CN105975687A - Method for constructing lumped model of band-pass coplanar waveguide micro-strip through hole-free transition structure - Google Patents

Abstract

The invention discloses a method for constructing a lumped model of a band-pass coplanar waveguide micro-strip through hole-free transition structure, and mainly aims at solving the problems that the lumped models of the conventional coplanar waveguide micro-strip structures cannot accurately simulate the broadband, band pass and low-frequency cut-off characteristics of through hole-free transition structures, and are onerous and parameter extraction and onerous time-consuming in parameter extraction and optimizations. The technical scheme is that the method comprises the following steps: 1, constructing an equivalent circuit according to physical characteristics of the transition structure; 2, carrying out three-dimensional electromagnetic simulation to obtain scattering parameters S1 of the used band-pass coplanar waveguide micro-strip through hole-free transition structure; 3, extracting initial values of capacitance, resistance and inductance elements in the equivalent circuit according to the scattering parameters S1; and 4, carrying out simulation optimization on the initial values so as to obtain final values of the elements in the equivalent circuit. According to the method disclosed in the invention, the band pass, broadband and low-frequency cut-off characteristics of the band-pass coplanar waveguide micro-strip through hole-free transition structure can be accurately simulated, and the parameter extraction and optimization process is simple, so that the method can be used for the design and on-wafer test of single-chip and hybrid microwave integrated circuits.

Description

Band face Waveguide-microbelt in all is without the lumped model construction method of through hole transition structure

Technical field

The invention belongs to microelectronics technology, be specifically related to the construction method of a kind of lumped model, can be used for monolithic micro- Ripple IC design, hybrid microwave integrated circuit design and On-wafer measurement.

Technical background

Since recent decades, along with microwave, the fast development of millimeter-wave technology, wireless mobile telecommunication technology and microwave are integrated Circuit engineering is developed rapidly and popularization and application.Due to transmission line knots such as microstrip line, co-planar waveguide, the line of rabbet joint and coplanar striplines Structure is all planar structure, their feature be exactly size Control in a plane, thus design, in the course of processing more square Just.Wherein, microstrip line and co-planar waveguide both transmission lines are the of paramount importance structures of composition microwave integrated circuit.

Microstrip line is the most popular a kind of planar transmission line, and microstrip transmission line is applied to low level frequency microwave technology In.Its advantage is that manufacturing expense is low, size is the least, weight is particularly lightweight, working band width and having and solid state device Good fit property；Its major defect be lost bigger, it is impossible in the case of high level use.Owing to microstrip line construction is simple, It is easy to the debugging of the integrated of device and circuit so that microstrip line has become as circuit structure first-selected in radio frequency, microwave circuit.

The basic structure of co-planar waveguide is made up of the ground level that the semo-infinite of a center conduction band and both sides is big, and center is led Band is as signal transmssion line, and two side band lines are as earth lead.Co-planar waveguide supports that Quasi-TEM mode is propagated, with traditional microstrip line Compare, have and be prone to processing, be prone to the most various microwave device, need not parcel and through hole, radiation loss are little etc. excellent Point.His characteristic impedance is only determined by conduction band width and groove width, and therefore size can be the least, but loss can increase therewith.With This is simultaneously as there is ground between two adjacent lines, between them to interfere with each other comparison faint, so what co-planar waveguide was constituted Circuit can ratio microstrip circuitry more crypto set, be particularly suitable for the application of microwave integrated circuit and monolithic integrated microwave circuit.Altogether The quasi-TEM mould of face waveguide has the advantage that frequency dispersion is weak, and this provides probability for design wideband circuit and device.

In many devices on a printed circuit, there are the most eurypalynous microstrip transmission line and co-planar waveguide, between them Connection can produce discontinuity, and such as the air gap, bending and step etc., signal transmission and reflection are had strongly by this discontinuity Impact, in some cases, magnetic field that accumulation causes and the uneven distribution of electric field make transmission line produce induction reactance or The effect of person's capacitive reactance.The input/output port of microwave experiment equipment mostly is coplanar waveguide form, at microwave electromagnetic characteristics now In it is frequently necessary to carry out the conversion of both transmission line forms, in order to reduce the loss that this discontinuity is brought, can To add coffret structure, this conversion is completed by co-planar waveguide microstrip transition structure,

During circuit design and On-wafer measurement, the RLC lumped model of accurate co-planar waveguide microstrip transitions circuit It is possible not only to emulate exactly the actual performance of transformational structure, and convenient under conditions of can calculating need not large amount of complex Complete De-embedding process, obtain main body circuit or the actual actual performance measuring device.But existing co-planar waveguide is micro- RLC lumped model with transition structure is mainly for there being the transformational structure of through-hole structure, and mainly for narrow-band low pass transition Structure is modeled, and accuracy is the highest, puies forward ginseng process indefinite.Therefore RLC lumped model is led to for accurate broadband belt Need nonetheless remain for substantial amounts of exploration.

