CN219162241U - Phase frequency characteristic dynamic measurement sweep generator - Google Patents

Abstract

The utility model discloses a phase frequency characteristic dynamic measurement sweep generator, which belongs to the technical field of phase measurement and comprises a singlechip control system, a DDS sweep excitation source, a measured network/device circuit, an amplitude detector, an A/D converter and a phase voltage conversion circuit; the output end of the singlechip control system is electrically connected with a DDS sweep frequency excitation source; the output end of the DDS sweep frequency excitation source is divided into three paths for outputting sweep frequency excitation signals: the first path is directly and electrically connected with the amplitude detector, the second path is respectively and electrically connected with the amplitude detector and the phase voltage conversion circuit after passing through a network/device circuit to be tested, and the third path is directly and electrically connected with the phase voltage conversion circuit; the output ends of the amplitude detector and the phase voltage conversion circuit are respectively and electrically connected with the input end of the singlechip control system through the A/D converter. The utility model can synchronously measure amplitude-frequency characteristics and high-precision phase-frequency characteristics in real time, and is convenient, practical, high in efficiency and low in cost.

Description

Phase frequency characteristic dynamic measurement sweep generator

Technical Field

The utility model belongs to the technical field of phase measurement, and particularly relates to a phase frequency characteristic dynamic measurement sweep generator.

Background

In the real world, the phase shift produced by different frequencies is not the same as the electronic signal passes through the electronic components, the electronic network. However, common phase measurements are made using oscilloscopes, universal counters, digital phasors, or vector network protocols. The universal counter and the digital phase meter can only display the phase of a single frequency point instantly.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art and provides a phase frequency characteristic dynamic measurement sweep generator.

In order to achieve the above purpose, the utility model is realized by adopting the following technical scheme:

the utility model provides a phase frequency characteristic dynamic measurement sweep generator which is characterized by comprising a singlechip control system, a DDS sweep excitation source, a measured network/device circuit, an amplitude detector, an A/D converter and a phase voltage conversion circuit;

the output end of the singlechip control system is electrically connected with a DDS frequency sweeping excitation source;

the output end of the DDS frequency sweep excitation source is divided into three paths for outputting frequency sweep excitation signals: the first path is directly and electrically connected with the amplitude detector, the second path is respectively and electrically connected with the amplitude detector and the phase voltage conversion circuit after passing through a network/device circuit to be tested, and the third path is directly and electrically connected with the phase voltage conversion circuit;

the output ends of the amplitude detector and the phase voltage conversion circuit are respectively and electrically connected with the input end of the singlechip control system through an A/D converter.

As a further improvement, the phase voltage conversion circuit comprises two signal input ends which are respectively and electrically connected with the tested network/device circuit and the DDS sweep frequency excitation source, wherein the signal input ends are respectively and electrically connected with the phase detector through a broadband logarithmic amplifier, and the phase voltage is output through the phase detector and is electrically connected with the A/D converter.

As a further improvement, the phase detector has a phase difference range of 180 °, the phase difference range being 0 ° to +180°, centered at 90 °, or 0 ° to-180 °, centered at-90 °;

the conversion rate during phase output is 30MHz, and the response time is 40 ns-500 ns;

the variation range of the output phase voltage is 0V-1.8V, the sensitivity of the output voltage is 10 mV/degree, and the measurement error is smaller than 0.5 degrees;

as a further improvement, the phase difference

When the output voltage is set to 1.8V;

when (when)

At this time, the output voltage was set to 30mV and the output current was set to 8mA.

As a further improvement, the wideband logarithmic amplifier is a 60dB logarithmic amplifier.

As a further improvement, the DDS swept excitation source is configured to output a swept excitation signal in three paths at each of the different frequency points.

