WO2022225155A1 - Radiomètre pour récepteur de micro-ondes et procédé associé de compensation d'erreurs - Google Patents

Radiomètre pour récepteur de micro-ondes et procédé associé de compensation d'erreurs Download PDF

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Publication number
WO2022225155A1
WO2022225155A1 PCT/KR2022/002082 KR2022002082W WO2022225155A1 WO 2022225155 A1 WO2022225155 A1 WO 2022225155A1 KR 2022002082 W KR2022002082 W KR 2022002082W WO 2022225155 A1 WO2022225155 A1 WO 2022225155A1
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Prior art keywords
duty
clock signal
value
microwave switch
demodulator
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PCT/KR2022/002082
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English (en)
Korean (ko)
Inventor
어윤성
장원일
김남영
김은성
신재우
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(주)이지템
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D1/00—Measuring arrangements giving results other than momentary value of variable, of general application
    • G01D1/04—Measuring arrangements giving results other than momentary value of variable, of general application giving integrated values
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D18/00—Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/48—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using wave or particle radiation means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K15/00—Testing or calibrating of thermometers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
    • H04L27/14—Demodulator circuits; Receiver circuits

Definitions

  • the present invention relates to a radiometer for a microwave receiver and an error compensation method thereof, and more particularly, to a switching clock error in a receiver of a Dicke radiometer, which is one of the temperature sensing receivers of the RF method for temperature sensing,
  • the present invention relates to an error compensation method that improves the accuracy of temperature detection by compensating an output error voltage caused by an error between path gains, and a radiometer receiver to which it is applied.
  • the amount of wavelength and component of light and radio waves radiated from a material can be expressed as a function of temperature.
  • the radiation signal B P has a value proportional to the square of the frequency and the temperature as shown in Equation 1 below according to the Raleigh-Jeans law.
  • the radiation power (P n ) within the frequency BW received by the antenna can be expressed as in Equation 2 below.
  • the radiometer can be classified into a total power radiometer and a Dicky radiometer as a receiver structure of the radiometer. Compared to powered radiometers, Dicky radiometers have very good temperature resolution.
  • FIG. 1 is a block diagram showing the structure of a receiver of a general Dickie radiometer.
  • the microwave switch (SW) (2) and the demodulator (4) are switched at the same clock, and the temperature of the object to be detected is TA through the antenna ( 1 ). It is received with radiant power corresponding to
  • a reference noise source (load) 3 of the reference temperature (T ref ) to be compared is provided, so that power according to the reference temperature (T ref ) can be applied therethrough.
  • the demodulator (4) is connected to the first path (P1), the microwave switch (SW) (2) is a reference noise source (load) ( When connected to 3), the demodulator 4 is connected to the second path P2. Accordingly, power corresponding to T A received through the antenna 1 is applied to the integrator 5 at the rear stage for half cycle, and power corresponding to the reference temperature (T ref ) becomes negative for the other half cycle and is input. .
  • the output value becomes the same as Equation 3 below, and eventually the output voltage becomes 0.
  • the Dicky radiometer has an output of T A -T ref , so there is no effect of the receiver's T RX , and it is insensitive to changes in the receiver gain. have.
  • Patent Document 1 Korean Patent No. 10-1950592 (Registered on February 14, 2019)
  • the present invention has been devised in view of the above problems, and an object of the present invention is to output error voltage due to the duty error ⁇ t of the clock and the gain error ⁇ A (or mismatch) of the demodulator in the Dickie radiometer receiver.
  • an object of the present invention is to output error voltage due to the duty error ⁇ t of the clock and the gain error ⁇ A (or mismatch) of the demodulator in the Dickie radiometer receiver.
  • Another object of the present invention is to provide a radiometer for a microwave receiver capable of accurately measuring the temperature TA of an object through correction of an output error voltage, and an error compensation method thereof.
  • a radiometer for a microwave receiver for achieving the above object includes a microwave switch selectively connecting an antenna and a reference noise source, a switch synchronized with the microwave switch, and input through the microwave switch A demodulator that multiplies the obtained signal by a predetermined gain value, an integrator that generates an output value by calculating a signal input from the demodulator, a duty corrector that adjusts a duty value of a clock signal for controlling the microwave switch, the duty corrector and a controller configured to generate a duty correction value of the clock signal based on an output value of the path switch and the integrator positioned between the microwave switch and the microwave switch.
  • the controller controls the duty corrector to an initial value, the demodulator multiplies the gain by the signal input through the microwave switch, and then transmits it to the demodulator, the demodulator a first correction step of calculating an output value by calculating the signal, calculating a duty correction value based on the output value, and generating a correction clock signal for controlling the microwave switch based on the duty correction value and a normal operation step of controlling the microwave switch based on the corrected clock signal.
