Back-reflecting circularly polarized microwave detection antenna

Abstract

The present invention discloses a back-reflective circularly polarized microwave detection antenna, wherein the back-reflective circularly polarized microwave detection antenna comprises a circularly polarized antenna body and a back-reflection cavity, wherein the circularly polarized antenna body comprises a radiation source and a reference ground, wherein the radiation source is spaced apart from the reference ground, wherein the radiation source is circularly polarized, wherein the back-reflection cavity has a back-reflection cavity formed in the direction from the reference ground to the radiation source, wherein the back-reflection cavity has an electromagnetic radiation port in the direction from the radiation source to the reference ground, wherein the circularly polarized antenna body is arranged in the back-reflection cavity in a state where the radiation source is facing away from the electromagnetic radiation port, so as to synthesize the side lobe energy into the main beam by back-reflection to form a "suppression" effect on the side lobe, thereby forming a double improvement in the anti-interference capability and gain of the back-reflective circularly polarized microwave detection antenna.

Description

Technical Field

[0001] The invention relates to the field of microwave detection, in particular to a back-reflective circularly polarized microwave detection antenna used for microwave detection. Background Art

[0002] Microwave detection technology, as an important hub connecting people and objects, and objects and objects, has unique advantages in behavior detection and existence detection technology. It can detect moving objects without infringing on people's privacy, and therefore has broad application prospects. However, due to the lack of effective constraints and control measures for electromagnetic radiation, that is, the means of adjusting the shape of the electromagnetic radiation coverage range, especially the means of suppressing the electromagnetic radiation corresponding to the side lobe, the adaptability, anti-interference ability and stability of microwave detection technology in different application scenarios in practical applications are difficult to guarantee. Specifically, due to the lack of means of suppressing the electromagnetic radiation corresponding to the side lobe, the actual detection space of the existing microwave detection technology is difficult to control, so that when there is environmental interference in the electromagnetic radiation coverage range corresponding to the side lobe in the actual detection space outside the target detection space, including motion interference, electromagnetic interference and self-excited interference formed by the electromagnetic shielding environment of the electromagnetic radiation coverage range corresponding to the side lobe, it is difficult to guarantee the applicability, anti-interference ability and stability of the existing microwave detection technology.

[0003] The existing microwave detection technology mainly adopts a microwave detection module with a columnar radiation source structure and a microwave detection module with a planar radiation source structure, wherein the microwave detection module with a columnar radiation source structure has a radiation dead zone in the radiation space corresponding to its electromagnetic radiation coverage range. In actual use, such as in vertical detection applications, when the microwave detection module with a columnar radiation source structure is installed in a vertical direction such as a suspended ceiling, a ceiling, and a shed roof for vertical downward detection, the installation position of the microwave detection module with a columnar radiation source structure is usually lowered to reduce or avoid the radiation dead zone of the corresponding radiation space. The detection dead zone is formed in the space between the microwave detection module and the ground. At the same time, since the microwave detection module with a columnar radiation source structure has a larger side lobe than the microwave detection module with a planar radiation source structure, the microwave detection module with a columnar radiation source structure is more susceptible to environmental interference in the actual detection space outside the target detection space. In other words, the detection distance of the existing microwave detection module with a columnar radiation source structure in actual use is much smaller than the detection distance matched with its gain size, and has poor applicability and stability compared with the microwave detection module with a planar radiation source structure. Therefore, the existing microwave detection technology mostly adopts the microwave detection module with a planar radiation source structure.

[0004] Specifically, referring to the accompanying drawings of the present invention, Figure 1A and 1BAs shown, the structural principle and the corresponding radiation pattern of the existing microwave detection module 10P with a planar radiation source structure are respectively illustrated, wherein the microwave detection module 10P with a planar radiation source structure includes a planar radiation source 12P and a reference ground 11P, wherein the planar radiation source 12P and the reference ground 11P are arranged in parallel with each other and spaced apart, and the projection of the planar radiation source 12P on the reference ground 11P is located within the reference ground 11P, then a radiation gap 13P is formed between the planar radiation source 12P and the reference ground 11P, so that when the planar radiation source 12P is fed, the planar radiation source 12P can be coupled with the reference ground 11P and a radiation space 100P is formed from the radiation gap 13P with an axis perpendicular to the physical center point of the planar radiation source 12P as the central axis, wherein the radiation space 100P corresponds to the electromagnetic radiation coverage range of the microwave detection module 10P with the planar radiation source structure and corresponds to the actual detection space of the microwave detection module 10P with the planar radiation source structure. In actual use, the direction from the reference ground 11P to the planar radiation source 12P is the detection direction of the microwave detection module 10P of the planar radiation source structure, which corresponds to the Z-axis direction of the radiation space 100P in the figure. It can be seen that the projection surface of the radiation space 100P in this direction on the corresponding target detection surface tends to be circular, that is, the microwave detection module 10P of the planar radiation source structure is suitable for target detection spaces that require circular target detection surfaces and square target detection surfaces. Among them, since the target detection spaces that require circular target detection surfaces and square target detection surfaces are the majority in actual applications, the microwave detection module 10P of the planar radiation source structure has certain adaptability to the target detection space in actual applications. However, due to the lack of effective constraints and control measures on the radiation space 100P, especially the suppression of the radiation space 100P in the reverse direction of the detection direction with the planar radiation source 12P as the boundary, corresponding to the suppression of the side lobe 101P (including the back lobe and the side lobe) of the radiation space 100P, the microwave detection module 10P with the planar radiation source structure is difficult to resist the environmental interference of the electromagnetic radiation coverage range corresponding to the side lobe 101P in the actual detection space outside the corresponding target detection space, including motion interference, electromagnetic interference, and self-excited interference formed by the electromagnetic shielding environment of the electromagnetic radiation coverage range corresponding to the side lobe 101P.

[0005] In summary, due to the lack of effective constraints and control means for electromagnetic radiation, especially the means of suppressing electromagnetic radiation corresponding to the side lobes, the current microwave detection technology is difficult to stably adapt to the selection of different application scenarios and resist the environmental interference of the electromagnetic radiation coverage range corresponding to the side lobes in the actual detection space outside the corresponding target detection space. Therefore, obtaining effective means of adjusting the shape of the radiation space of the corresponding microwave detection module, especially the means of suppressing electromagnetic radiation corresponding to the side lobes, is not only conducive to improving the adaptability of microwave detection technology in different application scenarios, but also conducive to improving the anti-interference ability and stability of microwave detection technology in the corresponding application scenarios. Summary of the invention

[0006] An object of the present invention is to provide a back-reflecting circularly polarized microwave detection antenna, wherein the back-reflecting circularly polarized microwave detection antenna has a target detection direction and can form a radiation space that is suppressed in the reverse direction of the target detection direction, that is, a sublobe of the radiation space located in a non-target detection space is suppressed, and the electromagnetic radiation of the back-reflecting circularly polarized microwave detection antenna in the reverse direction of the target detection direction to the non-target detection space is correspondingly reduced, which is beneficial to avoid motion interference and electromagnetic interference of the non-target detection space in the reverse direction of the target detection direction, and improves the adaptability of the back-reflecting circularly polarized microwave detection antenna to the non-target detection space and the reliability of detection of the corresponding target detection space.

[0007] Another object of the present invention is to provide a back-reflecting circularly polarized microwave detection antenna, wherein the side lobe of the back-reflecting circularly polarized microwave detection antenna is suppressed, which is beneficial to avoiding self-excited interference caused by multiple reflections of the electromagnetic radiation corresponding to the side lobe in the electromagnetic shielding environment of the non-target detection space, thereby improving the adaptability of the back-reflecting circularly polarized microwave detection antenna to the non-target detection space and the reliability of detection of the corresponding target detection space.

