A W-band low-sidelobe corrugated horn antenna

Abstract

The application discloses a W-band low-sidelobe corrugated horn antenna, which comprises a waveguide input interface, a front steady mode part, a mode conversion part, a steady radiation part, a diffraction suppression aperture part and a non-uniform corrugated slot array.

Description

Technical Field

[0001] This invention relates to the field of microwave and millimeter-wave antenna technology, and more particularly to a W-band low sidelobe corrugated horn antenna. Background Technology

[0002] With the rapid development of millimeter-wave radar technology, the W-band (75-110GHz), especially the 93GHz band, has been widely used in fields such as foreign object detection on airport runways, high-resolution imaging, satellite communication feed systems, and meteorological monitoring due to its significant advantages such as short wavelength, large usable bandwidth, and high target resolution. In these applications, to achieve accurate long-range detection, antennas typically need to have a high gain of over 30dBi and excellent beam directivity.

[0003] Traditional W-band horn antennas generally employ a uniform cross-section or a simple linearly open metal cone structure. To further suppress cross-polarization components and improve the symmetry of the E-plane and H-plane radiation patterns, corrugated horn antennas are widely used in existing technologies. This involves machining a series of annular corrugated grooves of constant depth on the inner wall of the antenna. This type of equal-depth corrugated structure generates specific surface impedance through the corrugated grooves, which can achieve mixed-mode excitation to a certain extent, thereby obtaining a more symmetrical radiation pattern and a lower cross-polarization level than a bare-wall horn.

[0004] However, the aforementioned equal-depth corrugated horn antenna still has significant limitations in practical applications in the W-band. First, when the gain requirement increases to above 30 dBi, the antenna aperture size inevitably increases. Electromagnetic waves will generate strong diffraction effects at the aperture edges, leading to a significant increase in sidelobe levels. Typically, the first sidelobe level can only be controlled to around -20 dB. In strong clutter environments such as airport runway foreign object detection, the higher sidelobes will receive reflected signals from objects like light boxes and fences on both sides of the runway, causing numerous false alarms and severely interfering with the identification of centimeter-sized targets. Second, the equal-depth corrugated groove has limited ability to provide impedance transformation between the waveguide interface and the tapered flare section. At the extremely short wavelength of 93 GHz, deviations in groove depth processing can easily lead to insufficient conversion of rectangular waveguide modes to mixed modes, exciting higher-order modes, causing phase center jitter and main lobe distortion, and increasing return loss. Furthermore, for the non-uniform design of corrugated groove depth, most existing methods rely on empirical formulas and repeated manual iterative modeling, lacking precise design means to dynamically adjust impedance according to the mode state presented by electromagnetic waves at different spatial positions within the angular radius. This makes it extremely difficult to achieve deep suppression of sidelobes under extremely narrow beam conditions, and the design cycle is long and the structural accuracy is difficult to guarantee.

[0005] Therefore, existing technologies urgently need improvement to provide a corrugated horn antenna solution that simultaneously achieves high gain, ultra-low sidelobes, good impedance matching, and high beam symmetry in the W-band. Summary of the Invention

[0006] To address the technical problems existing in the background art, this invention proposes a W-band low sidelobe corrugated horn antenna.

[0007] This invention proposes a W-band low sidelobe ripple horn antenna, comprising: Waveguide input interface, used to connect to a standard waveguide system to input microwave signals in a rectangular waveguide mode; The pre-mode stabilization section has a smooth inner wall structure, which is used to provide mode stabilization space for the input microwave signal to suppress higher-order modes at the interface; The mode conversion section has a first set of corrugated grooves whose depth gradually decreases along the axial direction on its inner wall, which is used to smoothly convert the rectangular waveguide mode into the mixed mode. The steady-state radiating section has a second set of corrugated grooves on its inner wall with a constant depth, which is used to maintain the purity of the mixing mold and propagate along the opening angle; The diffraction suppression aperture section has a third set of corrugated grooves on its inner wall with a depth that gradually increases in the opposite direction along the axial direction, which is used to increase the equivalent impedance at the aperture edge to suppress edge diffraction. And a non-uniform corrugated groove array, which is composed of multiple corrugated grooves, including a first corrugated groove group, a second corrugated groove group and a third corrugated groove group; The waveguide input interface, the pre-mode stabilization unit, the mode conversion unit, the steady-state radiation unit, and the diffraction suppression aperture unit are sequentially and integrally connected along the axial direction, and the operating wavelength of the antenna is λ.

