Electric scanning radiometer device based on metasurface coding antenna

Abstract

The invention provides an electric scanning radiometer device based on a metasurface coding antenna, and the device comprises a metasurface coding antenna unit, and a receiving end of the metasurface coding antenna unit receives a microwave radiation signal from a target scene; the radiometer receiving channel is connected with the output end of the metasurface coding antenna unit, receives a microwave radiation signal and outputs a stable radiation power signal; the AD collector is connected with the output end of the radiometer receiving channel, receives the radiation power signal and converts the radiation power signal into a digital signal; the computer is connected with the output end of the AD collector, receives and stores the digital signal, and performs imaging processing according to the digital signal; and the computer is also connected with the control end of the metasurface coding antenna unit and transmits a beam scanning angle instruction to the metasurface coding antenna unit. Compared with an existing real aperture radiometer device, the coding phase control electric scanning mode has the advantages of being high in scanning speed, simple and light in system structure and economical in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of radiometer devices, and in particular to an electronic scanning radiometer device based on a metasurface coding antenna. Background Art

[0002] A radiometer is a passive test instrument used to measure the microwave radiation energy of an object. It is widely used in remote sensing, radio astronomy and other fields. With the advancement of sensor technology and signal processing technology, modern radiometers have not only greatly improved their sensitivity and accuracy, but also significantly improved their portability, data recording capabilities and wireless transmission functions. High-precision radiometers have become indispensable tools. Among them, the real aperture radiometer is used to measure the power of the microwave thermal radiation signal generated by the observation scene and the target itself. By measuring the data of the observation scene and the target in the horizontal and vertical directions, the reconstruction imaging of the radiation brightness temperature distribution of the observation scene and the target is realized.

[0003] The typical composition of the real aperture radiometer device, which has been widely used at home and abroad, includes a real aperture radiometer antenna, a receiving channel and an AD collector installed and fixed on a mechanical turntable. The mechanical turntable is controlled by a computer to realize the two-dimensional scanning measurement of the observation scene in the horizontal and vertical directions by the real aperture radiometer (antenna + receiving channel). The radiation brightness temperature distribution of the observation scene is reconstructed and imaged by processing the measurement data of the AD collector.

[0004] Based on the above development status, the applicant found that the existing real aperture radiometer device still has large errors. After research, it was found that this error is mainly caused by the fact that the traditional real aperture radiometer device needs to use a mechanical turntable to perform two-dimensional mechanical scanning of the observation scene and the target to achieve the reconstruction imaging of the radiation brightness temperature distribution of the observation scene and the target; resulting in the real aperture radiometer device introducing a turntable mechanical error during the imaging measurement process, which deteriorates the imaging quality. In addition, the mechanical scanning device also has the disadvantage of making the real aperture radiometer device complex and the imaging measurement time long. Summary of the invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art.

[0006] To this end, the present invention provides an electronic scanning radiometer device based on a metasurface coding antenna.

[0007] The present invention provides an electronic scanning radiometer device based on a metasurface coding antenna, comprising:

[0008] A metasurface coding antenna unit, comprising a receiving end, an output end and a control end, wherein the receiving end of the metasurface coding antenna unit receives a microwave radiation signal from a target scene;

[0009] A radiometer receiving channel is connected to the output end of the metasurface coding antenna unit, receives the microwave radiation signal, performs signal processing on the microwave radiation signal, and outputs a stable radiation power signal;

[0010] An AD collector is connected to the output end of the radiometer receiving channel, receives the radiation power signal and converts the radiation power signal into a digital signal;

[0011] A computer is connected to the output end of the AD collector, receives and stores the digital signal, and performs imaging processing according to the digital signal; the computer is also connected to the control end of the metasurface coding antenna unit, and transmits a beam scanning angle instruction to the metasurface coding antenna unit, and the beam scanning angle instruction is used to control the beam pointing of the metasurface coding antenna unit in the horizontal and vertical directions and electronic scanning.

[0012] The electronic scanning radiometer device based on the metasurface coding antenna according to the above technical solution of the present invention may also have the following additional technical features:

[0013] In the above technical solution, the metasurface coding antenna unit includes:

[0014] A transmission type metasurface coding array antenna, comprising a receiving end, an output end and a control end, wherein the receiving end of the transmission type metasurface coding array antenna serves as the receiving end of the metasurface coding antenna unit, and the output end of the transmission type metasurface coding array antenna serves as the output end of the metasurface coding antenna unit;

[0015] A voltage control module having an input end and an output end, wherein the output end of the voltage control module is coupled to the control end of the transmission metasurface coding array antenna;

[0016] A coding control module having an input end and an output end, wherein the input end of the coding control module is connected to a computer to receive the beam scanning angle instruction, and the output end of the coding control module is coupled to the input end of the voltage control module;

[0017] Among them, the coding control module controls the output voltage of the voltage control module according to the received beam scanning angle instruction, so as to realize the regulation and electronic scanning of the beam pointing of the transmissive metasurface coding array antenna in the horizontal and vertical directions.