Summary of the invention

It is an object of the invention to propose a kind of band face Waveguide-microbelt in all without the structure of through hole transition structure lumped model Method, to solve the deficiency of above-mentioned existing co-planar waveguide microstrip transition structure RLC lumped model, it is achieved to co-planar waveguide micro-strip mistake Cross the accurate simulation of structure broadband and bandpass characteristics.

For achieving the above object, technical scheme is as follows:

(1) according to the physical features structure equivalent circuit of transition structure:

1a) it is equivalent to the center signal line of coplanar waveguide structure input inductance L1, by mistake between co-planar waveguide and micro-strip The frequency selection effect of the section of crossing is equivalent to transition capacitance C1, the loss effect of changeover portion is equivalent to transition resistance R1, by micro-strip Part is equivalent to outputting inductance L2, and input inductance L1, transition capacitance C1, transition resistance R1 and outputting inductance L2 is sequentially connected in series Connect, form main line；

1b) capacity effect between co-planar waveguide center signal line and ground wire is equivalent to ground capacity C2, by coplanar ripple Loss effect between guiding center holding wire and ground wire is equivalent to earth resistance R2；Ground capacity is passed through in one end of earth resistance R2 C2 ground connection, the other end is connected to the junction inputting inductance L1 with transition capacitance C1；

(2) band used face Waveguide-microbelt in all dissipating without through hole transition structure is obtained by the emulation of 3 D electromagnetic simulation software Penetrate parameter S1；

(3) according to the initial value of electric capacity, resistance and inductance element in scattering parameter S1 extraction equivalent circuit, it may be assumed that input The initial value of inductance L1 is h1, the initial value of transition capacitance C1 is q1, the initial value of transition resistance R1 is w1, outputting inductance L2 Initial value h2, the initial value w2 of initial value q2 and earth resistance R2 of ground capacity C2；

(4) in the equivalent circuit obtaining (3), the initial value of each element carries out simulation optimization, until equivalent circuit emulation Scattering parameter S2 is consistent with the scattering parameter S1 that 3 D electromagnetic emulates, and obtains the end value of each element of equivalent circuit, it may be assumed that input electricity Sense end value H1 of L1, end value Q1 of transition capacitance C1, end value W1 of transition resistance R1, the end value of outputting inductance L2 H2, end value Q2 of ground capacity C2 and end value W2 of earth resistance R2, these final arguments are used for the integrated electricity of monolithic microwave The De-embedding of road, hybrid microwave integrated circuit design and On-wafer measurement calculates.

The invention has the beneficial effects as follows:

1) by introducing changeover portion electric capacity C1, the low-frequency cut-off characteristic of actual converted structure can be simulated, it is possible to accurately imitate The bandpass characteristics of true transformational structure；

2) by being simultaneously introduced high pass and low pass circuit in a model, it is possible to accurately simulate the wideband of true transformational structure Band characteristic；

3) there is the physical significance of reality due to each lamped element, determined in equivalent circuit by the tight derivation of equation The initial value of each element, uses the equivalent impedance circuit of simplification in derivation, simplifies the derivation of formula, save parameter The time extracted, obtained the end value of element by simple optimization process, by the simulation value of equivalent circuit and actual measurement It is worth good matching.

Accompanying drawing explanation

Fig. 1 is the flowchart of the present invention；

Fig. 2 is that the present invention models band used face Waveguide-microbelt in all without through hole transition structure figure；

Fig. 3 is the equivalent circuit diagram that Fig. 2 is built by the present invention；

Fig. 4 is the simplification equivalent impedance circuit diagram that the present invention uses when extracting Fig. 3 initial value；

Fig. 5 is the test curve comparison diagram of the simulation curve after Fig. 3 equivalent circuit optimizes and Fig. 2 transition structure.

Detailed description of the invention

Being described principle and the feature of the present invention below in conjunction with accompanying drawing, example is served only for explaining the present invention, and Non-for limiting the scope of the present invention.

