Ultra-wideband radar antenna array

Abstract

The utility model discloses an ultra wide band radar antenna array, the antenna array comprises a first antenna unit, a second antenna unit and a third antenna unit, the first antenna unit is used for transmitting radio frequency signals, the second antenna unit and the third antenna unit are used for receiving the radio frequency signals, and the third antenna unit is used for receiving the radio frequency signals. The first antenna unit, the second antenna unit and the third antenna unit are respectively arranged up and down, and the second antenna unit and the third antenna unit are bilaterally symmetrical with the center line of the first antenna unit. According to the ultra-wideband radar antenna array provided by the utility model, the transmitting antenna unit and the two receiving antenna units are respectively arranged up and down, so that the problem of occupation of antenna space is solved.

Description

Technical Field

[0001] This utility model relates to the field of anti-collision radar technology, and in particular to an ultra-wideband radar antenna array. Background Technology

[0002] With industrial and social development, the per capita ownership of electric vehicles, cars, and other motor vehicles is increasing year by year. On roads where motor vehicles travel, factors such as road conditions, nighttime driving, adverse weather conditions like rain and snow, and increased driver fatigue after long periods of driving often mean that drivers don't have enough reaction time when they notice a situation ahead. Therefore, there is an urgent need to develop a vehicle collision avoidance radar warning system to ensure driving safety in low visibility conditions and during long driving periods. Collision avoidance radar is a detection device that can issue visual and auditory warning signals to the driver in advance. Installed on a motor vehicle, it can detect pedestrians, vehicles, or surrounding obstacles attempting to approach the vehicle; it can also issue early warning signals to the driver and passengers of an impending collision, prompting the driver to take emergency measures to deal with special dangers and avoid losses.

[0003] Ultra-wideband (UWB) radar is suitable for a wide range of wireless systems. UWB radar signals are insensitive to channel fading, have low transmitted signal power spectral density, and consume significantly less power than existing traditional radio technologies. In particular, it exhibits low interference characteristics against other wireless systems and possesses strong anti-interference capabilities and high-precision range resolution. UWB radar operates on a principle similar to Time of Flight (TOF). A signal is transmitted from the transmitter, bounces back to the receiver after hitting an obstacle, and the transmission distance is calculated by multiplying the time difference between transmission and reception by the speed of light. UWB radar utilizes the Doppler effect of wireless signals to detect changes in the surrounding electromagnetic environment. Moving objects emit electromagnetic waves, and by applying a frequency shift to these waves, the presence of movement can be determined by observing the characteristics of changes in the surrounding environment.

[0004] Automotive collision avoidance radar systems based on ultra-wideband technology represent a novel detection technology. They detect targets by emitting GHz-level ultra-wideband signals, using radar principles for ranging and speed measurement, and determining the target's presence by detecting its echo. The primary design principle of automotive radar collision avoidance systems is to address the fact that traffic accidents often occur in complex road conditions, poor visibility, and driver fatigue. Therefore, their main design objective is to detect potentially dangerous targets ahead as early as possible, providing a multimedia warning display platform to promptly alert the driver to take appropriate action.

[0005] However, automotive collision avoidance radar systems based on ultra-wideband technology still have certain shortcomings, such as low accuracy and stability.

[0006] Therefore, there is a need to provide an ultra-wideband radar antenna array to solve the above problems. Utility Model Content

[0007] This invention addresses the problems and shortcomings of existing technologies by providing an ultra-wideband radar antenna array. By placing the transmitting antenna unit and two receiving antenna units vertically, the space occupied by the antenna is optimized.

[0008] This utility model embodiment provides an antenna array for an ultra-wideband radar antenna unit. The antenna array includes a first antenna unit, a second antenna unit, and a third antenna unit. The first antenna unit is used to transmit radio frequency signals, and the second and third antenna units are used to receive radio frequency signals. The first antenna unit, the second antenna unit, and the third antenna unit are placed vertically, and the second and third antenna units are symmetrical about the center line of the first antenna unit.

[0009] Preferably, the first antenna unit, the second antenna unit, and the third antenna unit each include a dielectric substrate carrier, a rectangular printed antenna patch, an insertable microstrip feed conductor, and a metal via.

[0010] The upper surface of the dielectric substrate carrier is provided with a rectangular printed antenna patch and an insertable microstrip feed conductor. The rectangular printed antenna patch is provided with a rectangular groove, and the insertable microstrip feed conductor is electrically connected to the rectangular printed antenna patch in the rectangular groove.

[0011] The rectangular printed antenna patch includes a first rectangular side and a second rectangular side. The first rectangular side is located along the length direction of the rectangular printed antenna patch, and the second rectangular side is located along the width direction of the rectangular printed antenna patch. The length of the first rectangular side and the length of the second rectangular side are matched with the target center frequency of the antenna.

[0012] A first gap and a second gap are symmetrically arranged between the insertable microstrip feed conductor and the rectangular printed antenna patch. The depth of the first gap and the second gap is less than or equal to half the side of the second rectangle, and the width of the first gap and the second gap is less than or equal to the width of the insertable microstrip feed conductor.

