UWB living body detection antenna

Abstract

The utility model discloses a kind of UWB living body detection antennas, including two radiation unit patches, feed probe, dielectric substrate, wave width adjusting plate and EBG radiation patch;Dielectric substrate includes oppositely arranged first plane and second plane stratum, radiation unit patch and EBG radiation patch are printed on the first plane, two radiation unit patches are arranged in the opposite side of first plane, EBG radiation patch is arranged in the middle of first plane;Feed probe one end is connected with radiation unit patch, the other end penetrates dielectric substrate and is connected with metal ring belt, and isolation band is arranged between metal ring belt and second plane stratum;Dielectric substrate is opened with the metallized through hole connected with EBG radiation patch and second plane stratum respectively;Two wave width adjusting plates are symmetrically provided on the side of radiation unit patch.The UWB living body detection antenna of the utility model improves the isolation degree between double antenna channel in limited space;Beam width can be effectively adjusted;Simple structure and simple processing.

Description

Technical Field

[0001] This utility model relates to the field of UWB liveness detection technology, and to a UWB liveness detection antenna, particularly to a UWB liveness detection antenna that can effectively balance antenna isolation and size while having a controllable directional beam coverage range. Background Technology

[0002] Ultra-wideband (UWB) technology has been widely used in the field of liveness detection due to its advantages such as high resolution, strong penetration, low power consumption, and strong anti-interference capabilities. The basic principle of UWB liveness detection is as follows: extremely narrow pulses of electromagnetic waves on the nanosecond or picosecond scale are emitted into the detection area. When these electromagnetic waves encounter objects such as humans, they are reflected, and the receiver picks up these echo signals. Because living targets (especially the chest cavity area) undergo weak periodic movements with breathing and heartbeat, these movements micro-modulate the time delay (i.e., phase) of the echo signals. By analyzing the echo signals, especially extracting vital signs (respiratory rate: 0.1-0.5Hz, heart rate: 0.8-2.0Hz), it is possible to detect and determine the presence of living beings behind walls or obstacles.

[0003] Ultra-wideband (UWB) liveness detection technology is a key technology for obstacle-free detection by analyzing the micro-Doppler modulation effect of human vital activities (such as breathing and heartbeat) on UWB electromagnetic waves. In this system, the antenna, as a key front-end component for electromagnetic wave energy conversion and radiation, directly determines the sensitivity, penetration depth, resolution, and anti-interference capability of the entire detection system. An ideal UWB liveness detection antenna should possess ultra-wideband characteristics, stable directional radiation characteristics, high gain, low return loss, and good time-domain fidelity (i.e., low pulse distortion).

[0004] Current antenna solutions for UWB radar detection have the following main shortcomings:

[0005] 1) Antenna isolation and size are mutually exclusive, which is the core contradiction in the design of UWB transmit and receive radar antennas. For a long time, there has been a dilemma: either accept a large device size for high isolation, or tolerate poor system performance and reliability for small size; 2) The coverage range of the antenna directional beam is difficult to control. In some application scenarios, the beam coverage range needs to be precisely controlled, especially in airborne and vehicle-mounted scenarios. Unnecessary signal overflow (signal spillover) will bring a series of problems such as interference, safety and performance degradation.

[0006] Therefore, developing a UWB live detection antenna that can effectively balance antenna isolation and size while maintaining controllable directional beam coverage is of great practical significance. Utility Model Content

[0007] Due to the aforementioned deficiencies in existing technologies, this invention provides a UWB liveness detection antenna that can effectively balance antenna isolation and size while maintaining controllable directional beam coverage, thereby solving the problem that existing UWB liveness detection schemes cannot balance antenna isolation and size and have difficulty controlling the directional beam coverage.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A UWB live detector antenna includes a radiating element patch, a feed probe, a dielectric substrate, a bandwidth adjustment plate, and an EBG radiating patch.

[0010] The dielectric substrate includes a first plane and a second plane ground layer arranged opposite to each other. The radiating element patch and the EBG radiating patch are printed on the first plane of the dielectric substrate. There are two radiating element patches, which are arranged on opposite sides of the first plane. The radiating element patches are used to realize the signal radiation of the UWB liveness detection antenna. The EBG radiating patch is arranged between the two radiating element patches and is used to isolate the radiating element patches.

[0011] One end of the feed probe is connected to the radiating unit patch, and the other end penetrates the dielectric substrate and is connected to the metal ring. An annular isolation strip is provided between the metal ring and the second planar ground layer.

[0012] The dielectric substrate also has metallized vias, and the two ends of the metallized vias are respectively connected to the EBG radiating patch and the second planar ground layer. The EBG radiating patch, the metallized vias and the second planar ground layer form an EBG structure, which provides a wider filter bandwidth and effectively improves the isolation of the radiating unit patch.

[0013] Two bandwidth adjustment plates are symmetrically arranged on both sides of the radiating unit patch to regulate the leakage of signal energy.