With reference to Fig. 1, the present invention to realize step as follows:

Step 1, builds equivalent circuit according to the physical features of transition structure.

As in figure 2 it is shown, the band face Waveguide-microbelt in all used by this example is without through hole transition structure, by co-planar waveguide, transition Section and microstrip line three part form.Wherein:

Co-planar waveguide, including center signal line and ground wire；

Changeover portion, including co-planar waveguide changeover portion and microstrip transition section two parts；

Co-planar waveguide changeover portion, including center signal line and the ground wire of width gradual change of width gradual change；

Co-planar waveguide is connected in series by respective center signal line with coplanar waveguide transition section, and microstrip transition section is with coplanar The center signal line of waveguide transition section is connected in series, and microstrip transition section is connected in series by transition line with microstrip line.

Above section is produced on the front of aluminium nitride substrate, and the back side is covered by metal level.

The structure that without through hole transition structure, above-mentioned band face Waveguide-microbelt in all is carried out equivalent circuit is carried out as follows:

1.1) it is equivalent to the center signal line of coplanar waveguide structure input inductance L1, by mistake between co-planar waveguide and micro-strip The frequency selection effect of the section of crossing is equivalent to transition capacitance C1, the loss effect of changeover portion is equivalent to transition resistance R1, by micro-strip Part is equivalent to outputting inductance L2, and input inductance L1, transition capacitance C1, transition resistance R1 and outputting inductance L2 is sequentially connected in series Connect, form main line；

1.2) capacity effect between co-planar waveguide center signal line and ground wire is equivalent to ground capacity C2, by coplanar ripple Loss effect between guiding center holding wire and ground wire is equivalent to earth resistance R2；Ground capacity is passed through in one end of earth resistance R2 C2 ground connection, the other end is connected to the junction inputting inductance L1 with transition capacitance C1, as shown in Figure 3.

Step 2. obtains the band used face Waveguide-microbelt in all scattering parameter S1 without through hole transition structure.

The acquisition of scattering parameter S1 has two kinds of methods, the first be by 3 D electromagnetic simulation software to transition structure three Dimension module carries out Electromagnetic Simulation, it is thus achieved that this transition structure scattering parameter S1, the advantage of the method is that of avoiding making real structure Trouble, and there is good accuracy；Second method is the transition structure produced and need modeling, to this transition structure Test, directly obtain its scattering parameter S1.This example uses first method, is i.e. emulated by 3 D electromagnetic simulation software Obtain the band used face Waveguide-microbelt in all scattering parameter S1 without through hole transition structure:

$S1=\left[\begin{array}{cc}S{1}_{11}& S{1}_{12}\\ S{1}_{21}& S{1}_{22}\end{array}\right],$

Wherein, S1₁₁For the input port voltage reflection coefficient of transition structure, S1₂₁Forward voltage for transition structure increases Benefit, S1₁₂For the backward voltage gain of transition structure, S1₂₂Output port voltage reflection coefficient for transition structure.

Step 3, according to the initial value of electric capacity, resistance and inductance element in scattering parameter S1 extraction equivalent circuit.

(3.1) the scattering parameter S1 obtained with the emulation of 3 D electromagnetic simulation software is converted into transfer matrix T:

$T=\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\left[\begin{array}{cc}\frac{(1+S{1}_{11})(1-S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}& Z_0\frac{(1+S{1}_{11})(1+S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ \frac{1}{Z_0}\frac{(1-S{1}_{11})(1-S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}& \frac{(1-S{1}_{11})(1+S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}\end{array}\right],$

Wherein, A is input and output voltage ratio during output open circuit, and B is the transfger impedance when output short-circuit, and C is when defeated Going out transfer admittance when opening a way, D is the input and output current ratio when output short-circuit, Z₀Characteristic impedance for system；

Equation below is obtained according to matrix relation between every:

$\left\{\begin{array}{c}A=\frac{(1+S{1}_{11})(1-S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ B=Z_0\frac{(1+S{1}_{11})(1+S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ C=\frac{1}{Z_0}\frac{(1-S{1}_{11})(1-S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ D=\frac{(1-S{1}_{11})(1+S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}\end{array}\right.;---<1>$