[0008] Preferably, the initial slot depth of the mode conversion section is 0.45 to 0.5 times the operating wavelength λ of the antenna, and the final slot depth of the mode conversion section is 0.25 to 0.33 times the operating wavelength λ of the antenna; the constant slot depth of the steady-state radiating section is equal to the final slot depth of the mode conversion section.

[0009] Preferably, the initial groove depth of the diffraction suppression aperture is equal to the constant groove depth of the steady-state radiating section, and the final groove depth is 0.33 to 0.35 times the operating wavelength λ of the antenna.

[0010] Preferably, the axial length of the front stabilizing section is 8 to 11 times the operating wavelength of the antenna.

[0011] Preferably, the period of the non-uniform corrugated groove array is 1.0 mm to 1.5 mm, and the groove depth varies from 1.0 mm to 1.6 mm.

[0012] Preferably, the waveguide input interface is a standard WR-10 rectangular waveguide interface.

[0013] Preferably, in the non-uniform corrugated groove array, adjacent corrugated grooves are spaced apart by metal teeth.

[0014] Preferably, the inner wall of the steady-state radiating section has a linear opening angle shape.

[0015] This invention proposes an airport runway foreign object detection system, comprising: Terahertz microwave source, used to generate a continuous frequency modulated signal with a center frequency of 93 GHz; A transmitter, connected to the terahertz microwave source, is used to transmit the continuously frequency-modulated signal to the transmitting antenna; The corrugated horn antenna described in any of the above is used as a transmitting antenna to radiate the continuous frequency modulation signal onto the runway surface in a high-gain, low-sidelobe beam. The corrugated horn antenna described in any of the above items is used as a receiving antenna to capture the echo signal reflected by foreign objects. A receiver, connected to the receiving antenna, is used to receive the echo signal; A central signal processor, connected to the receiver, is used to extract the main polarization component and cross-polarization component in the echo signal, and to separate foreign object features and runway background clutter by comparing the two. The main control server, connected to the central signal processor, is used to calculate the absolute coordinates and radar cross-section of the foreign object based on the processed target data and to determine the type of the foreign object. An alarm terminal, connected to the main control server, is used to issue alarm notifications based on the judgment results.

[0016] The present invention proposes a 6G millimeter-wave communication base station antenna, including the corrugated horn antenna as described in any of the above claims.

[0017] This invention proposes a W-band low-sidelobe corrugated horn antenna that overcomes the inherent contradiction between high gain and low sidelobes in traditional equal-depth corrugated antennas by employing a three-segment non-uniform groove depth corrugated structure of "decreasing-constant-increasing". Specifically, the gradually decreasing groove depth design of the mode conversion section achieves a smooth impedance transformation from rectangular waveguide modes to mixed modes, reducing return loss and ensuring mode conversion efficiency and signal transmission purity. The constant-depth corrugated structure of the steady-state radiating section maintains high-quality propagation of the mixed modes, ensuring excellent symmetry of the radiated beam. The diffraction suppression aperture section at the antenna's end features a unique reverse-increasing groove depth structure that creates equivalent impedance compensation at the aperture edge, forcing the surface current to attenuate rapidly before reaching the physical boundary, thereby deeply suppressing edge diffraction and significantly suppressing sidelobe levels. Thus, while maintaining high gain, the antenna achieves a highly symmetrical radiation pattern, extremely low cross-polarization components, and excellent anti-clutter interference capabilities, improving the detection and identification performance of small targets in strong clutter backgrounds. Attached Figure Description

[0018] Figure 1This is a schematic cross-sectional view of the W-band low sidelobe corrugated horn antenna proposed in this invention. Figure 2 This is a comparison (E-plane) of an embodiment of the W-band low sidelobe corrugated horn antenna proposed in this invention with the conventional technology in the azimuth angle = 90° direction; Figure 3 This is a comparison (H-plane) of an embodiment of the W-band low sidelobe corrugated horn antenna proposed in this invention with the conventional technology at azimuth angle = 0°. Figure 4 The E / H plane radiation pattern of one embodiment of a W-band low sidelobe corrugated horn antenna proposed in this invention. Figure 5 This refers to the E / H plane radiation pattern of traditional technology. Figure 6 This is a comparison (azimuth angle = 90°) of one embodiment of the W-band low sidelobe corrugated horn antenna proposed in this invention with the cross-polarization of conventional technology. Figure 7 This is a comparison (azimuth angle = 0°) of one embodiment of the W-band low sidelobe corrugated horn antenna proposed in this invention with the cross-polarization of conventional technology. Figure 8 This is a comparison diagram of the return loss S11 of an embodiment of the W-band low sidelobe corrugated horn antenna proposed in this invention and the conventional technology. Detailed Implementation