[0014] This novel UWB live detector antenna uses an EBG radiating patch, metallized vias, and a second planar ground layer to form an EBG structure. It boasts high space utilization and integration, effectively improving the isolation between single-anchor dual-antenna channels within a limited space. Simultaneously, the beamwidth adjustment plate effectively regulates the beamwidth, mitigating energy leakage of the detection signal and enabling directional beam coverage control to adapt to specific environments. The overall structure is simple and easy to manufacture, resembling a printed circuit board. It connects to the probe and the back circuitry (i.e., the second planar ground layer), making installation convenient, practical, and highly promising.

[0015] As a preferred technical solution:

[0016] As described above, in a UWB live detection antenna, two radiating element patches are arranged diagonally on opposite sides of a first plane.

[0017] As described above, in a UWB liveness detection antenna, the EBG radiating patches are centrally distributed in a periodic array on a first plane.

[0018] The EBG radiating patch is square, and the side length of the square is 1 / 4 of the wavelength corresponding to the designed center frequency. Of course, the structure of the EBG radiating patch of the UWB liveness detector antenna of this invention is not limited to this, and can be adjusted according to different requirements. For example, the square patch can be changed to a polygon, or a slit can be made in the middle of the patch.

[0019] As described above, in a UWB liveness detection antenna, the EBG radiating patch is an 8.5×8.5mm square patch arranged in a 3×3 array.

[0020] As described above, in a UWB live detection antenna, one end of the bandwidth adjustment plate is higher than the first plane, and the other end penetrates the dielectric substrate and is connected to the loop-shaped metal strip, with a gap strip between the loop-shaped metal strip and the second plane ground layer.

[0021] As described above, in a UWB liveness detection antenna, the bandwidth adjustment plate is 1.5mm higher than the first plane. Of course, it can be adjusted according to actual needs to achieve better isolation and spillover signal energy regulation.

[0022] The width of the slit strip is 0.5mm, but it can be adjusted according to actual needs.

[0023] In the UWB liveness detection antenna described above, the bandwidth adjustment plate is a double-layer plate.

[0024] As described above, the UWB live detector antenna uses a microstrip antenna chamfer perturbation method to achieve circular polarization in the radiating element patch, which has certain advantages in terms of anti-interference, anti-fading and anti-multipath effects.

[0025] The above technical solution is only one feasible technical solution of this utility model. The protection scope of this utility model is not limited to this. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0026] The above-mentioned utility model has the following advantages or beneficial effects:

[0027] This novel UWB live detector antenna uses an EBG radiating patch, metallized vias, and a second planar ground layer to form an EBG structure. It boasts high space utilization and integration, effectively improving the isolation between single-anchor dual-antenna channels within a limited space. Simultaneously, the beamwidth adjustment plate effectively regulates the beamwidth, mitigating energy leakage of the detection signal and enabling directional beam coverage control to adapt to specific environments. The overall structure is simple and easy to manufacture, resembling a printed circuit board. It connects to the probe and the back circuitry (i.e., the second planar ground layer), making installation convenient, practical, and highly promising. Attached Figure Description

[0028] The present invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; the focus is on illustrating the gist of the invention.

[0029] Figure 1 This is a top view of the UWB liveness detection antenna of this utility model;

[0030] Figure 2 This is a main cross-sectional view of the UWB liveness detection antenna of this utility model;

[0031] Figure 3 This is a simulation data diagram of the VSWR of the UWB liveness detection antenna of this utility model;

[0032] Figure 4 The diagram shows the simulation data of S11 and isolation of the UWB liveness detection antenna of this invention.

[0033] Figure 5 This is a simulation data diagram of the beamwidth of the UWB liveness detection antenna of this utility model;

[0034] Among them, 10-UWB live probe antenna, 11-radiating element patch, 12-feed probe, 121-metal ring, 13-dielectric substrate, 131-first plane, 132-second plane ground layer, 14-wavewidth adjustment plate, 151-EBG radiating patch, 152-metallized via. Detailed Implementation

[0035] The structure of this utility model will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the utility model.

[0036] Example 1

[0037] A UWB liveness detection antenna 10, such as Figures 1-2As shown, it includes a radiating unit patch 11, a feed probe 12, a dielectric substrate 13, a wavelength adjustment plate 14, and an EBG radiating patch 151.

[0038] Radiation element patch 11 achieves circular polarization using a microstrip antenna chamfer perturbation method;

[0039] The dielectric substrate 13 includes a first plane 131 and a second plane ground layer 132 arranged opposite to each other. Radiation unit patch 11 and EBG radiation patch 151 are printed on the first plane of the dielectric substrate 13. There are two radiation unit patches 11, and the two radiation unit patches 11 are arranged diagonally on opposite sides of the first plane 131. The radiation unit patches 11 are used to realize the signal radiation of the UWB live detection antenna 10. The EBG radiation patch 151 is centrally distributed on the first plane 131 in the form of a periodic array and is used to isolate the radiation unit patches 11. The EBG radiation patch 151 is a square and the side length of the square is 1 / 4 of the wavelength corresponding to the designed center frequency. Specifically, it is arranged in a 3×3 array and uses 8.5×8.5mm square patches.

[0040] One end of the feed probe 12 is connected to the radiating unit patch 11, and the other end penetrates the dielectric substrate 13 and is connected to the metal ring 121. An annular isolation strip is provided between the metal ring 121 and the second planar ground layer 132.

