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

Abstract

The invention provides a Doppler radar target simulator and a microwave radar sensing test system. According to the principle of Doppler radar, the circuit integrated on the circuit board of the simulator realizes that after receiving the microwave radar signal, it generates and returns the The echo signal of the detected target information is sent to the microwave radar, and by testing the radar's processing ability of the echo signal, it is deduced whether the function of the radar in the actual scene can meet the use requirements. The invention realizes quantitative, adjustable and repeatable target signals that are difficult to quantify, inflexible and poorly repeatable in the prior art, and can accurately set the speed information and amplitude information of the radar echo signal simulation target, so that the microwave radar test More economical and flexible, with better 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 radar, in particular to a Doppler radar target simulator and a microwave radar sensing test system.

Background technique

With the gradual deepening of the military-to-civilian use of radar technology, microwave radar, as a sensor, is used in a variety of consumer products. Microwave radar sensors can be installed secretly and are not affected by temperature, airflow, dust, and smog. They have the advantages of long life, fast response, higher sensitivity, and wide sensing area. It is used in consumer electronics products in many fields, including energy-saving lighting, security, smart home appliances, etc. In the development and production process of these microwave radar products, the performance detection of microwave radar is a very important link.

For the current energy-saving lighting, security, smart home appliances and other products, microwave radar sensor test solutions usually use anti-angle antennas, swingers, people walking or waving, etc. as detection targets for testing radar sensors. The disadvantages of this method are: testing The result is perceptual, hard to quantify, inflexible and poorly reproducible. Especially in the production test, when multiple radar sensor products are simultaneously detected and tested with the target, such a solution will amplify the deviation of the sensing results of different radar sensors, resulting in deterioration of consistency, and cannot truly test the real performance of radar products .

Contents of the invention

In view of the shortcomings of the prior art described above, the purpose 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.

In order to achieve the above object and other related objects, the present invention provides a Doppler radar target simulator, which is used to simulate the target speed and target amplitude of the simulated target, and the target simulator includes: integrated on the simulator circuit board Signal receiving module, low noise amplifier, first attenuator, signal conversion and phase shifting module, first mixer, second mixer, processing module, digital-to-analog conversion module, combiner, second attenuator, A power amplifier and a signal transmitting module; wherein, the signal receiving module, the low noise amplifier, the first attenuator, the signal conversion and phase shifting module are sequentially connected in series; the first mixer and the second mixer are respectively Connect the signal conversion and phase shifting module, the digital-to-analog conversion module and the combiner; the processing module is connected to the digital-to-analog conversion module; the combiner, the second attenuator, the power amplifier and the signal transmitting module are connected in series connection; the signal receiving module receives the electromagnetic wave signal sent by the radar sensor, and then sequentially passes through the low noise amplifier and the first attenuator to amplify the electromagnetic wave signal and adjust the amplitude of the electromagnetic wave; through the signal conversion and phase shifting The module converts the adjusted signal from a single-ended signal to a differential signal, and outputs a pair of orthogonal radio frequency signals; through the digital-to-analog conversion module according to the analog target parameters related to the analog target by the processing module The generated digital signal conforming to the characteristics of the analog target is converted into a pair of baseband analog quadrature signals conforming to the characteristics of the analog target; the baseband analog quadrature signal and the signal are respectively converted by the first mixer and the second mixer Mixing with the RF signal output by the phase shifting module, and then adding the signals mixed by the first mixer and the second mixer through the combiner; the added signals are sequentially subjected to the second attenuation The signal amplifier and the power amplifier perform signal amplification and electromagnetic wave amplitude adjustment, and the signal transmitting module returns the simulated target signal conforming to the target speed and target amplitude of the simulated target to the radar sensor.

In an embodiment of the present invention, the method of simulating the target speed of the simulated target includes: receiving, through the digital-to-analog conversion module, a digital signal generated by the processing module based on simulated target parameters related to the target speed of the simulated target And convert it into a baseband analog quadrature signal pair that meets the target speed, and use the baseband analog quadrature signal pair and the radio frequency output from the signal conversion and phase shifting module respectively through the first mixer and the second mixer The signals are mixed, and then the signals mixed by the first mixer and the second mixer are added through the combiner, so that the signals after the signal addition are sequentially passed through the second attenuator, the power The amplifier performs signal amplification and electromagnetic wave amplitude adjustment to generate an analog target signal corresponding to the target speed; wherein, the frequency deviation between the signal obtained by the combiner through signal addition and the RF signal output by the signal conversion and phase shifting module The amount of displacement corresponds to the frequency of the target velocity.

In an embodiment of the present invention, the method of simulating the target amplitude of the simulation target includes: setting one of the parameters of the low noise amplifier, the first attenuator, the second attenuator, the digital-to-analog converter, and the power amplifier Adjust the amplitude of the signal in one or more ways to generate an analog target signal corresponding to the target amplitude.

In an embodiment of the present invention, the signal receiving module includes: a built-in circularly polarized receiving antenna, a first radio frequency switch, and a receiving radio frequency head; wherein, the built-in circularly polarized receiving antenna is used to receive Electromagnetic wave signal; the receiving radio frequency head is used to connect the receiving antenna to receive the electromagnetic wave signal through the receiving antenna; the radio frequency switch is connected to the built-in circularly polarized antenna and the transmitting radio frequency head, and is used to control the The built-in circularly polarized antenna or the receiving antenna externally connected to the receiving radio frequency head corresponds to receiving the electromagnetic wave signal for inputting the electromagnetic wave signal into the low noise amplifier.