[0019] Reference Figures 1-8 The present invention proposes a W-band low sidelobe corrugated horn antenna, comprising: a waveguide input interface, a pre-mode stabilization section, a mode conversion section, a steady-state radiating section, and a diffraction suppression aperture section connected sequentially along the axial direction, wherein the antenna operates at a wavelength of λ.

[0020] Waveguide input interface, used to connect to a standard waveguide system to input microwave signals in a rectangular waveguide mode.

[0021] Specifically, the waveguide input interface is a standard WR-10 rectangular waveguide interface.

[0022] The pre-mode stabilization section has a smooth inner wall structure, which is used to provide mode stabilization space for the input microwave signal to suppress higher-order modes at the interface.

[0023] In this embodiment, the axial length of the front stabilizing section is 8 to 11 times the operating wavelength of the antenna.

[0024] The mode conversion section has a first set of corrugated grooves on its inner wall with a depth that gradually decreases along the axial direction, which is used to smoothly convert the rectangular waveguide mode into a mixed mode.

[0025] In this embodiment, the initial slot depth of the mode conversion section is 0.45 to 0.5 times the operating wavelength λ of the antenna, and the final slot depth of the mode conversion section is 0.25 to 0.33 times the operating wavelength λ of the antenna.

[0026] The steady-state radiating section has a second set of corrugated grooves on its inner wall that maintains a constant depth, which is used to maintain the purity of the mixing mold and propagate along the opening angle.

[0027] In this embodiment, the constant groove depth of the steady-state radiating section is equal to the end groove depth of the mode conversion section.

[0028] Specifically, the inner wall of the steady-state radiating section has a linear opening angle shape.

[0029] The diffraction suppression aperture section has a third set of corrugated grooves on its inner wall with a depth that gradually increases in the opposite direction along the axial direction. This is used to increase the equivalent impedance at the aperture edge to suppress edge diffraction.

[0030] In this embodiment, the initial groove depth of the diffraction suppression aperture section is equal to the constant groove depth of the steady-state radiating section, and the final groove depth is 0.33 to 0.35 times the operating wavelength λ of the antenna.

[0031] And a non-uniform corrugated groove array, which consists of multiple corrugated grooves, including a first corrugated groove group, a second corrugated groove group and a third corrugated groove group.

[0032] Specifically, the period of the non-uniform corrugated groove array is 1.0 mm to 1.5 mm, and the groove depth varies from 1.0 mm to 1.6 mm.

[0033] It should be noted that in a non-uniform corrugated groove array, adjacent corrugated grooves are separated by metal teeth.

[0034] Example 1: The W-band low-sidelobe corrugated horn antenna of this embodiment is constructed by sequentially and integrally connecting a waveguide input interface, a pre-mode stabilization section, a mode conversion section, a steady-state radiating section, and a diffraction suppression aperture section along the axial direction, forming a closed electromagnetic wave propagation cavity. The inner wall of the antenna is machined with a non-uniform corrugated groove array consisting of multiple alternating annular corrugated grooves and metal teeth. This array covers all the corrugated grooves located in the mode conversion section, the steady-state radiating section, and the diffraction suppression aperture section.

[0035] In this embodiment, taking a W-band antenna with a center frequency of 93GHz as an example, 93GHz corresponds to λ≈3.23mm. The waveguide input interface adopts a standard WR-10 rectangular waveguide, whose internal cross-sectional dimensions are consistent with the external system feed source, and is used to feed microwave signals with a TE10 rectangular waveguide mode.

[0036] The pre-stabilizing section has an axial length of 30 mm, which is approximately 9.3 times the center operating wavelength λ, falling within the range of 8 to 11 times the operating wavelength λ. This pre-stabilizing section has a smooth inner wall section, which provides modal stabilization space for the input TE10 mode, suppressing transient higher-order modes excited by interface discontinuities and ensuring structural strength at small apertures.

