Radar module and radar system

Abstract

This disclosure provides a radar module, i.e., a radar system, comprising a PCB substrate, at least two antenna elements, and a radar chip. The difference in the feed path from the radar chip to two adjacent antenna elements is related to the offset angle of the radar module's main radiation direction. The technical solution provided in this disclosure adjusts the deflection of the radar module's main radiation direction through feed path layout design, and, in conjunction with logic algorithms, enables fixed-frequency continuous wave radar to detect and identify moving objects. The technical solution provided in this disclosure is designed based on a shared antenna array for both transmit and receive channels, meeting the requirements for lightweight and integrated design, effectively reducing the size of the radar module, and has widespread applicability.

Description

Technical Field

[0001] This disclosure relates to the field of radar detection technology, specifically, it discloses a radar module and a radar system. Background Technology

[0002] As radar technology is increasingly being transferred from military to civilian applications, microwave radar, as a sensor, is being used in a variety of consumer products. Microwave radar sensors can be concealed and are unaffected by temperature, airflow, dust, or smoke. They have advantages such as long lifespan, fast response speed, higher sensitivity, and wide sensing area, and are also widely used in energy-saving lighting, smart home appliances, and other fields.

[0003] Conventional microwave radar sensors, especially fixed-frequency continuous-wave radar, can only detect the presence of moving objects within their detection range, but cannot distinguish the real-time trajectory of the moving objects relative to the fixed-frequency continuous-wave radar. Therefore, when multiple moving objects exist in the application scenario, fixed-frequency continuous-wave radar struggles to differentiate which moving objects are the targets to be detected and which are interference items to be ignored or eliminated. Summary of the Invention

[0004] This disclosure provides a radar module and a radar system. Specifically, the first aspect of this disclosure provides a radar module, including:

[0005] PCB substrate;

[0006] At least two antenna elements are disposed on the first plane of the PCB substrate. Each antenna element includes a transmitting feed point and a receiving feed point for simultaneously transmitting and receiving electromagnetic wave signals.

[0007] The radar chip is disposed on a second plane opposite to the first plane on a PCB substrate. It is connected to each transmit feed point through a transmit feed network and to each receive feed point through a receive feed network, wherein:

[0008] The transmit feed network and the receive feed network distribute the signal with equal power to all antenna elements;

[0009] The difference in the feed path from the radar chip to two adjacent antenna elements is related to the main radiation direction offset angle of the radar module.

[0010] In one possible implementation of the first aspect described above, in each antenna element, the line connecting the transmit feed point and the geometric center of the antenna element is perpendicular to the line connecting the receive feed point and the geometric center of the antenna element.

[0011] In one possible implementation of the first aspect above, the distance between any two adjacent antenna elements lies in the interval [0.4λ, 0.75λ].

[0012] Where λ is the wavelength of the electromagnetic wave in the air at radar frequency.

[0013] In one possible implementation of the first aspect above, where the radar module contains two antenna elements, the feed path difference is:

[0014]

[0015] Where ΔL is the feed path difference, ε is the dielectric constant of the PCB substrate, d is the distance between the two antenna elements, and θ is the main radiation direction offset angle of the radar module.

[0016] In one possible implementation of the first aspect described above, when the radar module includes several antenna elements, the feed path difference between any two adjacent antenna elements on the first side of the radar chip is:

[0017]

[0018] The feed path difference between any two adjacent antenna elements on the second side of the radar chip, opposite to the first side, is:

[0019]

[0020] Where N is a natural number, λ is the wavelength of the electromagnetic wave in the air at the radar frequency, ε is the dielectric constant of the PCB substrate, d is the distance between the antenna element closest to the radar chip on the first side and the antenna element closest to the radar chip on the second side, and θ is the offset angle of the main radiation direction of the radar module.

[0021] A second aspect of this disclosure provides a radar system including a baseband processing module and at least two radar modules as described in the first aspect above, wherein:

[0022] The baseband processing module is used to process the transmitted and received signals of the radar module;

[0023] The offset angle of the main radiation direction of each radar module is different, and there is no intersection between the main radiation directions of each radar module.

