CN104459395A - Calibration frequency mixer scaling method based on time-frequency double domains - Google Patents

Abstract

The invention provides a calibration frequency mixer scaling method based on time-frequency double domains. According to the calibration frequency mixer scaling method based on the time-frequency double domains, characteristic scaling data of a calibration frequency mixer are extracted by means of measured information of the vector network analyzer time domain and measured information of the frequency domain; in the time domain measurement mode, a signal containing frequency conversion loss information of the calibration frequency mixer on a time shaft, a port mismatch signal of the frequency mixer and a directional error of a complete machine are completely separated, can be extracted independently by means of a time domain gate and then are converted into the frequency domain. By the adoption of the calibration frequency mixer scaling method based on the time-frequency double domains, mutual influence between signals can be reduced, the requirements for the performance indexes of the calibration frequency mixer are lowered, the problem that scaling can not be conducted due to the fact that the frequency conversion loss of the frequency mixer is too large and beyond the reflective measurement dynamic range of a vector network analyzer is solved, the characterization precision of the calibration frequency mixer is improved, the scaling process of the calibration frequency mixer is simplified, and measurement and connection repeatability errors are reduced.

Description

A kind of calibration frequency mixer calibrating method based on time-frequency dual domain

Technical field

The present invention relates to microwave and millimeter wave part characteristic parameter testing technical field, be specifically related to a kind of calibration frequency mixer calibrating method based on time-frequency dual domain.

Background technology

Along with the extensive employing of digital modulation technique in such as broadband digital communication system of various advanced person, in order to reduce the bit error rate of system, designer not only needs the amplitude versus frequency characte being concerned about whole radio-frequency system, also requires to measure its phase-frequency characteristic simultaneously.Vector network analyzer is a kind of general microwave and millimeter wave surveying instrument, for what is called as identical in input and output frequencies such as amplifier, wave filter, diplexers widely used in radio-frequency system with frequency parts, the accurate measurement to its amplitude-frequency and phase frequency vectorial property can be realized.And for widely used as frequency conversion devices such as frequency mixer in radio-frequency system, because its input and output frequency is different, a difficult point to the measurement of its phase place and group delay property always, this is because phase measurement is based on common frequency measurement, two phase places existed between frequency difference signal can change along with the change of Measuring Time, are not definite values.

Must calibrate before using vector network analyzer to carry out the measurement of accurate frequency mixer vectorial property, one of them calibration steps needs between two calibration ports, connect the known calibration frequency mixer of a characteristic, the rf inputs mouth of this calibration frequency mixer and the matching properties of medium frequency output end mouth, forward direction and reverse conversion loss characteristic must be completely known, all known characteristic informations are Vector Message, namely comprise amplitude and phase information simultaneously.The calibration frequency mixer that utilization level is known can solve error term corresponding in complete machine error model in a calibration process, the thru calibration in the similar traditional S parameter full two-port calibration process of its effect.

Actual carry out the calibration of vector frequency mixer time, when first time uses certain calibration frequency mixer, its characteristic present's data are normally unknown.Vector network analyzer provides an extra frequency mixer and characterizes function and calibrate frequency mixer for this reason, extracts the vectorial property characterization data of calibration frequency mixer, and extracted result is kept in a calibration file, for using in a calibration process.Calibration frequency mixer is made up of a frequency mixer and a wave filter, the function of its median filter is the unwanted mixed product of filtering, connect the known reflectance standard (being generally open circuit device, short-circuiting device and load machinery calibrating device or Electronic Calibration part) of 3 characteristics at the filter output mouth of calibration frequency mixer during calibration, the demarcation of calibrating frequency mixer can be realized.

