CN116626619A - Doppler radar target simulator and microwave radar sensing test system - Google Patents

Doppler radar target simulator and microwave radar sensing test system Download PDF

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Publication number
CN116626619A
CN116626619A CN202310342643.3A CN202310342643A CN116626619A CN 116626619 A CN116626619 A CN 116626619A CN 202310342643 A CN202310342643 A CN 202310342643A CN 116626619 A CN116626619 A CN 116626619A
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target
signal
analog
radar
radio frequency
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林水洋
何德宽
俞建海
黄灵军
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Gekong Shanghai Intelligent Technology Co ltd
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Gekong Shanghai Intelligent Technology Co ltd
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Priority to CN202310342643.3A priority Critical patent/CN116626619A/en
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/40Means for monitoring or calibrating
    • G01S7/4052Means for monitoring or calibrating by simulation of echoes
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

According to the Doppler radar principle, after receiving a microwave radar signal, a circuit integrated on a circuit board of the simulator generates and returns an echo signal containing detection target information to the microwave radar, and whether the function of the radar in an actual scene can meet the use requirement is deduced by detecting the processing capacity of the radar on the echo signal. The method and the device realize quantification, adjustability and repeatability of the target signal which is difficult to quantify, inflexible and poor in repeatability in the prior art, can accurately set the speed information and the amplitude information of the radar echo signal simulation target, and enable the microwave radar test to be more economical and flexible and better in scene repeatability and controllability.

Description

Doppler radar target simulator and microwave radar sensing test system
Technical Field
The invention relates to the field of microwave radars, in particular to a Doppler radar target simulator and a microwave radar sensing test system.
Background
With the gradual deepening of radar technology from military to civil use, microwave radar is used as a sensor and applied to various consumer products. The microwave radar sensor can be installed in a hidden mode, is not influenced by temperature, air flow, dust, smoke and the like, has the advantages of long service life, high reaction speed, higher sensitivity, wide induction area and the like, gradually replaces the sensing technologies such as infrared, sound control and the like to be widely applied to consumer electronic products in multiple fields, comprises energy-saving illumination, security protection, intelligent household appliances and the like, and is an important link in the research and development of the microwave radar products and the production process of the microwave radar products.
For products such as present energy-saving illumination, security protection, intelligent household appliances, microwave radar sensor test scheme generally uses angle antenna, swaying ware, people walk or wave hand etc. as the detection target of test radar sensor, and the shortcoming of this kind of mode lies in: the test results are perceptively difficult to quantify, inflexible and poorly reproducible. Particularly, in the production test, when a plurality of radar sensor products are simultaneously detected and tested with targets, the scheme can amplify deviation of sensing results of different radar sensors, so that consistency is deteriorated, and the real performance of the radar products cannot be truly tested.
Disclosure of Invention
In view of the above drawbacks of the prior art, an object of the present invention is to provide a doppler radar target simulator and a microwave radar sensing test system for solving the above technical problems in the prior art.
To achieve the above and other related objects, the present invention provides a doppler radar target simulator for simulating a target speed and a target amplitude of a simulated target, the target simulator comprising: the signal receiving module, the low noise amplifier, the first attenuator, the signal conversion and phase shift module, the first mixer, the second mixer, the processing module, the digital-to-analog conversion module, the combiner, the second attenuator, the power amplifier and the signal transmitting module are integrated on the circuit board of the simulator; the signal receiving module, the low noise amplifier, the first attenuator and the signal conversion and phase shift module are sequentially connected in series; the first mixer and the second mixer are respectively connected with the signal conversion and phase shift module, the digital-to-analog conversion module and the combiner; the processing module is connected with the digital-to-analog conversion module; the combiner, the second attenuator, the power amplifier and the signal transmitting module are sequentially connected in series; the signal receiving module receives an electromagnetic wave signal sent by a radar sensor, and then sequentially amplifies the electromagnetic wave signal and adjusts the amplitude of the electromagnetic wave through the low-noise amplifier and the first attenuator; the signal conversion and phase shift module converts the regulated signal from a single-ended signal to a differential signal and outputs a pair of orthogonal radio frequency signals; converting, by the digital-to-analog conversion module, a pair of baseband analog quadrature signals that conform to the analog target characteristics from digital signals that conform to the analog target characteristics generated by the processing module based on analog target parameters related to the analog target; the first mixer and the second mixer respectively mix the baseband analog quadrature signal with the radio frequency signal output by the signal conversion and phase shift module, and then add the signals mixed by the first mixer and the second mixer through the combiner; the added signals sequentially pass through a second attenuator and a power amplifier to amplify the signals and adjust the amplitude of electromagnetic waves, and a signal transmitting module returns the analog target signals which accord with the target speed and the target amplitude of the analog target to the radar sensor.
In one embodiment of the present invention, the method for simulating the target speed of the simulation target includes: receiving a digital signal generated by the processing module based on an analog target parameter related to a target speed of an analog target through the digital-to-analog conversion module, converting the digital signal into a baseband analog orthogonal signal pair conforming to the target speed, respectively mixing the baseband analog orthogonal signal pair with a radio frequency signal output by the signal conversion and phase shift module through the first mixer and the second mixer, adding the signals mixed by the first mixer and the second mixer through the combiner, and sequentially carrying out signal amplification and electromagnetic wave amplitude adjustment on the signals added by the signals through the second attenuator and the power amplifier to generate an analog target signal conforming to the target speed; and the frequency offset between the signal obtained by adding the signals by the combiner and the radio frequency signal output by the signal conversion and phase shift module corresponds to the frequency of the target speed.