[0018] In the above technical solution, the radiometer receiving channel includes:

[0019] A radio frequency amplifier, coupled to the output end of the transmissive metasurface coding array antenna, for amplifying the millimeter wave signal received by the antenna;

[0020] A square-law detector, connected to the radio frequency amplifier, for converting the amplified millimeter-wave signal into a direct current signal;

[0021] A low-pass filter, connected to the square-law detector, for filtering out high-frequency noise in the output signal of the square-law detector;

[0022] The integrator is connected to the low-pass filter and is used to integrate the signal output by the low-pass filter to obtain a radiation power signal.

[0023] In the above technical solution, during the beam electronic scanning of the target scene, when the transmission metasurface coding array antenna beam is adjusted to the specified angle, the coding control module will feedback the beam adjustment signal to the computer. At this time, the computer will control the AD collector to collect and store the radiation power signal output by the radiometer receiving channel.

[0024] The above technical solution also includes:

[0025] An image display unit is connected to the computer and is used to display the imaging processing result.

[0026] In the above technical solution, the RF amplifier is a low-noise amplifier with a noise figure less than 4dB and a gain greater than 20dB, so as to minimize the noise introduced by the microwave radiation signal during the amplification process and improve the sensitivity of the system.

[0027] In the above technical solution, the square-law detector adopts a Schottky diode, which has high linearity and low insertion loss, and can accurately convert the amplified millimeter-wave signal into a DC signal to reduce signal distortion.

[0028] In the above technical solution, the cut-off frequency of the low-pass filter is 1 MHz, and the out-of-band suppression is greater than 30 dB, which can effectively filter out high-frequency noise and ensure that the signal processed by the integrator is smooth and stable.

[0029] In the above technical solution, the integration time of the integrator is adjustable in the range of 1 μs to 20 μs to adapt to the radiation signal intensity of different target scenes and improve the signal-to-noise ratio and response speed of the measurement.

[0030] In the above technical solution, the encoding control module is implemented using a field programmable gate array, which can quickly respond to the beam scanning angle instructions of the computer and accurately control the output voltage of the voltage control module to achieve high-precision beam pointing control.

[0031] In summary, due to the adoption of the above technical features, the beneficial effects of the present invention are:

[0032] The electronic scanning radiometer device based on the metasurface coded antenna provided by the present invention can effectively solve the problems of measurement error, long measurement time and system complexity caused by the mechanical turntable in the existing real aperture radiometer device; by adopting the coded phased electronic scanning method of the present invention, compared with the existing real aperture radiometer device, the present invention has the advantages of fast scanning speed, simple and light system structure and cost-effectiveness.

[0033] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0035] Figure 1 It is a module schematic diagram of an electronic scanning radiometer device based on a metasurface coding antenna according to an embodiment of the present invention.

[0036] in, Figure 1 The corresponding relationship between the reference numerals and the component names is as follows:

[0037] 1. Transmissive metasurface coding array antenna; 2. Voltage control module; 3. Coding control module; 4. RF amplifier; 5. Square-law detector; 6. Low-pass filter; 7. Integrator; 8. AD collector; 9. Computer; 10. Image display unit. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0040] Refer to the following Figure 1 To describe an electronically scanned radiometer device based on a metasurface coding antenna provided according to some embodiments of the present invention.

[0041] Some embodiments of the present application provide an electronic scanning radiometer device based on a metasurface coded antenna.

[0042] like Figure 1As shown, the first embodiment of the present invention proposes an electronic scanning radiometer device based on a metasurface coding antenna, including: a metasurface coding antenna unit, a radiometer receiving channel, an AD collector 8 and a computer 9.

[0043] The metasurface coding antenna unit has a receiving end, an output end and a control end, and the receiving end of the metasurface coding antenna unit receives a microwave radiation signal from a target scene; it should be noted that the metasurface coding antenna unit is used to implement a coded phased electronic scanning method.

[0044] The radiometer receiving channel is connected to the output end of the metasurface coding antenna unit, receives the microwave radiation signal, performs signal processing on the microwave radiation signal, and outputs a stable radiation power signal.

[0045] The AD collector 8 is connected to the output end of the radiometer receiving channel, receives the radiation power signal and converts the radiation power signal into a digital signal.

[0046] The computer 9 is connected to the output end of the AD collector 8, receives and stores the digital signal, and performs imaging processing according to the digital signal; the computer 9 is also connected to the control end of the metasurface coding antenna unit, and transmits a beam scanning angle instruction to the metasurface coding antenna unit, and the beam scanning angle instruction is used to control the beam pointing of the metasurface coding antenna unit in the horizontal and vertical directions and electronic scanning.