[0008] Another object of the present invention is to provide a back-reflective circularly polarized microwave detection antenna, wherein the back-reflective circularly polarized microwave detection antenna uses circularly polarized electromagnetic radiation to detect the movement of objects based on the principle of the Doppler effect, thereby improving the anti-attenuation characteristics and anti-rain and fog interference capabilities of the back-reflective circularly polarized microwave detection antenna, thereby facilitating meeting the high detection accuracy requirements for detecting moving objects and adapting to outdoor detection scenarios.

[0009] Another object of the present invention is to provide a back-reflecting circularly polarized microwave detection antenna, wherein the back-reflecting circularly polarized microwave detection antenna includes a radiation source, wherein the radiation source is circularly polarized so as to have a circularly polarized polarization mode when fed, corresponding to which the electromagnetic radiation of the back-reflecting circularly polarized microwave detection antenna has a circularly polarized form.

[0010] Another object of the present invention is to provide a back-reflecting circularly polarized microwave detection antenna, wherein based on the orthogonality of the rotational direction of circularly polarized electromagnetic radiation, the anti-multipath reflection interference capability of the back-reflecting circularly polarized microwave detection antenna is improved, and the correlation between the detection data obtained by the back-reflecting circularly polarized microwave detection antenna based on the Doppler effect principle and the moving object is improved, which is beneficial to improve the accuracy of the feedback of the detection data obtained by the back-reflecting circularly polarized microwave detection antenna based on the Doppler effect principle to the moving object.

[0011] Another object of the present invention is to provide a back-reflective circularly polarized microwave detection antenna, wherein the correlation and accuracy of the feedback of the detection data obtained by the back-reflective circularly polarized microwave detection antenna based on the principle of Doppler effect to the moving object are improved, and the detection accuracy of the corresponding back-reflective circularly polarized microwave detection antenna is improved, which is beneficial to improve the accuracy of the back-reflective circularly polarized microwave detection antenna in detecting weak movements, so that the back-reflective circularly polarized microwave detection antenna is suitable for detecting weak movements such as human movement, micro-movement, breathing and heartbeat, and is used for human presence detection.

[0012] Another object of the present invention is to provide a back-reflective circularly polarized microwave detection antenna, wherein the back-reflective circularly polarized microwave detection antenna includes a reference ground and has a back-reflection cavity formed in the direction from the reference ground to the radiation source, wherein the back-reflection cavity has an electromagnetic radiation port in the direction from the radiation source to the reference ground, wherein the radiation source is arranged at a distance from the reference ground in a state of facing away from the electromagnetic radiation port from the back-reflection cavity, so as to reversely form the target detection direction from the radiation source to the reference ground of the back-reflective circularly polarized microwave detection antenna relative to a traditional antenna that takes the reference ground to the radiation source as the target detection direction, and form the radiation space that is suppressed in the reverse direction of the target detection direction, that is, the side lobe of the radiation space located in the non-target detection space is suppressed.

[0013] Another object of the present invention is to provide a back-reflective circularly polarized microwave detection antenna, wherein the back-reflective circularly polarized microwave detection antenna includes a back-reflective cavity to form the back-reflective cavity, wherein the back-reflective cavity has a concave shape design from the radiation source to the reference ground, and the corresponding back-reflective cavity is convexly designed from the radiation source to the reference ground to improve the gain of the back-reflective circularly polarized microwave detection antenna and further suppress the side lobes of the radiation space located in the non-target detection space.

[0014] Another object of the present invention is to provide a back-reflective circularly polarized microwave detection antenna, wherein the back-reflective circularly polarized microwave detection antenna includes a metal ring and has an electromagnetic radiation channel defined by the metal ring, wherein the electromagnetic radiation channel extends from the electromagnetic radiation port in a radially expanded state, corresponding to the metal ring in a horn shape and connected to the electromagnetic radiation port at the narrow end of the horn shape, so as to further improve the gain of the back-reflective circularly polarized microwave detection antenna, and suppress the side lobes of the radiation space located in the non-target detection space, and the back-reflection cavity has a concave shape design from the radiation source to the reference ground, forming a state in which the back-reflection cavity is located in the gap area of ​​the radiation space, that is, the back-reflective circularly polarized microwave detection antenna is in a "side-lobe-free" state.

[0015] Another object of the present invention is to provide a back-reflective circularly polarized microwave detection antenna, wherein the back-reflective circularly polarized microwave detection antenna includes a dielectric ring and has an annular channel defined by the dielectric ring, wherein the dielectric ring is configured to have a relative dielectric constant greater than or equal to 5, wherein the annular channel extends from the circumference of the electromagnetic radiation port and is connected to the back-reflection cavity through the electromagnetic radiation port to improve the gain of the back-reflective circularly polarized microwave detection antenna and suppress the side lobes of the radiation space located in the non-target detection space.

[0016] Another object of the present invention is to provide a back-reflecting circularly polarized microwave detection antenna, wherein based on the structural arrangement that the radiation source comes from the back-reflecting cavity and is spaced apart from the reference ground in a state of facing away from the electromagnetic radiation port, back-reflection of the electromagnetic radiation of the back-reflecting circularly polarized microwave detection antenna from the reference ground to the radiation source is formed, so as to reversely form the target detection direction of the back-reflecting circularly polarized microwave detection antenna from the radiation source to the reference ground relative to a traditional antenna that takes the reference ground to the radiation source as the target detection direction, and form the radiation space that is suppressed in the reverse direction of the target detection direction, wherein based on the morphological optimization of the back-reflecting cavity and the electromagnetic radiation channel, it is possible to form a state in which the back-reflecting cavity is located in the gap area of ​​the radiation space, that is, the back-reflecting circularly polarized microwave detection antenna is in a "sidelobe-free" state.

[0017] One object of the present invention is to provide a back-reflecting circularly polarized microwave detection antenna, wherein based on the corresponding shape setting of the back-reflecting cavity, and setting the radiation originating from the back-reflecting cavity back to the electromagnetic radiation port, the backward radiation and lateral radiation corresponding to the back lobe and the side lobe, after reflection synthesis, form a main beam radiated from the back-reflecting cavity through the electromagnetic radiation port, that is, by means of back-reflection, the side lobe energy is synthesized into the main beam to form a "suppression" effect on the side lobe, thereby improving the anti-interference ability of the back-reflecting circularly polarized microwave detection antenna, and at the same time improving the radiation conversion efficiency of the back-reflecting circularly polarized microwave detection antenna, correspondingly improving the gain of the back-reflecting circularly polarized microwave detection antenna.

[0018] According to one aspect of the present invention, the present invention provides a back-reflective circularly polarized microwave detection antenna, the back-reflective circularly polarized microwave detection antenna comprising:

[0019] a circularly polarized antenna body, wherein the circularly polarized antenna body comprises a radiation source and a reference ground, wherein the radiation source is spaced apart from the reference ground, wherein the radiation source is circularly polarized; and

[0020] A back reflection cavity, wherein the back reflection cavity has a back reflection cavity formed in the direction from the reference ground to the radiation source, wherein the back reflection cavity has an electromagnetic radiation port in the direction from the radiation source to the reference ground, wherein the circularly polarized antenna body is arranged in the back reflection cavity in a state where the radiation source is facing away from the electromagnetic radiation port.

[0021] In one embodiment, the back-reflection cavity has an annular side cavity wall and a bottom wall facing the electromagnetic radiation port to form the back-reflection cavity defined by the annular side cavity wall and the bottom wall, wherein the circularly polarized antenna body is in a state where the radiation source is facing away from the electromagnetic radiation port, corresponding to a state where the direction from the bottom wall to the electromagnetic radiation port is opposite to the direction from the reference ground to the radiation source.