[0024] In one possible implementation of the second aspect above, the radar system is used to determine whether the motion of a target conforms to predetermined rules, including:

[0025] Whether the time when the radar module detects that the signal strength of the target object exceeds the threshold meets the first preset range, a corresponding first judgment result is generated.

[0026] The radar module determines whether the time difference between detecting that the signal strength of the target exceeds the threshold meets the second preset range, and generates a corresponding second judgment result.

[0027] The radar module determines whether the order in which the signal strength of the target object exceeds the threshold conforms to a preset order and generates a corresponding third judgment result.

[0028] If the first, second, and third judgment results are all yes, then the motion of the target object is judged to conform to the established rules.

[0029] A third aspect of this disclosure provides another radar system, including a baseband processing module and a radar module provided in the first aspect above, wherein:

[0030] The baseband processing module is used to process the transmitted and received signals of the radar module;

[0031] The radar module has two split radiation directions, which are symmetrically distributed.

[0032] In one possible implementation of the third aspect above, the radar module includes two antenna elements;

[0033] The power supply path difference is:

[0034]

[0035] Where ΔL′ is the feed path difference, N is a natural number, ε is the dielectric constant of the PCB substrate, and λ is the wavelength of the electromagnetic wave in air at the radar frequency.

[0036] In one possible implementation of the third aspect above, the radar system is used to determine whether the motion of a target conforms to predetermined rules, including:

[0037] The radar module determines whether the number of times it detects a target object's signal strength exceeding a threshold falls within a fourth preset range, and then generates a corresponding fourth judgment result.

[0038] Whether the time when the radar module detects that the signal strength of the target exceeds the threshold meets the fifth preset range, the corresponding fifth judgment result is generated.

[0039] The radar module determines whether the time difference between detecting a target's signal strength exceeding a threshold conforms to the sixth preset range and generates the corresponding sixth judgment result.

[0040] If the fourth, fifth, and sixth judgment results are all yes, then the motion of the target object is judged to conform to the established rules.

[0041] Compared with the prior art, this disclosure has the following beneficial effects:

[0042] In the technical solution proposed in this disclosure, the main radiation direction of the radar module is deflected and adjusted by designing the layout of the feed path between the radar chip and the antenna module. Using the radar module provided in this disclosure, in radar systems employing dual or multiple modules, each radar module can have a different main radiation direction; simultaneously, in radar systems employing a single module, the main radiation direction can be split into two symmetrical directions. Combined with corresponding logic algorithms, this enables fixed-frequency continuous wave radar to detect and identify moving objects. The technical solution provided in this disclosure is designed based on a shared antenna array for both transmitting and receiving channels, meeting the requirements for lightweight and integrated design, effectively reducing the size of the radar module, and has significant potential for widespread application. Attached Figure Description

[0043] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0044] Figure 1a According to an embodiment of this disclosure, a schematic diagram of a radar module comprising two antenna elements is shown from a top-down perspective.

[0045] Figure 1b According to an embodiment of this disclosure, a schematic diagram of a radar module comprising two antenna elements is shown from a downward viewing angle.

[0046] Figure 2 According to an embodiment of this disclosure, a schematic diagram of the deflection of the main radiation direction of a radar module is shown;

[0047] Figure 3 According to an embodiment of this disclosure, a schematic diagram of the trace length of a power supply network is shown;

[0048] Figure 4 According to an embodiment of this disclosure, a schematic diagram of the structure of a radar module comprising multiple antenna elements is shown;

[0049] Figure 5 According to an embodiment of this disclosure, a detection schematic diagram of a radar system including dual radar modules is shown;

[0050] Figure 6 According to an embodiment of this disclosure, a schematic diagram of the output logic signal of a radar system including dual radar modules is shown;

[0051] Figure 7 According to an embodiment of this disclosure, a detection schematic diagram of a radar system including a single radar module is shown;

[0052] Figure 8 According to an embodiment of this disclosure, a schematic diagram of the output logic signal of a radar system including a single radar module is shown. Specific implementation methods