In an embodiment of the present invention, the method for simulating the target amplitude of the simulation target includes: and adjusting the amplitude of the signal by setting one or more of parameters of a low noise amplifier, a first attenuator, a second attenuator, a digital-to-analog converter and a power amplifier to generate an analog target signal corresponding to the target amplitude.
In an embodiment of the present invention, the signal receiving module includes: a circular polarization receiving antenna, a first radio frequency switch and a receiving radio frequency head are arranged in the antenna; the built-in circularly polarized receiving antenna is used for receiving electromagnetic wave signals in the orthogonal direction; the receiving radio frequency head is used for externally connecting a receiving antenna so as to receive electromagnetic wave signals through the receiving antenna; the radio frequency switch is connected with the built-in circularly polarized antenna and the transmitting radio frequency head and is used for controlling the built-in circularly polarized antenna or a receiving antenna externally connected with the receiving radio frequency head to correspondingly receive electromagnetic wave signals so as to input the electromagnetic wave signals to the low noise amplifier.
In an embodiment of the present invention, the signal transmitting module includes: a circular polarization transmitting antenna, a second radio frequency switch and a transmitting radio frequency head are arranged in the antenna; the built-in circularly polarized transmitting antenna is used for transmitting a simulated target signal in the form of circularly polarized electromagnetic waves; the transmitting radio frequency head is used for being externally connected with a transmitting antenna so as to transmit the analog target signal through the transmitting antenna; the radio frequency switch is connected with the built-in circular polarization transmitting antenna and the transmitting radio frequency head and is used for controlling the transmitting antenna externally connected with the built-in circular polarization transmitting antenna or the transmitting radio frequency head to transmit the simulation target signal.
In an embodiment of the present invention, the built-in circular polarized receiving antenna and the built-in circular polarized transmitting antenna are respectively embedded in the front surface of the simulator circuit board, and the back surface of the simulator circuit board is respectively provided with a feed network which is matched with the built-in circular polarized receiving antenna and the built-in circular polarized transmitting antenna; the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna are respectively provided with a first feeding point and a second feeding point, and the first feeding point and the second feeding point connect the antennas with the corresponding feeding network in a metal via way; the first feeding point and the second feeding point are equal in distance from the geometric center of the corresponding antenna, and connecting lines of the two feeding points to the geometric center are orthogonal to each other; the built-in circularly polarized receiving antenna is combined with a corresponding feed network to receive electromagnetic wave signals sent by the radar sensor; the built-in circularly polarized transmitting antenna is combined with a corresponding feed network to send the generated simulated target signal in the form of the transmitted circularly polarized electromagnetic wave to the radar sensor.
In an embodiment of the present invention, the signal conversion and phase shift module includes: a signal conversion section for converting the adjusted signal from a single-ended signal to a differential signal; and the phase shifting component is connected with the signal conversion component and is used for shifting the phase of the converted differential signal and outputting a pair of orthogonal radio frequency signals.
In an embodiment of the invention, the processing module is configured to set the simulation target parameter based on a control instruction of a control end of an upper computer connected to the doppler radar target simulator, and generate a digital signal according with a characteristic of the simulation target.
In an embodiment of the invention, the doppler radar target simulator is connected with the control end of the upper computer through a USB interface.
To achieve the above and other related objects, the present invention provides a microwave radar sensing test system, comprising: the radar sensors are respectively arranged on a tool plane of the fixed tool; the Doppler radar target simulator is arranged in the normal direction along the tool plane; the Doppler radar target simulator simulates the target speed and the target amplitude of the simulation target sequentially based on the received electromagnetic waves transmitted by the radar sensors and the simulation target parameters related to the simulation target, and returns the simulation target signals conforming to the target speed and the target amplitude of the simulation target to the corresponding radar sensors.
As described above, the invention is a Doppler radar target simulator and a microwave radar sensing test system, which have the following beneficial effects: according to the Doppler radar principle, after a microwave radar signal is received through a circuit integrated on a simulator circuit board, an echo signal containing detection target information is generated and returned to the microwave radar, and whether the function of the radar in an actual scene can meet the use requirement is deduced by detecting the processing capacity of the radar on the echo signal. The method and the device realize quantification, adjustability and repeatability of the target signal which is difficult to quantify, inflexible and poor in repeatability in the prior art, can accurately set the speed information and the amplitude information of the radar echo signal simulation target, and enable the microwave radar test to be more economical and flexible and better in scene repeatability and controllability.
Drawings
Fig. 1 is a schematic diagram of a doppler radar target simulator according to an embodiment of the invention.
Fig. 2 is a schematic diagram of a doppler radar target simulator according to an embodiment of the invention.
Fig. 3 is a schematic structural diagram of an antenna plane and a feed network plane according to an embodiment of the invention.
Fig. 4 is a schematic diagram showing a trace length relationship of a feeding network according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of a 5.8G doppler radar target simulator according to an embodiment of the invention.
FIG. 6 is a schematic diagram of an application test environment of a microwave radar sensing test system according to an embodiment of the invention.
Fig. 7 shows a schematic view of a radar sensor installation in an embodiment of the present invention.
FIG. 8 is a diagram showing the axial ratio index of the simulator at each principal direction angle in an embodiment of the invention.
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict.
In the following description, reference is made to the accompanying drawings, which illustrate several embodiments of the invention. It is to be understood that other embodiments may be utilized and that mechanical, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present invention. The following detailed description is not to be taken in a limiting sense, and the scope of embodiments of the present invention is defined only by the claims of the issued patent. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Spatially relative terms, such as "upper," "lower," "left," "right," "lower," "below," "lower," "above," "upper," and the like, may be used herein to facilitate a description of one element or feature as illustrated in the figures relative to another element or feature.