[0037] The inner wall of the mode conversion section is provided with a first set of corrugated grooves, the groove depth of which decreases linearly along the axial direction from the end near the pre-stabilized mode section to the end near the steady-state radiating section. In the 93GHz band, the initial groove depth is 1.5mm, or approximately 0.46λ, and the groove depth at the end decreases to a standard depth of 1.02mm, or approximately 0.31λ. Through the large-depth corrugated grooves in the initial section, the mode conversion section electrically achieves a continuous transition from the high impedance of the rectangular waveguide to the surface impedance of the corrugated structure, thereby smoothly and without reflection converting the TE10 mode into the HE11 mixed mode with an axisymmetric field distribution, reducing return loss.

[0038] The steady-state radiating section is the main conical opening section of the antenna, with a linear opening angle on the inner wall and a second set of corrugated slots. The depth of these corrugated slots remains a constant standard depth of 1.02 mm throughout the entire length, and the corrugation period P is set to 1.2 mm. During the opening process of the hybrid mode, the constant-depth corrugated slots maintain the boundary conditions of an approximately ideal magnetic conductor on the inner wall, enabling the HE11 mode to transmit stably with extremely high purity, ensuring that the beam has a consistent phase center and symmetrical amplitude distribution in both the E and H planes.

[0039] The diffraction suppression aperture section is located at the very end of the antenna. Its inner wall features a third group of corrugated grooves with a gradually increasing groove depth. This section initially has a groove depth equal to the standard depth of 1.02 mm, increasing linearly along the axial direction to 1.10 mm at the aperture edge, approximately 0.34λ. The deepened corrugated grooves increase the equivalent inductive reactance of the inner wall, creating a progressive clamping effect on the surface current. This forces the surface current to decay rapidly before reaching the physical aperture, physically eliminating the edge diffraction field that causes high sidelobes. The period of this section remains at 1.2 mm.

[0040] In this embodiment, adjacent corrugated grooves in the non-uniform corrugated groove array are physically separated by metal teeth. The period P of all corrugated grooves is uniformly 1.2 mm, and the groove depth varies from 1.02 mm to 1.5 mm. The impedance of the inner wall of each section transitions continuously according to the change in groove depth, ensuring the smoothness of electromagnetic coupling.

[0041] In this embodiment, the antenna is made of copper or aluminum, and gold or silver can also be plated on the aluminum or brass surface.

[0042] like Figures 2-8As shown, the non-uniform corrugated horn antenna provided by this invention achieves deep suppression of sidelobe levels, significant improvement of beam symmetry, extreme suppression of cross-polarization, and comprehensive optimization of impedance matching while maintaining high gain.

[0043] like Figure 2 As shown in the figure, this application compares the far-field radiation pattern of the antenna E-plane with that of the prior art. At an elevation angle of -14.01°, i.e., at the position of the first sidelobe, this application successfully reduced the gain to -1.26 dBi, which is an optimization of approximately 10 dB compared to the gain of 8.59 dBi in the conventional technology. This intuitively demonstrates that the present invention, through the design of the increasing reverse groove depth at the end of the diffraction suppression aperture, successfully creates a clamping effect on the edge surface current, thus eliminating the edge diffraction field from a physical mechanism.

[0044] like Figure 3 As shown in the figure, this invention compares the far-field radiation patterns of the antenna in the H-plane with those of the prior art. Within the main lobe region and adjacent angles, the radiation characteristics of this invention remain highly consistent with the prior art, with no loss in main lobe width or gain level. This indicates that the sidelobe depth suppression achieved in the E-plane by this invention does not come at the expense of H-plane performance or main lobe energy, but rather represents selective and precise suppression of edge diffraction while maintaining high overall antenna gain and narrow beam characteristics.

[0045] like Figure 4 As shown in the figure, this diagram separately illustrates the overlap between the E-plane and H-plane radiation patterns of the antenna in this application within the main lobe range. The two curves almost completely overlap at the top and sides of the main lobe, presenting an ideal circular symmetrical beam. This demonstrates that this application, through precise control of the HE11 mixed-mode boundary conditions via various non-uniform corrugated slots, enables the E-plane and H-plane to have consistent phase center and amplitude taper in the wide-angle domain, achieving extremely high aperture efficiency.