In an embodiment of the present invention, the signal transmitting module includes: a built-in circularly polarized transmitting antenna, a second radio frequency switch, and a transmitting radio frequency head; wherein, the built-in circularly polarized transmitting antenna is used to transmit circularly polarized electromagnetic waves The analog target signal in the form; the transmitting radio frequency head is used for externally connecting the transmitting antenna to transmit the analog target signal through the transmitting antenna; the radio frequency switch is connected to the built-in circularly polarized transmitting antenna and the transmitting radio frequency head , used to control the transmission of analog target signals by the built-in circularly polarized transmitting antenna or the transmitting antenna externally connected to the transmitting radio head.

In an embodiment of the present invention, the built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna are respectively embedded in the front of the simulator circuit board, and the back of the simulator circuit board is respectively provided with the The feeding network provided with the built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna; the built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna are respectively provided with a first feeding point and a second feeding point, And the first feed point and the second feed point connect the antenna to the corresponding feed network in the form of metal vias; wherein, the first feed point and the second feed point connect to the corresponding antenna The distances between the geometric centers of the two feeding points are equal and the lines connecting the two feeding points to the geometric centers are orthogonal to each other; the built-in circularly polarized receiving antenna will receive the electromagnetic wave signal sent by the radar sensor by combining with the corresponding feeding network; The built-in circularly polarized transmitting antenna sends the generated simulated target signal in the form of emitted circularly polarized electromagnetic waves to the radar sensor by combining with the corresponding feeding network.

In an embodiment of the present invention, the signal conversion and phase shifting module includes: a signal conversion component, used to convert the adjusted signal from a single-ended signal to a differential signal; a phase shifting component, connected to the signal conversion component , used to shift the phase of the converted differential signal to output a pair of quadrature radio frequency signals.

In an embodiment of the present invention, the processing module is used to set the parameters of the simulated target based on the control instructions of the upper computer control terminal connected to the Doppler radar target simulator, and generate digital data that conforms to the characteristics of the simulated target. Signal.

In an embodiment of the present invention, the Doppler radar target simulator is connected to the control terminal of the host computer through a USB interface.

In order to achieve the above object and other related objects, the present invention provides a microwave radar sensor testing system, the system includes: a plurality of radar sensors, respectively installed on the tooling plane of the fixed tooling; the Doppler radar target simulation The device is installed in the normal direction along the tooling plane; wherein, the Doppler radar target simulator is based on the received electromagnetic waves emitted by each radar sensor and the simulated target parameters related to the simulated target. The target velocity of the simulated target and the target range are simulated, and each simulated target signal conforming to the target speed and target range of the simulated target is returned to the corresponding radar sensor.

As mentioned above, the present invention is a Doppler radar target simulator and a microwave radar sensing test system, which has the following beneficial effects: According to the principle of Doppler radar, the circuit integrated on the simulator circuit board realizes the After the microwave radar signal, generate and return the echo signal containing the detection target information to the microwave radar. By testing the radar's processing ability of the echo signal, it can be deduced whether the function of the radar in the actual scene can meet the use requirements. The invention realizes quantitative, adjustable and repeatable target signals that are difficult to quantify, inflexible and poorly repeatable in the prior art, and can accurately set the speed information and amplitude information of the radar echo signal simulation target, so that the microwave radar test More economical and flexible, with better scene repeatability and controllability.

Description of drawings

FIG. 1 is a schematic structural diagram of a Doppler radar target simulator in an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a Doppler radar target simulator in an embodiment of the present invention.

FIG. 3 is a schematic structural diagram of the antenna surface and the feeding network surface in an embodiment of the present invention.

FIG. 4 is a schematic diagram showing the relationship between the trace lengths of the feed network in an embodiment of the present invention.

Fig. 5 is a schematic structural diagram of a 5.8G Doppler radar target simulator in an embodiment of the present invention.

FIG. 6 is a schematic diagram of the application test environment of the microwave radar sensor test system in an embodiment of the present invention.

Fig. 7 is a schematic diagram showing the installation of a radar sensor in an embodiment of the present invention.

FIG. 8 is a schematic diagram of the axial ratio indicators of the simulator in each main direction angle in an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

It should be noted that in the following description, reference is made to the accompanying drawings, which describe several embodiments of the present invention. It is to be understood that other embodiments may be utilized, and mechanical, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present invention. The following detailed description should not be considered limiting, 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", "below", "below", "lower", "above", "upper", etc., may be used in the text to facilitate Describes the relationship of one element or feature shown in the drawings to another element or feature.

Throughout the specification, when it is said that a certain part is "connected" to another part, this includes not only the case of "direct connection" but also the case of "indirect connection" with other elements interposed therebetween. In addition, when it is said that a certain part "includes" a certain component, it does not mean that other components are excluded, but it means that other components may be included, unless there is a particularly contrary description.