Throughout the specification, when a portion is said to be "connected" to another portion, this includes not only the case of "direct connection" but also the case of "indirect connection" with other elements interposed therebetween. In addition, when a certain component is said to be "included" in a certain section, unless otherwise stated, other components are not excluded, but it is meant that other components may be included.
The first, second, and third terms are used herein to describe various portions, components, regions, layers and/or sections, but are not limited thereto. These terms are only used to distinguish one portion, component, region, layer or section from another portion, component, region, layer or section. Thus, a first portion, component, region, layer or section discussed below could be termed a second portion, component, region, layer or section without departing from the scope of the present invention.
Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, operations, elements, components, items, categories, and/or groups. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; A. b and C). An exception to this definition will occur only when a combination of elements, functions or operations are in some way inherently mutually exclusive.
According to the Doppler radar principle, after receiving a microwave radar signal, a circuit integrated on a circuit board of the simulator generates and returns an echo signal containing detection target information to the microwave radar, and whether the function of the radar in an actual scene can meet the use requirement is deduced by detecting the processing capacity of the radar on the echo signal. The method and the device realize quantification, adjustability and repeatability of the target signal which is difficult to quantify, inflexible and poor in repeatability in the prior art, can accurately set the speed information and the amplitude information of the radar echo signal simulation target, and enable the microwave radar test to be more economical and flexible and better in scene repeatability and controllability.
The radar sensor adopted by the test object can be a microwave radar of any required working frequency band, such as radars of different working frequency bands of 5.8GHz, 10GHz, 24GHz, 60GHz, 77GHz and the like. Therefore, the Doppler radar target simulator can realize the test of the microwave radar in any working frequency band.
The embodiments of the present application will be described in detail below with reference to the attached drawings so that those skilled in the art to which the present application pertains can easily implement the present application. This application may be embodied in many different forms and is not limited to the embodiments described herein.
Fig. 1 shows a schematic structural diagram of a doppler radar target simulator in an embodiment of the present invention.
The Doppler radar target simulator is used for simulating the target speed and the target amplitude of a simulation target.
The target simulator includes: the signal receiving module 1, the low noise amplifier 2, the first attenuator 3, the signal conversion and phase shift module 4, the first mixer 5, the second mixer 6, the processing module 7, the digital-to-analog conversion module 8, the combiner 9, the second attenuator 10, the power amplifier 11 and the signal transmitting module 12 are integrated on the circuit board of the simulator; specifically, the digital-to-analog conversion module 8 may be a digital-to-analog converter, or may be a digital frequency synthesizer or the like for generating an intermediate frequency signal. The processing module 7 may be a microprocessor MCU, or may adopt other schemes such as FPGA.
The signal receiving module 1, the low noise amplifier 2, the first attenuator 3 and the signal conversion and phase shift module 4 are sequentially connected in series; specifically, the signal receiving module 1 is connected with the low noise amplifier 2, the low noise amplifier 2 is connected with the first attenuator 3, and the first attenuator 3 is connected with the signal conversion and phase shift module 4. The first mixer 5 and the second mixer 6 are connected in parallel and are respectively connected with the signal conversion and phase shift module 4, the digital-to-analog conversion module 8 and the combiner 9; the processing module 7 is connected with the digital-to-analog conversion module 8; the combiner 9, the second attenuator 10, the power amplifier 11 and the signal transmitting module 12 are sequentially connected in series; specifically, the combiner 9 is connected to the second attenuator 10, the second attenuator 10 is connected to the power amplifier 11, and the power amplifier 11 is connected to the signal transmitting module 12.
The signal receiving module 1 receives an electromagnetic wave signal sent by a radar sensor, then carries out signal amplification through the low noise amplifier 2, and then carries out electromagnetic wave amplitude adjustment on the electromagnetic wave signal through the first attenuator 3; the signal conversion and phase shift module 4 converts the regulated signal from single-ended signal to differential signal, and outputs a pair of orthogonal radio frequency signals and transmits the signals to the first mixer 5 and the second mixer 6; meanwhile, the processing module 7 converts the digital signal which is generated based on the analog target parameter related to the analog target and accords with the analog target feature into a pair of baseband analog orthogonal signals which accord with the analog target feature through the digital-to-analog conversion module 8 according to the digital signal which accords with the analog target feature; the first mixer 5 and the second mixer 6 respectively mix the baseband analog quadrature signal with the radio frequency signal output by the signal conversion and phase shift module 4, and then add the signals mixed by the first mixer 5 and the second mixer 6 through the combiner 9; the added signals sequentially pass through a second attenuator 10 and a power amplifier 11 for signal amplification and electromagnetic wave amplitude adjustment, and an analog target signal which accords with the target speed and the target amplitude of an analog target is returned to the radar sensor by a signal transmitting module 12.
Preferably, the PCB size of the simulator circuit board is only 80 x 60mm, the space requirement on the use environment is low, and the high-integration and miniaturization design is realized.
In one embodiment, the manner in which the target speed of the simulated target is simulated includes:
receiving, by the digital-to-analog conversion module 8, a digital signal generated by the processing module 7 based on an analog target parameter related to a target speed of an analog target and converting the digital signal into a baseband analog quadrature signal pair conforming to the target speed, wherein the baseband analog quadrature signal pair comprises an intermediate frequency signal 1 and an intermediate frequency signal 2, mixing the baseband analog quadrature signal pair with a radio frequency signal output by the signal conversion and phase shift module 4 through the first mixer 5 and the second mixer 6 respectively, and adding the signals mixed by the first mixer 5 and the second mixer 6 through the combiner 9 so as to enable the signals added by the signals to be amplified by the second attenuator 10 and the power amplifier 11 in sequence and adjust the amplitude of electromagnetic waves to generate an analog target signal conforming to the target speed;
wherein, the frequency offset between the signal obtained by adding the signals by the combiner 9 and the radio frequency signal output by the signal conversion and phase shift module 4 corresponds to the frequency of the target speed. And the sign of the frequency offset is related to the distance between the simulation target and the corresponding radar, the sign is far away when the sign is negative, and the sign is near when the sign is positive.