In order to realize calibrating frequency mixer calibration accurately, following restriction must be done to calibration frequency mixer:

1) working frequency range can cover and need calibrate frequency range;

2) frequency mixer must be reciprocity, and namely prevention at radio-frequency port must be consistent to the magnitude-phase characteristics of prevention at radio-frequency port conversion loss to intermediate frequency port, intermediate frequency port;

3) frequency mixer rf inputs mouth should have good port match, and its return loss should be better than 10dB;

4) conversion loss in frequency mixer forward direction and direction is enough low, should be less than 10dB;

Ensured by the implementation of frequency mixer the requirement of frequency mixer reciprocity property, most passive frequency mixer all can meet this requirement.But the matching performance of the actual calibration frequency mixer used its prevention at radio-frequency port general is all not high, reflection coefficient of port loss is many lower than 10dB, when carrying out the calibration of calibration frequency mixer, the signal arriving prevention at radio-frequency port through forward direction and reverse double conversion is submerged in the mismatch signal of prevention at radio-frequency port completely, cause calibration precision to decline, directly affect the calibration accuracy of complete machine and the precision of vector frequency mixer measurement.In addition, for much work to the frequency mixer of microwave and millimeter wave section and harmonic mixer, how far its unidirectional conversion loss exemplary amplitude value is greater than 10dB, when causing calibrating vector network analyzer port accepts to the signal comprising conversion loss width phase information be less than the residual directional error signal of complete machine, exceed the dynamic range of reflection measurement, now cannot calibrate frequency mixer.In addition traditional frequency mixer calibration process needs to carry out No. 3 frequency mixer and measures connection after completing single port calibration, whole process is more loaded down with trivial details.

By describing above and can finding out: because traditional calibration frequency mixer calibration process carries out on frequency domain completely, a lot of restriction is had to the technical indicator of frequency mixer, cannot calibrate it when calibrating mixer conversion loss and being excessive, calibration precision is poor, and process is loaded down with trivial details.

Summary of the invention

The object of this invention is to provide a kind of calibration frequency mixer calibrating method based on time-frequency dual domain, to reduce the requirement to calibration frequency mixer performance index, expand the conversion loss scope of calibration calibration frequency mixer, improve the precision of calibration frequency mixer calibration, simplify the calibration process of calibration frequency mixer.

For reaching above-mentioned purpose, embodiments providing a kind of calibration frequency mixer calibrating method based on time-frequency dual domain, comprising:

The radio frequency incident frequencies, local frequency, the mixing number of times that characterize frequency mixer are set, calculate IF-FRE;

RF input power, local oscillation power are set, make described frequency mixer be operated in correct linear condition, and consistent when when making sign frequency mixer, the input state of local oscillation power is calibrated with vector frequency mixer;

Vector network analyzer does single port calibration within the scope of described frequency mixer radio frequency incoming frequency;

Described sign frequency mixer prevention at radio-frequency port is connected with the calibration port of vector network analyzer, connect local oscillation signal, and connecting the known high reverse--bias standard of a characteristic at the intermediate-frequency filter output port of calibration calibration frequency mixer, the known features value of this reflectance standard in mixer intermediate-frequency reference frequency output is Γ _iF;

Arrange single triggering make vector network analyzer complete single pass and be in hold mode, corresponding frequency domain measurement value is S ₁₁;

By in the time domain measurement function of vector network analyzer, measurement pattern is set to be with logical impulse pattern, and opens this time domain measurement function, obtains two separated pulses on a timeline; Wherein, the first time domain impulse comprises the S of calibration calibration frequency mixer _11RFinformation, the second time domain impulse comprise calibrate calibration frequency mixer front reverse conversion loss T ₁, T ₂with reflectance standard characteristic information Γ _iF;

The center of time domain door is placed in the crest of described first time domain impulse, the initial sum stop value of described time domain door is placed in respectively the trough of the described first time domain impulse left and right sides, select the type of described time domain door logical for being with, open described time domain door function, close described time domain measurement function and return frequency domain, extract the frequency domain information corresponding to the first time domain impulse, the frequency-region signal corresponding to it is the S of described sign frequency mixer _11RF;

Reopen described time domain measurement function, and close described time domain door function, the center of described time domain door is placed in the crest of described second time domain impulse, the initial sum of this time domain door is stopped the trough that should be placed in described second time domain impulse both sides respectively, selecting the type of this time domain door logical for being with, opening this time domain door function, closing described time domain measurement pattern and return frequency domain, extract the frequency domain information corresponding to the second time domain impulse, the frequency domain measurement value of its correspondence is S _11T;