The terms first, second, and third mentioned herein are used to describe various parts, components, regions, layers, and/or sections, but are not limited thereto. These terms are only used to distinguish some part, component, region, layer or section from another part, component, region, layer or section. Therefore, a first part, component, region, layer or section described below may refer to a second part, 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 should be further understood that the terms "comprising", "comprising" indicate the presence of stated features, operations, elements, components, items, species, and/or groups, but do not exclude one or more other features, operations, elements, components, Existence, occurrence, or addition of items, categories, and/or groups. The terms "or" and "and/or" as used herein are to be construed as inclusive, or to mean either one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C" . Exceptions to this definition will only occur when combinations of elements, functions or operations are inherently mutually exclusive in some way.

The invention provides a Doppler radar target simulator and a microwave radar sensing test system. According to the principle of Doppler radar, the circuit integrated on the circuit board of the simulator realizes that after receiving the microwave radar signal, it generates and returns the The echo signal of the detected target information is sent to the microwave radar, and by testing the radar's processing ability of the echo signal, it is deduced whether the function of the radar in the actual scene can meet the use requirements. The invention realizes quantitative, adjustable and repeatable target signals that are difficult to quantify, inflexible and poorly repeatable in the prior art, and can accurately set the speed information and amplitude information of the radar echo signal simulation target, so that the microwave radar test More economical and flexible, with better scene repeatability and controllability.

The radar sensor used in the test object of the present invention can be a microwave radar of any required working frequency band, such as radars of different working frequency bands such as 5.8GHz, 10GHz, 24GHz, 60GHz, 77GHz and so on. Therefore, the Doppler radar target simulator of the present application can realize testing of microwave radars in any working frequency band.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the technical field of the present invention can easily implement them. The present invention can be embodied in various forms and is not limited to the embodiments described here.

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 velocity and target amplitude of the simulated target.

The target simulator includes: a signal receiving module 1 integrated on the simulator circuit board, a low noise amplifier 2, a first attenuator 3, a signal conversion and phase shifting module 4, a first mixer 5, a second mixer 6, a processing module 7, a digital-to-analog conversion module 8, a combiner 9, a second attenuator 10, a power amplifier 11, and a signal transmitting module 12; specifically, the digital-to-analog conversion module 8 may be a digital-to-analog converter, A device such as a digital frequency synthesizer can also be used to generate the intermediate frequency signal. The processing module 7 may be a microprocessor MCU, or other schemes such as FPGA may be used.

Wherein, the signal receiving module 1, the low noise amplifier 2, the first attenuator 3, and the signal conversion and phase shifting module 4 are sequentially connected in series; specifically, the signal receiving module 1 is connected to the low noise amplifier 2, and the low noise amplifier 2 The first attenuator 3 is connected, and the first attenuator 3 is connected to the signal conversion and phase shifting module 4 . The first mixer 5 and the second mixer 6 are connected in parallel, and are respectively connected to the signal conversion and phase shifting module 4, the digital-to-analog conversion module 8 and the combiner 9; the processing module 7 is connected to the 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 a power amplifier 11 , and the power amplifier 11 is connected to the signal transmitting module 12 .

The electromagnetic wave signal sent by the radar sensor is received by the signal receiving module 1, and then the signal is amplified by the low noise amplifier 2, and then the electromagnetic wave signal is adjusted by the first attenuator 3; and then converted and shifted by the signal The phase module 4 converts the adjusted signal from a single-ended signal to a differential signal, and outputs a pair of orthogonal radio frequency signals and transmits them to the first mixer 5 and the second mixer 6; at the same time, the The digital signal conforming to the characteristics of the analog target generated by the processing module 7 based on the analog target parameters related to the analog target is converted into a pair of baseband conforming to the characteristics of the analog target by the digital-to-analog conversion module 8 according to the digital signal conforming to the feature of the analog target Analog quadrature signal: Mix the baseband analog quadrature signal with the RF signal output by the signal conversion and phase shifting module 4 respectively by the first mixer 5 and the second mixer 6, and then pass through the The combiner 9 adds the signals mixed by the first mixer 5 and the second mixer 6; the added signal passes through the second attenuator 10 and the power amplifier 11 successively for signal amplification and electromagnetic wave amplitude Adjust, and the signal transmitting module 12 returns the simulated target signal conforming to the target speed and target amplitude of the simulated target to the radar sensor.

Preferably, the PCB size of the simulator circuit board is only 80*60mm, which requires less space for the use environment, and realizes high integration and miniaturization design.

In an embodiment, the manner of simulating the target speed of the simulated target includes:

The digital-to-analog conversion module 8 receives the digital signal generated from the processing module 7 based on the analog target parameters related to the target speed of the analog target and converts it into a baseband analog quadrature signal pair that meets the target speed, including an intermediate frequency signal 1 and Intermediate frequency signal 2, and the baseband analog quadrature signal is mixed with the radio frequency signal output by the signal conversion and phase shifting module 4 respectively through the first mixer 5 and the second mixer 6, and then passed through The combiner 9 adds the signals mixed by the first mixer 5 and the second mixer 6, so that the added signal passes through the second attenuator 10 and the power amplifier 11 in sequence. Signal amplification and electromagnetic wave amplitude adjustment generate an analog target signal corresponding to the target speed;

Wherein, the frequency offset between the signal obtained by the combiner 9 through signal addition and the radio frequency signal output by the signal conversion and phase shifting module 4 corresponds to the frequency of the target speed. Moreover, the sign of the frequency offset is related to the distance between the simulated target and the corresponding radar. If the sign is negative, it means far away, and if the sign is positive, it means close.