[0053] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0054] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least regionally based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0055] As explained in the background section, existing fixed-frequency continuous-wave radars can only detect the presence of moving objects within their detection range, but cannot distinguish the real-time trajectory of the moving object relative to the radar. This is because the main radiation direction of the antenna module in traditional fixed-frequency continuous-wave radars is often perpendicular to the module's PCB substrate. A single radar module can only detect whether an object is approaching in the main radiation direction, but cannot detect the object's motion relative to the radar. To overcome this problem, some embodiments of this disclosure provide a dual-radar-module radar system. By increasing the distance between the two radar modules in the system, the two radar modules can detect the moving object sequentially when it moves in the main radiation direction, thereby acquiring the object's trajectory. However, this requires the spacing between the two radar modules to occupy more layout space, resulting in low space utilization, which does not meet the design requirements of most consumer electronics products.

[0056] In other embodiments of this disclosure, by artificially deflecting the radar module at a certain angle during installation, the main radiation direction of the radar module can be deflected relative to the radar system. Two or more different deflection angles can enable the detection of the motion state of an object. This approach does not require increasing the distance between the two radar modules, but it requires special structural design, and it also suffers from low space utilization. Furthermore, individual products often require customized design, limiting its widespread applicability.

[0057] It is worth noting that existing modulated signal radars, such as frequency modulated continuous wave radars, can also monitor the motion state of targets because they have the ability to measure target distance. However, due to their high operating costs and high energy consumption during daily use, they are not within the scope of discussion of the technical solutions disclosed herein.

[0058] To overcome the problems encountered in the background technology and the foregoing embodiments, some embodiments of this disclosure provide a radar module. This radar module includes a PCB substrate, at least two antenna elements, and a radar chip. The deflection of the main radiation direction of the radar module is achieved through the positioning of the radar chip and antenna elements and the arrangement of the feeding network. Specifically, Figures 1a to 1b A schematic diagram of a radar module comprising two antenna elements is shown, wherein:

[0059] like Figure 1a As shown, two antenna elements 200 are disposed on the first plane of the PCB substrate 100 (generally the upper surface of the PCB substrate in the vertical direction). Each antenna element 200 adopts the form of a microstrip patch antenna, and includes a transmitting feed point 201 and a receiving feed point 202, respectively, for simultaneously transmitting and receiving electromagnetic wave signals. Figure 1a In the illustrated embodiment, the line connecting the transmitting feed point 201 and the geometric center of the antenna element 200 is perpendicular to the line connecting the receiving feed point 202 and the geometric center of the antenna element 200. This ensures the orthogonality of the transmitted and received signals and minimizes interference between them. The spacing d between the two antenna elements can be located in the interval [0.4λ, 0.75λ], where λ is the wavelength of the electromagnetic wave in air at the radar frequency, thus ensuring that the performance of the synthesized beam meets the preset design requirements.

[0060] like Figure 1b As shown, the radar chip 300 is disposed on a second plane (generally the lower surface of the PCB substrate in the vertical direction) opposite to the first plane in the PCB substrate 100 and located near the center of the second plane. It is connected to each transmit feed point 201 through a transmit feed network 301 and to each receive feed point 202 through a receive feed network 302. Both the transmit feed network 301 and the receive feed network 302 integrate the function of a power divider, distributing equal power of the signal to the two antenna elements 200.

[0061] Through the above Figures 1a to 1b The basic structural settings of the radar module provided in the above embodiments have been explained and described. The following will, in conjunction with the accompanying drawings, specifically explain how the main radiation direction deflection function of the radar module is achieved by adjusting the layout structure of the feed network in the technical solution of this disclosure.