[0022] In one embodiment, the central axis of the annular side cavity wall is defined corresponding to a plane perpendicular to the central axis of the annular side cavity wall, and the section curve of the annular side cavity wall is annular, wherein the length of the section of the annular side cavity wall by a straight line perpendicularly intersecting the central axis of the annular side cavity wall is the diameter D of the annular side cavity wall, and the diameter D of the annular side cavity wall satisfies 3λ / 4≤D≤5λ / 4, wherein λ is a wavelength parameter corresponding to the frequency parameter of the back-reflecting circularly polarized microwave detection antenna.

[0023] In one embodiment, the reference ground is configured as an annular sheet structure, so that the electromagnetic radiation port is formed based on the annular sheet structure design of the reference ground.

[0024] In one embodiment, the aperture D of the electromagnetic radiation port is set to satisfy λ / 8≤D≤λ.

[0025] In one embodiment, the central axis direction of the annular side cavity wall is taken as the height direction of the annular side cavity wall, and the height parameter H of the annular side cavity wall satisfies λ / 8≤H≤λ.

[0026] In one embodiment, the annular side cavity wall of the back-reflecting cavity is configured to be annular, and corresponding to a plane perpendicular to the central axis of the annular side cavity wall, a section curve of the annular side cavity wall is circular.

[0027] In one embodiment, the electromagnetic radiation port is arranged coaxially with the annular side cavity wall, that is, the central axis of the annular side cavity wall passes through the physical center of the electromagnetic radiation port and is perpendicular to the plane where the electromagnetic radiation port is located.

[0028] In one embodiment, the back reflection cavity has a concave shape design in the direction from the radiation source to the reference ground, and the back reflection cavity is correspondingly provided with the bottom wall in a convex state in the direction from the radiation source to the reference ground.

[0029] In one embodiment, the back reflection cavity is configured to have a bottom wall that is conical in the direction from the radiation source to the reference ground.

[0030] In one embodiment, the back-reflective circularly polarized microwave detection antenna further includes a metal ring and has an electromagnetic radiation channel defined by the metal ring, wherein the electromagnetic radiation channel extends from the electromagnetic radiation port in a radially expanded state, corresponds to the metal ring and is horn-shaped and connected to the electromagnetic radiation port at the narrow end of the horn.

[0031] In one embodiment, the back-reflective circularly polarized microwave detection antenna further includes a dielectric ring and has an annular channel defined by the dielectric ring, wherein the dielectric ring is configured to have a relative dielectric constant greater than or equal to 5, wherein the annular channel extends from the periphery of the electromagnetic radiation port and is connected to the back-reflection cavity through the electromagnetic radiation port.

[0032] In one embodiment, the reference ground is integrally formed in the back reflection cavity.

[0033] In one embodiment, the radiation source includes a plurality of radiation elements, wherein each of the radiation elements has a feeding point deviated from the physical center point of the radiation element, wherein each of the radiation elements is arranged symmetrically with respect to a line connecting the physical center point of the radiation element and the feeding point, wherein the direction from the reference ground to the radiation source is the axial direction of the circularly polarized antenna body, and the feeding point and the physical center point of each of the radiation elements are arranged at intervals in the circumferential direction of the axial direction to form a circularly polarized arrangement of the radiation elements and the radiation source is circularly polarized.

[0034] In one embodiment, each of the radiation elements is disposed at a physical center point and is electrically connected to the reference ground.

[0035] In one embodiment, each of the radiation elements is disposed at a physical center point and is electrically connected to the reference ground in the form of a metallized via.

[0036] In one embodiment, each of the radiation elements is arranged to be concave in a direction perpendicular to a line connecting a physical center point of the radiation element and the feeding point and in a direction toward the physical center point of the radiation element.

[0037] In one embodiment, the circularly polarized antenna body further comprises a radiation source substrate, wherein the radiation source substrate is disposed between the radiation source and the reference ground to form and support a structural state in which the radiation source and the reference ground are spaced apart.

[0038] In one embodiment, the circularly polarized antenna body further includes an independent reference ground, wherein the independent reference ground is configured as a sheet-shaped conductor, wherein the radiation source is configured on one side of the independent reference ground and spirally extends in a direction perpendicular to the independent reference ground to form a circular polarization setting for the radiation source. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A It is a structural schematic diagram of a microwave detection module with an existing planar radiation source structure.

[0040] Figure 1B It is the radiation pattern of the microwave detection module of the existing planar radiation source structure.

[0041] Figure 2A The figure is a schematic diagram of an optimized structure of a circularly polarized antenna body of a back-reflective circularly polarized microwave detection antenna in an independent state according to an embodiment of the present invention.

[0042] Figure 2B The figure is the radiation pattern of the above-mentioned optimized structure in an independent state according to the present invention.

[0043] Figure 3A It is a schematic structural diagram of the circularly polarized antenna body of the back-reflective circularly polarized microwave detection antenna in an independent state according to the above embodiment of the present invention.

[0044] Figure 3B 1 is a radiation pattern of the circularly polarized antenna body of the back-reflective circularly polarized microwave detection antenna in an independent state according to the above embodiment of the present invention.

[0045] Figure 4A The figure is a schematic diagram of the three-dimensional structure of a back-reflective circularly polarized microwave detection antenna according to an embodiment of the present invention.

[0046] Figure 4B It is a schematic cross-sectional structural diagram of the back-reflective circularly polarized microwave detection antenna according to the above embodiment of the present invention.

[0047] Figure 4C It is a schematic diagram of the radiation direction of the back-reflective circularly polarized microwave detection antenna according to the above embodiment of the present invention.

[0048] Figure 5A It is a three-dimensional structural schematic diagram of the back-reflective circularly polarized microwave detection antenna according to a modified embodiment of the above embodiment of the present invention.

[0049] Figure 5B It is a schematic cross-sectional structural diagram of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned variant embodiment of the present invention.

[0050] Figure 5C It is a schematic diagram of the radiation direction of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned variant embodiment of the present invention.

[0051] Fig. 6AIt is a schematic diagram of the three-dimensional structure of the back-reflective circularly polarized microwave detection antenna according to an optimized embodiment of the above embodiment of the present invention.

[0052] Figure 6B It is a schematic cross-sectional structural diagram of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned optimized embodiment of the present invention.

[0053] Figure 6C It is a schematic diagram of the radiation direction of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned optimized embodiment of the present invention.

[0054] Fig. 7A It is a schematic diagram of the three-dimensional structure of the back-reflective circularly polarized microwave detection antenna according to an optimized embodiment of the above-mentioned variant embodiment of the present invention.

[0055] Figure 7B It is a schematic cross-sectional structural diagram of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned optimized embodiment of the present invention.

[0056] Figure 7C It is a schematic diagram of the radiation direction of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned optimized embodiment of the present invention.

[0057] Fig. 8A It is a schematic diagram of the three-dimensional structure of the back-reflective circularly polarized microwave detection antenna according to another optimized embodiment of the above-mentioned variant embodiment of the present invention.

[0058] Figure 8B It is a schematic cross-sectional structural diagram of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned optimized embodiment of the present invention.

[0059] Figure 8C It is a schematic diagram of the radiation direction of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned optimized embodiment of the present invention.

[0060] Fig. 9A The figure is a schematic structural diagram of a combination of an independent reference ground and a radiation source having a circular polarization mode according to the present invention in an independent state.

[0061] Fig. 9B It is a schematic diagram of the radiation direction of the above combination in an independent state according to the present invention.