In order to describe the manner of simulating the target speed of the simulated target in more detail, it will be described in conjunction with the following specific embodiments.

The RF signal received by the Doppler radar target simulator is a sine wave RF _in , which can be simplified and defined as cos(ω _r t), without considering the phase shift and delay of air transmission, after the signal conversion and phase shifting module 4 Two paths of orthogonal signals cos(ω _r t) and sin(ω _r t) are obtained, which enter the first mixer 5 and the second mixer 6 respectively. 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 a phase difference of 90°, wherein the intermediate frequency signal 1 can be simplified and defined as cos(ω _d t), and the intermediate frequency signal 2 can be The simplified definition is sin(ω _d t).

Then the mixed frequency output signal result of the first mixer 5 is:

cos(ω _r t)·cos(ω _d t); (1)

The mixed frequency output signal result of the second mixer 6 is:

sin(ω _r t) sin(ω _d t); (2)

After the output signal results of the first mixer 5 and the second mixer 6 are synthesized and added by the combiner 9, the output signal result RF _out is obtained as follows:

RF _out =cos(ω _r t)·cos(ω _d t)+sin(ω _r t)·sin(ω _d t); (3)

RF _out =cos((ω _r -ω _d )t); (4)

It can be seen that the frequency of the input radar signal RF _in of the Doppler radar target simulator is ω _r /2π, the frequency of the output signal RF _out is (ω _r -ω _d )/2π, and the output signal of the Doppler radar target simulator is The frequency offset of RF _out compared to the input signal RF _in is (-ω _d )/2π, and this frequency offset is a negative value. The simulated scene is the Doppler frequency shift frequency corresponding to the target speed when the target is far away from the radar.

Furthermore, by setting and changing the parameters of the digital-to-analog conversion module 8 to generate intermediate frequency signals 1 and 2 with different frequencies, target analog signals with different speeds can be simulated.

In the same way, the digital signal sent to the digital-to-analog conversion module 8 can be adjusted by modifying the analog target parameter set by the processing module 7, and the phase relationship between the intermediate frequency signal 1 and the intermediate frequency signal 2 can be adjusted. At this time, the intermediate frequency signal 1 It can be simplified and defined as sin(ω _d t), and the intermediate frequency signal 2 can be simplified and defined as cos(ω _d t).

Then the mixed frequency output signal result of the first mixer 5 is:

cos(ω _r t) sin(ω _d t); (5)

The mixed frequency output signal result of the second mixer 6 is:

sin(ω _r t) cos(ω _d t); (6)

After the output signal results of the first mixer 5 and the second mixer 6 are synthesized and added by the combiner 9, the output signal result RF _out is obtained as follows:

RF _out =cos(ω _r t)·sin(ω _d t)+sin(ω _r t)·cos(ω _d t); (7)

RF _out =cos((ω _r +ω _d )t); (8)

At this time, the frequency of the input radar signal RF _in of the Doppler radar target simulator is ω _r /2π, the frequency of the output signal RF _out is (ω _r +ω _d )/2π, and the output signal RF of the Doppler radar target simulator is The frequency offset of _out compared to the input signal RF _in is (+ω _d )/2π, and this frequency offset is a positive value. The simulated scene is the Doppler frequency shift frequency corresponding to the speed of the target approaching the radar.

In an embodiment, the manner of simulating the target range of the simulated target includes:

By setting one or more of the parameters of the low noise amplifier, the parameters of the first attenuator, the parameters of the second attenuator, the parameters of the power amplifier, and the analog target parameters related to the target amplitude, the corresponding signal corresponding to the target amplitude is generated. Simulate target signal.

Among them, the Doppler can be controlled by adjusting the parameters of the low-noise amplifier 2, the first attenuator 3, the second attenuator 10, the power amplifier 11, and the digital-to-analog converter 8 to control the amplitude of the intermediate frequency signal sent. The output power of the radar target simulator can achieve the purpose of simulating the target amplitude, and can flexibly meet various usage scenarios of different input power and different output power target simulation.

The analog target amplitude can also be realized by adjusting the analog target parameters of the processing module 7 and then adjusting and controlling the amplitude of the intermediate frequency signal sent by the digital-to-analog converter 8 .

As shown in Figure 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 external receiving antenna receives the electromagnetic wave signal emitted by the radar;

Wherein, the built-in circularly polarized receiving antenna 101 is used to receive electromagnetic wave signals in orthogonal directions;

The receiving radio frequency head 102 is used to connect an external receiving antenna to receive electromagnetic wave signals through the receiving antenna; the receiving antenna can be set according to requirements.

The radio frequency switch 103 is connected to the built-in circularly polarized antenna and the transmitting radio frequency head, and is used to control the corresponding reception of electromagnetic wave signals by the built-in circularly polarized antenna or the externally connected receiving antenna of the receiving radio frequency head, so as to provide The electromagnetic wave signal is input to a 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; 121 or the radio frequency head 123 plus an external transmitting antenna transmits an analog target signal to the radar sensor;

Wherein, the built-in circularly polarized transmitting antenna 121 is used to transmit an analog target signal in the form of circularly polarized electromagnetic waves;

The transmitting radio frequency head 122 is used to connect an external transmitting antenna, so as to transmit the analog target signal through the transmitting antenna; the transmitting antenna can be set according to 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 to control the transmission of analog target signals by the built-in circularly polarized transmitting antenna or the externally connected transmitting antenna of the transmitting radio frequency head .

