CN102339245B - System and method for compensating circuit direct-current (DC) offset - Google Patents

Abstract

A circuit DC offset compensation system is installed and operated in a computer. The system includes: a data acquisition module, which is used to read the multi-port circuit system data file from the data storage unit of the computer, and obtain the multi-port scattering parameter f(s _k ) from the multi-port circuit system data file; a parameter checking module , is used to check whether the frequency domain distribution of the above scattering parameter f(s _k ) contains data with f(s _k ) being 0, and if the data with f(s _k ) being 0 is not included, perform an interpolation algorithm to complement f( s _k ) is 0 data; and an offset compensation module is used to perform vector fitting DC offset compensation on the scattering parameter f(s _k ), and generate a rational function after compensation. The invention also provides a circuit DC offset compensation method. The implementation of the invention can compensate the DC offset of the circuit generated by the vector fitting algorithm.

Description

Circuit DC offset compensation system and method

technical field

The invention relates to the field of signal simulation and measurement, in particular to a circuit DC offset compensation system and method.

Background technique

Scatter parameter (also known as S parameter) is a network parameter based on the relationship between incident wave and reflected wave, which is suitable for microwave circuit analysis. Describe the circuit network. Scattering parameters are widely used in package and printed circuit board (PCB) channel models.

Scattering parameters can be mathematically expressed in the form of rational functions through vector fitting algorithms. In the circuit simulation operation process, the Hspice circuit simulation software developed by Synopsys uses the rational function matrix (rfm) standard file format to represent rational functions, and uses the recursive convolution (recurisive convolution) algorithm to process the scattering parameter model Time-domain transient problems can improve the efficiency of simulation operations.

However, the rational function obtained when operating on the scattering parameters using the vector fitting algorithm is an approximate result, resulting in a direct current (DC) level error of the circuit. When using the Hspice circuit simulation software, the DC level error of this circuit will affect the time-domain transient simulation results. Referring to FIG. 1 , it is a vector fitting result of 24 port scattering parameters of a memory (DDR3) system through 52 pole-residues. It can be seen from the partial enlarged diagram on the right side of Fig. 1 that there is a level error of 0.1dB when the frequency is 0 (that is, the DC part). This 0.1dB DC level error will cause a 6.98mV DC offset when using Hspice for rational function matrix time domain simulation.

Contents of the invention

In view of the above, it is necessary to provide a circuit DC offset compensation system capable of compensating the circuit DC offset generated by the vector fitting algorithm.

In view of the above, it is necessary to provide a circuit DC offset compensation method capable of compensating the circuit DC offset generated by the vector fitting algorithm.

The circuit DC offset compensation system is installed and operated in a computer. The system includes: a data acquisition module, which is used to read the multi-port circuit system data file from the data storage unit of the computer, and obtain the multi-port scattering parameter f(s _k ) from the multi-port circuit system data file; a parameter checking module , is used to check whether the frequency domain distribution of the above scattering parameter f(s _k ) contains data with f(s _k ) being 0, and if the data with f(s _k ) being 0 is not included, perform an interpolation algorithm to complement f( s _k ) is 0 data; and an offset compensation module is used to perform vector fitting DC offset compensation on the scattering parameter f(s _k ), and generate a rational function after compensation.

The method for compensating the DC offset of the circuit includes the following steps: reading the multi-port circuit system data file from the data storage unit of the computer, and obtaining the multi-port scattering parameter f(s _k ) from the multi-port circuit system data file ; Check whether the frequency domain distribution of the above scattering parameter f(s _k ) contains data with f(s _k ) being 0, and if it does not contain data with f(s _k ) being 0, perform an interpolation algorithm to supplement f(s _k ) is 0 data; and performing vector fitting DC offset compensation on the scattering parameter f(s _k ), to generate a rational function after compensation.

Compared with the prior art, the circuit DC offset compensation system and method of the vector fitting algorithm of the present invention use the multi-port circuit system data in the Touchstone format to simulate and generate the Hspice rational function matrix in the standard file format (*.rfm). This rational function matrix can improve the instantaneous DC level problem in the time domain of the scattering parameter model.

Description of drawings

Figure 1 is the vector fitting result of the scattering parameters of 24 ports.

FIG. 2 is an implementation structure diagram of a preferred embodiment of the circuit DC offset compensation system of the present invention.

Fig. 3 is a flow chart of a preferred embodiment of the circuit DC offset compensation method of the present invention.

FIG. 4 is a detailed flowchart of step S14 in FIG. 3 .