  • the radiometer for a microwave receiver and its error compensation method it is possible to reduce the influence of temperature measurement due to the receiver gain deviation in a radiometer, which is a radio wave type temperature sensor, and to achieve excellent temperature resolution. .
  • a radiometer which is a radio wave type temperature sensor
  • a Dickie receiver with superior temperature resolution compared to the total power radiometer structure it is possible to prevent function degradation due to a clock duty error and a mismatch of gains between the demodulator and two paths. , it is possible to achieve accurate temperature measurement.
  • FIG. 1 is a block diagram showing the structure of a receiver of a general Dickie radiometer.
  • FIG. 2 illustrates a problem caused by a receiver error of a Dickie radiometer, and a problem caused by a gain error between a switching clock and a demodulator path.
  • FIG. 3 is a diagram for explaining the first correction step of the error compensation method according to the present invention and the operation of the receiver at that time.
  • FIG. 4 is a view for explaining the second correction step of the error compensation method according to the present invention and the operation of the receiver at that time.
  • 5 is a view for explaining the overall operation of the error compensation method according to the present invention and the receiver during normal operation.
  • FIG. 6 is a flowchart showing the flow of an error compensation method according to the present invention.
  • FIG. 3 is a diagram for explaining the first correction step of the error compensation method according to the present invention and the operation of the receiver at that time.
  • the receiver 100 includes a microwave switch 120 , a receiver 140 , a detector 150 , a demodulator 160 , an integrator 170 , a controller 180 and a duty corrector 190 .
  • a microwave switch 120 a microwave switch 120 , a receiver 140 , a detector 150 , a demodulator 160 , an integrator 170 , a controller 180 and a duty corrector 190 .
  • the microwave switch 120 (or RF switch (radio frequency switch)) is connected to the antenna 110 , and the power corresponding to T A received through the antenna 110 and the reference received through the reference noise source 130 .
  • the power corresponding to the temperature (T ref ) is switched and is transmitted to the demodulator 160 after receiving the input.
  • the demodulator 160 is connected to the first path P1
  • the demodulator 160 is connected to the second path P2.
  • the receiver 140 includes one or more low noise amps (LNAs) for amplifying the signal transmitted through the microwave switch 120 and a bandpass filter for limiting white noise of the signal amplified thereby.
  • LNAs low noise amps
  • the configuration may be variously changed. It has an average system power gain (G RX ).
  • the system temperature (T SYS ) is defined as the sum of T A and the receiver noise temperature (T RX ).
  • the sensitivity of the radiometer is the minimum change in the system temperature (T SYS ).
  • the detector 150 (or a square detector) has a detector constant C d . It has a function of converting an input modulated power signal into an output voltage signal corresponding to temperature.
  • the signal passing through the detector 150 is input to the demodulator 160, at this time, the demodulator 160 is synchronized with the microwave switch 120, so that the microwave switch 120 is the antenna 110 ) when connected to the first path (P1), when the microwave switch 120 is connected to the reference noise source 130 is connected to the second path (P2). That is, the demodulator 160 may include a demodulator switch 165 (or a switching circuit) synchronized with the microwave switch 120 .
  • the signal passing through the demodulator 160 is input to an integrator 170 , and the integrator 170 accumulates signal values for a predetermined time, and transmits the value to the controller 180 .
  • the controller 180 controls the duty value of the clock for controlling the microwave switch 120 in a digital or analog manner.
  • the controller 180 may be an MCU.
  • a switch driver (not shown) may be separately provided, and the controller 180 may control the switch driver.
  • a square wave generator (not shown) for generating a predetermined clock signal may be further included.
  • the controller 180 controls the duty calibrator (duty calibrator) (190) to control the duty of the clock signal input to the microwave switch (120).
  • the receiver 100 includes a duty corrector 190, and the duty of the clock signal for determining the switching timing of the microwave switch 120 and the demodulator switch 165 control That is, the duty corrector 190 is connected to the microwave switch 130 and the demodulator switch 165 .
  • a path switch 195 may be provided between the duty corrector 190 and the microwave switch 130 , and the input from the controller 180 or the duty corrector 190 by the on/off of the path switch 195 .
  • the duty signal is input or not input to the microwave switch 130 .
  • the duty corrector 190 operates as an initial value, and the duty error ⁇ t is inputted to the demodulator 160 as it is.
  • the path switch 195 is turned off (OFF), the microwave switch 120 is connected to the reference noise source 130 for applying power according to the reference temperature (T ref ).
  • T ref reference temperature
  • a value output from the integrator 170 is as shown in Equation (4).
  • V out uncal : output value before correction (error voltage)
  • k constant
  • B bandwidth
  • G RX average system power gain
  • C d detector constant
  • T ref Reference temperature
  • T RX System temperature
  • A:Gain ⁇ A:Gain error
  • the error voltage V out,uncal is generated by the mismatch of A+ ⁇ A in the demodulator 160 and the duty error ⁇ t(t 1 -t 2 ) of the switching clock.
  • the second calibration step is performed.
  • FIG. 4 is a view for explaining the second correction step of the error compensation method according to the present invention and the operation of the receiver at that time.
  • the error voltage V out,uncal is applied to the controller 180 , and based on the value, the controller 180 may control the duty corrector 190 and the path switch 195 .