According to the known features value Γ of reflectance standard in mixer intermediate-frequency reference frequency output _iF, frequency domain measurement value S corresponding to described second pulse _11Tand equation S _11T=T ₁t ₂Γ _iF, it is known,

S is calculated according to following equation _22IF:

$S_{22\mathrm{IF}}=\frac{1}{{\mathrm{\Γ}}_{\mathrm{IF}}}+\frac{S_{11T}}{(S_{11}-S_{11\mathrm{RF}}){\mathrm{\Γ}}_{\mathrm{IF}}}.$

Wherein, described calibration frequency mixer is reciprocity;

The front anti-and reverse conversion loss T of described calibration frequency mixer ₁and T ₂determine by following equation:

$T_1=T_2=\±\sqrt{\frac{S_{11T}}{{\mathrm{\Γ}}_{\mathrm{IF}}}}.$

Further, according to equation two the value amplitudes obtained are equal, phase 180 °;

Wherein, real T ₁and T ₂value only have 1, by S _11T/ Γ _iFcorresponding group delay duration is determined.

Technique scheme has following beneficial effect:

The method utilizes the metrical information in vector network analyzer time domain and frequency domain two territories to extract calibration frequency mixer property scale data simultaneously; Comprise the signal of calibration mixer conversion loss information and the port mismatch signal of frequency mixer under time domain measurement pattern on a timeline, the directional error of complete machine is completely separated, time domain door can be utilized to extract respectively and transform to frequency domain again; The method can reduce influencing each other between each signal, reduce the requirement to calibration frequency mixer performance index, solve the excessive difficult problem exceeding vector network analyzer reflection measurement dynamic range and can not carry out calibrating of mixer conversion loss, improve the precision that calibration frequency mixer characterizes; Simplify calibration frequency mixer calibration process, reduce and measure connection reproducibility error.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is vector frequency mixer calibration error model;

Fig. 2 is calibration frequency mixer calibration model;

Fig. 3 is the process flow diagram of a kind of calibration frequency mixer calibrating method based on time-frequency dual domain of the embodiment of the present invention;

Fig. 4 is the structural representation of the calibration frequency mixer used that the embodiment of the present invention uses;

Fig. 5 is in the embodiment of the present invention, the oscillogram of time domain measurement.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

The measurement of Modern Vector Network Analyzer by adopting unique technology scheme can realize frequency mixer amplitude and phase propetry.The vector network analyzer used is four port network analysers, inner integrated two independently signal source and parametric mixer switches, and two sources are respectively used to radio-frequency (RF) excited in frequency mixer measuring process and local oscillator drives.Also can use two-port vector network analyzer, now local oscillation signal by one, outside independently signal source and power splitter provide, error model corresponding to whole measurement composition system is as shown in Figure 1.Whole vector frequency mixer calibration process comprises source calibration, radio frequency and IF-FRE two-port and calibrates for error and transmit tracker and calibrate for error 3 stages.The characterisitic parameter of frequency mixer is directly related with source and local oscillation power, and power meter calibrates for error in conjunction with two-port and can realize removing the source of system mismatch error and the calibration of local oscillation signal power level.Machinery or Electronic Calibration part are used for carrying out two-port and calibrate for error, and determine the directivity E in error model _dRF, source coupling E _sRF, skin tracking E _rRFwith load matched E _lIFtotally 4 kinds of systematic errors.When carrying out the calibration of vector frequency mixer and measure, also must use a parametric mixer, parametric mixer is connected to the R of port one front panel jumper wire device always ₁export and R ₁between input, wherein vector network analyzer R ₁source exports reference signal and is directly inputted to R when carrying out port match calibration and measuring by inner switch ₁reference receiver, is carrying out transmitting action points E in error model _tcalibration solve when measuring with mixer conversion loss vectorial property, R ₁source reference signal is switched to the input of parametric mixer by inner electronic switch, and the mixed frequency signal produced after the local oscillator mixing identical with measuring frequency mixer is input to inner R ₁reference receiver, for the output of measuring frequency mixer provides with reference signal frequently.When carrying out frequency mixer transmission tracker and calibrating for error, the calibration frequency mixer that connection performance is completely known between two calibration ports, the thru calibration of the similar traditional two-port calibration of process, determines the transmission tracking error item E in error model shown in Fig. 1 _t.