(3.2) equivalent circuit being made up of lamped element in step 1 is simplified again, be reduced to be hindered by input Anti-Z₁, output impedance Z₂With earth impedance Z₃The equivalent circuit of these three impedance composition, wherein input impedance Z₁With output impedance Z₂ It is connected in series, earth impedance Z₃One end and input impedance Z₁With output impedance Z₂Junction in parallel, earth impedance Z₃Another End ground connection, as shown in Figure 4；

(3.3) by transfer matrix T input impedance Z₁, output impedance Z₂With earth impedance Z₃Three impedance meters are shown as:

$T=\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\left[\begin{array}{cc}1+\frac{Z_1}{Z_3}& Z_1+Z_2+\frac{Z_1{Z}_2}{Z_3}\\ \frac{1}{Z_3}& 1+\frac{Z_2}{Z_3}\end{array}\right]---<2>$

Equation below is obtained according to every corresponding relation in formula<2>matrix:

$\left\{\begin{array}{c}A=1+\frac{Z_1}{Z_3}\\ B=Z_1+Z_2+\frac{Z_1{Z}_2}{Z_3}\\ C=\frac{1}{Z_3}\\ D=1+\frac{Z_2}{Z_3}\end{array}\right.;---<3>$

According to formula<3>, by input impedance Z₁, output impedance Z₂With earth impedance Z₃These three impedance meter is shown as transfer matrix T Function, it may be assumed that

$\left\{\begin{array}{c}{Z}_1=\frac{A-1}{C}\\ Z_2=\frac{D-1}{C}\\ Z_3=\frac{1}{C}\end{array}\right.---<4>$

Wushu<1>brings formula<4>into, obtains input impedance Z₁, output impedance Z₂With earth impedance Z₃Three impedances concrete Value；

(3.4) functional relationship between impedance and initial value is set up:

By input impedance Z₁It is expressed as inputting the function of the initial value h1 of inductance L1,

Impedance Z will be exported₂It is expressed as the initial value h2 of outputting inductance L2, the initial value q1 of transition capacitance C1 and transition resistance The function of the initial value w1 of R1,

By earth impedance Z₃It is expressed as the function of the initial value w2 of the initial value q2 and earth resistance R2 of ground capacity C2, That is:

$\left\{\begin{array}{c}{Z}_1=j\mathrm{\&omega;}h1\\ Z_2=w1+j\mathrm{\&omega;}h2+\frac{1}{j\mathrm{\&omega;}q1}\\ Z_3=w2+\frac{1}{j\mathrm{\&omega;}q2}\end{array}\right.---<5>$

Wherein ω is angular frequency；

(3.5) formula<5>is utilized to calculate the initial value of each element in equivalent circuit:

(3.5a) to input impedance Z in formula<5>₁Take imaginary part: Im (Z₁)=ω h1, then draws the curve about ω, calculates Slope of a curve, obtains the value of h1, and wherein Im is for taking imaginary part,

(3.5b) to output impedance Z in formula<5>₂Treating excess syndrome portion: Re (Z₂)=w1, obtains the value of w1, and wherein, Re is treating excess syndrome portion；

(3.5c) by output impedance Z in formula<5>₂It is multiplied by ω, then takes imaginary part:Draw about ω² Curve, the slope of calculated curve, obtain the value of h2, the intercept of calculated curve, obtain the value of q1；

(3.5d) to earth impedance Z in formula<5>₃Treating excess syndrome portion: Re (Z₃)=w2, obtains the value of w2；

(3.5e) to earth impedance Z in formula<5>₃It is multiplied by ω, takes imaginary part:Obtain the value of q2.

Step 4. carries out simulation optimization to the initial value of element each in equivalent circuit, obtains the final of each element of equivalent circuit Value.

(4.1) equivalent circuit determining initial value is emulated, obtain emulation scattering parameter S2:

$S2=\left[\begin{array}{cc}S{2}_{11}& S{2}_{12}\\ S{2}_{21}& S{2}_{22}\end{array}\right],$

Wherein, S2₁₁For the input port voltage reflection coefficient of equivalent circuit emulation, S2₂₁Forward for equivalent circuit emulation Voltage gain, S2₁₂For the backward voltage gain of equivalent circuit emulation, S2₂₂Output port voltage reflection for equivalent circuit emulation Coefficient；

