CN111880001B - A sensor based on thermal compensation - Google Patents
A sensor based on thermal compensation Download PDFInfo
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- CN111880001B CN111880001B CN202010904316.9A CN202010904316A CN111880001B CN 111880001 B CN111880001 B CN 111880001B CN 202010904316 A CN202010904316 A CN 202010904316A CN 111880001 B CN111880001 B CN 111880001B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R21/00—Arrangements for measuring electric power or power factor
- G01R21/02—Arrangements for measuring electric power or power factor by thermal methods, e.g. calorimetric
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R21/00—Arrangements for measuring electric power or power factor
- G01R21/14—Compensating for temperature change
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Abstract
The invention belongs to the technical field of terahertz power measurement, and provides a sensor based on thermal compensation, which is additionally provided with a compensation end inside, wherein a working end and the compensation end are provided with the same waveguide structure and a sensing chip, a first copper sheet and a second copper sheet which surround a first waveguide and a second waveguide are additionally arranged between the compensation end and the working end and serve as thermal short-circuit structures, so that the sensing chips of the working end and the compensation end have the same thermal structure, and have the same response to environmental temperature change, the initial direct current bias power of the working end at any moment can be obtained through the direct current bias power change of the compensation end, the initial direct current bias power of the working end is compensated according to the corresponding relation between the direct current bias power change of the compensation end and the initial direct current bias power of the working end, errors of terahertz power measurement caused by temperature change and other factors are reduced, and the accuracy of terahertz power measurement can be improved.
Description
Technical Field
The invention relates to the technical field of terahertz power measurement, in particular to a thermal compensation sensor capable of improving the measurement accuracy of terahertz power.
Background
Terahertz (THz) is one of the wave frequency units, also called terahertz or terahertz, used for representing electromagnetic wave frequency, is a new radiation source with a plurality of unique advantages, and is a very important crossing front field, which provides a very large opportunity for technical innovation, national economic development and national security, and possibly brings about revolutionary development of scientific technology. Terahertz waves refer to electromagnetic waves with frequencies in the range of 0.1-10 THz (with wavelengths of 3000-30 μm), and the wavelengths of the terahertz waves are between microwaves and infrared light, so that the terahertz waves have very strong complementary characteristics relative to electromagnetic waves in other wave bands in application.
Compared with microwaves and millimeter waves, the terahertz detection system can obtain higher resolution, has outstanding anti-interference capability and unique anti-stealth capability, and has the advantages of wide field of view, good searching capability, suitability for severe weather conditions and the like. The superior characteristics of the terahertz waves make the terahertz waves have very important academic and application values, and great attention is paid to the research and application of terahertz science and technology in various countries of the world.
Terahertz measurement is the technical basis of each link for the obstetric research of terahertz technology, terahertz power is the basic parameter of terahertz devices, components, instruments and systems, and terahertz power measurement is the key measurement of the parts. The current direct current alternative sensor is widely applied to terahertz power measurement, a direct current alternative method is adopted, the direct current alternative method is a common technology in a calorimetric terahertz power sensor, a thermistor is connected into a four-wire self-balancing bridge to ensure the constant resistance value of the thermistor, and the microwave power absorbed by the thermistor is obtained through calculation by the initial direct current bias power without microwave power and the direct current bias power added with the microwave power. However, in the measurement process, the initial DC bias power can fluctuate due to factors such as temperature change, so that the accuracy of microwave power measurement is affected. Therefore, when the direct current power sensor is applied to terahertz power measurement, the problem that the direct current power sensor is susceptible to temperature exists, and the terahertz power measurement value is changed even if the temperature of the surface of the sensor is changed due to fluctuation of room temperature, so that the terahertz power measurement result is inaccurate.
Disclosure of Invention
In order to solve the technical problems, the invention provides the thermal compensation sensor capable of improving the terahertz power measurement accuracy, and the compensation structure based on the symmetrical load and the thermal short circuit can compensate the influence caused by temperature change, so that the measurement error caused by the temperature change is reduced, and the terahertz measurement accuracy of the sensor in a complex temperature environment is improved.
A thermal compensation based sensor comprising:
A housing;
The working end comprises a first waveguide and a first sensing chip, and the compensating end comprises a second waveguide and a second sensing chip;
A first copper sheet and a second copper sheet, both surrounding the first waveguide and the second waveguide;
The first waveguide is the same as the second waveguide, and the first sensing chip is the same as the second sensing chip, wherein the first sensing chip comprises a first thermistor, and the second sensing chip comprises a second thermistor.