In order to describe the manner in which the target speed of the simulation target is simulated in more detail, the following specific examples are described.
The Doppler radar target simulator receives the radio frequency signal sent by the radar as sine wave RF in Can be simply defined as cos (omega) r t), without considering the phase shift and delay of the air transmission, obtaining two paths of orthogonal signals cos (omega) after the signal conversion and phase shift module 4 r t) and sin (ω) r t) respectively enter the first mixer 5 and the second mixer 6. The intermediate frequency signal 1 and the intermediate frequency signal 2 sent by the digital-to-analog conversion module 7 are baseband quadrature signals with the same frequency and amplitude and 90 degrees phase difference, wherein the intermediate frequency signal 1 can be simply defined as cos (omega) d t), the intermediate frequency signal 2 can be simply defined as sin (ω) d t)。
The mixed output signal of the first mixer 5 results in:
cos(ω r t)·cos(ω d t); (1)
the mixed output signal of the second mixer 6 results in:
sin(ω r t)·sin(ω d t); (2)
the output signal results of the first mixer 5 and the second mixer 6 are synthesized and added by a combiner 9 to obtain an output signal result RF out The method comprises the following steps:
RF out =cos(ω r t)·cos(ω d t)+sin(ω r t)·sin(ω d t); (3)
RF out =cos((ω rd )t); (4)
it follows that the incoming radar signal RF of the doppler radar target simulator in Frequency omega r Output signal RF of/2 pi out Frequency is (omega) rd ) 2 pi Doppler radar target modelAnalog output signal RF out Compared with the input signal RF in The frequency offset is (-omega) d ) And/2 pi, wherein the frequency offset is a negative value, and the simulated scene is a Doppler frequency shift frequency corresponding to the target speed when the target is far away from the radar.
And the parameters of the digital-to-analog conversion module 8 can be changed to generate intermediate frequency signals 1 and intermediate frequency signals 2 with different frequencies, so that target analog signals with different speeds can be simulated.
Similarly, the digital signal sent to the digital-to-analog conversion module 8 may be adjusted by modifying the analog target parameters set by the processing module 7 to adjust the phase relationship between the intermediate frequency signal 1 and the intermediate frequency signal 2, and at this time, the intermediate frequency signal 1 may be simply defined as sin (ω) d t), the intermediate frequency signal 2 can be defined simply as cos (ω) d t)。
The mixed output signal of the first mixer 5 results in:
cos(ω r t)·sin(ω d t); (5)
the mixed output signal of the second mixer 6 results in:
sin(ω r t)·cos(ω d t); (6)
the output signal results of the first mixer 5 and the second mixer 6 are synthesized and added by a combiner 9 to obtain an output signal result RF out The method comprises the following steps:
RF out =cos(ω r t)·sin(ω d t)+sin(ω r t)·cos(ω d t); (7)
RF out =cos((ω rd )t); (8)
at this time, the radar signal RF input by the doppler radar target simulator in Frequency omega r Output signal RF of/2 pi out Frequency is (omega) rd ) Output signal RF of Doppler radar target simulator out Compared with the input signal RF in The frequency offset is (+ω) d ) And/2 pi, wherein the frequency offset is a positive value, and the simulated scene is Doppler frequency shift frequency corresponding to the speed when the target approaches the radar.
In one embodiment, the manner in which the target amplitude of the simulated target is simulated includes:
and generating an analog target signal corresponding to the target amplitude by setting one or more modes of parameters of the low-noise amplifier, parameters of the first attenuator, parameters of the second attenuator, parameters of the power amplifier and analog target parameters related to the target amplitude.
The output power of the doppler radar target simulator can be controlled by utilizing various combinations of adjusting parameters of the low noise amplifier 2, the first attenuator 3, the second attenuator 10, the power amplifier 11, the digital-to-analog converter 8, controlling the amplitude of the intermediate frequency signal, and the like, so that the purpose of simulating the target amplitude is achieved, and the use scenes of target simulation of various different input powers and different output powers can be flexibly met.
The analog target amplitude can also be realized by adjusting the analog target parameter of the processing module 7, and further adjusting and controlling the amplitude of the intermediate frequency signal sent by the digital-to-analog converter 8.
As shown in fig. 2, the signal receiving module includes: a built-in circularly polarized receiving antenna 101, a first radio frequency switch 102 and a receiving radio frequency head 103; the application can receive electromagnetic wave signals emitted by a radar by connecting an internal circularly polarized receiving antenna 101 or a receiving radio frequency head 102 and an external receiving antenna;
wherein, the built-in circularly polarized receiving antenna 101 is used for receiving electromagnetic wave signals in orthogonal directions;
the receiving rf head 102 is configured to be externally connected to a receiving antenna, so as to receive an electromagnetic wave signal through the receiving antenna; the receiving antenna is set according to the requirement.
The radio frequency switch 103 is connected to the built-in circularly polarized antenna and the transmitting radio frequency head, and is used for controlling the corresponding receiving of electromagnetic wave signals by the built-in circularly polarized antenna or the receiving antenna externally connected with the receiving radio frequency head, so as to input the electromagnetic wave signals to the low noise amplifier.
