 are respectively located at the front end and back end of graphene 9;

Let the output signal be the fundamental wave f ₀ , the frequency multiplication times be N, the output signal after frequency multiplication is Nf ₀ , and the frequency component of the signal to be recovered is (2n+1)f ₀ , where n=1, 2, 3, 4...and (2n+1)≠N;

The input reflection network 7 is in a matching state to f ₀ , and is in a grounded state for the signal frequency component to be recovered;

The output reflection network 8 is in a matching state to Nf ₀ , and is in a state of total reflection to the fundamental wave and the harmonic component to be recovered, and the total reflection is to reflect the fundamental wave and the harmonic component to be recovered back to the input through graphene 9. Reflection Network 7.

The input reflection network 7 and the output reflection network 8 use a 50-ohm microstrip line 6 in parallel with high and low impedance resonant circuits to realize the reflection and recovery of harmonic components.

The design method of graphene 9 odd harmonic frequency multiplier is as follows:

(1) According to the input signal and the frequency multiplication times, the output frequency is obtained;

(2) Determine the recovered signal frequency components;

(3) design the input reflection network 7 and the output reflection network 8 to obtain the graphene 9 frequency multiplier high-frequency substrate 2;

(4) obtain the graphene 9 frequency multiplier with the graphene 9 frequency multiplier high-frequency substrate 2;

(5) Design external structures such as cavity 3 and cover plate 1 to obtain a graphene 9 odd harmonic frequency multiplier.

Combining Example 1 and Comparative Example 1, it can be known that graphene 9 can generate echo signals, so we need to be in a state of total reflection for the fundamental wave and the harmonic components to be recovered, resulting in the input reflection network 7 and the output reflection network 8 must be set. , resulting in complex structure design of the frequency multiplier, high frequency multiplication loss, and low working efficiency.

In the present invention, due to the good nonlinear microwave characteristics of molybdenum disulfide 10, no echo signal is generated, the circuit design is very simple, and the frequency doubling effect is good, and it has a natural even-order harmonic suppression function, and the output frequency component only contains fundamental Odd harmonics are affected, so the circuit design is simple.

Referring to Fig. 2 and Fig. 4, it can be seen from the comparison of Fig. 2 and Fig. 4 that in Example 1, molybdenum disulfide 10 is used, and the third frequency doubling is equivalent to the fundamental wave output, which reduces the branch recovery part. When the excitation frequency is 1GHz and the excitation power is 18dBm, the frequency multiplication loss of the third harmonic is equivalent to the frequency multiplication loss of the first harmonic. Comparative Example 1 uses graphene 9, but the third frequency doubling loss of the graphene 9 frequency multiplier is half of the spare loss of the first harmonic.

Referring to Figure 6 and Figure 7, it can be seen from the comparison of Figure 6 and Figure 7 that at the same frequency, the ratio of the triple frequency of graphene 9 to the fundamental wave loss is 0.001-0.006, a difference of about 25dBm; The ratio of frequency to fundamental wave loss is 0.1-0.4, which is equivalent to the fundamental wave.

Comparative Example 2: Referring to FIG. 8 , the nonlinear resistance frequency multiplication is adopted, and the frequency multiplication efficiency of all the nonlinear resistance frequency multipliers decreases according to the square of the frequency multiplication times. That is to say, no matter what kind of structure and software the designer uses to design the non-linear resistance frequency doubling, the maximum efficiency of its double frequency is less than 25%; triple frequency is less than 11.1%; quadruple frequency is less than 5.25%; and so on. .

Resistor R is driven by the power supply Vs. The back part of the circuit is a plurality of band-pass filters, which are used to isolate harmonics and output power. For example, when the frequency is W, the nth frequency multiplier is the nth harmonic of the fundamental wave, and the output frequency is nW.

In the case of high power requirements or broadband requirements, we often use nonlinear resistors for frequency doubling.

波阶段，非线性电抗倍频器也不满足Manly-Rowe公式，因此其高效率的优势也不像在微波阶段如此明显。如图1，在输入频率为ω时，n次倍频器即为基波的n次谐波，输出频率为nω。反应了非线性电阻倍频的输入功率P1与输出功率Pn之间的关系的不等式，称为Page-Pantell不等式。Its advantages are its stability and wider bandwidth. But its disadvantage is that its frequency doubling efficiency is low, so the application is not popular with reactive frequency doubling. but in mm

In the wave stage, the nonlinear reactive frequency doubler also does not satisfy the Manly-Rowe formula, so the advantage of its high efficiency is not as obvious as in the microwave stage. As shown in Figure 1, when the input frequency is ω, the nth frequency multiplier is the nth harmonic of the fundamental wave, and the output frequency is nω. The inequality that reflects the relationship between the input power P1 and the output power Pn of the non-linear resistance frequency doubling is called the Page-Pantell inequality.