[0062] Fig. 10A It is a three-dimensional structural schematic diagram of the back-reflective circularly polarized microwave detection antenna according to another variant embodiment of the above combination using the above variant embodiment of the present invention.

[0063] Fig. 10BIt is a schematic cross-sectional structural diagram of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned variant embodiment of the present invention.

[0064] Fig. 10C It is a schematic diagram of the radiation direction of the back-reflective circularly polarized microwave detection antenna according to the above-mentioned variant embodiment of the present invention. DETAILED DESCRIPTION

[0065] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0066] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0067] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0068] Referring to the accompanying drawings of the present invention FIG. 2A to FIG. 8C , which corresponds to FIG. 4A to FIG. 8C , the structures and radiation patterns of the back-reflective circularly polarized microwave detection antenna 10 according to different embodiments of the present invention are respectively illustrated; corresponding to Figure 3A and Figure 3B , a circularly polarized antenna body 11 of the back-reflective circularly polarized microwave detection antenna 10 is independently illustrated, that is, Figure 3A and Figure 3B The structure and radiation pattern of an implementation structure of the circularly polarized antenna body 11 of the back-reflective circularly polarized microwave detection antenna 10 of the present invention in an independent state are illustrated to help understand and assist in describing the present invention without constituting a limitation on the back-reflective circularly polarized microwave detection antenna 10 of the present invention; corresponding to Figure 2A and Figure 2B ,exist Figure 3AThe optimized structure of the circularly polarized antenna body 11 in an independent state shown in the figure is independently illustrated for the purpose of understanding and assisting in describing the present invention and does not constitute a limitation on the back-reflective circularly polarized microwave detection antenna 10 of the present invention.

[0069] Specifically, corresponding to Figure 3A and Figure 3B The circularly polarized antenna body 11 includes a reference ground 111 and a radiation source 112, wherein the radiation source 112 is arranged in a state spaced from the reference ground 111 to form a radiation gap 113 between the radiation source 112 and the reference ground 111, so that when the radiation source 112 is fed, the radiation source 112 can couple with the reference ground 111 and form a radiation space 100 from the radiation gap 113, wherein the radiation space 100 corresponds to the electromagnetic radiation coverage of the circularly polarized antenna body 11 and corresponds to the actual detection space of the circularly polarized antenna body 11 in an independent state. Specifically, the radiation space 100 has a maximum radiation direction in the direction from the reference ground 111 to the radiation source 112, and the direction from the reference ground 111 to the radiation source 112 is the target detection direction of the circularly polarized antenna body 11 in an independent state, corresponding to the Z-axis direction in the figure. The radiation space 100 is divided by the plane where the radiation source 112 is located (i.e., the plane defined by the X-axis and the Y-axis in the figure), and the radiation space 100 has a side lobe 101 which is located in the opposite direction of the target detection direction, with the plane where the radiation source 112 is located as the boundary, that is, the side lobe 101 corresponds to the electromagnetic radiation of the circularly polarized antenna body 11 in the reverse direction of the target detection direction, with the plane where the radiation source 112 is located as the boundary. It can be understood that the electromagnetic radiation of the circularly polarized antenna body 11 in the reverse direction of the target detection direction is the electromagnetic radiation of the non-target detection space, that is, the side lobe 101 is to avoid the adverse factors of motion interference and electromagnetic interference of the non-target detection space. The suppression of the side lobe 101 of the radiation space 100 can improve the adaptability of the circularly polarized antenna body 11 to the non-target detection space, and the reliability of detection of the corresponding target detection space.

[0070] Furthermore, the radiation source 112 of the circularly polarized antenna body 11 is circularly polarized so as to have a circularly polarized polarization mode when fed, correspondingly making the electromagnetic radiation of the circularly polarized antenna body 11 have a circularly polarized form, wherein based on the orthogonality of the circularly polarized electromagnetic radiation, the anti-attenuation characteristics and anti-rain and fog interference capabilities of the circularly polarized antenna body 11 can be improved. However, at the same time, limited by the orthogonality of the circularly polarized electromagnetic radiation, the current Doppler microwave detection device that detects the movement of objects based on the Doppler effect principle of electromagnetic waves and uses a transmitter and receiver integrated design is considered to be unable to use circularly polarized electromagnetic waves.

[0071] Specifically, corresponding to Figure 3A In the illustrated embodiment of the circularly polarized antenna body 11, the radiation source 112 includes a plurality of radiation elements 1121, wherein each radiation element 1121 is linearly polarized, wherein the direction from the reference ground 111 to the radiation source 112 is the axial direction of the circularly polarized antenna body 11, and the arrangement of each radiation element 1121 satisfies the linear polarization, and the polarization direction of each radiation element 1121 is distributed in the same circumferential direction of the axial direction, thereby forming a circularly polarized arrangement of the radiation elements 1121 and circularly polarizing the radiation source 112.

[0072] In particular, each of the radiating elements 1121 has a feeding point 11211 deviated from the physical center point of the radiating element 1121, wherein each of the radiating elements 1121 is arranged symmetrically with respect to the line connecting the physical center point of the radiating element 1121 and the feeding point 11211, and the polarization direction of each of the radiating elements 1121 is the direction of the line connecting the feeding point 11211 to the physical center point of the radiating element 1121, wherein based on the above-mentioned circular polarization arrangement of each of the radiating elements 1121, the feeding point 1121 and the physical center point of each of the radiating elements 1121 are arranged at intervals in the circumferential direction of the axial direction.

[0073] Furthermore, each of the radiating elements 1121 is arranged at a physical center point and is electrically connected to the reference ground 111. Specifically, each of the radiating elements 1121 is arranged at a physical center point and is electrically connected to the reference ground 111 in the form of a metallized via, thereby forming a stable and consistent electrical connection relationship between each of the radiating elements 1121 and the reference ground 111, which is beneficial to improving the anti-interference capability of the circularly polarized antenna body 11 by narrowing the bandwidth of the circularly polarized antenna body 11.

[0074] In particular, in this implementation structure of the circularly polarized antenna body 11, each of the radiating elements 1121 is concavely arranged in a direction perpendicular to the line connecting the physical center point of the radiating element 1121 and the feeding point 11211 and in a direction toward the physical center point of the radiating element 1121, so as to maintain the circumference of the radiating element 1121 while facilitating reducing the size of the radiating element 1121, and suppressing the side lobe 101 of the circularly polarized antenna body 11 in a manner that balances the potential distribution of the radiating element 1121.

[0075] It is worth mentioning that the circularly polarized antenna body 11 further includes a radiation source substrate 114, wherein the radiation source substrate 114 is disposed between the radiation source 112 and the reference ground 111 to form and support a structural state in which the radiation source 112 is spaced apart from the reference ground 111. In other words, the radiation gap 113 is not a description of a gap in the structure of the circularly polarized antenna body 11, but rather a description of an electrical medium between the radiation source 112 and the reference ground 111 based on a state in which the radiation source 112 is fed, and does not constitute a limitation on the structure between the radiation source 112 and the reference ground 111. The radiation source substrate 114 of a corresponding material may be fully or partially filled between the radiation source 112 and the reference ground 111 to form and support a structural state in which the radiation source 112 is spaced apart from the reference ground 111.

[0076] In particular, it is adapted to the structural design of the back-reflective circularly polarized microwave detection antenna 10. In this implementation structure of the circularly polarized antenna body 11, the reference ground 111 is set to be an annular sheet structure, corresponding to Figure 3B Based on the annular sheet structure of the reference ground 111, the side lobe 101 of the radiation space 100 of the circularly polarized antenna body 11 in an independent state has a larger volume share, and the corresponding circularly polarized antenna body 11 has a larger side lobe 101 in an independent state, which is not conducive to the adaptability of the circularly polarized antenna body 11 to the non-target detection space and the reliability of detection of the corresponding target detection space.