[0046] like Figure 5 As shown, this figure illustrates the E-plane and H-plane radiation patterns of a conventional equal-depth corrugated horn antenna. Figure 4 In stark contrast, the E-plane and H-plane curves of traditional technologies exhibit significant separation within the main lobe region, with inconsistent beamwidths and shapes. This asymmetry stems from the inability of the equal-depth corrugated structure to differentiate the boundary conditions of different planes within the horn angle, resulting in uneven aperture field distribution. This, in turn, leads to deterioration of cross-polarization and reduced efficiency, which is one of the core shortcomings that this application aims to overcome.

[0047] like Figure 6As shown in the figure, this comparison illustrates the cross-polarization level of this application and conventional technologies within the main lobe range in a critical plane with an azimuth angle of 90°. Conventional technologies exhibit relatively high cross-polarization components, which can introduce significant interference in polarization-sensitive applications. In contrast, the cross-polarization curve of this application drops substantially throughout the main lobe, suppressed to an extremely low level. This is attributed to the precise control of electromagnetic field scattering behavior within the corrugated groove through the non-uniform slot depth design, which enhances the antenna's polarization purity, crucial for accurate target identification.

[0048] like Figure 7 As shown in the figure, this comparison illustrates the cross-polarization performance of this application and the prior art within a plane with an azimuth angle of 0°. It can be clearly seen that the cross-polarization level of this application maintains the same excellent level as the conventional technology, without any degradation. Combined with... Figure 6 The results confirm that the non-uniform corrugated structure of this application, while achieving ultra-low sidelobes and ultra-low cross-polarization in the E-plane, does not have any negative impact on the radiation performance of the other planes and the main polarization, demonstrating the high completeness of the design scheme and the selectivity of electromagnetic control.

[0049] like Figure 8 As shown in the figure, this application compares the return loss (S11) characteristics at the input port with those of the prior art. Traditional equal-depth corrugated structures may exhibit high reflection peaks in their return loss curves within the band due to impedance abrupt changes at the waveguide interface. In contrast, the return loss of this application is suppressed to below -28dB throughout the entire operating frequency band, and the curve is flat and stable without resonance spikes. This is attributed to the gradual impedance transformation provided by the deep corrugated groove at the beginning of the mode conversion section, which smoothly transitions the rectangular waveguide mode to the mixed mode, allowing almost all the feed energy to enter the antenna without reflection, ensuring extremely high transmission efficiency.

[0050] In this embodiment, when the antenna is operating, a 93GHz microwave signal is fed in through the WR-10 waveguide input interface. It is first stabilized into a pure TE10 mode in the pre-mode stabilization section. After entering the mode conversion section, impedance transformation and mode conversion are completed through corrugated grooves that gradually decrease in depth, efficiently forming a HE11 hybrid mode. The hybrid mode propagates along a linear opening angle in the steady-state radiating section, with the beam cross-section gradually expanding, while the constant-depth corrugations maintain the high purity and symmetry of the field distribution. When the electromagnetic wave reaches the diffraction suppression aperture section, the deepened corrugated grooves at the edges forcibly attenuate the surface current, causing the amplitude of the edge field on the aperture surface to decrease rapidly, ultimately radiating into free space with a highly symmetrical, low-sidelobe narrow beam.

[0051] This invention proposes an airport runway foreign object detection system, comprising: Terahertz microwave source, used to generate a continuous frequency modulated signal with a center frequency of 93 GHz; The transmitter, connected to a terahertz microwave source, is used to transmit continuously frequency modulated signals to the transmitting antenna; The corrugated horn antenna of any of the above is used as a transmitting antenna to radiate a continuous frequency modulated signal onto the runway surface in a high-gain, low-sidelobe beam. The corrugated horn antenna mentioned above can be used as a receiving antenna to capture the echo signal reflected by foreign objects. A receiver, connected to a receiving antenna, is used to receive echo signals; The central signal processor, connected to the receiver, is used to extract the main polarization component and cross-polarization component in the echo signal, and to separate foreign object features from runway background clutter by comparing the two. The main control server, connected to the central signal processor, is used to calculate the absolute coordinates and radar cross-section of the foreign object based on the processed target data and to determine the type of foreign object. The alarm terminal is connected to the main control server and is used to issue alarm notifications based on the judgment results.