In one embodiment, in order to prevent the problem of large differences in analog signal amplitude due to different antenna polarization directions of radar products, and to reduce the extreme difference caused by the difference in the spatial placement of the tested products when measuring multiple tested radar products. The problem of large signal differences between individualized deflection individuals.

The built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna are used for signal reception and signal transmission.

As shown in Figure 3a, the built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna are respectively embedded in the front (antenna face) of the simulator circuit board, and as shown in Figure 3b, on the simulator circuit board The back side (feeding network surface) is respectively provided with the feeding network supporting the set of the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna; the built-in circular polarization receiving antenna and the built-in circular polarization transmitting antenna are respectively set There are a first feed point and a second feed point, and the first feed point and the second feed point connect the antenna to the corresponding feed network in the form of metal vias; wherein, the first The distances from the first feed point and the second feed point to the geometric center of the corresponding antenna are equal, and the lines connecting the two feed points to the geometric center are orthogonal to each other;

The built-in circularly polarized receiving antenna is combined with the corresponding feeding network to obtain the received electromagnetic wave signal sent by the radar sensor; the built-in circularly polarized transmitting antenna is combined with the corresponding feeding network to generate the generated transmitting circle A simulated target signal in the form of polarized electromagnetic waves is sent to the radar sensor.

Each feed network is provided with a power divider and a resistor; wherein, one end of the power divider is connected to the first feed point and the second feed point of the corresponding antenna, and the other end is connected to the circuit board of the simulator. The low-noise amplifier or power amplifier; the resistance bridges the first specific position and the second specific position respectively set on the transmission section from the first feed point and the second feed point to the power divider, and the resistance The resistance value is twice the impedance value of the transmission microstrip line.

If the feed network is set corresponding to the built-in circularly polarized receiving antenna, one end is connected to the first feeding point and the second feeding point of the built-in circularly polarized receiving antenna; noise amplifier. If the feed network is set corresponding to the built-in circularly polarized transmitting antenna, one end is connected to the first feeding point and the second feeding point of the built-in circularly polarized transmitting antenna; Amplifier; preferably, the power splitter is a one-to-two power splitter.

Preferably, the length of each section of the transmission line of the feeder network has special requirements. In order to synthesize accurate circularly polarized electromagnetic waves, as _shown in FIG. The length of the transmission section L between the electrical points 2 satisfies the first length relationship between _B2 ; and corresponds to the transmission section length L _DA between the first specific position A and the power divider D and corresponds to the second specific position The length L _DB of the transmission section between the position B and the power divider D satisfies the second length relationship, so as to ensure that the phase difference relationship between the two feed points is exactly 90°, and the power is equal, and an accurate circular polarization is synthesized electromagnetic waves. The length L _ARB of the transmission section corresponding to the first specific position A passing through the resistor R to the second specific position B and the length of the transmission segment corresponding to the first specific position A passing through the power divider D and then to the second specific position B _LADB satisfies the third length relation.

Wherein, the first length relationship includes:

And among them, λ is the wavelength of the electromagnetic wave in the air at the operating frequency of the radar, ε is the dielectric constant of the circuit board, and N is a natural number.

And, the second length relationship is corresponding to the transmission section length L _DA between the first specific position A and the power divider D and corresponding to the transmission between the second specific position B and the power divider D The segment lengths L _DB are equal.

At this time, the phase difference of the two feeding points is 90°, the power is equal, and the electromagnetic waves respectively excited are a pair of linearly polarized waves orthogonal to each other, and the synthesized waveform is a circularly polarized wave.

The third length relationship includes:

And wherein, L _ARB is the length of the transmission section from the first specific position A to the second specific position B through the resistor R, and _LADB is the length of the transmission section from the first specific position A through the power divider D to the second specific position The length of the transmission section of B, λ is the wavelength of electromagnetic waves in the air at the radar operating frequency, ε is the dielectric constant of the circuit board, and N is a natural number.

In one embodiment, the feeding circuit may additionally adopt schemes such as electric bridge, balun plus phase shifter; the implementation of the built-in circularly polarized receiving and transmitting antenna may additionally adopt other schemes such as antenna angle cutting and slotting.

In one embodiment, as shown in Figure 2, the signal conversion and phase shifting module includes:

A signal conversion component 41, configured to convert the adjusted signal from a single-ended signal to a differential signal;

The phase shifting component 42 is connected to the signal converting component, and is used for phase shifting the converted differential signal and outputting a pair of orthogonal radio frequency signals.

It should be noted that the signal conversion component 41 may be a balun, or a power divider, a coupler and other devices. The phase shifting component 42 may be a phase shifter, or a microstrip line shifting device. Moreover, the signal conversion part 41 and the phase shifting part 42 of the signal conversion and phase shifting module can also be realized by using an electric bridge.

In one embodiment, the Doppler radar target simulator is connected with a host computer control terminal; further, as shown in Figure 1, the processing module 7 is connected to the host computer control terminal 13, for based on the host computer control terminal The control instruction of 13 sets the parameters of the analog target and generates a digital signal conforming to the characteristics of the analog target.