In whole 3 step calibrations, front 2 step Technical comparing are ripe, and the calibration accuracy of the 3rd step depends primarily on the calibration calibration data of frequency mixer and the matching degree of actual characteristic.

Calibration frequency mixer calibrate the model that uses as shown in Figure 2, and whole calibration process is exactly the S that will determine calibration frequency mixer _11RF, S _22IF, T ₁and T ₂totally 4 values, concrete steps are as follows:

1) first vector network analyzer carries out single port calibration, the directivity E in Confirming model _dRF, source coupling E _sRF, skin tracking E _rRFthe systematic error of totally 3 complete machines;

2) will the prevention at radio-frequency port of calibration calibration frequency mixer be needed to be connected with the vector network analyzer port carrying out single port calibration, the local oscillator port of calibration frequency mixer connects local oscillation signal, for ensureing calibration accuracy, completely the same when the local oscillator input state during calibration of calibration frequency mixer must be calibrated with vector frequency mixer;

3) for Fig. 2 institute representation model, the S corresponding to calibration frequency mixer prevention at radio-frequency port ₁₁measured value is as follows:

$S_{11}=S_{11\mathrm{RF}}+\frac{T_1{T}_2{\mathrm{\Γ}}_{\mathrm{IF}}}{1-S_{22\mathrm{IF}}{\mathrm{\Γ}}_{\mathrm{IF}}}...\left(1\right)$

4) connect the known reflectance standard of 3 characteristics respectively at the output port of calibration mixer filter, the characteristic value that 3 reflectance standard are known on mixer intermediate-frequency output frequency is respectively Γ _1IF, Γ _2IFand Γ _3IF, the single port S of the calibration frequency mixer prevention at radio-frequency port that vector network analyzer is corresponding ₁₁measured value is respectively M _1RF, M _2RFand M _3RF, error model according to Fig. 2, the property scale value that can obtain frequency mixer is as follows:

$S_{11\mathrm{RF}}=\frac{{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{2\mathrm{IF}}{M}_{3\mathrm{RF}}(M_{1\mathrm{RF}}-M_{2\mathrm{RF}})+{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}{M}_{2\mathrm{RF}}(M_{3\mathrm{RF}}-M_{1\mathrm{RF}})+{\mathrm{\Γ}}_{2\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}{M}_{1\mathrm{RF}}(M_{2\mathrm{RF}}-M_{3\mathrm{RF}})}{{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{2\mathrm{IF}}(M_{1\mathrm{RF}}-M_{2\mathrm{RF}})+{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{3\mathrm{RF}}-M_{1\mathrm{RF}})+{\mathrm{\Γ}}_{2\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{2\mathrm{RF}}-M_{3\mathrm{RF}})}...\left(2\right)$

$S_{22\mathrm{IF}}=\frac{{\mathrm{\Γ}}_{2\mathrm{IF}}(M_{1\mathrm{RF}}-M_{3\mathrm{RF}})+{\mathrm{\Γ}}_{1\mathrm{IF}}(M_{3\mathrm{RF}}-M_{2\mathrm{RF}})+{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{2\mathrm{RF}}-M_{1\mathrm{RF}})}{{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{2\mathrm{IF}}(M_{1\mathrm{RF}}-M_{2\mathrm{RF}})+{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{3\mathrm{RF}}-M_{1\mathrm{RF}})+{\mathrm{\Γ}}_{2\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{2\mathrm{RF}}-M_{3\mathrm{RF}})}...\left(3\right)$