As a further improvement, the tested network/device circuit comprises a program controlled attenuator, a power amplifier, a tested network/device and a program controlled amplifier/attenuator which are connected in series in sequence,

the output sweep frequency excitation signal of the DDS sweep frequency excitation source is electrically connected with the program-controlled attenuator through a first path, and the output end of the singlechip control system is respectively and electrically connected with the program-controlled attenuator and the program-controlled amplifier/attenuator.

As a further improvement, the singlechip control system also comprises a phase data acquisition module, a phase data processing module and a phase characteristic display module;

the phase data acquisition module is used for acquiring the DDS sweep frequency excitation source converted into the digital signal by the A/D converter in real time and outputting three paths of sweep frequency excitation signals at different frequency points;

the phase data processing module is used for carrying out digital filtering processing on three paths of sweep frequency excitation signals converted by the digital signals in real time and carrying out amplitude-frequency characteristic and phase-frequency characteristic measurement;

and the phase characteristic display module is used for displaying amplitude-frequency characteristics and phase-frequency characteristic curves in real time.

Compared with the prior art, the utility model has the beneficial effects that: the utility model provides a phase frequency characteristic dynamic measurement sweep generator, which is characterized in that a DDS sweep excitation source, a tested network/device circuit, an amplitude detector, an A/D converter and a phase voltage conversion circuit which are mutually combined are added into a sweep generator circuit, the output end of the DDS sweep excitation source is configured to be divided into three paths for outputting sweep excitation signals, and amplitude frequency characteristic and high-precision phase frequency characteristic measurement are synchronously carried out in real time after the processing of the amplitude detector, the A/D converter and the like.

Drawings

FIG. 1 is a circuit block diagram of a phase frequency characteristic dynamic measurement sweep generator provided by an embodiment of the present utility model;

fig. 2 is a circuit block diagram of a phase voltage conversion circuit according to an embodiment of the present utility model.

Detailed Description

The utility model is further described below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present utility model, and are not intended to limit the scope of the present utility model.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art in a specific case.

Examples

As shown in FIG. 1, the embodiment of the utility model provides a phase frequency characteristic dynamic measurement sweep generator which is characterized by comprising a singlechip control system, a DDS sweep excitation source, a measured network/device circuit, an amplitude detector, an A/D converter and a phase voltage conversion circuit.

The output end of the singlechip control system is electrically connected with and controls the DDS frequency sweep excitation source, and the DDS frequency sweep excitation source is configured to output frequency sweep excitation signals in three paths at different frequency points.

The output end of the DDS sweep frequency excitation source is divided into three paths for outputting sweep frequency excitation signals: the first path is directly and electrically connected with the amplitude detector, the second path is respectively and electrically connected with the amplitude detector and the phase voltage conversion circuit after passing through the network/device circuit to be tested, and the third path is directly and electrically connected with the phase voltage conversion circuit.

The output ends of the amplitude detector and the phase voltage conversion circuit are respectively and electrically connected with the input end of the singlechip control system through the A/D converter.

As shown in fig. 2, the phase voltage conversion circuit includes two signal input terminals electrically connected to the network/device circuit under test and the DDS sweep frequency excitation source, and the signal input terminals are electrically connected to the phase detector through a wideband logarithmic amplifier, and output phase voltage through the phase detector to be electrically connected to the a/D converter.

In this embodiment, the wideband logarithmic amplifier is a 60dB logarithmic amplifier.

The phase difference measurement range of the phase detector is 0-180 degrees;

the conversion rate during phase output is 30MHz, and the response time is 40 ns-500 ns;

the variation range of the output phase voltage is 0V-1.8V, the sensitivity of the output voltage is 10 mV/degree, and the measurement error is smaller than 0.5 degrees;

when the phase difference is

When the output voltage is 1.8V;

when (when)

When the output voltage was 30mV, the output current was 8mA.