In one embodiment, as shown in fig. 2, the signal transmitting module 12 includes: a built-in circularly polarized transmitting antenna 121, a second radio frequency switch 122 and a transmitting radio frequency head 123; according to the application, the simulation target signal can be transmitted to the radar sensor through the built-in circularly polarized transmitting antenna 121 or the radio frequency head 123 and an external transmitting antenna;
Wherein the built-in circularly polarized transmitting antenna 121 is used for transmitting a simulated target signal in the form of circularly polarized electromagnetic waves;
the transmitting rf head 122 is configured to be externally connected to a transmitting antenna, so as to transmit the analog target signal through the transmitting antenna; the transmitting antenna is set according to the requirements.
The radio frequency switch 123 is connected to the built-in circularly polarized transmitting antenna 121 and the transmitting radio frequency head 122, and is used for controlling the transmitting antenna externally connected with the built-in circularly polarized transmitting antenna or the transmitting radio frequency head to transmit the analog target signal.
In an embodiment, in order to prevent the problem of large difference in analog signal amplitude caused by different polarization directions of antennas of radar products, the problem of large signal difference between polarized deflection individuals caused by difference in spatial arrangement positions of the tested products when multiple tested radar products are measured is reduced.
And adopting the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna to receive and transmit signals.
As shown in fig. 3a, the built-in circular polarized receiving antenna and the built-in circular polarized transmitting antenna are respectively embedded in the front surface (antenna surface) of the simulator circuit board, and as shown in fig. 3b, the back surface (feed network surface) of the simulator circuit board is respectively provided with a feed network which is matched with the built-in circular polarized receiving antenna and the built-in circular polarized transmitting antenna; the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna are respectively provided with a first feeding point and a second feeding point, and the first feeding point and the second feeding point connect the antennas with the corresponding feeding network in a metal via way; the first feeding point and the second feeding point are equal in distance from the geometric center of the corresponding antenna, and connecting lines of the two feeding points to the geometric center are orthogonal to each other;
The built-in circularly polarized receiving antenna is combined with a corresponding feed network to acquire a received electromagnetic wave signal sent by the radar sensor; the built-in circularly polarized transmitting antenna is combined with a corresponding feed network to send the generated simulated target signal in the form of the transmitted circularly polarized electromagnetic wave to the radar sensor.
Each feed network is provided with a power divider and a resistor; one end of the power divider is connected with a first feeding point and a second feeding point of the corresponding antenna, and the other end of the power divider is connected with the low-noise amplifier or the power amplifier arranged on the simulator circuit board; the resistor bridges the first specific position and the second specific position which are respectively arranged on the transmission sections from the first feeding point and the second feeding point to the power divider, and the resistance value of the resistor is twice the impedance value of the transmission microstrip line.
If the feed network is arranged corresponding to the built-in circular polarization receiving antenna, one end of the feed network is connected with a first feed point and a second feed point of the built-in circular polarization receiving antenna; the other end is connected with a low noise amplifier after being combined by a power divider. If the feed network is arranged corresponding to the built-in circular polarization transmitting antenna, one end of the feed network is connected with a first feed point and a second feed point of the built-in circular polarization transmitting antenna; the other end is connected with a power amplifier after being combined through a power divider; preferably, the power divider is a one-to-one second-power divider.
Preferably, the length of each section of transmission line of the feed network has special requirements. In order to synthesize an accurate circularly polarized electromagnetic wave, as shown in FIG. 4, the transmission segment length L between the first specific position A and the first feeding point 1 A1 And a transmission segment length L between the second specific position B and the second feeding point 2 B2 The first length relation is satisfied; and corresponds to the transmission section length L between the first specific position A and the power divider D DA And a transmission section length L between the second specific position B and the power divider D DB The second length relation is met to ensure that the phase difference relation of the two feed points is 90 degrees accurately, the power is equal, and the accurate circularly polarized electromagnetic wave is synthesized. A transmission section length L corresponding to the first specific position A to the second specific position B through a resistor R ARB And a transmission section length L corresponding to the first specific position A passing through the power divider D and then reaching the second specific position B ADB The third length relationship is satisfied.
Wherein the first length relationship comprises:
and wherein lambda is the wavelength of electromagnetic wave in air at the radar working frequency, epsilon is the dielectric constant of the circuit board, and N is a natural number.
And the second length relation is corresponding to the transmission section length L between the first specific position A and the power divider D DA And a transmission section length L between the second specific position B and the power divider D DB Equal.
At this time, the phase difference between the two feeding points is 90 °, the power is equal, the electromagnetic waves excited respectively are a pair of linear polarized waves orthogonal to each other, and the synthesized wave form is a circular polarized wave.
The third length relationship includes:
and wherein L ARB For the transmission section length L from the first specific position A to the second specific position B through the resistor R ADB And for the length of a transmission section from the first specific position A to the second specific position B through the power divider D, lambda is the wavelength of electromagnetic waves in air at the radar working frequency, epsilon is the dielectric constant of a circuit board, and N is a natural number.
The feeding circuit in one embodiment may additionally employ a bridge, balun, phase shifter, etc.; the implementation of the built-in circular polarization receiving and transmitting antenna can additionally adopt other schemes such as antenna corner cutting, slotting and the like.
In one embodiment, as shown in fig. 2, the signal conversion and phase shift module includes:
a signal conversion section 41 for converting the adjusted signal from a single-ended signal to a differential signal;
and a phase shifting unit 42 connected to the signal converting unit, for shifting the phase of the converted differential signal and outputting a pair of orthogonal radio frequency signals.
The signal conversion unit 41 may be a balun, or a device such as a power divider or a coupler may be used. The phase shifting unit 42 may be a phase shifter or a microstrip line phase shifting device. And the signal conversion part 41 and the phase shift part 42 of the signal conversion and phase shift module may also be implemented using a bridge.