[0062] Specifically, Figure 2 A schematic diagram of the main radiation direction deflection of a radar module is shown. It can be understood that the main radiation direction of the radar module in its initial state should be perpendicular to the A1 direction of the PCB substrate 100. In order to realize the detection of the motion state of an object by a fixed-frequency continuous wave radar, the main radiation direction needs to be adjusted from the A1 direction to the A2 direction. The angle θ between the A2 direction and the A1 direction is the main radiation direction offset angle of the radar module. The relationship between the main radiation direction offset angle of the radar module and the phase difference between the antenna element 200 is shown in the following equation (1):

[0063]

[0064] in, λ is the phase difference between antenna elements 200, d is the distance between antenna elements 200 (the distance here can be equivalent to the distance between the geometric centers of two antenna elements, rather than the distance between the nearest edges of two antenna elements, the same below), λ is the wavelength of electromagnetic waves in air at radar frequency, and θ is the offset angle of the main radiation direction of the radar module.

[0065] The phase difference between antenna elements 200 and the physical distance difference from radar chip 300 to antenna element 200 in the feed network are shown in equation (2) below:

[0066]

[0067] Where ε is the dielectric constant of the PCB substrate.

[0068] Combining equations (1) and (2) above, we can obtain:

[0069]

[0070] Where ΔL is the feed path difference, ε is the dielectric constant of the PCB substrate, d is the distance between the two antenna elements, and θ is the main radiation direction offset angle of the radar module.

[0071] Specifically, Figure 3 A schematic diagram of the trace length of a feed network is shown. The feed path difference is actually mapped to the trace length of the feed network. The trace length difference between the transmitting feed network 301 and the receiving feed network 302 is the same. It can be understood that the magnitude of the feed path difference determines the magnitude of the offset angle of the main radiation direction, and the distribution of the feed path difference determines the direction of the offset angle of the main radiation direction.

[0072] In the above embodiments, a schematic diagram of the radar module comprising two antenna elements 200 and the distribution of the feed network are provided with reference to the accompanying drawings. In other embodiments of this disclosure, Figure 4A schematic diagram of another radar module is shown, in which... Figure 4 The radar module shown contains multiple antenna elements 200, each with identical specifications. Figure 4 Only the antenna array arrangement and feed network routing of antenna elements 200a to 200d are shown. The difference between the distance between feed node B and feed node B1 and the distance between feed node B and feed node B2 is the same as that disclosed in formula (3) in the previous embodiment. The difference between the distance between feed node A and feed node A1 and the distance between feed node A and feed node A2 is also the same as that disclosed in formula (3) in the previous embodiment, and will not be repeated here. The difference in feed paths between the extended antenna elements 200c and 200d and their adjacent antenna elements is:

[0073]

[0074]

[0075] Where L1 is the distance between feeder node A1 and feeder node A3, L2 is the distance between feeder node A2 and feeder node A4, and N is a natural number.

[0076] Understandable, Figure 4 The diagram only shows the antenna array arrangement and feed network routing of antenna elements 100a to 100d. If more antenna elements are added, and the odd-numbered antenna elements are arranged sequentially on the left side of the radar chip 300, and the even-numbered antenna elements are arranged sequentially on the right side of the radar chip 300, then the distance (i.e., the feed path difference) between any two adjacent antenna elements arranged on the left side of the radar chip is L1, and the distance (i.e., the feed path difference) between any two adjacent antenna elements arranged on the left side of the radar chip is L2, and so on. This will not be elaborated here.

[0077] Combining the above formulas (4) and (5) with the aforementioned formula (3), we can obtain:

[0078]

[0079]

[0080] Where N is a natural number, λ is the wavelength of the electromagnetic wave in the air at the radar frequency, ε is the dielectric constant of the PCB substrate, d is the distance between the geometric centers of antenna element 100a and antenna element 100b, and θ is the offset angle of the main radiation direction of the radar module.

[0081] Through the above description of the embodiments, the technical solution provided by this disclosure enables the control of the main radiation direction deflection angle of the radar module by the feed network structure characteristics (i.e., the feed path difference between adjacent antenna elements) when using different numbers of antenna elements. However, simply controlling the deflection of the main radiation direction of the radar module cannot directly achieve the detection of the motion trajectory of a moving object. The following will explain and illustrate how a radar system using this type of radar module can achieve the detection of the motion trajectory of a moving object.