[0013] The antenna unit is divided into an antenna layer, a ground metal layer, an intermediate metal layer, and a metal layer containing radio frequency traces, chips, and peripheral circuits from top to bottom. The insert-type microstrip feed conductor is electrically connected to one end of the metal via. The other end of the metal via passes through the ground metal layer and the intermediate metal layer and is electrically connected to the metal layer containing radio frequency traces, chips, and peripheral circuits.

[0014] Preferably, the first antenna element, the second antenna element, and the third antenna element are all antenna arrays of intermediate-insertion microstrip-fed antenna elements.

[0015] Alternatively, the first antenna element is a center-inserted microstrip-fed antenna element, and the second and third antenna elements are both offset-inserted microstrip-fed antenna elements, with the offset position close to the edge of the PCB board, forming an antenna array.

[0016] Alternatively, the first antenna element is a center-inserted microstrip-fed antenna element, and the second and third antenna elements are both offset-inserted microstrip-fed antenna elements, with the offset position close to the center line of the PCB board, forming an antenna array.

[0017] Alternatively, the first antenna element, the second antenna element, and the third antenna element are all biased insertion microstrip fed antenna elements, and the biased positions of the second antenna element and the third antenna element are close to the edge of the PCB board to form an antenna array.

[0018] Alternatively, the first antenna unit, the second antenna unit, and the third antenna unit are all biased insertion microstrip fed antenna units, and the biased positions of the second antenna unit and the third antenna unit are close to the center line of the PCB board to form an antenna array.

[0019] Preferably, the end of the insertable microstrip feed conductive strip of the first antenna unit points to the lower end of the PCB board, and the ends of the insertable microstrip feed conductive strips of the second antenna unit and the third antenna unit respectively point to the upper end of the PCB board.

[0020] Alternatively, the ends of the insert-type microstrip feed conductors of the first antenna unit, the second antenna unit, and the third antenna unit respectively point to the upper end of the PCB board.

[0021] Alternatively, the end of the insertable microstrip feed conductor of the first antenna unit points to the upper end of the PCB board, and the ends of the insertable microstrip feed conductors of the second and third antenna units respectively point to the lower end of the PCB board.

[0022] Alternatively, the ends of the insert-type microstrip feed conductors of the first antenna unit, the second antenna unit, and the third antenna unit respectively point to the lower end of the PCB board.

[0023] Preferably, the gaps between the first antenna unit, the second antenna unit, and the third antenna unit are all provided with a nested open resonant ring periodic structure for decoupling.

[0024] Preferably, the nested open-ring periodic structure includes multiple open-ring units;

[0025] Each of the plurality of open resonant ring units is a polygonal structure including an inner ring and an outer ring with an opening, and the number of sides of each of the plurality of open resonant ring units is K, where K≥8;

[0026] The plurality of open resonant ring units form a T-shaped array, which is used to isolate the first antenna unit, the second antenna unit and the third antenna unit;

[0027] The number of open-loop resonant units between the first antenna unit and the second antenna unit is N1, N1≥4; the number of open-loop resonant units between the first antenna unit and the third antenna unit is N2, N2≥4; and the number of open-loop resonant units between the second antenna unit and the third antenna unit is N3, N3≥6.

[0028] The spacing between the inner and outer rings is 0.1-0.5 mm, and the spacing between the plurality of open resonant ring units is 0.2-0.8 mm.

[0029] Compared with the prior art, the technical solution of this utility model embodiment has the following beneficial effects:

[0030] The ultra-wideband radar antenna array of this utility model includes a first antenna unit, a second antenna unit, and a third antenna unit. The first antenna unit is used to transmit radio frequency signals, and the second and third antenna units are used to receive radio frequency signals. The first antenna unit, the second antenna unit, and the third antenna unit are placed vertically, and the second and third antenna units are symmetrical about the center line of the first antenna unit. By placing the transmitting antenna unit and the two receiving antenna units vertically, the problem of antenna space occupation is optimized.

[0031] Furthermore, by symmetrically setting the two receiving antennas to the centerline of the transmitting antenna, it is ensured that the receiving antennas receive signals with similar amplitudes after being emitted by the transmitting antenna and reflected by objects.

[0032] Furthermore, by designing a periodic metamaterial structure based on nested open resonant ring units, the isolation between the transmitted and received signals can be effectively improved, and the coupling between the two receiving antennas can also be improved.

[0033] Furthermore, while ensuring a compact space, the design achieves effective bandwidth and inter-unit isolation, realizing the ranging and angle measurement functions of a single-transmitter dual-receiver ultra-wideband radar, with an angle measurement range of ±70°. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model, not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of an ultra-wideband radar antenna unit according to a preferred embodiment.

[0036] Figure 2 This is a schematic diagram of the structure of the intermediate-insertion microstrip-fed antenna unit in a preferred embodiment.

[0037] Figure 3 This is a schematic diagram of the structure of a biased insertion microstrip fed antenna unit according to a preferred embodiment.

[0038] Figure 4 The first antenna unit, the second antenna unit, and the third antenna unit, which are all intermediate-insertion microstrip-fed antenna units in a preferred embodiment, are shown in the antenna array schematic diagram.