In one embodiment, the doppler radar target simulator is connected with an upper computer control end; further, as shown in fig. 1, the processing module 7 is connected to the upper computer control terminal 13, and is configured to set the simulation target parameter based on a control instruction of the upper computer control terminal 13, and generate a digital signal according with the simulation target feature.
The analog target parameters of the processing module 7 can be modified by the upper computer control end so as to modify the parameters of the digital-to-analog conversion module, and the frequency, amplitude and phase relation of the intermediate frequency signal 1 and the intermediate frequency signal 2 are adjusted so as to adjust the target speed, the target amplitude and whether the target is close or far to the detection target analog signal.
In an embodiment, the doppler radar target simulator is connected to the upper computer control end through a USB interface, the upper computer control end identifies a serial port of the doppler radar target simulator through the connected USB interface, and the serial port can modify internal parameters of the processing module to adjust characteristics of the simulation target, so that the parameter modification takes effect in real time and can be powered down and stored as required, and the upper computer can not be used to modify the target parameters if the simulation target parameters are not required to be modified next time. In the implementation process of the scheme, the low-power consumption design is considered, the USB of the control end of the upper computer can be used for supplying power, and the cost of a direct-current power supply is not required to be increased additionally.
In order to better illustrate the Doppler radar target simulator, the present invention provides the following specific embodiments.
Example 1: A5.8G Doppler radar target simulator. Fig. 5 is a schematic structural diagram of a 5.8G doppler radar target simulator in an embodiment.
The 5.8G Doppler radar target simulator comprises: the device comprises a receiving antenna, a radio frequency switch, a receiving radio frequency head, a transmitting antenna, a transmitting radio frequency head, a low noise amplifier, an attenuator, a balun, a phase shifter, a first mixer, a second mixer, a microprocessor, a digital-to-analog converter, a combiner, a power amplifier, an upper computer control end and a self-lapping set software tool;
the receiving antenna or the receiving radio frequency head is added with an external receiving antenna to receive electromagnetic wave signals emitted by the 5.8G radar, the signals are amplified by a low noise amplifier, then the amplitude of the electromagnetic wave signals is adjusted by a radio frequency attenuator, then single-ended signals are converted into differential signals by a balun, and a pair of orthogonal radio frequency signals are output by a phase shifter; meanwhile, the microprocessor outputs a digital signal which accords with the analog target characteristics according to preset parameters, the digital signal is converted into a pair of baseband analog orthogonal signals which accord with the analog target characteristics through a digital-to-analog converter, the pair of signals are mixed with radio frequency signals through mixers 1 and 2 respectively, then the two paths of signals are added through a combiner, then the output signal is attenuated or amplified appropriately through an attenuator and a power amplifier to meet the target analog amplitude requirement, and then the analog target signal is returned to the radar through a transmitting antenna or a transmitting radio frequency head and an external transmitting antenna. If the target characteristic parameters need to be modified, an upper computer end tool of the self-grinding matching sleeve can be used for modifying the internal parameters of the microprocessor through the serial port to adjust the simulation target characteristics, the parameter modification takes effect in real time and can be powered down and stored according to the needs, and if the simulation target parameters do not need to be modified next time, the upper computer can not be used for reconfiguring the simulation target parameters.
The built-in receiving and transmitting circular polarized antenna adopts the on-board antenna with the 90-degree phase-shifting power divider and the double-hole back feed, if the circular polarized antenna is adopted for signal receiving and transmitting, the scheme cost is low, the implementation is easy, the consistency is high, the use is convenient, the problem that the amplitude difference of analog signals is large due to different antenna polarization directions of radar products can be prevented, meanwhile, the problem that the signal difference among individuals is large due to polarization deflection caused by the difference of the space arrangement positions of the tested products when the tested radar products are measured is reduced, the measuring error is reduced, and the consistency of test results is improved.
Fig. 6 shows a schematic view of an application test environment of a microwave radar sensing test system according to an embodiment of the invention.
The Doppler radar target simulator can be applied to target simulation of a single radar sensor product, such as radar sensor product signal processing capability test analysis in the research and development process and the like; the method can also be simultaneously applied to target simulation of a plurality of radar sensor products, such as production test of a plurality of radar sensor products;
the system is in an external environment built by wave absorbing materials, comprising:
a plurality of radar sensors 61 to be measured mounted on a tool plane of the fixed tool 01;
A doppler radar target simulator 62 installed in a normal direction along the tool plane as a target simulator of the test system; it should be noted that the doppler radar target simulator 62 may implement all the functions of the doppler radar target simulator in the above embodiments, which will not be described in detail. In addition, the doppler radar target simulator 62 is also connected with the control end of the upper computer through a USB interface by using a USB power supply serial communication line.
It should be noted that, in the tool design for testing the radar sensor 61, in most cases, a mode of spreading along a plane is adopted, and the target simulator is arranged in a normal direction of the plane, so that the difference of detection results is small. However, the spreading of the radar sensors 61 is not limited to equidistant spreading, and in theory, the radar sensors 61 may be spaced apart from each other by a certain distance, and no requirement is imposed on the regularity of orientation and arrangement.
The doppler radar target simulator 62 sequentially simulates the target speed and the target amplitude of the simulation target based on the received electromagnetic waves emitted by the radar sensors 61 and the simulation target parameters related to the simulation target, and returns each simulation target signal conforming to the target speed and the target amplitude of the simulation target to the corresponding radar sensor 61.
Because the mounting position of the radar sensor has non-negligible dislocation relative to the target simulator, signal receiving and transmitting are not strictly transmitted according to the normal direction, so that polarization deflection exists; the Doppler microwave radar simulator 62 is adopted in the scheme, and for any deflected radar electromagnetic wave, circular polarization can be transmitted and received in a mode of reducing half power, so that the Doppler microwave radar simulator 62 corresponds to a plurality of radar sensors, and signals with consistent amplitudes can be transmitted and received.