Among them, the analog target parameters of the processing module 7 can be modified through the host computer control terminal, and then the parameters of the digital-to-analog conversion module can be modified, and the frequency, amplitude and phase relationship of the intermediate frequency signal 1 and the intermediate frequency signal 2 can be adjusted to detect the target analog signal. Make adjustments for target speed, target amplitude, and whether the target is moving closer or farther away.

In one embodiment, the Doppler radar target simulator is connected to the host computer control terminal through a USB interface, and the host computer control terminal recognizes the serial port of the Doppler radar target simulator through the connected USB interface. The serial port modifies the internal parameters of the processing module to adjust the characteristics of the simulated target. The parameter modification takes effect in real time and can be saved after power-off. If you do not need to modify the simulated target parameters for the next use, you can modify the target parameters without using the host computer. Considering the low power consumption design during the implementation of this solution, the USB power supply at the control terminal of the upper computer can be used without additional DC power supply costs.

In order to better illustrate the above-mentioned Doppler radar target simulator, the present invention provides the following specific embodiments.

Embodiment 1: A 5.8G Doppler radar target simulator. FIG. 5 is a schematic structural diagram of the 5.8G Doppler radar target simulator in the embodiment.

The 5.8G Doppler radar target simulator includes: receiving antenna, radio frequency switch, receiving radio frequency head, transmitting antenna, transmitting radio frequency head, low noise amplifier, attenuator, balun, phase shifter, first mixer, The second mixer, microprocessor, digital-to-analog converter, combiner, power amplifier, host computer control terminal and self-developed supporting software tools;

The receiving antenna or the receiving radio head plus an external receiving antenna to receive the electromagnetic wave signal emitted by the 5.8G radar, and the signal is amplified by the low noise amplifier, and then the amplitude of the electromagnetic wave signal is adjusted through the RF attenuator, and then the single-ended The signal is converted into a differential signal, and a pair of orthogonal RF signals are output by the phase shifter; at the same time, the microprocessor outputs a digital signal that meets the characteristics of the analog target according to the preset parameters, and is converted into a pair of RF signals that meet the analog target through a digital-to-analog converter. The characteristic baseband analog quadrature signal, this pair of signals are respectively mixed with the RF signal by the mixer 1, 2, and then the two signals are added by the combiner, and then the output signal is properly processed by the attenuator and the power amplifier. Attenuate or amplify to meet the target analog amplitude requirements, and then return the analog target signal to the radar through the transmitting antenna or transmitting radio frequency head plus an external transmitting antenna. If you need to modify the target characteristic parameters, you can use the self-developed upper computer tool to modify the internal parameters of the microprocessor through the serial port to adjust the simulated target characteristics. The parameter modification takes effect in real time and can be saved after power-off as needed. If you don’t need it next time To modify the simulation target parameters, you can reconfigure the simulation target parameters without using the host computer.

Among them, the built-in receiving and transmitting circularly polarized antennas use onboard antennas with 90° phase-shifting power splitters and dual-hole backfeeds. If circularly polarized antennas are used for signal transmission and reception, the solution is not only low in cost, easy to implement, and high in consistency , easy to use, and can also prevent the problem of large differences in analog signal amplitude due to different antenna polarization directions of radar products, and at the same time reduce the polarization deflection caused by the difference in the spatial placement of the tested products when measuring multiple tested radar products It leads to the problem of large signal differences among individuals, reduces measurement errors, and improves the consistency of test results.

FIG. 6 shows a schematic diagram of an application test environment of a microwave radar sensor test system in an embodiment of the present invention.

The Doppler radar target simulator can be applied to the target simulation of a single radar sensor product, such as the radar sensor product processing signal capability test and analysis during the research and development process; it can also be applied to the target simulation of multiple radar sensor products at the same time, such as complex Production testing of multiple radar sensor products;

The system is in an external environment made of absorbing materials, including:

A plurality of radar sensors 61 to be tested are installed on the tooling plane of the fixed tooling 01;

The Doppler radar target simulator 62 installed on the normal direction along the tooling plane is used as the target simulator of the test system; it should be noted that the Doppler radar target simulator 62 can realize the multiple functions of the above embodiments All the functions of the Puler radar target simulator will not be repeated here. In addition, the Doppler radar target simulator 62 is also connected to the control terminal of the host computer through a USB interface using a USB power supply serial port communication line.

It should be noted that, in most cases, the tooling design of the radar sensor 61 test is spread along the plane, and the target simulator is placed in the normal direction of the plane, so that the difference in detection results is small. However, the form of spreading the radar sensors 61 is not limited to spreading out at equal distances. In theory, the radar sensors 61 only need to be separated by a certain distance from each other, and there is no requirement for the regularity of orientation and arrangement.

Wherein, the Doppler radar target simulator 62 simulates the target speed and target amplitude of the simulated target based on the received electromagnetic waves emitted by each radar sensor 61 and the simulated target parameters related to the simulated target, and will conform to the Each simulated target signal simulating the target velocity and target amplitude of the target is returned to the corresponding radar sensor 61 .

Because the installation position of the radar sensor has a non-negligible dislocation relative to the target simulator, the signal transmission and reception is no longer strictly transmitted in the normal direction, so there is a polarization deflection; this scheme uses a Doppler microwave radar simulator 62 for radar electromagnetic waves deflected arbitrarily. Both polarizations can transmit and receive signals by reducing the power by half, so that the Doppler microwave radar simulator 62 can correspond to multiple radar sensors, and all signals with the same amplitude can be transmitted and received.