$T_1{T}_2=S_{11\mathrm{RF}}{S}_{22\mathrm{IF}}+\frac{{\mathrm{\Γ}}_{1\mathrm{IF}}{M}_{1\mathrm{RF}}(M_{2\mathrm{RF}}-M_{3\mathrm{RF}})+{\mathrm{\Γ}}_{2\mathrm{IF}}{M}_{2\mathrm{RF}}(M_{3\mathrm{RF}}-M_{2\mathrm{RF}})+{\mathrm{\Γ}}_{3\mathrm{IF}}{M}_{3\mathrm{RF}}(M_{1\mathrm{RF}}-M_{2\mathrm{RF}})}{{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{2\mathrm{IF}}(M_{1\mathrm{RF}}-M_{2\mathrm{RF}})+{\mathrm{\Γ}}_{1\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{3\mathrm{RF}}-M_{1\mathrm{RF}})+{\mathrm{\Γ}}_{2\mathrm{IF}}{\mathrm{\Γ}}_{3\mathrm{IF}}(M_{2\mathrm{RF}}-M_{3\mathrm{RF}})}...\left(4\right)$

$T_1=T_2=\±\sqrt{T_1{T}_2}...\left(5\right)$

Equation (5) can obtain two values, and these two value amplitudes are equal, phase 180 °, but actual value only has 1, correct T ₁and T ₂choosing by T of phase value ₁t ₂corresponding group delay duration is determined, is exactly more than traditional calibration frequency mixer calibrating method.

At present when carrying out the calibration of calibration frequency mixer vector, carry out on frequency domain completely, now vector network analyzer port accepts is to the composite signal be made up of following signal:

1) the directional error signal that complete machine is residual, determines the dynamic range of reflection measurement, also determines the amplitude range of calibration calibration mixer conversion loss simultaneously;

2) through the various mismatch signal of multiple reflections and Multipath Transmission;

3) other frequency mixer output components various reflected by intermediate-frequency filter turn back to the signal of prevention at radio-frequency port through frequency conversion again;

4) get back to prevention at radio-frequency port through upper and lower double conversion and comprise the signal calibrating sideband conversion loss width phase information needed for frequency mixer.

Characteristic present data S wherein in the frequency mixer of calibration shown in Fig. 2 model _11RF, T ₁, T ₂and S _22IFbe used for solving the error term E in the vector frequency mixer calibration error model shown in Fig. 1 _t.Because the signal comprising calibration frequency mixer vector converter loss information need through upper and lower double conversion, and actual itself the prevention at radio-frequency port matching properties of calibration frequency mixer used is usually poor, cause the signal comprising calibration mixer conversion loss width phase information received far below port mismatch signal and the some other useless mixed product frequency variation signal again of calibrating frequency mixer, like this when significantly the change of mismatch error signal magnitude-phase characteristics is drifted about for other, the T solved in frequency mixer calibration process can be caused ₁and T ₂there is comparatively big error in value, directly affects the precision of vector frequency mixer calibration below, and then the precision that impact vector frequency mixer is measured.When to microwave and millimeter wave frequency range and harmonic mixer calibration, because conversion loss is very large, comprise the amplitude of calibration mixer conversion loss information signal even lower than the directional error signal of vector network analyzer complete machine, exceed the dynamic range of reflection measurement, now cannot calibrate calibration frequency mixer.The calibration process calibrating frequency mixer in addition completes after single port is calibrated to be needed to measure through 3 times to connect, and not only process is loaded down with trivial details, and too much measurement connection procedure can introduce extra measurement connection reproducibility error, reduces the precision that calibration frequency mixer is calibrated.