  • the duty corrector 190 may use both an analog method and a digital method.
  • the clock signal is a square wave signal in which logic states H(1) and L(0) appear periodically.
  • the duty compensator 190 is implemented as a circuit using an analog method, an inverter cell is used, but the load capacitance (C) or resistance (R) component of the rise and fall is changed according to the analog voltage to change the clock Adjust the duty ratio. That is, the lengths of the H section t1 and the L section t 2 within one period T can be changed.
  • the control of the capacitance (C) or the resistance (R) is digitally turned on/off using a switch array, not an analog voltage, so that the clock signal is Rising timing and falling timing may be adjusted to change the lengths of the H sections t1 and L sections t 2 within one period T.
  • the configuration and operation of the duty corrector 190 described above is only an example, and may be implemented in various other ways.
  • the controller 180 corrects the mismatch described above by changing the length of the H period t 1 (or L period t 2 ) of the clock signal.
  • the controller 180 controls the duty corrector 190 to change the length of the H section (t 1 ) to t 1 '(t 1 +t cal ). Accordingly, the output voltage (V out ) is changed to 0 to cancel the error, and at this time, t cal for determining t 1 ' in the correction duty value is as shown in Equation 5 below.
  • V out,cal output value after correction (error voltage)
  • k constant
  • B bandwidth
  • G RX average system power gain
  • C d detector constant
  • T ref Reference temperature
  • T RX System temperature
  • A Gain
  • ⁇ A Gain error
  • t 0 Length of H/L section of initial clock signal value
  • ⁇ t Duty error of switching clock
  • the controller 180 may control the duty corrector 190 to decrease t 1 if the value is positive and increase t1 if the value is negative. After the correction, if the output value (V out,cal ) finds a t 1 value at which 0 becomes 0, the value t 1 ' at that time becomes the correction duty value.
  • the controller 180 stores the corrected duty value derived by the above process, and then uses the fixed duty control value to control the microwave switch 120 during normal operation.
  • 5 is a view for explaining the overall operation of the error compensation method according to the present invention and the receiver during normal operation.
  • the controller 180 controls the path switch 195 to an ON state, and controls the microwave switch 120 based on the correction duty value. .
  • the controller 180 controls the path switch 195 to an ON state, and controls the microwave switch 120 based on the correction duty value.
  • 6 is a flowchart showing the flow of an error compensation method according to the present invention.
  • the error compensation method according to the present invention is largely divided into a first correction step, a second correction step, and a normal operation step.
  • the first correction step is a process of receiving an output value while controlling the initial value, and a duty error and a gain error may be determined through the output value.
  • the second correction step is a process of calculating a duty correction value based on the output value and generating a corrected clock signal based thereon. Finally, the normal operating phase of operating the receiver based on the corrected clock signal is achieved.
  • the controller controls the duty corrector as an initial value, and a clock signal including the duty error is directly transferred to the demodulator to control switching.
  • the microwave switch 120 is fixedly connected to the reference noise source 130 to receive only the reference temperature signal.
  • the signal is input to the demodulator 160 through circuits such as a receiver and a detector, and is multiplied by a predetermined gain A.
  • the gain can be described as including the gain error ⁇ A.
  • a signal including the gain error ⁇ A and the duty error ⁇ t is passed through the integrator 170 to generate an output value (error voltage V out, uncal ) ( S200 ).
  • the step S200 is a step of blocking the connection between the duty corrector and the microwave switch so that a clock signal including a duty error is not transmitted to the microwave switch, and a reference noise source in which the microwave switch inputs a reference temperature signal
  • the step of being fixedly connected to 130 may be further included.
  • step S200 the controller 180 shortens the H section of the clock signal if the output value (error voltage including the gain error and the duty error) of the integrator 170 is positive, and if it is negative, the H section of the clock signal It is possible to calculate the duty correction value at which the output value becomes 0 while repeatedly setting the .
  • the controller 180 calculates a duty correction value based on the output value, and generates a correction clock signal for controlling the microwave switch 120 and the switch 165 of the demodulator by controlling the duty corrector 190 based on this. do (S210).
  • the duty correction value may be defined by Equation 7 below.
  • the length of the H section (t 1 ′) and the L section length (t 2 ′) of the corrected clock signal may be defined as in Equation 8 below.
  • the microwave switch 120 operates normally. In other words, the antenna 110 and the reference noise source 130 are switched according to the corrected clock signal (S220).
  • the demodulator 160 is synchronized with the microwave switch 120, switching is performed in the same cycle.
  • the error compensation method in the radiometer receiver described above may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium.
  • the computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination.
  • the program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.
  • Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks.
  • - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like.
  • Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.
  • the hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radiation Pyrometers (AREA)
  • Electromagnetism (AREA)