In the application of the invention, the sensor is additionally provided with the compensation end inside, wherein the working end and the compensation end have the same waveguide structure and sensing chip, and the first copper sheet and the second copper sheet which surround the first waveguide and the second waveguide are additionally arranged between the compensation end and the working end as thermal short-circuit structures, so that the sensing chips of the working end and the compensation end have the same thermal structure, and have the same response to the environmental temperature change, the initial direct current bias power of the working end at any moment can be obtained through the direct current bias power change of the compensation end, the initial direct current bias power of the working end is compensated according to the corresponding relation between the direct current bias power change of the compensation end and the initial direct current bias power of the working end, the error of terahertz power measurement caused by factors such as temperature change is reduced, and the accuracy of terahertz power measurement can be improved.
Drawings
1. FIG. 1 is a schematic diagram of the internal structure of a DC power sensor in the prior art;
2. FIG. 2 is a schematic diagram of a sensor based on thermal compensation according to an embodiment of the present invention;
3. FIG. 3 is a graph of DC bias power ripple in a thermal compensation based sensor according to an embodiment of the present invention;
4. Fig. 4 is a graph of dc bias power change before and after adding terahertz power to a sensor based on thermal compensation according to an embodiment of the present invention;
5. Fig. 5 is a graph comparing a direct current bias power curve based on a thermal compensation sensor and a predicted bias power curve of a thermistor at a working end according to an embodiment of the present invention.
Best mode for carrying out the invention
In order to make the high-precision flow calibration device provided by the invention more clearly understood by those skilled in the art, the following detailed description will be given with reference to the accompanying drawings.
As shown in fig. 1, the internal structure of the dc power sensor in the prior art comprises a sensing chip and a waveguide, wherein the sensing chip comprises a wave absorbing layer, a circuit layer, a shielding layer and an insulating layer, the wave absorbing layer is used for absorbing terahertz waves and converting the terahertz power into thermal effect, the circuit layer comprises a thermistor, the thermistor is arranged in a circuit of a four-wire current self-balancing bridge to keep the resistance value constant, the thermal effect generated by the wave absorbing layer is transferred to the circuit layer when the terahertz power is added, the temperature of the thermistor needs to be kept constant in order to keep the resistance value constant, the dc bias power of the thermistor correspondingly decreases, if the terahertz power is not added, the thermistor is biased on a specific resistance value R in advance by the dc bias power P dc1 and keeps the specific resistance value R unchanged in a closed-loop control manner, the closed-loop circuit automatically reduces the dc bias power P dc1 to keep the circuit balanced after the terahertz power is added, the absorbed power of the sensing chip is set as P mw, the new dc balance power is P dc2, and the variation of the dc bias power P dc1 is usually called as P sub instead of the power
Psub＝Pdc1-Pdc2 (1)
Because the area of the sensing chip is small, the thermistor has the same response to millimeter wave power and direct current power, thus having
Psub＝Pmw (2)
However, when the ambient temperature changes, the initial dc bias power P dc1 required to keep the thermistor resistance constant also changes all the time. Since the real-time P dc1 cannot be obtained by adding the microwave power in the measuring process, and since a certain time is required for adding the power or turning off the power system to reach the thermal equilibrium state, it is not feasible to detect the current time P dc1 by continuously turning off the power. P dc1 before the start of measurement is taken as the initial dc bias power in the subsequent measurement, or P dc1 is measured once before or after the start of measurement and the initial dc power at each moment in the measurement process is obtained by using an interpolation method, but obviously, both methods introduce larger uncertainty.
Therefore, the embodiment of the invention adds the compensation terminal in the direct current power sensor, thereby providing a sensor based on thermal compensation, which is used for solving the technical problem of errors in terahertz power measurement caused by factors such as temperature change, and the like, as shown in fig. 2, the sensor specifically comprises:
A housing;
The working end comprises a first waveguide and a first sensing chip, and the compensating end comprises a second waveguide and a second sensing chip;
A first copper sheet and a second copper sheet, both surrounding the first waveguide and the second waveguide;
The first waveguide is the same as the second waveguide, and the first sensing chip is the same as the second sensing chip, wherein the first sensing chip comprises a first thermistor, and the second sensing chip comprises a second thermistor.
The sensor should of course also comprise waveguide flanges for mounting the first and second waveguides, according to common knowledge in the art.
The sensor provided by the embodiment of the invention is additionally provided with the compensation end inside, wherein the working end and the compensation end have the same waveguide structure and sensing chip, and the first copper sheet and the second copper sheet which surround the first waveguide and the second waveguide are additionally arranged between the compensation end and the working end as a thermal short circuit structure, so that the sensing chips of the working end and the compensation end have the same thermal structure, and have the same response to environmental temperature change.