[0052] The present invention proposes a 6G millimeter-wave communication base station antenna, including a corrugated horn antenna as described above.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A W-band low sidelobe corrugated horn antenna, characterized in that, include: Waveguide input interface, used to connect to a standard waveguide system to input microwave signals in a rectangular waveguide mode; The pre-mode stabilization section has a smooth inner wall structure, which is used to provide mode stabilization space for the input microwave signal to suppress higher-order modes at the interface; The mode conversion section has a first set of corrugated grooves whose depth gradually decreases along the axial direction on its inner wall, which is used to smoothly convert the rectangular waveguide mode into the mixed mode. The steady-state radiating section has a second set of corrugated grooves on its inner wall with a constant depth, which is used to maintain the purity of the mixing mold and propagate along the opening angle. The diffraction suppression aperture section has a third set of corrugated grooves on its inner wall with a depth that gradually increases in the opposite direction along the axial direction, which is used to increase the equivalent impedance at the aperture edge to suppress edge diffraction. And a non-uniform corrugated groove array, which is composed of multiple corrugated grooves, including a first corrugated groove group, a second corrugated groove group and a third corrugated groove group; The waveguide input interface, the pre-mode stabilization unit, the mode conversion unit, the steady-state radiation unit, and the diffraction suppression aperture unit are sequentially and integrally connected along the axial direction, and the operating wavelength of the antenna is λ.

2. The W-band low sidelobe corrugated horn antenna according to claim 1, characterized in that, The initial slot depth of the mode conversion section is 0.45 to 0.5 times the operating wavelength λ of the antenna, and the final slot depth of the mode conversion section is 0.25 to 0.33 times the operating wavelength λ of the antenna; the constant slot depth of the steady-state radiating section is equal to the final slot depth of the mode conversion section.

3. The W-band low sidelobe corrugated horn antenna according to claim 1 or 2, characterized in that, The initial groove depth of the diffraction suppression aperture section is equal to the constant groove depth of the steady-state radiating section, and the final groove depth is 0.33 to 0.35 times the operating wavelength λ of the antenna.

4. The W-band low sidelobe corrugated horn antenna according to claim 1, characterized in that, The axial length of the front-mounted stabilizing section is 8 to 11 times the operating wavelength of the antenna.

5. The W-band low sidelobe corrugated horn antenna according to claim 1, characterized in that, The period of the non-uniform corrugated groove array is 1.0 mm to 1.5 mm, and the groove depth varies from 1.0 mm to 1.6 mm.

6. The W-band low sidelobe corrugated horn antenna according to claim 1, characterized in that, The waveguide input interface is a standard WR-10 rectangular waveguide interface.

7. The W-band low sidelobe corrugated horn antenna according to claim 1, characterized in that, In the non-uniform corrugated groove array, adjacent corrugated grooves are spaced apart by metal teeth.

8. The W-band low sidelobe corrugated horn antenna according to claim 1, characterized in that, The inner wall of the steady-state radiating section has a linear opening angle shape.

9. A foreign object detection system for airport runways, characterized in that, include: Terahertz microwave source, used to generate a continuous frequency modulated signal with a center frequency of 93 GHz; A transmitter, connected to the terahertz microwave source, is used to transmit the continuously frequency-modulated signal to the transmitting antenna; The corrugated horn antenna as described in any one of claims 1 to 8 is used as a transmitting antenna to radiate the continuous frequency modulation signal onto the runway surface in a high-gain, low-sidelobe beam. The corrugated horn antenna as described in any one of claims 1 to 8 is used as a receiving antenna to capture the echo signal reflected by a foreign object. A receiver, connected to the receiving antenna, is used to receive the echo signal; A central signal processor, connected to the receiver, is used to extract the main polarization component and cross-polarization component in the echo signal, and to separate foreign object features and runway background clutter by comparing the two. The main control server, connected to the central signal processor, is used to calculate the absolute coordinates and radar cross-section of the foreign object based on the processed target data and to determine the type of the foreign object. An alarm terminal, connected to the main control server, is used to issue alarm notifications based on the judgment results.

10. A 6G millimeter-wave communication base station antenna, characterized in that, Including the corrugated horn antenna as described in any one of claims 1 to 8.

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