[0077] In contrast, referring to the accompanying drawings of the present invention, Figure 2A and Figure 2B Indicated, in Figure 3A An optimized structure of the circularly polarized antenna body 11 in an independent state is independently illustrated, wherein in this optimized structure of the circularly polarized antenna body 11, the reference ground 111 is set to a circular sheet structure, corresponding to Figure 2B Based on the optimization of transforming the reference ground 111 from an annular sheet structure to a circular sheet structure, the side lobe 101 of the radiation space 100 is reduced, which is beneficial to improve the adaptability of the circularly polarized antenna body 11 to the non-target detection space and the reliability of detection of the corresponding target detection space.

[0078] However, even the above-mentioned optimized structure of the circularly polarized antenna body 11 of the back-reflective circularly polarized microwave detection antenna 10 of the present invention in an independent state does not show obvious suppression of the side lobe 101 compared with the radiation space 100P of the microwave detection module 10P of the existing planar radiation source structure, and is limited by the orthogonality of the rotational direction of circularly polarized electromagnetic radiation, the circularly polarized antenna body 11 cannot adopt an integrated transceiver design in an independent state.

[0079] Based on the above-mentioned structure of the circularly polarized antenna body 11 in an independent state and the description of the radiation space 100, further reference is made to the accompanying drawings of the specification of the present invention. FIG. 4A to FIG. 8C , the structure and radiation pattern of the back-reflective circularly polarized microwave detection antenna 10 according to different embodiments of the present invention are respectively illustrated, wherein by back-reflecting the electromagnetic radiation of the back-reflective circularly polarized microwave detection antenna 10 from the reference ground 111 to the radiation source 112, relative to the traditional antenna with the reference ground 111 to the radiation source 112 as the target detection direction and the circularly polarized antenna body 11 in an independent state, the target detection direction of the back-reflective circularly polarized microwave detection antenna 10 from the radiation source 112 to the reference ground 111 (corresponding to the Z-axis direction in the figure) is reversely formed, and a reverse direction of the target detection direction is formed The suppressed radiation space 100, that is, the sublobe 101 of the radiation space 100 located in the reverse direction of the target detection direction with the plane where the radiation source 112 is located (that is, the plane defined by the X-axis and the Y-axis in the figure) as the boundary, correspondingly reduces the electromagnetic radiation of the back-reflecting circularly polarized microwave detection antenna 10 in the non-target detection space in the reverse direction of the target detection direction, thereby facilitating the avoidance of motion interference and electromagnetic interference of the non-target detection space in the reverse direction of the target detection direction, and improving the adaptability of the back-reflecting circularly polarized microwave detection antenna 10 to the non-target detection space and the reliability of detection of the corresponding target detection space.

[0080] It is worth mentioning that the side lobe 101 of the back-reflective circularly polarized microwave detection antenna 10 is suppressed, which is beneficial to avoiding self-excited interference caused by multiple reflections of the electromagnetic radiation corresponding to the side lobe 101 in the electromagnetic shielding environment of the non-target detection space, thereby improving the adaptability of the back-reflective circularly polarized microwave detection antenna 10 to the non-target detection space and the reliability of detection of the corresponding target detection space.

[0081] Furthermore, since the electromagnetic radiation of the circularly polarized antenna body 11 is in a circularly polarized form, the anti-attenuation characteristics and anti-rain and fog interference capabilities of the back-reflective circularly polarized microwave detection antenna 10 are improved, which is conducive to meeting the high detection accuracy requirements for detecting moving objects and adapting to outdoor detection scenarios.

[0082] In addition, based on the orthogonality of the rotational direction of circularly polarized electromagnetic radiation, the anti-multipath reflection interference capability of the back-reflective circularly polarized microwave detection antenna 10 is improved, and the correlation between the detection data obtained by the back-reflective circularly polarized microwave detection antenna 10 based on the Doppler effect principle and the moving object is improved, which is beneficial to improve the accuracy of the feedback of the detection data obtained by the back-reflective circularly polarized microwave detection antenna 10 based on the Doppler effect principle on the moving object.

[0083] Furthermore, the correlation and accuracy of the detection data obtained by the back-reflective circularly polarized microwave detection antenna 10 based on the principle of Doppler effect and the feedback of the moving object are improved, and the detection accuracy of the back-reflective circularly polarized microwave detection antenna 10 is improved, which is beneficial to improve the accuracy of the back-reflective circularly polarized microwave detection antenna 10 in detecting weak movements, so that the back-reflective circularly polarized microwave detection antenna 10 is suitable for detecting weak movements such as human movement, micro-movement, breathing and heartbeat, and is used for human presence detection.

[0084] Specifically, the back-reflective circularly polarized microwave detection antenna 10 has a back-reflection cavity 120 formed in the direction from the reference ground 111 to the radiation source 112, wherein the back-reflection cavity 120 has an electromagnetic radiation port 121 in the direction from the radiation source 112 to the reference ground 111, and the circularly polarized antenna body 10 is correspondingly arranged in a state where the radiation source 112 is facing away from the electromagnetic radiation port 121, thereby forming back-reflection of the electromagnetic radiation of the back-reflective circularly polarized microwave detection antenna 10 from the reference ground 111 to the radiation source 112.

[0085] In particular, based on the back-reflection of the electromagnetic radiation with an initial rotational direction from the reference ground 111 to the direction of the radiation source 112 by the back-reflection circularly polarized microwave detection antenna 10, the electromagnetic radiation of the back-reflection circularly polarized microwave detection antenna 10 in the target detection direction is reversed relative to the initial rotational direction, and the electromagnetic echo formed by the first reflection of the corresponding electromagnetic radiation by the corresponding moving object located in the target detection direction has the initial rotational direction, and due to the structural relationship that the circularly polarized antenna body 10 is arranged in a state where the radiation source 112 is facing away from the electromagnetic radiation port 121, the electromagnetic echo with the initial rotational direction satisfies the conditions of being received by the radiation source 112 in both the transmission path and the rotational direction.

[0086] That is to say, by setting the back-reflection cavity 120 in the direction from the reference ground 111 to the radiation source 112, and setting the circularly polarized antenna body 10 with the radiation source 112 facing away from the electromagnetic radiation port 121, the back-reflection circularly polarized microwave detection antenna 10 can retain the orthogonality of the circularly polarized electromagnetic radiation to improve the anti-interference characteristics, while adopting an integrated transceiver design and being applied to microwave detection based on the Doppler effect principle.

[0087] Furthermore, the back-reflective circularly polarized microwave detection antenna 10 includes a back-reflective cavity 12 , wherein the back-reflective cavity 120 is formed in the back-reflective cavity 12 .

[0088] In particular, when the circularly polarized antenna body 11 is in a state where the radiation source 112 is facing away from the electromagnetic radiation port 121, the reference ground 111 of the circularly polarized antenna body 11 is arranged to be electrically connected to the back-reflection cavity 12, including but not limited to a direct contact electrical connection relationship, and an electrical connection relationship formed by the connection of corresponding power-carrying circuits.

[0089] Furthermore, in these embodiments of the present invention, when the circularly polarized antenna body 11 is in a state where the radiation source 112 faces away from the electromagnetic radiation port 121 , the electromagnetic radiation port 121 is formed on the circularly polarized antenna body 11 based on an annular sheet structure design of the reference ground 111 .