[0082] In some embodiments of this disclosure, a radar system is also provided. This radar system may include a baseband processing module and the radar module provided in the above embodiments. The baseband processing module is communicatively connected to the radar module and is used to process the transmitted and received signals of the radar module. It is understood that the baseband processing module can be equivalent to a protocol processor, responsible for data processing and storage. The baseband processing module components may include digital signal processors (DSPs), microcontrollers (MCUs), memory (SRAM, Flash), etc., which will not be elaborated here. The actual judgment function implementation of the baseband processing module will be described in detail later.

[0083] In one possible implementation of the above embodiments, specifically, Figure 5 A radar system comprising dual radar modules is shown. For example... Figure 5 As shown, in this specific implementation, both the first radar module 501 and the second radar module 502 are connected to the baseband processing module 500. Figure 5In the reference frame shown, the main radiation direction of the first radar module 501 is shifted to the left by θ°, and the main radiation direction of the second radar module 502 is deflected to the right by θ°. The radar module provided in the aforementioned main radiation embodiment achieves symmetrical deflection of the two main radiation directions in the left and right directions. In this scenario, if the target 503 moves from left to right along the detectable direction of the radar system, it can be seen that at time t1, when the target 502 passes through the main radiation direction of the first radar module 501, the electromagnetic wave signal received by the first radar module 501 is the strongest. At times t2 and t3, because the target 502 is far from the main radiation direction of the first radar module 501, the electromagnetic wave signal received by the first radar module 501 is relatively weak. For the second radar module 502, at times t1 and t2, because the target 502 is far from the main radiation direction of the second radar module 502, the electromagnetic wave signal received is relatively weak. However, when the target 503 moves into the main radiation direction of the second radar module 502 at time t3, the electromagnetic wave signal received is relatively strong. It is understood that by using two different main radiation directions, the motion state of the target can be detected and acquired accordingly. In some other possible implementations of the above embodiments, the radar system can also use more than two radar modules, as long as the offset angle of the main radiation direction of each radar module is different and there is no intersection between the main radiation directions of each radar module. The more radar modules there are, the higher the detectable range and detection accuracy of the motion state of the target. Those skilled in the art can design the number of radar modules carried by the radar system according to actual needs, which is not limited here.

[0084] In possible implementations of the above embodiments, Figure 6 A schematic diagram of the output logic signal of a radar system including dual radar modules is shown. If a preset threshold is set for the signal strength received by the radar modules, and the signal strength exceeds this threshold, a square wave signal is output to the baseband processing module. Then, in situations such as... Figure 5 The schematic diagram of the square wave signals output by radar module 501 and radar module 502 in the scenario shown is as follows: Figure 6 As shown. Furthermore, to determine whether the motion state of the detection target 503 conforms to the preset motion trajectory or motion state, the following analysis can be performed:

[0085] 1) Determine whether the time it takes for the radar module to detect a target signal strength exceeding a threshold falls within the first preset range:

[0086] If so, it means that in such a case Figure 5In the scenario shown, radar module 501 and radar module 502 respectively detected that the target 503 passed through the main radiation direction, and the speed of the target 503 when passing through the main radiation direction conformed to the preset motion state.

[0087] 2) Determine whether the time difference between the radar module detecting the signal strength of the target exceeding the threshold meets the second preset range: if so, it indicates that the signal strength exceeds the threshold within the second preset range. Figure 5 In the scenario shown, the speed of the detection target 503 when passing through the area between the main radiation directions of radar module 501 and radar module 502 conforms to the preset motion state.

[0088] 3) Determine whether the order in which the radar module detects target signal strength exceeding the threshold conforms to a preset order: if so, it indicates that... Figure 5 In the scenario shown, the first radar module 501 outputs a square wave signal first, followed by the second radar module 502, and the direction of motion of the detected target 503 conforms to the following... Figure 5 The trajectory of the motion from left to right in the coordinate system shown.