Description of main component symbols

computer 1

DC offset compensation system 12

Data acquisition module 121

Parameter checking module 122

Offset Compensation Module 123

Format conversion module 124

Data Storage Unit 10

CPU 11

output device 2

Detailed ways

As shown in FIG. 1 , it is an implementation structure diagram of a preferred embodiment of a circuit DC offset compensation system 12 of the present invention. In this embodiment, the DC offset compensation system 12 is installed and runs in the computer 1 . The computer 1 includes a data storage unit 10 and a central processing unit (central processing unit, CPU) 11 . The computer 1 is connected to an output device 2, such as a monitor. Data storage unit 10 is used for storing the multi-port (N-ports) circuit system data file of Touchstone format (such as *.SNP), and this multi-port circuit system data file comprises the multi-port (N-ports) scattering parameter f( s _k ). Wherein, the f(s _k ) represents the value of the scattering parameter at each frequency point. The Touchstone format is a standard file format (Touchstone File Format Specification) for data storage regulated by the IBIS Association. Described DC offset compensation system 12 is used for reading the multi-port (N-ports) circuit system data file of Touchstone standard file format in the data storage unit 10, and the multi-port in the multi-port circuit system data file The scattering parameters are processed to generate a rational function compensated for the DC offset, and the rational function is output to an output device 2, such as a display.

The DC offset compensation system 12 includes a data acquisition module 121 , a parameter checking module 122 , an offset compensation module 123 , and a format conversion module 124 . The module referred to in the present invention is a computer program segment capable of accomplishing a specific function, which is more suitable than a program for describing the execution process of software in a computer, so the description of software in the present invention is described as a module.

The data acquisition module 121 is used to read the multi-port circuit system data file in the Touchstone standard file format from the data storage unit 10, and obtain the multi-port scattering parameter f(s _k ) from the multi-port circuit system data file. Wherein, the f(s _k ) represents the value of the scattering parameter at each frequency point, and s _k is the frequency of the scattering parameter.

The parameter checking module 122 is used to check whether the frequency domain distribution of the scattering parameter f(s _k ) contains data with a frequency of 0, that is, whether there is data with f(s _k ) being 0. When the data with a frequency of 0 is not included, the interpolation algorithm is executed to complement the data with a frequency of 0. A frequency of 0 is DC. The interpolation algorithm is a method of determining some intermediate points between known points on an ideal trajectory profile according to a given mathematical function.

The offset compensation module 123 is used for performing vector fitting DC compensation on the scattering parameter f(s _k ), and generating a rational function after compensation. Among them, the DC compensation method of vector fitting is as follows:

(1) Use the formula:

Where u=1˜M/2, M is the number of extremums, and the initial extremum P _m is calculated.

(2) The (σf) _fit (s) function and the unknown variable r _m in the σ _fit (s) function, d, Form an X matrix, where:

${\left(\mathrm{\σ\; f}\right)}_{\mathrm{fit}}\left(\mathrm{the\; s}\right)=f\left(0\right)+\mathrm{the\; s}(\underset{m=1}{\overset{m}{\mathrm{\Σ}}}\frac{r_m}{\mathrm{the\; s}-p_m}+d)$ and ${\mathrm{\σ}}_{\mathrm{fit}}\left(\mathrm{the\; s}\right)=\underset{m=1}{\overset{m}{\mathrm{\Σ}}}\frac{{\tilde{r}}_m}{\mathrm{the\; s}-p_m}+1$

And substitute the initial extremum P _m and the scattering parameter f(s _k ) into matrix A and matrix B respectively to form the following equation:

^{Then calculate} the ^unknown variable r _m , d, Therefore, the (σf) _fit (s) function and the σ _fit (s) function are calculated.

(3) When the above (2) has been executed only once, record the function (σf) _fit (s) obtained above as (σf) _{fit_old} (s), and use the formula:

Wherein, p _m =z _m , m=1~M, recalculate the initial extremum p _m , and use the recalculated p _m to re-execute (2) to obtain the updated (σf) _fit (s ) function and σ _fit (s) function.

(4) When the above (2) has been executed twice or more, judge whether |(σf) _fit (s)-(σf) _{fit_old} (s)|<tol, where tol is a user preset error value. If the judgment result is No, return to execute (3), and if the judgment result is Yes, use the updated σ _fit (s) function as a rational function after compensation.