The expression of the phase output voltage is:

in the method, in the process of the utility model,

the unit is mV/degree for phase difference slope voltage; />

For each signal phase, the units are degrees; u (U) _INA 、U _INB For the input signal voltage, the phase detector has a phase difference range of 180 degrees, wherein the phase difference range adopts 0 degrees to +180 degrees, takes 90 degrees as the center, or adopts 0 degrees to-180 degrees, and takes-90 degrees as the center; according to the difference of the slopes of the phase difference response characteristic curves between 0 degrees and 180 degrees and between 0 degrees and 180 degrees, the phase difference of the 2 measured signals can be judged to be positive or negative.

In this embodiment, as shown in fig. 1, the network/device circuit to be tested includes a programmable attenuator, a power amplifier, a network/device to be tested, and a programmable amplifier/attenuator connected in series. The output sweep frequency excitation signal of the DDS sweep frequency excitation source is electrically connected with the program controlled attenuator through a first path, and the output end of the singlechip control system is respectively and electrically connected with the program controlled attenuator and the program controlled amplifier/attenuator.

In this embodiment, the single-chip microcomputer control system further includes a phase data acquisition module, a phase data processing module, and a phase characteristic display module;

the phase data acquisition module is used for acquiring the DDS sweep frequency excitation source converted into the digital signal by the A/D converter in real time and outputting three paths of sweep frequency excitation signals at different frequency points;

the phase data processing module is used for carrying out digital filtering processing on the three paths of sweep frequency excitation signals converted by the digital signals in real time and measuring amplitude-frequency characteristics and phase-frequency characteristics;

and the phase characteristic display module is used for displaying amplitude-frequency characteristics and phase-frequency characteristic curves in real time.

The measuring principle and the measuring method of the phase frequency characteristic dynamic measuring sweep generator in the embodiment of the utility model are described in the following steps.

The DDS frequency sweep excitation source is controlled to output frequency sweep excitation signals in three paths on different frequency points and is configured to:

the first path of sweep frequency excitation signal is directly input into the amplitude detector through an electric signal, the second path of sweep frequency excitation signal is respectively input into the amplitude detector and the phase voltage conversion circuit through the electric signal after passing through the tested network/device circuit, and the third path of sweep frequency excitation signal is input into the phase voltage conversion circuit;

two input ends of the phase voltage conversion circuit respectively receive a second path of sweep frequency excitation signal and a third path of sweep frequency excitation signal, the second path of sweep frequency excitation signal and the third path of sweep frequency excitation signal are processed by corresponding broadband logarithmic amplifiers and then input into a phase detector to obtain a phase difference between the second path of sweep frequency excitation signal and the third path of sweep frequency excitation signal so as to obtain a corresponding phase difference output voltage, and the phase difference output voltage is converted into a digital signal by an A/D converter and is transmitted to a singlechip control system;

the amplitude detector receives the first path of sweep frequency excitation signal and the second path of sweep frequency excitation signal respectively, and obtains the corresponding modulation signal after detection and demodulation, and the modulation signal is converted into digital signal parameters by the A/D converter and is transmitted to the singlechip control system;

and the singlechip control system statistically displays amplitude-frequency characteristics and phase-frequency characteristic curves corresponding to the tested network/device under different frequencies according to the acquired digital signal parameters.

Because the sweep frequency excitation signal of the DDS sweep frequency excitation source is self-contained in the sweep frequency instrument, the frequency of each frequency point is known, and the phase difference parameters of each corresponding point are acquired and displayed, so that the phase frequency characteristic curve corresponding to the tested network/device can be conveniently acquired.

If an oscilloscope is used for measuring the phase, the phase difference can be roughly calculated according to the signal period by looking at the scale of the phase difference between two measured signals, and the measuring mode has poor precision and inconvenient data reading. If the digital universal counter or the digital phase meter is used, the measurement result can be read out quickly, but only the phase difference of single frequency can be displayed immediately; if the phase frequency characteristics of a certain frequency band are dynamically displayed, there is no way to achieve this.