Because traditional calibration frequency mixer calibration process carries out on frequency domain completely, have a lot of restriction to the technical indicator of frequency mixer, cannot calibrate it when calibrating mixer conversion loss and being excessive, calibration precision is poor, and process is loaded down with trivial details.For the deficiency that conventional calibration frequency mixer calibration process exists, patent of the present invention proposes a kind of calibration frequency mixer calibrating method based on time-frequency dual domain, mainly solves the deficiency of following two aspects:

1) reduce the requirement to calibration frequency mixer performance index, expand the conversion loss scope of calibration calibration frequency mixer, improve the precision of calibration frequency mixer calibration.The calibration frequency mixer calibrating method based on time-frequency dual domain that the present invention extracts utilizes the metrical information in time domain and frequency domain two territories to carry out the calibration of calibration frequency mixer simultaneously, under time domain measurement pattern, the mismatch reflected signal of frequency mixer prevention at radio-frequency port on a timeline, remaining directivity error signal be distinct with the signal carrying two-way conversion loss information, can be extracted respectively by the time domain door of vector network analyzer, and then switch back to frequency domain, can not influence each other between each signal, because this reducing the requirement to indexs such as mixer ports coupling and conversion loss, solve the difficult problem cannot calibrated when mixer conversion loss is excessive exceedes reflection measurement dynamic range simultaneously, and the precision of calibrating frequency mixer and calibrating can be improved further compared with traditional method,

2) calibration process of calibration frequency mixer is simplified.Traditional frequency mixer calibration process also needs after completing single port calibration to carry out measuring for 3 times to connect, when the calibration frequency mixer calibrating method based on time-frequency dual domain that patent of the present invention proposes is because calibrating, each signal is separated at time shaft, time domain door can be utilized to extract respectively, therefore only need carry out measuring connection for 1 time after completing single port calibration and can complete calibration, simplify the calibration process of calibration frequency mixer.

Embodiment one

The calibration frequency mixer that the present embodiment uses as shown in Figure 4, is made up of the frequency mixer of forward direction reverse conversion loss characteristic reciprocity and a wave filter.Before so-called calibration frequency mixer, reverse characteristic reciprocity refers to that forward exports identical with phase propetry with the amplitude of conversion loss during oppositely from intermediate-frequency filter delivery outlet to frequency mixer radio frequency mouth Up/Down Conversion from calibration frequency mixer radio frequency mouth to intermediate-frequency filter.Intermediate-frequency filter is used for extracting the mixing sideband signals needed, and the mixed components useless to other presents high reflection characteristic, and namely these garbage signals all can be reflected back the intermediate frequency port of frequency mixer by intermediate-frequency filter, and gets back to radio frequency mouth by mixing again.The model that calibration frequency mixer property scale uses as shown in Figure 2, when carrying out calibration frequency mixer and calibrating, the response signal b that vector network analyzer port accepts arrives _1RF3 part signals are comprised: prevention at radio-frequency port mismatch signal, to be reflected by intermediate-frequency filter and to get back to the useless mixing sideband signals of prevention at radio-frequency port through mixing again, carry the signal of required sideband mixer conversion loss information except residual directional error signal.Front two parts of signals does not change with the load termination situation of intermediate-frequency filter, and Part III changes along with the termination of intermediate-frequency filter, and this is the principle of conventional calibration frequency mixer calibration.The calibration frequency mixer calibrating method based on time-frequency dual domain that the present embodiment proposes is as follows:

Fig. 3 is the process flow diagram of the calibration frequency mixer calibrating method based on time-frequency dual domain of the present embodiment, as shown in Figure 3, comprising:

Step 301, arranges the radio frequency incident frequencies, local frequency, the mixing number of times that characterize frequency mixer, calculates IF-FRE;

Step 302, arranges RF input power, local oscillation power, makes described frequency mixer be operated in correct linear condition, and consistent when when making sign frequency mixer, the input state of local oscillation power is calibrated with vector frequency mixer;

Step 303, vector network analyzer does single port calibration within the scope of described frequency mixer radio frequency incoming frequency;

Step 304, described sign frequency mixer prevention at radio-frequency port is connected with the calibration port of vector network analyzer, connect local oscillation signal, and connecting the known high reverse--bias standard of a characteristic at the intermediate-frequency filter output port of calibration calibration frequency mixer, the known features value of this reflectance standard in mixer intermediate-frequency reference frequency output is Γ _iF;