[0041] The dielectric substrate 13 also has a metallized via 152, and the two ends of the metallized via 152 are connected to the EBG radiating patch 151 and the second planar ground layer 132 respectively. The EBG radiating patch 151, the metallized via 152 and the second planar ground layer 132 form an EBG structure.

[0042] Two pulse width adjustment plates 14 are symmetrically arranged on both sides of the radiating unit patch 11. One end of the pulse width adjustment plate 14 is 1.5 mm higher than the first plane 131, and the other end penetrates the dielectric substrate 13 and is connected to the loop metal strip. A gap strip with a width of 0.5 mm is provided between the loop metal strip and the second plane ground layer 132.

[0043] By printing radiating element patches and EBG radiating patch arrays on the first plane of a dielectric substrate, the radiating element patches are fed to the second plane ground layer through probes and separated from the second plane ground layer by an annular gap to achieve the feeding function. Then, the EBG radiating patch array is connected to the second plane ground layer through metallized vias, thus forming an EBG structure. This structure can effectively filter specific frequency bands to achieve high isolation performance. In addition, a bandwidth adjustment plate is added on both sides of the radiating element patch. The bandwidth adjustment plate is higher than the first plane and is not connected to the second plane ground layer, so as to realize the control of the antenna pattern, thereby affecting the energy distribution around the vehicle and playing a role in regulating signal overflow.

[0044] The simulation data graphs for the above-mentioned UWB live detector antenna, including VSWR, S11 and isolation, and beamwidth, are as follows: Figures 3-5 As shown in the figure, the isolation is above 35dB in the 9th band of the channel, the half-power beamwidth will increase, the energy will be more concentrated directly below, and the overflow will be reduced.

[0045] Verification has shown that the UWB live probe antenna of this invention, composed of an EBG radiating patch, metallized vias, and a second planar ground layer, exhibits high space utilization and integration. It effectively improves the isolation between single-anchor dual-antenna channels within a limited space. Simultaneously, the beamwidth adjustment plate effectively regulates the beamwidth, mitigating energy leakage of the probe signal and enabling directional beam coverage control to adapt to specific environments. The overall structure is relatively simple and easy to manufacture, taking the form of a printed circuit board. It connects to the probe and the back circuitry (i.e., the second planar ground layer), making installation convenient, practical, and highly promising.

[0046] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the substantive content of this utility model, and will not be elaborated here.

[0047] The preferred embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above. Devices and structures not described in detail herein should be understood as being implemented in a conventional manner within the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this utility model using the disclosed methods and techniques, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. This does not affect the essential content of this utility model. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, still fall within the protection scope of the technical solution of this utility model.

Claims

1. A UWB liveness detection antenna, characterized in that: This includes radiating unit patches, feed probes, dielectric substrates, pulse width adjustment boards, and EBG radiating patches. The dielectric substrate includes a first plane and a second plane ground layer arranged opposite to each other. The radiating element patch and the EBG radiating patch are printed on the first plane of the dielectric substrate. There are two radiating element patches, which are arranged on opposite sides of the first plane. The radiating element patches are used to realize the signal radiation of the UWB liveness detection antenna. The EBG radiating patch is arranged between the two radiating element patches and is used to isolate the radiating element patches. One end of the feed probe is connected to the radiating unit patch, and the other end penetrates the dielectric substrate and is connected to the metal ring. An annular isolation strip is provided between the metal ring and the second planar ground layer. The dielectric substrate also has metallized vias, and the two ends of the metallized vias are respectively connected to the EBG radiating patch and the second planar ground layer. The EBG radiating patch, the metallized vias and the second planar ground layer constitute the EBG structure. Two pulse width adjustment plates are symmetrically arranged on both sides of the radiating unit patch.

2. The UWB liveness detection antenna according to claim 1, characterized in that, Two radiating element patches are arranged diagonally on opposite sides of the first plane.

3. The UWB liveness detection antenna according to claim 2, characterized in that, The EBG radiation patches are centrally distributed on the first plane in the form of a periodic array. The EBG radiation patch is a square, and the side length of the square is 1 / 4 of the wavelength corresponding to the designed center frequency.

4. A UWB liveness detection antenna according to claim 3, characterized in that, The EBG radiation patch is an 8.5×8.5mm square patch arranged in a 3×3 array.

5. A UWB liveness detection antenna according to claim 1, characterized in that, One end of the wavewidth adjustment plate is higher than the first plane, and the other end penetrates the dielectric substrate and is connected to the loop metal strip, with a gap strip between the loop metal strip and the second plane ground layer.

6. A UWB liveness detection antenna according to claim 5, characterized in that, The wavewidth adjustment plate is 1.5mm higher than the first plane; The width of the slit band is 0.5 mm.

7. A UWB liveness detection antenna according to claim 1, characterized in that, The wavewidth adjustment plate is a double-layer plate.

8. A UWB liveness detection antenna according to claim 1, characterized in that, The radiating element patch is circularly polarized using a microstrip antenna chamfer perturbation method.

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