[0047] In some embodiments, the metasurface coding antenna unit includes a transmissive metasurface coding array antenna 1, a voltage control module 2 and a coding control module 3.

[0048] The transmission type metasurface coding array antenna 1 has a receiving end, an output end and a control end. The receiving end of the transmission type metasurface coding array antenna 1 serves as the receiving end of the metasurface coding antenna unit, and the output end of the transmission type metasurface coding array antenna 1 serves as the output end of the metasurface coding antenna unit. Specifically, the transmission type metasurface coding array antenna 1 uses the characteristics of the metasurface to regulate the propagation of electromagnetic waves. The transmission type metasurface coding array antenna 1 controls the transmission phase of the electromagnetic wave through a coding sequence, thereby realizing functions such as beam directionality, focusing or multi-beam generation. This antenna has the characteristics of high gain, high sensitivity, lightness, and reconfigurability, and is suitable for application scenarios with limited space.

[0049] The voltage control module 2 has an input end and an output end, and the output end of the voltage control module 2 is coupled to the control end of the transmission metasurface coding array antenna 1 .

[0050] The coding control module 3 has an input end and an output end. The input end of the coding control module 3 is connected to the computer 9 to receive the beam scanning angle instruction. The output end of the coding control module 3 is coupled to the input end of the voltage control module 2.

[0051] In this embodiment, the coding control module 3 controls the output voltage of the voltage control module 2 according to the received beam scanning angle instruction, so as to realize the regulation and electronic scanning of the beam pointing of the transmission metasurface coding array antenna 1 in the horizontal and vertical directions.

[0052] In some embodiments, during the process of beam electronic scanning of the target scene, when the beam of the transmissive metasurface coding array antenna 1 is adjusted to a specified angle, the coding control module 3 will feedback a signal that the beam has been adjusted to a certain position to the computer 9, and at this time the computer 9 will control the AD collector 8 to collect and store the radiation power signal output by the radiometer receiving channel. Repeat the above measurement process, and after the AD collector 8 completes the collection of the corresponding signal of the target scene scanning area, the computer 9 performs imaging processing on the stored data.

[0053] In some embodiments, the electronic scanning radiometer device further comprises an image display unit 10, which is connected to the computer 9 and is used to display the imaging processing result. In a specific embodiment, the image display unit 10 is configured as a high-definition display.

[0054] In some embodiments, continue to refer to Figure 1 The radiometer receiving channel includes: a radio frequency amplifier 4, a square-law detector 5, a low-pass filter 6 and an integrator 7.

[0055] The RF amplifier 4 is coupled to the output end of the transmission metasurface coding array antenna 1, and is used to amplify the millimeter wave signal received by the antenna. Specifically, the main function of the RF amplifier 4 is to amplify the weak RF signal received from the antenna to a sufficient level so that the subsequent circuit can effectively process it. It usually has a higher gain and a lower noise factor to ensure that the signal does not introduce too much noise during the amplification process, thereby ensuring the sensitivity of the system. In a specific embodiment, the RF amplifier 4 is a low-noise amplifier with a noise factor of less than 4dB and a gain of greater than 20dB, so as to minimize the noise introduced by the microwave radiation signal during the amplification process and improve the sensitivity of the system.

[0056] The square-law detector 5 is connected to the RF amplifier 4 and is used to convert the amplified millimeter-wave signal into a DC signal; specifically, the function of the square-law detector 5 is to convert the amplitude information of the RF signal into a DC voltage or current signal. It extracts the power information of the signal through a square operation, thereby realizing the measurement of the radiation power. In the radiometer, the square-law detector 5 converts the amplified RF signal into a DC signal for subsequent processing by the integrator 7. The output signal of the square-law detector 5 fluctuates rapidly, so it needs to be smoothed by the integrator 7. In a specific embodiment, the square-law detector 5 uses a Schottky diode, which has high linearity and low insertion loss, and can accurately convert the amplified millimeter-wave signal into a DC signal to reduce signal distortion.

[0057] The low-pass filter 6 is connected to the square-law detector 5 and is used to filter out the high-frequency noise in the output signal of the square-law detector 5; specifically, the function of the low-pass filter 6 is to filter out the high-frequency noise and unnecessary high-frequency components, and only retain the low-frequency signal. It ensures that the detected signal is smooth before being processed by the integrator 7, thereby improving the signal-to-noise ratio of the signal. In the radiometer receiving channel, the low-pass filter 6 filters out the high-frequency noise in the output signal of the square-law detector 5, making the signal smoother and facilitating the integration processing of the integrator 7. In a specific embodiment, the cut-off frequency of the low-pass filter 6 is 1MHz, and the out-of-band suppression is greater than 30dB, which can effectively filter out the high-frequency noise and ensure that the signal processed by the integrator 7 is smooth and stable.