In one embodiment, as shown in FIG. 6 , the Doppler microwave radar simulator 61 is installed along the normal direction of the tooling plane, and the distance from the tooling plane is d. Then d satisfies the fixed distance relationship;

Wherein, the fixed distance relationship includes:

And among them, D is the diagonal length of the fixed tooling of the radar sensor, and λ is the wavelength in the air corresponding to the electromagnetic wave at the radar operating frequency.

In a specific embodiment, 9 radar sensors to be tested and a target simulator are used for testing, and 9 radar sensors to be tested are installed on a fixed tooling, as shown in Figure 7, spread out in a nine-square grid; the target simulator uses The Doppler radar target simulator is installed in the normal direction along the tooling plane, and the distance from the tooling is d, and the value of d satisfies the formula (11);

For the simulator designed with linear polarization, in the face of the problem of polarization deflection, it can only keep the electromagnetic wave component consistent with its own polarization direction for receiving and sending, and discard the component with a different direction from its own; and the proportion of the choice is based on the deflection The degree varies, which eventually leads to fluctuations in the size of the transmitted signal received by the simulator. Under the circular polarization design, the receiving and transmitting electromagnetic waves of the target simulator can be disassembled into any two orthogonal linear polarizations of equal amplitude, one of which coincides with the deflected radar electromagnetic wave, and the other is orthogonal to it; therefore , for radar electromagnetic waves deflected arbitrarily, circular polarization can transmit and receive signals by reducing the power by half, so that the simulator can correspond to multiple radar sensors, and all signals with the same amplitude can be transmitted and received. Moreover, in the general circular polarization design, after the circular polarization is decomposed into two orthogonal linear polarizations, the ratio of the amplitudes of the two linear polarizations is called the axial ratio. Generally, when the axial ratio is ≤3dB, it is considered to meet the circular polarization design requirements. Figure 8 shows the axial ratio indicators of the target simulator of this scheme at each main direction angle. It can be seen that the axial ratio indicators of this scheme are basically kept below 1dB, and the circular polarization is stricter than the general standard.

Thus, compared with the prior art, the present invention has the following advantages:

1. Based on the technical scheme of the present invention, the microwave radar test scheme is more economical and flexible, the scene repeatability and controllability are better, and the qualitative measurement of the previous random target scene is transformed into the quantitative measurement of the fixed target information. , problem analysis and production process play an important role.

2. Based on the design of the technical solution of the present invention including a built-in circularly polarized antenna, the harsh requirements on the antenna polarization direction of radar products are reduced during use, and the performance difference of simulated targets caused by improper placement of the antenna polarization direction of radar products is reduced Big question.

3. In the batch radar product test scenario, it also reduces the problem of large differences in the performance of simulated targets due to differences in the location of batch radar products, and improves the consistency of batch test results.

4. Based on the technical solution of the present invention, the highly integrated and miniaturized design is adopted, which is convenient to carry and install, and has no barriers to use in a narrow environment. The relative size of the corresponding shielding environment can be relatively small, saving the space and cost of the shielding environment.

5. Based on the technical solution of the present invention, considering the design of low power consumption, the USB interface of the upper computer can meet the power supply demand, and does not need to occupy an additional DC power supply, which is convenient to use and saves the cost of purchasing DC power supply.

In summary, the Doppler radar target simulator and the microwave radar sensing test system of the present invention, according to the principle of Doppler radar, realize generating And return the echo signal containing the detection target information to the microwave radar, and deduce whether the function of the radar in the actual scene can meet the use requirements by testing the radar's processing ability of the echo signal. The invention realizes quantitative, adjustable and repeatable target signals that are difficult to quantify, inflexible and poorly repeatable in the prior art, and can accurately set the speed information and amplitude information of the radar echo signal simulation target, so that the microwave radar test More economical and flexible, with better scene repeatability and controllability.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (10)