The voltage and current across the resistor R can be expressed by Fourier series as:

where Vn and In are:

Voltage v(t) and current i(t) are real functions, so Vn=V-n*

and In=I-n*. Therefore, the nth harmonic power can be obtained by the following formula:

Multiply both sides of formula (1-1) by n2In* and sum up to get:

Taking the partial derivatives on both sides of formula (1-2), we can get:

So bring in formula (1-6), we get:

Again v(0)=v(T) and i(0)=i(T). Then the partial derivative of i(t) with respect to t also has periodicity, so the first term on the right-hand side of formula (1-8) is always equal to 0.

Then formula (1-8) can be simplified, and combined with formula (1-5), we can get:

For positive nonlinear resistors, the integral of equation (1-9) is always greater than zero. So you can get:

Connect a resistive load to the fundamental frequency and the frequency of the desired harmonic order n, and connect a reactive load to the remaining harmonics, the formula (1-10) can be simplified as P1+n2Pn>0, and the input power P1 is greater than 0, and the harmonic power Pn<0, the maximum efficiency of the nonlinear resistance frequency multiplier is:

Formula (1-11) expresses the frequency multiplication efficiency of all non-linear resistance frequency multipliers, which decreases according to the square of the frequency multiplication times. That is to say, no matter what kind of structure and software the designer uses to design the nonlinear resistance frequency multiplier, the maximum efficiency of the frequency doubler is less than 25%; the frequency tripler is less than 11.1%; the frequency quadruple is less than 6.25% ; and so on.

Comparative Example 3: Referring to FIG. 9 , the nonlinear reactance frequency doubling is adopted. In the nonlinear reactance frequency doubler, the frequency doubling efficiency can reach 100% in an ideal state. However, in the actual circuit, due to the poor matching and the senior loss of the diode, the frequency doubling loss always exists.

Capacitor C is driven by power supplies Vs1 and Vs2. The back part of the circuit is a plurality of band-pass filters, which are used to isolate harmonics and output power.

Nonlinear reactive frequency doublers can be divided into two categories: diode frequency doublers and transistor frequency doublers. The commonly used diode frequency doubling diodes are varactor diodes and step diodes. The former is often used for low-order frequency doubling, and its efficiency is high. According to the Manly-Rowe formula of the nonlinear reactance frequency doubling principle, it can reach 100% in an ideal state. Step diodes are often used for high-order frequency multiplication. Since the varactor high-order frequency multiplier needs an idle circuit to implement, the step diode is simpler in circuit.

If a steady-state sine voltage wave is loaded on the varactor, its current and voltage waveforms will be distorted, resulting in harmonic components. The size of the harmonic component has a great relationship with the nonlinearity of the diode.

As shown in Figure 9, the Manly-Rowe formula for frequency doubling of nonlinear reactance expresses the relationship between input power and output power. Among them, the capacitor C is driven by the sources Vs1 and Vs2. The back part of the circuit is a plurality of band-pass filters, which are used to isolate harmonics, and the output requires power.

The Manly-Rowe formula states: For any lossless nonlinear reactive element, power is conserved. This relation can be used for oscillators, parametric amplifiers and frequency doubling frequency converters for microwave and even lightwave frequency bands. This formula is generally used to budget for power gain and frequency doubling conversion efficiency.

In the nonlinear reactive frequency multiplier, the frequency multiplication efficiency can reach 100% under ideal conditions. However, in the actual circuit, due to poor matching and the loss of the diode itself, the frequency doubling loss always exists.

Claims (1)

1. a molybdenum disulfide odd-order harmonic microwave frequency multiplier, comprising a cavity, an input coaxial joint and an output coaxial joint respectively positioned at both ends of the cavity, a cover plate that matches the cavity, it is characterized in that: the described A molybdenum disulfide frequency multiplier high-frequency substrate is arranged in the cavity, and the molybdenum disulfide frequency multiplier high-frequency substrate includes a high-frequency substrate and a microstrip line arranged on the high-frequency substrate and connected to the input coaxial connector and the output coaxial connector of the microstrip line respectively. , there are gaps between the microstrip lines, and molybdenum disulfide is arranged between the gaps; The manufacturing method of described molybdenum disulfide odd harmonic microwave frequency multiplier is: (1) According to the input signal and the frequency multiplication times, the output frequency is obtained; (2) Design the microstrip line and microstrip gap according to the input frequency and output frequency; (3) Transfer molybdenum disulfide to the microstrip gap.

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