[0058] The integrator 7 is connected to the low-pass filter 6, and is used to integrate the signal output by the low-pass filter 6 to obtain a radiation power signal. Specifically, the function of the integrator 7 is to integrate the signal output by the low-pass filter 6 over time, so as to obtain an average value within a certain time range. The integrator 7 can effectively reduce the short-term fluctuation of the signal and improve the stability and signal-to-noise ratio of the measurement. In the radiometer, the integrator 7 integrates the signal output by the low-pass filter 6 to obtain the average value of the radiation power. The length of the integration time will affect the measurement accuracy and response speed. A longer integration time can improve the signal-to-noise ratio, but will reduce the response speed of the system. In a specific embodiment, the integration time of the integrator 7 is adjustable in the range of 1μs to 20μs to adapt to the radiation signal intensity of different target scenes and improve the signal-to-noise ratio and response speed of the measurement.

[0059] In some embodiments, the encoding control module 3 is implemented using a field programmable gate array (FPGA), which can quickly respond to the beam scanning angle instructions of the computer 9 and accurately control the output voltage of the voltage control module 2 to achieve high-precision beam pointing control.

[0060] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0061] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic scanning radiometer device based on a metasurface coding antenna, characterized in that: include: A metasurface coding antenna unit, comprising a receiving end, an output end and a control end, wherein the receiving end of the metasurface coding antenna unit receives a microwave radiation signal from a target scene; A radiometer receiving channel is connected to the output end of the metasurface coding antenna unit, receives the microwave radiation signal, performs signal processing on the microwave radiation signal, and outputs a stable radiation power signal; An AD collector is connected to the output end of the radiometer receiving channel, receives the radiation power signal and converts the radiation power signal into a digital signal; A computer is connected to the output end of the AD collector, receives and stores the digital signal, and performs imaging processing according to the digital signal; the computer is also connected to the control end of the metasurface coding antenna unit, and transmits a beam scanning angle instruction to the metasurface coding antenna unit, and the beam scanning angle instruction is used to control the beam pointing of the metasurface coding antenna unit in the horizontal and vertical directions and electronic scanning.

2. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 1 is characterized in that: The metasurface coding antenna unit comprises: A transmission type metasurface coding array antenna, comprising a receiving end, an output end and a control end, wherein the receiving end of the transmission type metasurface coding array antenna serves as the receiving end of the metasurface coding antenna unit, and the output end of the transmission type metasurface coding array antenna serves as the output end of the metasurface coding antenna unit; A voltage control module, having an input end and an output end, wherein the output end of the voltage control module is coupled to the control end of the transmission metasurface coding array antenna; A coding control module having an input end and an output end, wherein the input end of the coding control module is connected to a computer to receive the beam scanning angle instruction, and the output end of the coding control module is coupled to the input end of the voltage control module; Among them, the coding control module controls the output voltage of the voltage control module according to the received beam scanning angle instruction, so as to realize the regulation and electronic scanning of the beam pointing of the transmissive metasurface coding array antenna in the horizontal and vertical directions.

3. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 2 is characterized in that: The radiometer receiving channel includes: A radio frequency amplifier, coupled to the output end of the transmissive metasurface coding array antenna, for amplifying the millimeter wave signal received by the antenna; A square-law detector, connected to the radio frequency amplifier, for converting the amplified millimeter-wave signal into a direct current signal; A low-pass filter, connected to the square-law detector, for filtering out high-frequency noise in the output signal of the square-law detector; The integrator is connected to the low-pass filter and is used to integrate the signal output by the low-pass filter to obtain a radiation power signal.

4. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 2 is characterized in that: During the beam electronic scanning of the target scene, when the transmission metasurface coding array antenna beam is adjusted to the specified angle, the coding control module will feedback a signal to the computer indicating that the beam has been adjusted to the correct angle. At this time, the computer will control the AD collector to collect and store the radiation power signal output by the radiometer receiving channel.

5. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 1 is characterized in that: Also includes: An image display unit is connected to the computer and is used to display the imaging processing result.

6. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 3 is characterized in that: The radio frequency amplifier is a low noise amplifier with a noise figure less than 4dB and a gain greater than 20dB.

7. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 3 is characterized in that: The square-law detector adopts a Schottky diode.

8. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 3 is characterized in that: The cut-off frequency of the low-pass filter is 1 MHz, and the out-of-band suppression is greater than 30 dB.

9. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 3 is characterized in that: The integration time of the integrator is adjustable in the range of 1 μs to 20 μs.

10. The electronic scanning radiometer device based on the metasurface coding antenna according to claim 4 is characterized in that: The encoding control module is implemented by using a field programmable gate array.

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