Step 305, arrange single triggering and make vector network analyzer complete single pass and be in hold mode, corresponding frequency domain measurement value is S ₁₁;

Step 306, by the time domain measurement function of vector network analyzer, measurement pattern is set to be with logical impulse pattern, and opens this time domain measurement function, obtains two separated pulses on a timeline; Wherein, the first time domain impulse comprises the S of calibration calibration frequency mixer _11RFinformation, the second time domain impulse comprise calibrate calibration frequency mixer front reverse conversion loss T ₁, T ₂with reflectance standard characteristic information Γ _iF;

Now time domain measurement waveform as shown in Figure 5, is two separated pulses on a timeline.

Step 307, the center of time domain door is placed in the crest of described first time domain impulse, the initial sum stop value of described time domain door is placed in respectively the trough of the described first time domain impulse left and right sides, select the type of described time domain door logical for being with, open described time domain door function, close described time domain measurement function and return frequency domain, extract the frequency domain information corresponding to the first time domain impulse, the frequency-region signal corresponding to it is the S of described sign frequency mixer _11RF;

Step 308, reopen described time domain measurement function, and close described time domain door function, the center of described time domain door being placed in the crest of described second time domain impulse, the initial sum of this time domain door is stopped the trough that should be placed in described second time domain impulse both sides respectively, selecting the type of this time domain door logical for being with, open this time domain door function, close described time domain measurement pattern and return frequency domain, extract the frequency domain information corresponding to the second time domain impulse, the frequency domain measurement value of its correspondence is S _11T;

Error model according to Fig. 2, S _11Tvalue is:

S _11T＝T ₁T ₂Γ _IF；

Step 309, according to the known features value Γ of reflectance standard in mixer intermediate-frequency reference frequency output _iF, frequency domain measurement value S corresponding to described second pulse _11Tand equation S _11T=T ₁t ₂Γ _iF, can obtain,

Because calibration frequency mixer is reciprocity, so the front anti-and reverse conversion loss T of described calibration frequency mixer ₁and T ₂calculate by following equation:

$T_1=T_2=\±\sqrt{\frac{S_{11T}}{{\mathrm{\Γ}}_{\mathrm{IF}}}}.$

Further, can obtain two values according to this equation, these two value amplitudes are equal, phase 180 °, but actual value only has 1, real T ₁and T ₂value is by S _11T/ Γ _iFcorresponding group delay duration is determined.

Step 310, calculates S according to following equation _22IF:

$S_{22\mathrm{IF}}=\frac{1}{{\mathrm{\Γ}}_{\mathrm{IF}}}+\frac{S_{11T}}{(S_{11}-S_{11\mathrm{RF}}){\mathrm{\Γ}}_{\mathrm{IF}}};$

This equation is by equation (1) $S_{11}=S_{11\mathrm{RF}}+\frac{T_1{T}_2{\mathrm{\Γ}}_{\mathrm{IF}}}{1-S_{22\mathrm{IF}}{\mathrm{\Γ}}_{\mathrm{IF}}}$ Obtain.

Technique scheme has following beneficial effect:

The method utilizes the metrical information in vector network analyzer time domain and frequency domain two territories to extract calibration frequency mixer property scale data simultaneously; Comprise the signal of calibration mixer conversion loss information and the port mismatch signal of frequency mixer under time domain measurement pattern on a timeline, the directional error of complete machine is completely separated, time domain door can be utilized to extract respectively and transform to frequency domain again; The method can reduce influencing each other between each signal, reduce the requirement to calibration frequency mixer performance index, solve the excessive difficult problem exceeding vector network analyzer reflection measurement dynamic range and can not carry out calibrating of mixer conversion loss, improve the precision that calibration frequency mixer characterizes; Simplify calibration frequency mixer calibration process, reduce and measure connection reproducibility error.