The embodiment of the utility model not only maintains the original amplitude-frequency characteristic measurement function, but also realizes the dynamic measurement function of low-cost and high-precision phase-frequency characteristics, can realize the measurement of the phase-frequency characteristics of-180 DEG to +180 DEG on a sweep generator, and can be widely applied to production lines of college laboratories, scientific research units and enterprises.

The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present utility model, and such modifications and variations should also be regarded as being within the scope of the utility model.

Claims (8)

1. The phase frequency characteristic dynamic measurement sweep generator is characterized by comprising a singlechip control system, a DDS sweep excitation source, a measured network/device circuit, an amplitude detector, an A/D converter and a phase voltage conversion circuit;

the output end of the singlechip control system is electrically connected with a DDS frequency sweeping excitation source;

the output end of the DDS frequency sweep excitation source is divided into three paths for outputting frequency sweep excitation signals: the first path is directly and electrically connected with the amplitude detector, the second path is respectively and electrically connected with the amplitude detector and the phase voltage conversion circuit after passing through a network/device circuit to be tested, and the third path is directly and electrically connected with the phase voltage conversion circuit;

the output ends of the amplitude detector and the phase voltage conversion circuit are respectively and electrically connected with the input end of the singlechip control system through an A/D converter.

2. The dynamic phase frequency characteristic measuring sweep generator of claim 1 wherein the phase voltage conversion circuit includes two signal inputs electrically connected to the measured network/device circuit and the DDS swept excitation source, respectively, the signal inputs being electrically connected to the phase detector via a wideband logarithmic amplifier, respectively, and the phase voltage output via the phase detector being electrically connected to the a/D converter.

3. The dynamic measurement sweep generator of phase frequency characteristics according to claim 2, wherein the phase detector has a phase difference range of 180 ° with 0 ° to +180°, centered at 90 °, or with 0 ° to-180 °, centered at-90 °;

the conversion rate during phase output is 30MHz, and the response time is 40 ns-500 ns;

the output phase voltage variation range is 0V-1.8V, the output voltage sensitivity is 10 mV/degree, and the measurement error is less than 0.5 degrees.

4. A phase frequency characteristic dynamic measurement sweep generator as claimed in claim 3 wherein the output voltage is set to 1.8V at a phase difference ΔΦ=0°; when ΔΦ=180°, the output voltage was set to 30mV, and the output current was set to 8mA.

5. The phase frequency characteristic dynamic measurement sweep generator of claim 4 wherein the wideband logarithmic amplifier is a 60dB logarithmic amplifier.

6. The phase frequency characteristic dynamic measurement sweep generator of claim 2 wherein the DDS swept excitation source is configured to output a swept excitation signal in three separate paths at each different frequency point.

7. The dynamic phase frequency characteristics measuring sweep generator of any one of claims 1 to 6 wherein the measured network/device circuit includes a programmable attenuator, a power amplifier, a measured network/device and a programmable amplifier/attenuator in series in order,

the output sweep frequency excitation signal of the DDS sweep frequency excitation source is electrically connected with the program-controlled attenuator through a first path, and the output end of the singlechip control system is respectively and electrically connected with the program-controlled attenuator and the program-controlled amplifier/attenuator.

8. The phase frequency characteristic dynamic measurement sweep generator of claim 7, wherein the single-chip microcomputer control system further comprises a phase data acquisition module, a phase data processing module and a phase characteristic display module;

the phase data acquisition module is used for acquiring the DDS sweep frequency excitation source converted into the digital signal by the A/D converter in real time and outputting three paths of sweep frequency excitation signals at different frequency points;

the phase data processing module is used for carrying out digital filtering processing on three paths of sweep frequency excitation signals converted by the digital signals in real time and carrying out amplitude-frequency characteristic and phase-frequency characteristic measurement;

and the phase characteristic display module is used for displaying amplitude-frequency characteristics and phase-frequency characteristic curves in real time.

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