[0089] It is understood that, in possible implementations of the above embodiments, if the judgment results of the above three judgment items in the baseband processing module are all yes, it can be determined that the detected target 503 conforms to the preset motion trajectory and motion state; if the judgment result of any one item is no, it indicates that the detected target 503 does not conform to the preset motion trajectory and / or motion state. That is, based on the technical solution provided by this disclosure, the fixed-frequency continuous wave radar can have a certain degree of ability to judge the motion trajectory of objects, can eliminate motion interference signals of non-target objects, and is suitable for flexible application scenarios such as hand-scan recognition and gate number counting where the target object moves along the tangential direction of the radar sensor. At the same time, the radar module design has high space utilization, effectively reducing the size and volume of the radar module and radar system.

[0090] In another possible implementation of the above embodiments, Figure 7 A radar system comprising a single radar module is shown. For example... Figure 7 As shown, in this specific implementation, the radar module 701 remains connected to the baseband processing module 700. To detect the moving target 702, the main radiation direction of the radar module 701 needs to be set to two symmetrical directions. Specifically, the phase difference in formula (1) provided in the aforementioned embodiment can be... Set to a constant value to achieve splitting symmetry in the main radiation direction, that is:

[0091]

[0092] Combining the above formulas (2) and (8), we can obtain:

[0093]

[0094] Where ΔL' is the difference in the feed path between the two antenna elements in a single radar module, N is a natural number, ε is the dielectric constant of the PCB substrate, and λ is the wavelength of the electromagnetic wave in the air at the radar frequency. At this time, the angle of the main radiation direction deflection of the radar module is approximately 40°.

[0095] In a possible implementation of the above embodiments, further, Figure 8 A schematic diagram of the output logic signal of a radar system including a single radar module is shown. Similarly, a preset threshold is set for the signal strength received by the radar module. When the signal strength exceeds this threshold, a square wave signal is output to the baseband processing module. Then, in the case of... Figure 7 The schematic diagram of the square wave signal output by radar module 701 in the scenario shown is as follows: Figure 8 As shown. Correspondingly, in order to determine whether the motion state of the detection target 702 conforms to the preset motion trajectory or motion state, the following aspects can be considered for judgment and analysis:

[0096] 1) Determine whether the number of times the radar module detects a target with a signal strength exceeding a threshold falls within the fourth preset range:

[0097] If so, it means that in such a case Figure 7 In the scenario shown, the detection target 702 passed through two main radiation directions in sequence.

[0098] 2) Determine whether the time it takes for the radar module to detect a target signal strength exceeding a threshold falls within the fifth preset range:

[0099] If so, it means that in such a case Figure 7 In the scenario shown, the speed of the detection target 702 when passing through the two main radiation directions conforms to the preset motion state.

[0100] 3) Determine whether the time difference between the radar module detecting the signal strength of the target exceeding the threshold meets the sixth preset range: if so, it indicates that... Figure 7 In the scenario shown, the speed of the detection target 702 when passing through the area between the two main radiation directions conforms to the preset motion state.

[0101] It is understood that, in possible implementations of the above embodiments, if the judgment results of the above three judgment items in the baseband processing module are all yes, it can be determined that the detected target 702 conforms to the preset motion trajectory and motion state; if the judgment result of any one item is no, it indicates that the detected target 702 does not conform to the preset motion trajectory and / or motion state. It is worth noting that, in a radar system using a single radar module, compared to a radar system using a dual radar module, since it is unclear which main radiation direction the first arriving square wave signal belongs to, the radar system using a single radar module cannot achieve the detection capability of the motion direction of the detected target 702.

[0102] In summary, this disclosure provides a radar module and a radar system using this radar module. In the technical solution proposed in this disclosure, the main radiation direction of the radar module is deflected and adjusted by designing the layout of the feed path between the radar chip and the antenna module. Using the radar module provided in this disclosure, in radar systems using dual or multiple modules, each radar module can have a different main radiation direction; simultaneously, in radar systems using a single module, the main radiation direction can be split into two symmetrical directions. Combined with corresponding logic algorithms, this enables fixed-frequency continuous wave radar to detect and identify moving objects. The technical solution provided in this disclosure is designed based on a shared antenna array for both transmitting and receiving channels, meeting the requirements for lightweight and integrated design, effectively reducing the size of the radar module, and has widespread applicability.