Those skilled in the art can also recognize the various illustrative components, blocks (illustrativelogical block) that the embodiment of the present invention is listed, unit, and step can pass through electronic hardware, computer software, or both combinations realize.For the replaceability (interchangeability) of clear displaying hardware and software, above-mentioned various illustrative components (illustrativecomponents), unit and step have universally described their function.Such function is the designing requirement realizing depending on specific application and whole system by hardware or software.Those skilled in the art for often kind of specifically application, can use the function described in the realization of various method, but this realization can should not be understood to the scope exceeding embodiment of the present invention protection.

Above-described embodiment; object of the present invention, technical scheme and beneficial effect are further described; be understood that; the foregoing is only the specific embodiment of the present invention; the protection domain be not intended to limit the present invention; within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (3)

1., based on a calibration frequency mixer calibrating method for time-frequency dual domain, it is characterized in that, comprising:

The radio frequency incident frequencies, local frequency, the mixing number of times that characterize frequency mixer are set, calculate IF-FRE;

RF input power, local oscillation power are set, make described frequency mixer be operated in correct linear condition, and consistent when when making sign frequency mixer, the input state of local oscillation power is calibrated with vector frequency mixer;

Vector network analyzer does single port calibration within the scope of described frequency mixer radio frequency incoming frequency;

Described sign frequency mixer prevention at radio-frequency port is connected with the calibration port of vector network analyzer, connect local oscillation signal, and connecting the known high reverse--bias standard of a characteristic at the intermediate-frequency filter output port of calibration calibration frequency mixer, the known features value of this reflectance standard in mixer intermediate-frequency reference frequency output is Γ _iF;

Arrange single triggering make vector network analyzer complete single pass and be in hold mode, corresponding frequency domain measurement value is S ₁₁;

By in the time domain measurement function of vector network analyzer, measurement pattern is set to be with logical impulse pattern, and opens this time domain measurement function, obtains two separated pulses on a timeline; Wherein, the first time domain impulse comprises the S of calibration calibration frequency mixer _11RFinformation, the second time domain impulse comprise calibrate calibration frequency mixer front reverse conversion loss T ₁, T ₂with reflectance standard characteristic information Γ _iF;

The center of time domain door is placed in the crest of described first time domain impulse, the initial sum stop value of described time domain door is placed in respectively the trough of the described first time domain impulse left and right sides, select the type of described time domain door logical for being with, open described time domain door function, close described time domain measurement function and return frequency domain, extract the frequency domain information corresponding to the first time domain impulse, the frequency-region signal corresponding to it is the S of described sign frequency mixer _11RF;

Reopen described time domain measurement function, and close described time domain door function, the center of described time domain door is placed in the crest of described second time domain impulse, the initial sum of this time domain door is stopped the trough that should be placed in described second time domain impulse both sides respectively, selecting the type of this time domain door logical for being with, opening this time domain door function, closing described time domain measurement pattern and return frequency domain, extract the frequency domain information corresponding to the second time domain impulse, the frequency domain measurement value of its correspondence is S _11T;

According to the known features value Γ of reflectance standard in mixer intermediate-frequency reference frequency output _iF, frequency domain measurement value S corresponding to described second pulse _11Tand equation S _11T=T ₁t ₂Γ _iF, it is known,

S is calculated according to following equation _22IF:

$S_{22\mathrm{IF}}=\frac{1}{{\mathrm{\Γ}}_{\mathrm{IF}}}+\frac{S_{11T}}{(S_{11}-S_{11\mathrm{RF}}){\mathrm{\Γ}}_{\mathrm{IF}}}.$

2. method according to claim 1, is characterized in that:

Described calibration frequency mixer is reciprocity;

The front anti-and reverse conversion loss T of described calibration frequency mixer ₁and T ₂determine by following equation:

$T_1=T_2=\±\sqrt{\frac{S_{11T}}{{\mathrm{\Γ}}_{\mathrm{IF}}}}.---\left(7\right)$

3. method according to claim 2, is characterized in that:

According to equation two the value amplitudes obtained are equal, phase 180 °;

Wherein, real T ₁and T ₂value only have 1, by S _11T/ Γ _iFcorresponding group delay duration is determined.