As shown in fig. 3, in the embodiment of the invention, in the environment under the control of the central air conditioner, the initial dc bias power of the working end still has the fluctuation of 180 μw at the maximum in the condition of the dc bias power fluctuation in the sensor based on the thermal compensation, but the dc bias power of the compensation end has the same response as the working end to the environment temperature fluctuation.
Because the direct current bias power of the compensation end has the same response to the environmental temperature fluctuation as that of the working end, the initial direct current bias power of the working end at any moment can be obtained through the direct current bias power change of the compensation end, so that the initial direct current bias power of the working end is compensated according to the corresponding relation between the direct current bias power change of the compensation end and the initial direct current bias power of the working end, errors of terahertz power measurement caused by factors such as temperature change are reduced, and the accuracy of terahertz power measurement can be improved.
Specifically, the first thermistor at the working end is denoted as a resistor a, and according to the basic law of heat transfer theory, it is known that:
Wherein P A is the sum of DC bias power and terahertz power absorbed by a first thermistor at a working end, T A and T B are the temperature of the first thermistor at the working end and the temperature of a second thermistor at a compensation end respectively, C is the heat capacity of a first sensing chip at the working end or a second sensing chip at the compensation end, T G is the temperature of a shell, the shell can be heat ground, the heat of the first sensing chip at the working end and the second sensing chip at the compensation end is transmitted to the shell for heat dissipation, h is the heat transfer coefficient of the surface of the shell, A is the equivalent heat dissipation area, R G,A is the equivalent heat resistance to the shell, and R AB is the equivalent heat resistance between the working end and the compensation end.
When terahertz power is added, the first waveguide wall loss power heats up. Part of heat is transferred to the first thermistor, which is equivalent to that the DC bias power is reduced when the ambient temperature is increased, so that the sum P A of the DC bias power and the microwave power absorbed by the first thermistor at the working end is as follows:
where P W is the power lost by the first waveguide wall, proportional to the added terahertz power, and k is its equivalent to the dc bias power.
The second thermistor at the compensation end is marked as a resistor B, and as a first copper sheet and a second copper sheet are added between the compensation end and the working end, the first copper sheet and the second copper sheet surround the first waveguide and the second waveguide, the first copper sheet and the second copper sheet surrounding the two waveguides are used as a thermal short circuit structure, the thermal short circuit structure has good heat conductivity, and the waveguide heating power has influence on the direct current substitution of the first sensing chip and the second sensing chip at the working end and the compensation end, so the direct current bias power and the terahertz power P B absorbed by the second thermistor at the compensation end are as follows:
Wherein R G,B is the second thermistor of the compensation end is the equivalent thermal resistance to the housing.
When terahertz power is added, the second waveguide wall loss power heats up. Part of heat is transferred to the second thermistor, which is equivalent to that the DC bias power is reduced when the ambient temperature is increased, so that the sum P B of the DC bias power and the terahertz power absorbed by the second thermistor at the compensation end is as follows:
Wherein P W is the power of the wall loss of the second waveguide, and since the first waveguide and the second waveguide are the same, the power of the wall loss of the waveguide is the same, and k is the equivalent coefficient of the power to the dc bias power in proportion to the added terahertz power.
For equation (3), solving the equation and substituting the initial condition T A＝TG yields:
The above equation shows the course of the first thermistor temperature as a function of the added power in the initial case where the thermistor temperature is the outside temperature after sufficient cooling. Steady state conditions can be obtained when t approaches infinity:
When the terahertz power is not generated, the deformation can be obtained:
When the terahertz power is added, the following steps are obtained:
The same second thermistor for the compensation terminal has:
when there is no terahertz power, then:
When terahertz power is added, then:
Therefore, it can be seen that the thermistor has stable resistance and stable temperature in steady state, the power P W lost in the waveguide is proportional to the terahertz incident power, when the incident power is stable, P W is a constant, and when the terahertz power is not added, P W is 0. Therefore, when the external environment temperature T G changes, in order to make the equation hold, the dc bias power will change accordingly.
Preferably, the first waveguide, the second waveguide, the first thermistor and the second thermistor are provided with fillers on the outer surfaces, and the fillers can be compact high-thermal-resistance filler nano silicon dioxide so as to reduce the influence of convection on thermal analysis. Considering that the heat conduction is mainly carried out through a wave-guiding heat ground path, after the first waveguide, the second waveguide, the first thermistor and the second thermistor are provided with fillers, one item of hA is negligible, and the equivalent heat resistance to the ground is correspondingly reduced.
Therefore, according to the formulas (3) to (12), after the first waveguide, the second waveguide, the first thermistor and the second thermistor are provided with the filler, the external environment temperature change is set to be DeltaT G, and the direct current bias power absorbed by the first thermistor at the working end needs to be changedThe DC bias power absorbed by the second thermistor at the compensation end needs to be changedAfter terahertz power is added, the influence of waveguide loss power P W on the working end and the compensation end is consistent, and when the waveguide loss power is changed to delta P W, the direct current bias power of the working end and the compensation end is changed to-k delta P W.