Abstract

Selon la présente invention, un radiomètre destiné à un récepteur de micro-ondes comprend : un commutateur à micro-ondes ; un démodulateur, qui comporte un commutateur synchronisé avec le commutateur à micro-ondes et qui multiplie, par une valeur prédéterminée de gain, un signal traversant le commutateur à micro-ondes ; un intégrateur, permettant de générer une valeur de sortie par calcul d'un signal provenant du démodulateur ; un étalonneur de service, étalonnant la valeur de service d'un signal d'horloge pour commander le commutateur à micro-ondes ; un commutateur de trajets, situé entre l'étalonneur de service et le commutateur à micro-ondes ; et un dispositif de commande, permettant de générer la valeur d'étalonnage de service du signal d'horloge d'après la valeur de sortie de l'intégrateur. Un récepteur radiomètre de Dicke peut donc étalonner une tension d'erreur de sortie grâce à une erreur cyclique (Δt) d'une horloge et à une erreur de service (ΔA) (ou désappariement) d'un démodulateur et peut mesurer précisément la température (TA) d'un objet cible à travers l'étalonnage de la tension d'erreur de sortie.
PCT/KR2022/002082 2021-04-22 2022-02-11 Radiomètre pour récepteur de micro-ondes et procédé associé de compensation d'erreurs WO2022225155A1 (fr)

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KR102316907B1 (ko) * 2021-04-22 2021-10-25 (주)이지템 마이크로웨이브 수신기용 라디오미터 및 그의 에러 보상방법

Citations (5)

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JPH06142060A (ja) * 1992-11-12 1994-05-24 Olympus Optical Co Ltd 無侵襲温度計測装置
US20130272339A1 (en) * 2012-04-17 2013-10-17 Penn State Research Foundation System and method for combined microwave heating and radiometry for characterizing biological tissues
CN102680803B (zh) * 2012-05-04 2014-11-12 华中科技大学 基于参考负载温度实时监测的微波狄克辐射计
KR102152133B1 (ko) * 2019-04-30 2020-09-04 엘아이지넥스원 주식회사 밀리미터파 라디오미터 시스템
KR102316907B1 (ko) * 2021-04-22 2021-10-25 (주)이지템 마이크로웨이브 수신기용 라디오미터 및 그의 에러 보상방법

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KR101950592B1 (ko) 2017-06-26 2019-02-21 국방과학연구소 라디오미터의 온도 의존성 보상 방법

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06142060A (ja) * 1992-11-12 1994-05-24 Olympus Optical Co Ltd 無侵襲温度計測装置
US20130272339A1 (en) * 2012-04-17 2013-10-17 Penn State Research Foundation System and method for combined microwave heating and radiometry for characterizing biological tissues
CN102680803B (zh) * 2012-05-04 2014-11-12 华中科技大学 基于参考负载温度实时监测的微波狄克辐射计
KR102152133B1 (ko) * 2019-04-30 2020-09-04 엘아이지넥스원 주식회사 밀리미터파 라디오미터 시스템
KR102316907B1 (ko) * 2021-04-22 2021-10-25 (주)이지템 마이크로웨이브 수신기용 라디오미터 및 그의 에러 보상방법

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