[0090] In particular, the aperture d of the electromagnetic radiation port 121 is set to satisfy λ / 8≤d≤λ, where λ is a wavelength parameter corresponding to the frequency parameter of the back-reflective circularly polarized microwave detection antenna 10 .

[0091] It can be understood that in some other embodiments of the present invention, the electromagnetic radiation port 121 is formed in the back-reflection cavity 12, and when the electromagnetic radiation port 121 is formed in the back-reflection cavity 12, the part of the back-reflection cavity 12 facing away from the radiation source 112 has electrical characteristics equivalent to those of the reference ground 111 and is allowed to be set to be integrally formed with the reference ground 111 as an integral sheet structure, which also conforms to the structural description that the electromagnetic radiation port 121 is formed in the circularly polarized antenna body 11 based on the annular sheet structure design of the reference ground 111, and the present invention is not limited to this.

[0092] Furthermore, the back-reflection cavity 12 has an annular side cavity wall 122, and a bottom wall 123 facing the electromagnetic radiation port 121 to form the back-reflection cavity 120 defined by the annular side cavity wall 122 and the bottom wall 123, wherein the circularly polarized antenna body 10 is in a state where the radiation source 112 is facing away from the electromagnetic radiation port 121, corresponding to a state where the direction from the bottom wall 123 to the electromagnetic radiation port 121 is opposite to the direction from the reference ground 111 to the radiation source 112, wherein the central axis of the annular side cavity wall 122 is defined, that is, the annular side cavity wall 122 is perpendicular to The section curve on the plane of the central axis of the annular side cavity wall 122 is annular, wherein the central axis direction of the annular side cavity wall 122 is the height direction of the annular side cavity wall 122, the height parameter H of the annular side cavity wall 122 satisfies λ / 8≤H≤λ, and the length of the section of the annular side cavity wall 122 by a straight line perpendicularly intersecting the central axis of the annular side cavity wall 122 is the diameter D of the annular side cavity wall 122, and the diameter D of the annular side cavity wall 122 satisfies D=λ within an error range of 25%, that is, the diameter D of the annular side cavity wall 122 satisfies 3λ / 4≤D≤5λ / 4.

[0093] In particular, based on the circular polarization setting of the radiation source 112, the annular side cavity wall 122 of the back-reflection cavity 12 is preferably set to be a circular ring, and the section curve of the annular side cavity wall 122 on the plane perpendicular to the central axis of the annular side cavity wall 122 is circular, and the electromagnetic radiation port 121 is preferably set to be coaxial with the annular side cavity wall 122, that is, the central axis of the annular side cavity wall 122 passes through the physical center of the electromagnetic radiation port 121 and is perpendicular to the plane where the electromagnetic radiation port 121 is located.

[0094] Referring to the accompanying drawings of the present invention Figure 4A , Figure 4B as well as Figure 4C In this embodiment of the present invention, the back reflection cavity 12 is provided with the bottom wall 123 having a planar state, corresponding to Figure 4C , compared to Figure 3B The radiation space 100 of the circularly polarized antenna body 11 in an independent state is shown, and Figure 2B The radiation space 100 of the circularly polarized antenna body 11 shown in the figure has an optimized structure in an independent state, and the side lobe 101 of the radiation space 100 of the back-reflective circularly polarized microwave detection antenna 10 is significantly suppressed.

[0095] Further reference is made to the accompanying drawings of the present invention. Figure 5A , Figure 5B as well as Figure 5CIn this embodiment of the present invention, the back reflection cavity 120 has a concave shape design from the radiation source 112 to the reference ground 111, and the corresponding back reflection cavity 12 is designed to be convex in the direction from the radiation source 112 to the reference ground 111, that is, the back reflection cavity 12 is provided with the bottom wall 123 which is convex in the direction from the radiation source 112 to the reference ground 111, including but not limited to convex surfaces in conical surface shapes and arc surface shapes.

[0096] based on Figure 5C and Figure 4C By comparison, the convex design of the back-reflection cavity 12 in the direction from the radiation source 112 to the reference ground 111 shows an effect of improving the gain of the back-reflection circularly polarized microwave detection antenna 10.

[0097] Further reference is made to the accompanying drawings of the present invention. Fig. 6A , Figure 6B as well as Figure 6C In this embodiment of the present invention, the back-reflective circularly polarized microwave detection antenna 10 is relative to Figure 4A and Figure 4B The back-reflective circularly polarized microwave detection antenna 10 further includes a metal ring 13 and has an electromagnetic radiation channel 130 defined by the metal ring 13, wherein the electromagnetic radiation channel 130 extends from the electromagnetic radiation port 121 in a radially expanded state, and the metal ring 13 is horn-shaped and connected to the electromagnetic radiation port 121 at the narrow end of the horn shape, wherein based on Figure 6C and Figure 4C , the setting of the metal ring 13 presents a further suppression effect on the side lobe 101 of the radiation space 100 located in the non-target detection space.

[0098] Further reference is made to the accompanying drawings of the present invention. Fig. 7A , Figure 7B as well as Figure 7C In this embodiment of the present invention, the back-reflective circularly polarized microwave detection antenna 10 is relative to Figure 5A and Figure 5B The back-reflective circularly polarized microwave detection antenna 10 further includes a metal ring 13 and has an electromagnetic radiation channel 130 defined by the metal ring 13, wherein the electromagnetic radiation channel 130 extends from the electromagnetic radiation port 121 in a radially expanded state, and the metal ring 13 is horn-shaped and connected to the electromagnetic radiation port 121 at the narrow end of the horn shape, wherein based on Figure 7C and Figure 5CBy comparison, the setting of the metal ring 13 shows a further suppression effect on the side lobe 101 of the radiation space 100 located in the non-target detection space and an improvement effect on the gain of the back-reflective circularly polarized microwave detection antenna 10.

[0099] That is to say, the combination of the raised design of the back-reflection cavity 12 in the direction from the radiation source 112 to the reference ground 111 and the setting of the metal ring 13 presents an enhanced effect of suppressing the side lobe 101 of the radiation space 100 located in the non-target detection space and enhancing the gain of the back-reflection circularly polarized microwave detection antenna 10, rather than simply presenting the superposition of the effect of suppressing the side lobe 101 of the radiation space 100 located in the non-target detection space and the effect of enhancing the gain of the back-reflection circularly polarized microwave detection antenna 10.

[0100] Correspondingly, refer to the accompanying drawings of the present invention. Figure 7C Based on the combination of the raised design of the back-reflection cavity 12 in the direction from the radiation source 112 to the reference ground 111 and the setting of the metal ring 13, the back-reflection cavity 12 is located in the gap area of ​​the radiation space 100, that is, the back-reflection circularly polarized microwave detection antenna 10 is in an ideal state of "no side lobes".

[0101] Further reference is made to the accompanying drawings of the present invention. Fig. 8A , Figure 8B as well as Figure 8C In this embodiment of the present invention, the back-reflective circularly polarized microwave detection antenna 10 is relative to Figure 5A and Figure 5B The back-reflective circularly polarized microwave detection antenna 10 further includes a dielectric ring 14 and has an annular channel 140 defined by the dielectric ring 14, wherein the dielectric ring 14 is configured to have a relative dielectric constant greater than or equal to 5, wherein the annular channel 140 extends from the periphery of the electromagnetic radiation port 121 and communicates with the back-reflection cavity 120 through the electromagnetic radiation port 121, wherein based on Figure 8C and Figure 5C By comparison, the setting of the dielectric ring 14 shows an effect of improving the gain of the back-reflective circularly polarized microwave detection antenna 10.