(4.2) error function of input port voltage reflection coefficient is defined as error (S₁₁), by forward voltage gain Error function is defined as error (S₂₁), the error function of backward voltage gain is defined as error (S₁₂), by output port electricity The error function of pressure reflection coefficient is defined as error (S₂₂) it is defined respectively as:

error(S₁₁)=| S2₁₁-S1₁₁|/|S1₁₁|

error(S₂₁)=| S2₂₁-S1₂₁|/|S1₂₁|

error(S₁₂)=| S2₁₂-S1₁₂|/|S1₁₂|

error(S₂₂)=| S2₂₂-S1₂₂|/|S1₂₂|；

(4.3) initial value to above-mentioned equivalent circuit of the random optimization program in computer aided design software ADS is utilized Iterative computation 100 times, obtains the parameter of initial optimization；

(4.4) parameter of initial optimization is carried out again with gradients optimization routine in computer aided design software ADS Iterative computation, as error (S₁₁)、error(S₁₂)、error(S₂₁)、error(S₂₂) be respectively less than 0.5 time, optimization terminates, and obtains Input end value H1 of inductance L1, end value Q1 of transition capacitance C1, end value W1 of transition resistance R1, outputting inductance L2 are Final value H2, end value Q2 of ground capacity C2 and end value W2 of earth resistance R2.

The effect of the present invention can be further illustrated by following emulation and test result:

Emulation and test 1, carried out without through hole transition structure the face Waveguide-microbelt in all of the band in Fig. 2 by the inventive method Imitate extraction and the optimization of initial value of each element initial value in the structure of circuit, equivalent circuit, finally give in equivalent circuit each The end value of individual element, as shown in table 1.

The parameter value of each element in table 1 equivalent circuit

Element	Numerical value	Element	Numerical value
				L1	219.64pH	C2	33.34fF
L2	15pH	R1	1.07Ω
				C1	514.9fF	R2	4.47Ω

Emulation and test 2, contrast actual measured results with simulation result.

The accuracy of each component value in order to extract in proof list 1, observes the simulation value of equivalent-circuit model and actual mistake Cross the fitting degree between the test value of structure, the transition structure in Fig. 2 tested, and with the simulation result of equivalent circuit Contrast.

For the ease of being implemented in built-in testing, in Fig. 2 two transition structure differential concatenations are tested, testability now Can be the superposition of transition structure performance in two Fig. 2, two transition structure differential concatenations be formed structure simultaneously and carry out equivalent electric The foundation of road model, and emulate, actual measured results is contrasted with simulation result, result such as Fig. 5.

Fig. 5 showing, insertion loss S (2,1) curve, reflection loss curve S (1,1) and emulation that test obtains obtain Insertion loss curve (2,1) curve, reflection loss curve S (1,1), from figure 5 it can be seen that this equivalent-circuit model can Frequency range 5～50GHz simulates the bandpass characteristics of transformational structure, it is possible to the insertion loss of Accurate Curve-fitting transition structure and Reflection loss.Simulation curve can simulate the broadband character of real devices, bandpass characteristics and low-frequency cut-off characteristic, illustrates to introduce Electric capacity C1 can efficiently solve current lumped model cannot accurate simulation broadband character, bandpass characteristics and low-frequency cut-off characteristic Shortcoming.

The foregoing is only presently preferred embodiments of the present invention, be not limited to the present invention, all spirit in the present invention and Within principle, any amendment of being made, equal replacement, improvement etc., should be included within the scope of the present invention.

Claims (4)

1. band face Waveguide-microbelt in all is without a construction method for through hole transition structure lumped model, including:

(1) according to the physical features structure equivalent circuit of transition structure:

1a) it is equivalent to the center signal line of coplanar waveguide structure input inductance L1, by changeover portion between co-planar waveguide and micro-strip Frequency selection effect be equivalent to transition capacitance C1, the loss effect of changeover portion is equivalent to transition resistance R1, by micro-strip part It is equivalent to outputting inductance L2, and input inductance L1, transition capacitance C1, transition resistance R1 and outputting inductance L2 is sequentially connected in series even Connect, form main line；

1b) capacity effect between co-planar waveguide center signal line and ground wire is equivalent to ground capacity C2, by co-planar waveguide Loss effect between heart holding wire and ground wire is equivalent to earth resistance R2；One end of earth resistance R2 is connect by ground capacity C2 Ground, the other end is connected to the junction inputting inductance L1 with transition capacitance C1；

(2) the band used face Waveguide-microbelt in all scattering ginseng without through hole transition structure is obtained by the emulation of 3 D electromagnetic simulation software Number S1；