In one embodiment, as shown in fig. 6, the doppler microwave radar simulator 61 is mounted in a direction normal to the tool plane at a distance d from the tool plane. D satisfies a fixed distance relationship;
wherein the fixed distance relationship comprises:
and D is the diagonal length of the radar sensor fixing tool, and lambda is the wavelength in the air corresponding to the electromagnetic wave under the radar working frequency.
In a specific embodiment, 9 radar sensors to be tested and a target simulator are adopted for testing, and the 9 radar sensors to be tested are installed on a fixed tool, and are spread out in a nine-grid plane as shown in fig. 7; the target simulator adopts a Doppler radar target simulator, and is arranged in the normal direction along the plane of the tool, the distance from the tool is d, and the d value meets the formula (11);
For a simulator of linear polarization design, facing the problem of polarization deflection, only electromagnetic wave components consistent with the self polarization direction can be reserved for receiving and transmitting, and components different from the self direction are abandoned; the proportion of the selection is changed according to different deflection degrees, and finally the magnitude of the received transmitting signal of the simulator is caused to fluctuate. Under the design of circular polarization, the received and emitted electromagnetic waves of the target simulator can be disassembled into any two equal-amplitude orthogonal linear polarizations, wherein one polarization coincides with the deflected radar electromagnetic waves, and the other polarization is orthogonal to the deflected radar electromagnetic waves; therefore, for any deflected radar electromagnetic wave, circular polarization can transmit and receive signals in a mode of reducing half power, so that the simulator corresponds to a plurality of radar sensors, and signals with consistent amplitude can be transmitted and received. In the general circular polarization design, the ratio of the magnitudes of two linear polarizations after the circular polarization is split into two orthogonal linear polarizations is called an axial ratio. When the axial ratio is less than or equal to 3dB, the circular polarization design requirement is considered to be met. And fig. 8 shows the axial ratio index of the target simulator in the present solution at each main direction angle, it can be seen that the axial ratio index in the present solution is basically kept below 1dB, and the circular polarization strictness is higher than the general standard.
Thus, compared with the prior art, the invention has the following advantages:
1. based on the technical scheme of the invention, the microwave radar testing scheme is more economical and flexible, has better scene repeatability and controllability, is changed from the previous qualitative measurement of a random target scene to the quantitative measurement of fixed target information, and plays an important role in the research and development of the radar, the problem analysis and the production process.
2. The technical scheme provided by the invention comprises a design of the built-in circularly polarized antenna, so that the harsh requirement on the polarization direction of the antenna of the radar product is reduced in the use process, and the problem of large performance difference of the simulation target caused by improper placement of the polarization direction of the antenna of the radar product is solved.
3. In a batch radar product testing scene, the problem of large performance difference of simulation targets caused by position difference of batch radar products is also reduced, and the consistency of results of batch testing is improved.
4. According to the technical scheme, the high-integration and miniaturized design is adopted, the portable shielding device is convenient to carry and install, no obstacle is caused when the portable shielding device is used in a narrow environment, the relative size of the corresponding shielding environment can be relatively small, and the space and cost of the shielding environment are saved.
5. Based on the technical scheme of the invention, the USB interface of the upper computer can meet the power supply requirement in consideration of low-power consumption design, and does not need to occupy a direct current power supply additionally, thereby being convenient to use and saving the cost of purchasing the direct current power supply.
In summary, according to the doppler radar target simulator and the microwave radar sensing test system, the circuit integrated on the simulator circuit board is used for generating and returning the echo signal containing the detection target information to the microwave radar after receiving the microwave radar signal according to the doppler radar principle, and whether the function of the radar in an actual scene can meet the use requirement is deduced by detecting the processing capability of the radar on the echo signal. The method and the device realize quantification, adjustability and repeatability of the target signal which is difficult to quantify, inflexible and poor in repeatability in the prior art, can accurately set the speed information and the amplitude information of the radar echo signal simulation target, and enable the microwave radar test to be more economical and flexible and better in scene repeatability and controllability.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. It is therefore intended that all equivalent modifications and changes made by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the appended claims.

Claims (10)

1. A doppler radar target simulator for simulating a target speed and a target amplitude of a simulated target, the target simulator comprising:
the signal receiving module, the low noise amplifier, the first attenuator, the signal conversion and phase shift module, the first mixer, the second mixer, the processing module, the digital-to-analog conversion module, the combiner, the second attenuator, the power amplifier and the signal transmitting module are integrated on the circuit board of the simulator;
the signal receiving module, the low noise amplifier, the first attenuator and the signal conversion and phase shift module are sequentially connected in series; the first mixer and the second mixer are respectively connected with the signal conversion and phase shift module, the digital-to-analog conversion module and the combiner; the processing module is connected with the digital-to-analog conversion module; the combiner, the second attenuator, the power amplifier and the signal transmitting module are sequentially connected in series;
the signal receiving module receives an electromagnetic wave signal sent by a radar sensor, and then sequentially amplifies the electromagnetic wave signal and adjusts the amplitude of the electromagnetic wave through the low-noise amplifier and the first attenuator; the signal conversion and phase shift module converts the regulated signal from a single-ended signal to a differential signal and outputs a pair of orthogonal radio frequency signals; converting, by the digital-to-analog conversion module, a pair of baseband analog quadrature signals that conform to the analog target characteristics from digital signals that conform to the analog target characteristics generated by the processing module based on analog target parameters related to the analog target; the first mixer and the second mixer respectively mix the baseband analog quadrature signal with the radio frequency signal output by the signal conversion and phase shift module, and then add the signals mixed by the first mixer and the second mixer through the combiner; the added signals sequentially pass through a second attenuator and a power amplifier to amplify the signals and adjust the amplitude of electromagnetic waves, and a signal transmitting module returns the analog target signals which accord with the target speed and the target amplitude of the analog target to the radar sensor.