As mentioned earlier, the Hspice circuit simulation software developed by Synopsys uses the rational function matrix standard file format. In order to be compatible with the Hspice circuit simulation software, the format conversion module 124 is used to convert the generated compensated rational function into a rational function matrix standard file format. The conversion process is as follows:

First, the scattering parameter f(s _k ) is expressed in the following matrix form:

$\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; NN</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>\end{array}\right]$

Secondly, substituting S _ij (s) in the above matrix, where i, j=1～N, respectively into the rational function after compensation, the following matrix can be obtained:

$S\left(\mathrm{the\; s}\right)\&ap;\hat{S}\left(\mathrm{the\; s}\right)=\left[\begin{array}{cccc}{\hat{S}}_{11}\left(\mathrm{the\; s}\right)& {\hat{S}}_{12}\left(\mathrm{the\; s}\right)& ...& {\hat{S}}_{1N}\left(\mathrm{the\; s}\right)\\ {\hat{S}}_{\mathrm{twenty\; one}}\left(\mathrm{the\; s}\right)& {\hat{S}}_{\mathrm{twenty\; two}}\left(\mathrm{the\; s}\right)& ...& {\hat{S}}_{2N}\left(\mathrm{the\; s}\right)\\ ...& ...& ...& ...\\ {\hat{S}}_{N1}\left(\mathrm{the\; s}\right)& {\hat{S}}_{N2}\left(\mathrm{the\; s}\right)& ...& {\hat{S}}_{\mathrm{NN}}\left(\mathrm{the\; s}\right)\end{array}\right],$ in, ${\hat{S}}_{\mathrm{ij}}\left(\mathrm{the\; s}\right)={\hat{S}}_{\mathrm{ij}}\left(0\right)+\mathrm{the\; s}(\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{r_m^{i,j}}{{\mathrm{the\; s}-p}_m^{i,j}}+d^{i,j}),$

Finally, the above matrix in Synthesize the following rational function matrix standard form:

${\hat{S}}_{\mathrm{ij}}\left(\mathrm{the\; s}\right)=\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{{\tilde{r}}_m^{i,j}}{\mathrm{the\; s}-p_m^{i,j}}+{\tilde{d}}^{i,j}+{\mathrm{the\; se}}^{i,j},$ in, ${\tilde{r}}_m^{i,j}=p_m^{i,j}{r}_m^{i,j},$ ${\tilde{d}}_m^{i,j}={\hat{S}}_{\mathrm{ij}}\left(0\right)+\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}{r}_m^{i,j},$ $e_m^{i,j}=d_m^{i,j}.$

As shown in FIG. 2 , it is a flow chart of a preferred embodiment of the circuit DC offset compensation method of the present invention.

Step S10 , the data acquisition module 121 reads the multi-port circuit system data file in the Touchstone standard file format from the data storage unit 10 .

In step S11, the data acquisition module 121 acquires the multi-port scattering parameter f(s _k ) from the above-mentioned multi-port circuit system data file. Wherein, the f(s _k ) represents the value of the scattering parameter at each frequency point, and s _k is the frequency of the scattering parameter.

In step S12, the parameter checking module 122 checks whether the frequency domain distribution of the scattering parameter f(s _k ) contains data with a frequency of 0, that is, whether there is data with f(s _k ) being 0. A frequency of 0 is DC.

When the data with a frequency of 0 is not included, go to step S13, and the parameter checking module 122 executes an interpolation algorithm to complement the data with a frequency of 0. The interpolation algorithm is a method of determining some intermediate points between known points on an ideal trajectory profile according to a given mathematical function.

When data with a frequency of 0 is included, enter step S14, and the offset compensation module 123 performs vector fitting DC compensation on the scattering parameter f(s _k ), generates a rational function after compensation, and stores the rational function after compensation to the data storage unit 10. For a detailed flowchart of this step, see Figure 4 below.

In step S15, the format conversion module 124 converts the generated compensated rational function into a rational function matrix standard file format. The conversion process is as follows:

First, the scattering parameter f(s _k ) is expressed in the following matrix form:

$\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; NN</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span>\end{array}\right]$

Secondly, substituting S _ij (s) in the above matrix, where i, j=1～N, respectively into the rational function after compensation, the following matrix can be obtained:

$S\left(\mathrm{the\; s}\right)\&ap;\hat{S}\left(\mathrm{the\; s}\right)=\left[\begin{array}{cccc}{\hat{S}}_{11}\left(\mathrm{the\; s}\right)& {\hat{S}}_{12}\left(\mathrm{the\; s}\right)& ...& {\hat{S}}_{1N}\left(\mathrm{the\; s}\right)\\ {\hat{S}}_{\mathrm{twenty\; one}}\left(\mathrm{the\; s}\right)& {\hat{S}}_{\mathrm{twenty\; two}}\left(\mathrm{the\; s}\right)& ...& {\hat{S}}_{2N}\left(\mathrm{the\; s}\right)\\ ...& ...& ...& ...\\ {\hat{S}}_{N1}\left(\mathrm{the\; s}\right)& {\hat{S}}_{N2}\left(\mathrm{the\; s}\right)& ...& {\hat{S}}_{\mathrm{NN}}\left(\mathrm{the\; s}\right)\end{array}\right],$ in, ${\hat{S}}_{\mathrm{ij}}\left(\mathrm{the\; s}\right)={\hat{S}}_{\mathrm{ij}}\left(0\right)+\mathrm{the\; s}(\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{r_m^{i,j}}{{\mathrm{the\; s}-p}_m^{i,j}}+d^{i,j}),$

Finally, the above matrix in Synthesize the following rational function matrix standard form:

${\hat{S}}_{\mathrm{ij}}\left(\mathrm{the\; s}\right)=\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{{\tilde{r}}_m^{i,j}}{\mathrm{the\; s}-p_m^{i,j}}+{\tilde{d}}^{i,j}+{\mathrm{the\; se}}^{i,j},$ in, ${\tilde{r}}_m^{i,j}=p_m^{i,j}{r}_m^{i,j},$ ${\tilde{d}}_m^{i,j}={\hat{S}}_{\mathrm{ij}}\left(0\right)+\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}{r}_m^{i,j},$ $e_m^{i,j}=d_m^{i,j}.$

Referring to FIG. 4 , it is a detailed flowchart of step S14 in FIG. 3 .

Step S140, the offset compensation module 123 uses the formula:

Where u=1˜M/2, M is the number of extremums, and the initial extremum P _m is calculated.

In step S141, the offset compensation module 123 converts the (σf) _fit (s) function and the unknown variables r _m , d _, Form an X matrix, where:

${\left(\mathrm{\&sigma;\; f}\right)}_{\mathrm{fit}}\left(\mathrm{the\; s}\right)=f\left(0\right)+\mathrm{the\; s}(\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{r_m}{\mathrm{the\; s}-p_m}+d)$ and ${\mathrm{\&sigma;}}_{\mathrm{fit}}\left(\mathrm{the\; s}\right)=\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{{\tilde{r}}_m}{\mathrm{the\; s}-p_m}+1$

And substitute the initial extremum P _m and the scattering parameter f(s _k ) into matrix A and matrix B respectively to form the following equation:

^{Then calculate} the ^unknown variable r _m , d, Therefore, the (σf) _fit (s) function and the σ _fit (s) function are calculated.

In step S142, the offset compensation module 123 determines whether the above step S141 has been performed only once. In the case that the above step S141 is executed only once, the process proceeds to step S143, and the offset compensation module 123 records the obtained function (σf) _fit (s) as (σf) _{fit_old} (S).

In step S144, the offset compensation module 123 uses the formula:

Wherein, p _m =z _m , m=1~M, recalculate the initial extremum p _m , and use the recalculated p _m to return to step S141 to obtain the updated (σf) _fit (s) function and σ _fit (s) function.

In the case that the above-mentioned step S141 has been executed twice or more than twice, in step S145, the offset compensation module 123 judges whether |(σf) _fit (s)-(σf) _{fit_old} (s)|<tol, wherein , tol is a user preset error value.

In the case that the judgment result is no, return to step S144, and in the case of yes, enter step S145, the offset compensation module 123 uses the updated, i.e. the last generated σ _fit (s) function as compensation The following rational function.

Claims (8)

1. A circuit dc offset compensation system installed and operating in a computer, the system comprising:

a data acquisition module for reading the multi-port circuit system data file from the data storage unit of the computer and acquiring the multi-port scattering parameter f(s) from the multi-port circuit system data file_k)；

A parameter checking module for checking the scattering parameter f(s)_k) Whether f(s) is included in the frequency domain distribution of (1)_k) Data of 0, if f(s) is not included_k) When the data is 0, executing interpolation algorithm to complement f(s)_k) Data of 0; and

offset compensation module for compensating scattering parameter f(s)_k) Performing vector-fitted DC offset compensation to generate a compensated rational function, comprising:

(1) using the formula:

where u is 1-M/2, M is the number of extreme values, and calculating the initial extreme value P_m；