(3) according to the initial value of electric capacity, resistance and inductance element in scattering parameter S1 extraction equivalent circuit, it may be assumed that input inductance The initial value of L1 is h1, the initial value of transition capacitance C1 is q1, the initial value of transition resistance R1 is w1, outputting inductance L2 initial It is worth the initial value w2 of the initial value q2 and earth resistance R2 of h2, ground capacity C2；

(4) in the equivalent circuit obtaining (3), the initial value of each element carries out simulation optimization, until the scattering of equivalent circuit emulation Parameter S2 is consistent with the scattering parameter S1 that 3 D electromagnetic emulates, and obtains the end value of each element of equivalent circuit, it may be assumed that input inductance L1 End value H1, end value Q1 of transition capacitance C1, end value W1 of transition resistance R1, end value H2 of outputting inductance L2, connect End value Q2 of ground electric capacity C2 and end value W2 of earth resistance R2, these final arguments are used for monolithic integrated microwave circuit, mix The De-embedding closing microwave integrated circuit design and On-wafer measurement calculates.

Method the most according to claim 1, it is characterised in that: step is emulated by 3 D electromagnetic simulation software in (2) To band used face Waveguide-microbelt in all without the scattering parameter S1 of through hole transition structure, it is to be emulated by 3 D electromagnetic simulation software To band used face Waveguide-microbelt in all without the scattering parameter S1 of through hole transition structure:

$S1=\left[\begin{array}{cc}S{1}_{11}& S{1}_{12}\\ S{1}_{21}& S{1}_{22}\end{array}\right],$

Wherein, S1₁₁For the input port voltage reflection coefficient of transition structure, S1₂₁For the forward voltage gain of transition structure, S1₁₂ For the backward voltage gain of transition structure, S1₂₂Output port voltage reflection coefficient for transition structure.

Method the most according to claim 1, it is characterised in that: step (3) is extracted electric capacity, inductance and electricity in equivalent circuit The initial value of resistance, is carried out as follows:

(3.1) the scattering parameter S1 obtained with the emulation of 3 D electromagnetic simulation software is converted into transfer matrix T:

$T=\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\left[\begin{array}{cc}\frac{(1+S{1}_{11})(1-S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}& Z_0\frac{(1+S{1}_{11})(1+S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ \frac{1}{Z_0}\frac{(1-S{1}_{11})(1-S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}& \frac{(1-S{1}_{11})(1+S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}\end{array}\right],$

Wherein, A is input and output voltage ratio during output open circuit, and B is the transfger impedance when output short-circuit, and C is for opening when output Transfer admittance during road, D is the input and output current ratio when output short-circuit, Z₀Characteristic impedance for system.

Obtain according to matrix relation between every:

$\left\{\begin{array}{c}A=\frac{(1+S{1}_{11})(1-S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ B=Z_0\frac{(1+S{1}_{11})(1+S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ C=\frac{1}{Z_0}\frac{(1-S{1}_{11})(1-S{1}_{22})-S{1}_{12}S{1}_{21}}{2S{1}_{21}}\\ D=\frac{(1-S{1}_{11})(1+S{1}_{22})+S{1}_{12}S{1}_{21}}{2S{1}_{21}}\end{array}\right.;---<1>$

(3.2) equivalent circuit being made up of lamped element in (1) is simplified again, be equivalent to by input impedance Z₁, output impedance Z₂ With earth impedance Z₃The equivalent circuit of three impedance compositions, wherein input impedance Z₁With output impedance Z₂It is connected in series, earth impedance Z₃One end and input impedance Z₁With output impedance Z₂Junction in parallel, earth impedance Z₃Other end ground connection；

(3.3) by transfer matrix T input impedance Z₁, output impedance Z₂With earth impedance Z₃Three impedance meters are shown as:

$T=\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\left[\begin{array}{cc}1+\frac{Z_1}{Z_3}& Z_1+Z_2+\frac{Z_1{Z}_2}{Z_3}\\ \frac{1}{Z_3}& 1+\frac{Z_2}{Z_3}\end{array}\right]---<2>$

Can obtain according to corresponding relation every in matrix:

$\left\{\begin{array}{c}A=1+\frac{Z_1}{Z_3}\\ B=Z_1+Z_2+\frac{Z_1{Z}_2}{Z_3}\\ C=\frac{1}{Z_3}\\ D=1+\frac{Z_2}{Z_3}\end{array}\right.;---<3>$