1. a Doppler radar target simulator, is characterized in that, is used for simulating the target velocity and the target amplitude of simulated target, and described target simulator comprises: Signal receiving module, low noise amplifier, first attenuator, signal conversion and phase shifting module, first mixer, second mixer, processing module, digital-to-analog conversion module, combiner integrated on the simulator circuit board device, a second attenuator, a power amplifier and a signal transmitting module; Wherein, the signal receiving module, low noise amplifier, first attenuator, signal conversion and phase shifting module are sequentially connected in series; the first mixer and the second mixer are respectively connected to the signal conversion and phase shifting module , a digital-to-analog conversion module and a combiner; the processing module is connected to the digital-to-analog conversion module; the combiner, the second attenuator, the power amplifier and the signal transmission module are sequentially connected in series; The electromagnetic wave signal sent by the radar sensor is received by the signal receiving module, and then the electromagnetic wave signal is amplified and the amplitude of the electromagnetic wave is adjusted through the low noise amplifier and the first attenuator in turn; through the signal conversion and phase shifting module, the The adjusted signal is converted from a single-ended signal to a differential signal, and outputs a pair of orthogonal radio frequency signals; through the digital-to-analog conversion module, according to the analog target parameters generated by the processing module based on the analog target The digital signal conforming to the characteristics of the analog target is converted into a pair of baseband analog quadrature signals conforming to the characteristics of the analog target; the baseband analog quadrature signal and the signal are converted and shifted by the first mixer and the second mixer respectively The RF signal output by the phase module is mixed, and then the signals mixed by the first mixer and the second mixer are added through the combiner; the added signal passes through the second attenuator, The power amplifier performs signal amplification and electromagnetic wave amplitude adjustment, and the signal transmitting module returns the simulated target signal conforming to the target speed and target amplitude of the simulated target to the radar sensor. 2. according to the Doppler radar target simulator described in claim 1, it is characterized in that, the mode of simulating the target velocity of simulated target comprises: The digital signal generated by the processing module based on the analog target parameters related to the target speed of the analog target is received by the digital-to-analog conversion module and converted into a baseband analog quadrature signal pair that meets the target speed, and passed through the first mixer The frequency converter and the second mixer respectively mix the baseband analog quadrature signal pair with the radio frequency signal output by the signal conversion and phase shifting module, and then combine the first mixer and the The signals mixed by the second mixer are added, so that the signals added by the signals are sequentially passed through the second attenuator, the power amplifier for signal amplification and electromagnetic wave amplitude adjustment to generate an analog target signal corresponding to the target speed; Wherein, the frequency offset between the signal obtained by the combiner through signal addition and the radio frequency signal output by the signal conversion and phase shifting module corresponds to the frequency of the target speed. 3. according to the Doppler radar target simulator described in claim 1 or 2, it is characterized in that, the described mode of simulating the target amplitude of simulated target comprises: By setting one or more of the parameters of the low noise amplifier, the first attenuator, the second attenuator, the digital-to-analog converter, and the power amplifier, the amplitude of the signal is adjusted to generate an analog target signal corresponding to the target amplitude. 4. according to the Doppler radar target simulator described in claim 1, it is characterized in that, described signal receiving module comprises: built-in circularly polarized receiving antenna, the first radio frequency switch and receiving radio frequency head; Wherein, the built-in circularly polarized receiving antenna is used to receive electromagnetic wave signals in orthogonal directions; The receiving radio frequency head is used to connect an external receiving antenna to receive electromagnetic wave signals through the receiving antenna; The radio frequency switch is connected to the built-in circularly polarized antenna and the transmitting radio frequency head, and is used to control the corresponding reception of electromagnetic wave signals by the built-in circularly polarized antenna or the externally connected receiving antenna of the receiving radio frequency head, for the The electromagnetic wave signal is input to the low noise amplifier. 5. according to the Doppler radar target simulator described in claim 1, it is characterized in that, described signal transmitting module comprises: built-in circularly polarized transmitting antenna, the second radio frequency switch and transmitting radio frequency head; Wherein, the built-in circularly polarized transmitting antenna is used to transmit an analog target signal in the form of circularly polarized electromagnetic waves; The transmitting radio frequency head is used for externally connecting a transmitting antenna, so as to transmit the analog target signal through the transmitting antenna; The radio frequency switch is connected to the built-in circularly polarized transmitting antenna and the transmitting radio head, and is used to control the transmission of analog target signals by the built-in circularly polarized transmitting antenna or the externally connected transmitting antenna of the transmitting radio head. 6. according to the Doppler radar target simulator described in claim 4 or 5, it is characterized in that, described built-in circularly polarized receiving antenna and built-in circularly polarized transmitting antenna are respectively embedded in described simulator circuit board front, And on the back side of the circuit board of the simulator, there are respectively provided with feeding networks supporting the built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna; the built-in circularly polarized receiving antenna and the built-in circularly polarized transmitting antenna A first feed point and a second feed point are respectively provided, and the first feed point and the second feed point connect the antenna to the corresponding feed network in the form of metal vias; wherein, the The distances from the first feed point and the second feed point to the geometric center of the corresponding antenna are equal, and the lines connecting the two feed points to the geometric center are orthogonal to each other; The built-in circularly polarized receiving antenna will receive the electromagnetic wave signal sent by the radar sensor by combining with the corresponding feeding network; the built-in circularly polarized transmitting antenna will combine the generated transmitting circular pole The simulated target signal in the form of chemicalized electromagnetic waves is sent to the radar sensor. 7. according to the Doppler radar target simulator described in claim 1, it is characterized in that, described signal conversion and phase shifting module comprise: a signal conversion component, configured to convert the adjusted signal from a single-ended signal to a differential signal; The phase shifting part is connected to the signal converting part, and is used for shifting the phase of the converted differential signal and outputting a pair of orthogonal radio frequency signals. 8. according to the Doppler radar target simulator described in claim 1, it is characterized in that, described processing module is used for based on the control command setting of the upper computer control end that is connected with described Doppler radar target simulator The parameters of the simulated target are described, and a digital signal conforming to the characteristics of the simulated target is generated. 9. The Doppler radar target simulator according to claim 8, wherein the Doppler radar target simulator is connected with the host computer control terminal through a USB interface. 10. A microwave radar sensing test system, characterized in that the system comprises: Multiple radar sensors are respectively installed on the tooling plane of the fixed tooling; The Doppler radar target simulator according to any one of claims 1 to 9, installed along the normal direction of the tooling plane; Wherein, the Doppler radar target simulator simulates the target speed and target amplitude of the simulated target based on the received electromagnetic waves emitted by each radar sensor and the simulated target parameters related to the simulated target, and will conform to the simulated target Each analog target signal of the target speed and target amplitude is returned to the corresponding radar sensor.