[0102] It is worth mentioning that in some embodiments of the present invention, the electromagnetic radiation port 121 is formed in the back-reflection cavity 12, wherein based on the structural relationship that the circularly polarized antenna body 10 is arranged with the radiation source 112 facing away from the electromagnetic radiation port 121, and the reference ground 111 of the circularly polarized antenna body 11 is arranged to be electrically connected to the back-reflection cavity 12, the part of the back-reflection cavity 12 facing away from the radiation source 112, that is, the part where the electromagnetic radiation port 121 is formed, has electrical characteristics equivalent to the reference ground 111. Therefore, the circularly polarized antenna body 11 is allowed to be arranged with the part of the back-reflection cavity 12 facing away from the radiation source 112 as the reference ground 111, corresponding to the structural description that the part of the back-reflection cavity 12 facing away from the radiation source 112 and the reference ground 111 are integrally formed as a whole, and conforms to the structural description that the electromagnetic radiation port 121 is formed in the circularly polarized antenna body 11 based on the annular sheet structure design of the reference ground 111.

[0103] In particular, when the electromagnetic radiation port 121 is formed in the back-reflection cavity 12, the part of the back-reflection cavity 12 facing away from the radiation source 112, that is, the part where the electromagnetic radiation port 121 is formed, is also allowed to be set independently of the circularly polarized antenna body 11, that is, when the part of the back-reflection cavity 12 facing away from the radiation source 112 is described as the reference ground 111 of the circularly polarized antenna body 11, the circularly polarized antenna body 11 includes the reference ground 111 formed with the electromagnetic radiation port 121 and another independent reference ground independent of the reference ground 111, wherein on the basis of the circularly polarized setting of the radiation source 112, the specific structural designs of the independent reference ground and the radiation source 112 are diverse, and the present invention is not limited to this.

[0104] That is to say, in the state where the electromagnetic radiation port 121 is formed in the back reflection cavity 12, when the portion of the back reflection cavity 12 facing away from the radiation source 112 is described as the reference ground 111 of the circularly polarized antenna body 11, the combination of the independent reference ground and the radiation source 112 capable of forming circular polarization, and the combination of the reference ground 111 and the radiation source 112 capable of forming circular polarization do not constitute a restriction on the circularly polarized antenna body 11, based on the corresponding shape setting of the back reflection cavity 120, and setting the radiation source 112 in the back reflection cavity 120 facing away from the electromagnetic radiation port 121, The circularly polarized antenna body 11 corresponding to any combination of the independent reference ground and the radiation source 112 having a circular polarization polarization mode, and the circularly polarized antenna body 11 corresponding to any combination of the reference ground 111 and the radiation source 112 having a circular polarization polarization mode, can reversely form the target detection direction of the back-reflecting circularly polarized microwave detection antenna 10 from the radiation source 112 to the reference ground 111 relative to a traditional antenna that takes the reference ground 111 to the radiation source 112 as the target detection direction, and form the radiation space 100 that is suppressed in the reverse direction of the target detection direction.

[0105] For example, referring to the accompanying drawings of the present invention, Figures 9A to 10C ,in Fig. 9A and Fig. 9B The structure and radiation pattern of a combination of the independent reference ground 115 and the radiation source 112 in an independent state are respectively illustrated, wherein the corresponding Fig. 10A and Fig. 10B , based on the circularly polarized antenna body 11 corresponding to the above combination, corresponds to Figure 5A and Figure 5B The structure of the back-reflective circularly polarized microwave detection antenna 10 of a variant embodiment of the embodiment is shown schematically, wherein Fig. 10C The radiation pattern of the back-reflective circularly polarized microwave detection antenna 10 is illustrated.

[0106] Specifically, corresponding to Fig. 9A and Fig. 9BIn the above combination of the independent reference ground 115 and the radiation source 112 having a circular polarization mode, the radiation source 112 is configured as a spiral conductor to form a circular polarization setting for the radiation source 112, wherein the independent reference ground 115 is configured as a sheet conductor, wherein the radiation source 112 is arranged on one side of the independent reference ground 115 and extends spirally in a direction perpendicular to the independent reference ground 115, so that in the independent state of the above combination, when the radiation source 112 is fed, the radiation source 112 can be coupled with the independent reference ground 115 to form a radiation space 100, wherein the radiation space 100 corresponds to the actual detection space of the above combination in the independent state, specifically , the radiation space 100 has a maximum radiation direction in the direction from the independent reference ground 115 to the radiation source 112, and the direction from the independent reference ground 115 to the radiation source 112 is the target detection direction of the above combination in an independent state, corresponding to the Z-axis direction in the figure, wherein the radiation space 100 is divided by the plane where the independent reference ground 115 is located (that is, the plane defined by the X-axis and the Y-axis in the figure), and the radiation space 100 has a side lobe 101 located in the opposite direction of the target detection direction with the plane where the independent reference ground 115 is located as the boundary, that is, the side lobe 101 corresponds to the electromagnetic radiation of the above combination in the opposite direction of the target detection direction with the plane where the independent reference ground 115 is located as the boundary.

[0107] Further, referring to the accompanying drawings of the present invention, FIG. 10A to FIG. 10C The back-reflective circularly polarized microwave detection antenna 10 adopts the circularly polarized antenna body 11 corresponding to the above combination, that is, the circularly polarized antenna body 11 includes the reference ground 111 formed with the electromagnetic radiation port 121, the independent reference ground 115 independent of the reference ground 111, and the radiation source 112.

[0108] Specifically, the back-reflection circularly polarized microwave detection antenna 10 has the back-reflection cavity 120 formed in the direction from the reference ground 111 to the radiation source 112, wherein the back-reflection cavity 120 has the electromagnetic radiation port 121 in the direction from the radiation source 112 to the reference ground 111, wherein the back-reflection cavity 120 includes the back-reflection cavity 12, wherein the back-reflection cavity 120 and the electromagnetic radiation port 121 are formed in the back-reflection cavity 12, corresponding to the state in which the circularly polarized antenna body 10 is facing the electromagnetic radiation port 121 with the radiation source 112 back to the state, that is, the circularly polarized antenna body 10 is facing the electromagnetic radiation port 121 with the independent reference ground 115, so as to form a back-reflection of the electromagnetic radiation of the back-reflection circularly polarized microwave detection antenna 10 from the reference ground 111 to the radiation source 112.

[0109] It is worth mentioning that in this variant embodiment of the present invention, the electromagnetic radiation port 121 is formed in the back-reflection cavity 12, wherein based on the structural relationship that the circularly polarized antenna body 10 is arranged with the radiation source 112 facing away from the electromagnetic radiation port 121, and the reference ground 111 of the circularly polarized antenna body 11 is arranged to be electrically connected to the back-reflection cavity 12, the part of the back-reflection cavity 12 facing away from the radiation source 112, that is, the part where the electromagnetic radiation port 121 is formed, has electrical characteristics equivalent to those of the reference ground 111 and is described as the reference ground 111, corresponding to the structural description that the part of the back-reflection cavity 12 facing away from the radiation source 112 and the reference ground 111 are integrally formed as a whole, and conforms to the structural description that the electromagnetic radiation port 121 is formed in the circularly polarized antenna body 11 based on the annular sheet structure design of the reference ground 111.

[0110] Similarly, the back-reflection cavity 12 has the annular side cavity wall 122, and the bottom wall 123 facing the electromagnetic radiation port 121 to form the back-reflection cavity 120 defined by the annular side cavity wall 122 and the bottom wall 123. The circularly polarized antenna body 10 is in a state where the radiation source 112 is facing away from the electromagnetic radiation port 121, corresponding to a state where the direction from the bottom wall 123 to the electromagnetic radiation port 121 is opposite to the direction from the reference ground 111 to the radiation source 112.