(2) Will (sigma f)_fit(s) function and σ_fitThe unknown variables in the(s) function form an X matrix, where:

and

and will start extreme value P_mAnd a scattering parameter f(s)_k) Substituting into matrix a and matrix B, respectively, forms the following equation:

then by X ═ A^TA)^-1A^TB calculates the unknown variable, and therefore (σ f)_fit(s) function and σ_fit(s) a function;

(3) in the case where the above-mentioned (2) is executed only once, the function (σ f) to be calculated_fit(s) is reported as (σ f)_{fit_old}(s) and using the formula:

wherein p is_m＝z_mM is 1-M, and the initial extreme value p is recalculated_mAnd using the recalculated p_mRe-executing (2) to obtain updated (σ f)_fit(s) function and σ_fit(s) a function; and

(4) in the case where the above-mentioned (2) is performed twice or more, it is judged whether or not | (σ f)_fit(s)-(σf)_{fit_old}(s) | < tol, wherein tol is an error value preset by a user, returning to execute (3) in the case that the judgment result is no, and updating the sigma after updating in the case that the judgment result is yes_fitThe(s) function is used as a rational function after compensation.

2. The circuit dc offset compensation system of claim 1, further comprising:

and the format conversion module is used for converting the generated compensated rational function into a rational function matrix standard file format.

3. The circuit dc offset compensation system of claim 1, wherein said multi-port circuitry data file is stored in a data storage unit in a touchtone standard file format.

4. The circuit dc offset compensation system of claim 2, wherein said converting the generated compensated rational function into a rational function matrix standard archive format comprises:

(1) the scattering parameter f(s)_k) Expressed in the form of a matrix:

(2) s in the matrix is_ij(s), where i, j is 1 to N, and the compensated rational functions are substituted into the matrix, the following matrix is obtained:

wherein,and

(3) in the above matrixSynthesizing the following rational function matrix standard format:

wherein,

5. a method for compensating a DC offset of a circuit, the method comprising the steps of:

reading a multiport circuitry data file from a data storage unit of a computer and obtaining a multiport scattering parameter f(s) from the multiport circuitry data file_k)；

Examining the scattering parameter f(s)_k) Whether f(s) is included in the frequency domain distribution of (1)_k) Data of 0, if f(s) is not included_k) When the data is 0, executing interpolation algorithm to complement f(s)_k) Data of 0; and

for the scattering parameter f(s)_k) Performing vector-fitted DC offset compensation to generate a compensated rational function, comprising the steps of:

(1) using the formula:

where u is 1-M/2, M is the number of extreme values, and calculating the initial extreme value P_m；

(2) Will (sigma f)_fit(s) function and σ_fitThe unknown variables in the(s) function form an X matrix, where:

and

and will start extreme value P_mAnd a scattering parameter f(s)_k) Substituting into matrix a and matrix B, respectively, forms the following equation:

then by X ═ A^TA)^-1A^TB calculates the unknown variable, and therefore (σ f)_fit(s) function and σ_fit(s) a function;

(3) in the case where the above-mentioned (2) is executed only once, the function (σ f) to be calculated_fit(s) is reported as (σ f)_{fit_old}(s) and using the formula:

wherein p is_m＝z_mM is 1-M, and the initial extreme value p is recalculated_mAnd using the recalculated p_mRe-executing (2) to obtain updated (σ f)_fit(s) function and σ_fit(s) a function; and

(4) in the case where the above-mentioned (2) is performed twice or more, it is judged whether or not | (σ f)_fit(s)-(σf)_{fit_old}(s) | < tol, wherein tol is preset by a userIn the case that the judgment result is no, the procedure returns to the step (3), and in the case that the judgment result is yes, the updated sigma is used_fitThe(s) function is used as a rational function after compensation.

6. The method of circuit dc offset compensation of claim 5, further comprising:

and converting the generated compensated rational function into a rational function matrix standard file format.

7. The method as claimed in claim 5, wherein the multiport circuitry data file is stored in a data storage unit in a Touchstone standard file format.

8. The method of claim 6, wherein said step of converting the compensated rational function into a rational function matrix standard file format comprises the steps of:

(1) the scattering parameter f(s)_k) Expressed in the form of a matrix:

(2) s in the matrix is_ij(s), where i, j is 1 to N, and the compensated rational functions are substituted into the matrix, the following matrix is obtained:

wherein,and

(3) in the above matrixSynthesizing the following rational function matrix standard format:

wherein,