[0103] The above description is only a description of the preferred embodiment of the technical solution disclosed herein, and is not intended to limit the scope of the technical solution disclosed herein. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A radar module, characterized in that, include: PCB substrate; At least two antenna elements are disposed on the first plane of the PCB substrate, and each antenna element includes a transmitting feed point and a receiving feed point for simultaneously transmitting and receiving electromagnetic wave signals. A radar chip is disposed on a second plane in the PCB substrate opposite to the first plane, and is connected to each of the transmitting feed points through a transmitting feed network and to each of the receiving feed points through a receiving feed network, wherein: The transmit feed network and receive feed network distribute the signal with equal power to all the antenna elements; The difference in the feed path from the radar chip to two adjacent antenna elements is related to the main radiation direction offset angle of the radar module; In the case where the radar module contains two antenna elements, the feed path difference is: in, The difference in the power supply path, The dielectric constant of the PCB substrate is given. The distance between the two antenna elements. The offset angle of the main radiation direction of the radar module; Alternatively, if the radar module includes several antenna elements, the feed path difference between any two adjacent antenna elements on the first side of the radar chip is: The feed path difference between any two adjacent antenna elements on the second side of the radar chip opposite to the first side is: Where N is a natural number, The wavelength of electromagnetic waves in air at radar frequencies. The dielectric constant of the PCB substrate is given. The distance between the antenna element closest to the radar chip on the first side and the antenna element closest to the radar chip on the second side. The offset angle is the main radiation direction of the radar module.

2. The radar module as described in claim 1, characterized in that, In each of the antenna elements, the line connecting the transmit feed point and the geometric center of the antenna element is perpendicular to the line connecting the receive feed point and the geometric center of the antenna element.

3. The radar module as described in claim 1, characterized in that, The distance between any two adjacent antenna elements lies within the interval [0.4]. 0.75 ]middle; in, The wavelength of electromagnetic waves in air at radar frequencies.

4. A radar system, characterized in that, It includes a baseband processing module and at least two radar modules as described in any one of claims 1 to 3, wherein: The baseband processing module is used to process the transmitted and received signals of the radar module. The offset angle of the main radiation direction of each radar module is different, and there is no intersection between the main radiation directions of each radar module.

5. The radar system as described in claim 4, characterized in that, The radar system is used to determine whether the motion of a target conforms to predetermined rules, including: Whether the time when the radar module detects that the signal strength of the target object exceeds the threshold meets the first preset range, a corresponding first judgment result is generated. The radar module determines whether the time difference between detecting that the signal strength of the target exceeds the threshold conforms to the second preset range, and generates a corresponding second judgment result. The radar module generates a third judgment result based on whether the order in which the signal strength of the target object exceeds the threshold conforms to a preset order. If the first judgment result, the second judgment result, and the third judgment result are all yes, then the motion of the target object is determined to conform to the predetermined rule.

6. A radar system, characterized in that, It includes a baseband processing module and a radar module as described in any one of claims 1 to 3, wherein: The baseband processing module is used to process the transmitted and received signals of the radar module. The radar module has two split radiation directions, which are symmetrically distributed.

7. The radar system as described in claim 6, characterized in that, The radar system is used to determine whether the motion of a target conforms to predetermined rules, including: The radar module determines whether the number of times it detects a target object's signal strength exceeding a threshold falls within a fourth preset range, and generates a corresponding fourth judgment result. Whether the time when the radar module detects that the signal strength of the target object exceeds the threshold meets the fifth preset range, a corresponding fifth judgment result is generated. The radar module determines whether the time difference between detecting that the signal strength of the target exceeds the threshold conforms to the sixth preset range and generates the corresponding sixth judgment result. If the fourth, fifth, and sixth judgment results are all yes, then the motion of the target object is determined to conform to the predetermined rules.

Images