According to formula<3>, by input impedance Z₁, output impedance Z₂With earth impedance Z₃These three impedance meter is shown as the letter of transfer matrix T Number, it may be assumed that

$\left\{\begin{array}{c}{Z}_1=\frac{A-1}{C}\\ Z_2=\frac{D-1}{C}\\ Z_3=\frac{1}{C}\end{array}\right.---<4>$

Wushu<1>brings formula<4>into, obtains input impedance Z₁, output impedance Z₂With earth impedance Z₃The occurrence of three impedances；

(3.4) functional relationship between impedance and initial value is set up:

By input impedance Z₁It is expressed as inputting the function of the initial value h1 of inductance L1,

Impedance Z will be exported₂It is expressed as the initial value q1 and transition resistance R1 of the initial value h2 of outputting inductance L2, transition capacitance C1 The function of initial value w1,

By earth impedance Z₃It is expressed as the function of the initial value w2 of the initial value q2 and earth resistance R2 of ground capacity C2, it may be assumed that

$\left\{\begin{array}{c}{Z}_1=j\mathrm{\&omega;}h1\\ Z_2=w1+j\mathrm{\&omega;}h2+\frac{1}{j\mathrm{\&omega;}q1}\\ Z_3=w2+\frac{1}{j\mathrm{\&omega;}q2}\end{array}\right.---<5>$

Wherein ω is angular frequency；

(3.5) formula<5>is utilized to calculate the initial value of each element in equivalent circuit:

(3.5a) to input impedance Z in formula<5>₁Take imaginary part: Im (Z₁)=ω h1, then draws the curve about ω, calculated curve Slope, obtain the value of h1, wherein Im is for taking imaginary part,

(3.5b) to output impedance Z in formula<5>₂Treating excess syndrome portion: Re (Z₂)=w1, obtains the value of w1, and wherein, Re is treating excess syndrome portion；

(3.5c) by output impedance Z in formula<5>₂It is multiplied by ω, then takes imaginary part:Draw about ω²Song Line, the slope of calculated curve, obtain the value of h2, the intercept of calculated curve, obtain the value of q1；

(3.5d) to earth impedance Z in formula<5>₃Treating excess syndrome portion: Re (Z₃)=w2, obtains the value of w2；

(3.5e) to earth impedance Z in formula<5>₃It is multiplied by ω, takes imaginary part:Obtain the value of q2.

Method the most according to claim 1, it is characterised in that: initial value to element each in equivalent circuit in step (4) Carry out simulation optimization, carry out as follows:

(4.1) equivalent circuit determining initial value is emulated, obtain emulation scattering parameter S2:

$S2=\left[\begin{array}{cc}S{2}_{11}& S{2}_{12}\\ S{2}_{21}& S{2}_{22}\end{array}\right],$

Wherein, S2₁₁For the input port voltage reflection coefficient of equivalent circuit emulation, S2₂₁Forward voltage for equivalent circuit emulation Gain, S2₁₂For the backward voltage gain of equivalent circuit emulation, S2₂₂Output port voltage reflection system for equivalent circuit emulation Number；

(4.2) error function of input port voltage reflection coefficient is defined as error (S₁₁), by the error of forward voltage gain Function is defined as error (S₂₁), the error function of backward voltage gain is defined as error (S₁₂), by anti-for output port voltage The error function penetrating coefficient is defined as error (S₂₂) it is defined respectively as:

error(S₁₁)=| S2₁₁-S1₁₁|/|S1₁₁|

error(S₂₁)=| S2₂₁-S1₂₁|/| S1₂₁|

error(S₁₂)=| S2₁₂-S1₁₂|/| S1₁₂|

error(S₂₂)=| S2₂₂-S1₂₂|/| S1₂₂|；

(4.3) the initial value iteration to above-mentioned equivalent circuit of the random optimization program in computer aided design software ADS is utilized Calculate 100 times, obtain the parameter of initial optimization；

(4.4) parameter of initial optimization is iterated again with gradients optimization routine in computer aided design software ADS Calculate, as error (S₁₁)、error(S₁₂)、error(S₂₁)、error(S₂₂) be respectively less than 0.5 time, optimization terminates, and is inputted End value H1 of inductance L1, end value Q1 of transition capacitance C1, end value W1 of transition resistance R1, the end value of outputting inductance L2 H2, end value Q2 of ground capacity C2 and end value W2 of earth resistance R2.