2. The doppler radar target simulator of claim 1, wherein the means for simulating the target speed of the simulated target comprises:
receiving a digital signal generated by the processing module based on an analog target parameter related to a target speed of an analog target through the digital-to-analog conversion module, converting the digital signal into a baseband analog orthogonal signal pair conforming to the target speed, respectively mixing the baseband analog orthogonal signal pair with a radio frequency signal output by the signal conversion and phase shift module through the first mixer and the second mixer, adding the signals mixed by the first mixer and the second mixer through the combiner, and sequentially carrying out signal amplification and electromagnetic wave amplitude adjustment on the signals added by the signals through the second attenuator and the power amplifier to generate an analog target signal conforming to the target speed;
and the frequency offset between the signal obtained by adding the signals by the combiner and the radio frequency signal output by the signal conversion and phase shift module corresponds to the frequency of the target speed.
3. A doppler radar target simulator according to claim 1 or claim 2, wherein the means for simulating the target amplitude of the simulated target comprises:
And adjusting the amplitude of the signal by setting one or more of parameters of a low noise amplifier, a first attenuator, a second attenuator, a digital-to-analog converter and a power amplifier to generate an analog target signal corresponding to the target amplitude.
4. The doppler radar target simulator of claim 1, wherein the signal receiving module comprises: a circular polarization receiving antenna, a first radio frequency switch and a receiving radio frequency head are arranged in the antenna;
the built-in circularly polarized receiving antenna is used for receiving electromagnetic wave signals in the orthogonal direction;
the receiving radio frequency head is used for externally connecting a receiving antenna so as to receive electromagnetic wave signals through the receiving antenna;
the radio frequency switch is connected with the built-in circularly polarized antenna and the transmitting radio frequency head and is used for controlling the built-in circularly polarized antenna or a receiving antenna externally connected with the receiving radio frequency head to correspondingly receive electromagnetic wave signals so as to input the electromagnetic wave signals to the low noise amplifier.
5. The doppler radar target simulator of claim 1, wherein the signal transmitting module comprises: a circular polarization transmitting antenna, a second radio frequency switch and a transmitting radio frequency head are arranged in the antenna;
The built-in circularly polarized transmitting antenna is used for transmitting a simulated target signal in the form of circularly polarized electromagnetic waves;
the transmitting radio frequency head is used for being externally connected with a transmitting antenna so as to transmit the analog target signal through the transmitting antenna;
the radio frequency switch is connected with the built-in circular polarization transmitting antenna and the transmitting radio frequency head and is used for controlling the transmitting antenna externally connected with the built-in circular polarization transmitting antenna or the transmitting radio frequency head to transmit the simulation target signal.
6. The doppler radar target simulator according to claim 4 or 5, wherein the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna are embedded in the front surface of the simulator circuit board, and a feed network matched with the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna is arranged on the back surface of the simulator circuit board; the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna are respectively provided with a first feeding point and a second feeding point, and the first feeding point and the second feeding point connect the antennas with the corresponding feeding network in a metal via way; the first feeding point and the second feeding point are equal in distance from the geometric center of the corresponding antenna, and connecting lines of the two feeding points to the geometric center are orthogonal to each other;
The built-in circularly polarized receiving antenna is combined with a corresponding feed network to receive electromagnetic wave signals sent by the radar sensor; the built-in circularly polarized transmitting antenna is combined with a corresponding feed network to send the generated simulated target signal in the form of the transmitted circularly polarized electromagnetic wave to the radar sensor.
7. The doppler radar target simulator of claim 1, wherein the signal conversion and phase shift module comprises:
a signal conversion section for converting the adjusted signal from a single-ended signal to a differential signal;
and the phase shifting component is connected with the signal conversion component and is used for shifting the phase of the converted differential signal and outputting a pair of orthogonal radio frequency signals.
8. The doppler radar target simulator of claim 1, wherein the processing module is configured to set the simulated target parameters based on a control command from a host computer control terminal connected to the doppler radar target simulator, and generate a digital signal that meets a characteristic of the simulated target.
9. The doppler radar target simulator of claim 8, wherein the doppler radar target simulator is connected to a host computer control terminal through a USB interface.
10. A microwave radar sensing test system, the system comprising:
the radar sensors are respectively arranged on a tool plane of the fixed tool;
the doppler radar target simulator of any one of claims 1 to 9, mounted in a direction normal to the tool plane;
the Doppler radar target simulator simulates the target speed and the target amplitude of the simulation target sequentially based on the received electromagnetic waves transmitted by the radar sensors and the simulation target parameters related to the simulation target, and returns the simulation target signals conforming to the target speed and the target amplitude of the simulation target to the corresponding radar sensors.
CN202310342643.3A 2023-03-31 2023-03-31 Doppler radar target simulator and microwave radar sensing test system Pending CN116626619A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113030884A (en) * 2021-02-26 2021-06-25 隔空(上海)智能科技有限公司 Doppler radar testing device, Doppler radar testing method and Doppler radar sensor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113030884A (en) * 2021-02-26 2021-06-25 隔空(上海)智能科技有限公司 Doppler radar testing device, Doppler radar testing method and Doppler radar sensor
CN113030884B (en) * 2021-02-26 2024-03-29 隔空(上海)智能科技有限公司 Doppler radar testing device, testing method and Doppler radar sensor

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