[0111] Corresponds to Fig. 10C , compared to Fig. 9B In the radiation space 100 in an independent state of the illustrated combination of the independent reference ground 115 and the radiation source 112 , the side lobe 101 of the radiation space 100 of the back-reflective circularly polarized microwave detection antenna 10 is significantly suppressed.

[0112] It is worth mentioning that in this variant embodiment of the present invention, the conical concave shape of the back reflection cavity 120 in the direction from the radiation source 112 to the reference ground 111 is formed by a solid cone structure corresponding to the bottom wall 123 of the back reflection cavity 12, which is different from Figure 5A and Figure 5BThe back-reflection cavity 12 shown in the figure corresponds to the hollow cone structure of the bottom wall 123, that is, in these embodiments of the present invention, the specific form of the back-reflection cavity 12 forming the back-reflection cavity 120 does not constitute a limitation to the present invention, based on the corresponding shape setting of the back-reflection cavity 120, and setting the radiation source 112 in the back-reflection cavity 120 back to the electromagnetic radiation port 121, the target detection direction of the back-reflection circularly polarized microwave detection antenna 10 from the radiation source 112 to the reference ground 111 can be formed, and the radiation space 100 suppressed in the reverse direction of the target detection direction can be formed.

[0113] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0114] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A back-reflecting circularly polarized microwave detection antenna, characterized in that: include: a circularly polarized antenna body, wherein the circularly polarized antenna body comprises a radiation source and a reference ground, wherein the radiation source is spaced apart from the reference ground, wherein the radiation source is circularly polarized; and A back reflection cavity, wherein the back reflection cavity has a back reflection cavity formed in the direction from the reference ground to the radiation source, wherein the back reflection cavity has an electromagnetic radiation port in the direction from the radiation source to the reference ground, wherein the circularly polarized antenna body is arranged in the back reflection cavity in a state where the radiation source is facing away from the electromagnetic radiation port, wherein the back reflection cavity has an annular side cavity wall, and a bottom wall opposite to the electromagnetic radiation port to form the back reflection cavity defined by the annular side cavity wall and the bottom wall, wherein the state where the circularly polarized antenna body is in a state where the radiation source is facing away from the electromagnetic radiation port corresponds to a state where the direction from the bottom wall to the electromagnetic radiation port is opposite to the direction from the reference ground to the radiation source.

2. According to the back-reflective circularly polarized microwave detection antenna according to claim 1, the central axis of the annular side cavity wall is defined corresponding to a plane perpendicular to the central axis of the annular side cavity wall, and the section curve of the annular side cavity wall is annular, wherein the length of the section of the annular side cavity wall by a straight line perpendicularly intersecting the central axis of the annular side cavity wall is the diameter D of the annular side cavity wall, and the diameter D of the annular side cavity wall satisfies 3λ / 4≤D≤5λ / 4, wherein λ is a wavelength parameter corresponding to the frequency parameter of the back-reflective circularly polarized microwave detection antenna.

3. The back-reflective circularly polarized microwave detection antenna according to claim 2, wherein the reference ground is set to an annular sheet structure, so that the electromagnetic radiation port is formed based on the annular sheet structure design of the reference ground. 4 . The back-reflective circularly polarized microwave detection antenna according to claim 3 , wherein the aperture D of the electromagnetic radiation port is set to satisfy λ / 8≤D≤λ.

5. The back-reflective circularly polarized microwave detection antenna according to claim 4, wherein the central axis direction of the annular side cavity wall is the height direction of the annular side cavity wall, and the height parameter H of the annular side cavity wall satisfies λ / 8≤H≤λ.

6. The back-reflective circularly polarized microwave detection antenna according to claim 5, wherein the annular side cavity wall of the back-reflective cavity is configured to be annular, and corresponding to a plane perpendicular to the central axis of the annular side cavity wall, the cut curve of the annular side cavity wall is circular.

7. The back-reflective circularly polarized microwave detection antenna according to claim 6, wherein the electromagnetic radiation port is arranged to be coaxial with the annular side cavity wall, that is, the central axis of the annular side cavity wall passes through the physical center of the electromagnetic radiation port and is perpendicular to the plane where the electromagnetic radiation port is located.

8. The back-reflective circularly polarized microwave detection antenna according to claim 7, wherein the back-reflection cavity has a concave shape design in the direction from the radiation source to the reference ground, and the corresponding back-reflection cavity is provided with the bottom wall in a convex state in the direction from the radiation source to the reference ground. 9 . The back-reflective circularly polarized microwave detection antenna according to claim 8 , wherein the back-reflective cavity is provided with the bottom wall having a conical surface shape in the direction from the radiation source to the reference ground.

10. The back-reflective circularly polarized microwave detection antenna according to claim 9, wherein the back-reflective circularly polarized microwave detection antenna further comprises a metal ring and has an electromagnetic radiation channel defined by the metal ring, wherein the electromagnetic radiation channel extends from the electromagnetic radiation port in a radially expanded state, corresponds to the metal ring and is horn-shaped and connected to the electromagnetic radiation port at the narrow end of the horn.

11. The back-reflective circularly polarized microwave detection antenna according to claim 9, wherein the back-reflective circularly polarized microwave detection antenna further comprises a dielectric ring and has an annular channel defined by the dielectric ring, wherein the dielectric ring is configured to have a relative dielectric constant greater than or equal to 5, wherein the annular channel extends from the periphery of the electromagnetic radiation port and is connected to the back-reflection cavity through the electromagnetic radiation port. 12 . The back-reflective circularly polarized microwave detection antenna according to claim 9 , wherein the reference ground is integrally formed in the back-reflective cavity.

13. A back-reflecting circularly polarized microwave detection antenna according to any one of claims 1 to 12, wherein the radiation source comprises a plurality of radiation elements, wherein each of the radiation elements has a feeding point deviated from the physical center point of the radiation element, wherein each of the radiation elements is arranged symmetrically with respect to a line connecting the physical center point of the radiation element and the feeding point, wherein the direction from the reference ground to the radiation source is the axial direction of the circularly polarized antenna body, and the feeding points and physical center points of each of the radiation elements are arranged at intervals in the circumferential direction of the axial direction to form a circularly polarized arrangement of the radiation elements and the radiation source is circularly polarized.

14. The back-reflective circularly polarized microwave detection antenna according to claim 13, wherein each of the radiation elements is arranged at a physical center point and is electrically connected to the reference ground. 15 . The back-reflective circularly polarized microwave detection antenna according to claim 14 , wherein each of the radiation elements is arranged at a physical center point and is electrically connected to the reference ground in the form of a metallized via.

16. The back-reflective circularly polarized microwave detection antenna according to claim 15, wherein each of the radiation elements is concavely arranged in a direction perpendicular to a line connecting a physical center point of the radiation element and the feeding point and in a direction toward the physical center point of the radiation element.

17. A back-reflective circularly polarized microwave detection antenna according to claim 16, wherein the circularly polarized antenna body further comprises a radiation source substrate, wherein the radiation source substrate is arranged between the radiation source and the reference ground to form and support a structural state in which the radiation source and the reference ground are spaced apart.

18. The back-reflective circularly polarized microwave detection antenna according to any one of claims 1 to 11, wherein the reference ground is integrally formed in the back-reflective cavity.

19. The back-reflecting circularly polarized microwave detection antenna according to claim 18, wherein the circularly polarized antenna body further comprises an independent reference ground, wherein the independent reference ground is configured as a sheet-shaped conductor, wherein the radiation source is configured on one side of the independent reference ground and spirally extends in a direction perpendicular to the independent reference ground to form a circular polarization setting for the radiation source.

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