Therefore, when the terahertz power is not added, the direct current bias power absorbed by the first thermistor at the working end correspondingly changes into the direct current bias power absorbed by the second thermistor at the compensation end when the direct current bias power change delta P B is detected
Under the condition that terahertz power is added, the direct-current bias power absorbed by the second thermistor at the compensation end is detected to be changed intoIncluding the effects of temperature variations as well as the effects of waveguide wall heating. The DC bias power absorbed by the first thermistor at the working end is changed intoIgnoring the waveguide loss power change to Δp W can be approximately considered as
Therefore, when the ambient temperature is changed without the addition of terahertz power, the ratio of the DC bias power changes of the working end and the compensation end
As shown in fig. 4, according to the change situation of the direct current bias power before and after the terahertz power is added in the thermal compensation sensor provided by the embodiment of the invention, according to the overall change of the direct current bias power of the compensation end before and after the terahertz power is added, when the second thermistor end absorbs 2mW terahertz power, the direct current bias power of the compensation end is reduced by kΔp w approximately 36 μw.
Therefore, the errors caused by terahertz power measurement due to factors such as environmental temperature change are about:
The error of 1.08 mu W is negligible against the fluctuation influence of the maximum 180 mu W of the DC bias power caused by the environmental temperature change and other factors.
Therefore, when the compensation-side DC bias power variation DeltaP B is detected, the working-side DC bias power variation is
WhileThe DC bias power variation ratio delta P A/ΔPB of the working end and the compensation end can be obtained under the condition of no terahertz power and when the ambient temperature is changed. If it isWhen the value is approximately 1, Δp A＝ΔPB can be considered. In the inventive embodiment the temperature fluctuation causes a maximum of 180 muw of dc bias power variation,This approximation brings about an error of about 5.4 uW at the most.
The final working and compensating end thermistor dc bias power curves and predicted working end thermistor bias power curve pairs are shown in fig. 5.
The analysis of terahertz power curves in a short time has a large random error due to microscopic variations in the internal noise and/or air convection of the sensor. Preferably, the measurement result is preprocessed by an arithmetic mean filtering mode to reduce random errors caused by random noise disturbance.
Specifically, the compensation end and the working end are firstly connected into the working circuit and fully preheated, the zero clearing operation is carried out after the full preheating, namely, the initial direct current bias power of a group of the working end and the compensation end is measured without adding power, the average value is taken to be P A1 and P B1 respectively, the initial direct current balance power of the working end at the moment t is measured by taking P A1,t＝PA1+(PB,t-PB1);PB,t as the compensation end, and the replacement power of the working end at the moment t is calculated as P sub＝PA,t-PA1,t.
While the foregoing has been described in some detail to illustrate the principles and embodiments of the invention, it is to be understood that this disclosure is not to be interpreted as limiting, but to enable one of ordinary skill in the art to make and use the invention.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105785114A (en) * | 2016-04-15 | 2016-07-20 | 中国计量科学研究院 | Double-load power sensor |
| CN112067119A (en) * | 2020-09-01 | 2020-12-11 | 中国计量科学研究院 | A thermal compensation method based on terahertz power measurement |
| CN212540525U (en) * | 2020-09-01 | 2021-02-12 | 中国计量科学研究院 | Sensor based on thermal compensation |
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| US6181456B1 (en) * | 1999-04-01 | 2001-01-30 | Uniphase Telecommunications Products, Inc. | Method and apparatus for stable control of electrooptic devices |
| CN2439002Y (en) * | 2000-07-20 | 2001-07-11 | 肖卫 | PTC temperature compensator for refrigerator |
| CN101545931B (en) * | 2009-05-08 | 2011-07-20 | 电子科技大学 | Method for measuring high-temperature complex dielectric constants based on terminal short-circuit method |
| CN102507036A (en) * | 2011-11-23 | 2012-06-20 | 中国计量科学研究院 | MMW (millimeter wave) power sensor and calorimeter provided with same |
| CN110672205A (en) * | 2018-07-03 | 2020-01-10 | 浙江澍源智能技术有限公司 | Micro spectrometer device based on array waveguide grating |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105785114A (en) * | 2016-04-15 | 2016-07-20 | 中国计量科学研究院 | Double-load power sensor |
| CN112067119A (en) * | 2020-09-01 | 2020-12-11 | 中国计量科学研究院 | A thermal compensation method based on terahertz power measurement |
| CN212540525U (en) * | 2020-09-01 | 2021-02-12 | 中国计量科学研究院 | Sensor based on thermal compensation |
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