[0039] Figure 5 The first antenna element in the preferred embodiment is a center-inserted microstrip-fed antenna element, and the second and third antenna elements are both bias-inserted microstrip-fed antenna elements, with the bias position close to the edge of the PCB board.

[0040] Figure 6 The first antenna element in the preferred embodiment is a center-inserted microstrip-fed antenna element, and the second and third antenna elements are both bias-inserted microstrip-fed antenna elements, with the bias position close to the center line of the PCB board.

[0041] Figure 7 The first antenna unit, the second antenna unit, and the third antenna unit in the preferred embodiment are all biased insertion microstrip fed antenna units, and the biased positions of the second antenna unit and the third antenna unit are close to the edge of the PCB board.

[0042] Figure 8 The first antenna unit, the second antenna unit, and the third antenna unit in the preferred embodiment are all biased insertion microstrip fed antenna units, and the biased positions of the second antenna unit and the third antenna unit are close to the center line of the PCB board.

[0043] Figure 9 This is a schematic diagram of an antenna array with a nested open resonant ring periodic structure, representing a preferred embodiment.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Antenna element; 11. Dielectric substrate carrier; 12. Insert-type microstrip feed conductor; 13. Rectangular printed antenna patch; 131. First rectangular side; 132. Second rectangular side; 14. Metal via; 15. First slot; 16. Second slot; 17. Ground metal layer; 18. Intermediate metal layer; 19. Metal layer containing RF traces, chips and peripheral circuits;

[0046] 2. Center-inserted microstrip-fed antenna element; 21. Center-inserted microstrip-fed conductive strip;

[0047] 3. Offset insertion microstrip fed antenna element; 31. Offset insertion microstrip fed conductor;

[0048] 4. First antenna element;

[0049] 5. Second line unit;

[0050] 6. Third antenna unit;

[0051] 7. PCB board;

[0052] 8. Nested open-ring periodic structure. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0054] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0055] Based on the problems existing in the prior art, this utility model provides an ultra-wideband radar antenna array, which optimizes the antenna space occupation problem by placing the transmitting antenna unit and two receiving antenna units one above the other.

[0056] Based on the problems existing in the prior art, this utility model provides an ultra-wideband radar antenna unit. The antenna unit 1 includes a dielectric substrate carrier 11, an insertable microstrip feed conductor 12, a rectangular printed antenna patch 13, and a metal via 14.

[0057] The dielectric substrate carrier 11 serves as the carrier for the rectangular printed antenna patch 13, and its dielectric constant is greater than or equal to 2, while its loss tangent is less than or equal to 10°. -3 Its thickness is less than or equal to 3mm.

[0058] like Figure 1 As shown, a rectangular printed antenna patch 13 and an insertable microstrip feed conductor 12 are disposed on the upper surface of the dielectric substrate carrier 11. The rectangular printed antenna patch 13 is provided with a rectangular groove, and the insertable microstrip feed conductor 12 is electrically connected to the rectangular printed antenna patch 13 in the rectangular groove.

[0059] The rectangular printed antenna patch 13 includes a first rectangular side 131 along the length direction of the patch 13 and a second rectangular side 132 along the width direction of the patch 13. The lengths of the first rectangular side 131 and the second rectangular side 132 are matched with the target center frequency of the antenna. The lengths of the first rectangular side 131 and the second rectangular side 132 can adjust the center frequency of the antenna to a certain extent. The center frequency of the antenna operation decreases as the first rectangular side 131 and the second rectangular side 132 increase.

[0060] A first slot 15 and a second slot 16 are symmetrically arranged between the insert-type microstrip feed conductor 12 and the rectangular printed antenna patch 13. The depth of the first slot 15 and the second slot 16 is less than or equal to half the side 132 of the second rectangle, and the width of the first slot 15 and the second slot 16 is less than or equal to the width of the insert-type microstrip feed conductor 12. The depth of the first slot 15 and the second slot 16 can match the feed of the insert-type microstrip feed conductor 12 to the target input impedance, and the width of the first slot 15 and the second slot 16 can adjust the matched antenna bandwidth.

[0061] Antenna element 1 is divided into an antenna layer, a ground metal layer 17, an intermediate metal layer 18, and a metal layer 19 containing RF traces, chips, and peripheral circuits, from top to bottom. An insert-type microstrip feed conductor 12 is electrically connected to one end of a metal via 14. The other end of the metal via 14 passes through the ground metal layer 17 and the intermediate metal layer 18 and is electrically connected to the metal layer 19 containing RF traces, chips, and peripheral circuits. The ground plane of the ground metal layer 17 serves as a signal isolation ground plane, matching the rectangular printed antenna patch 13 to ensure effective electromagnetic wave radiation. The radar signal originates from the chip port, passes through the intermediate metal layer 18 and the RF traces on the metal layer 19 containing RF traces, chips, and peripheral circuits, and connects to the metal via 14 in the intermediate metal layer 18. Then, the signal current passes through the metal via 14 and connects to the insert-type microstrip feed conductor 12 to the rectangular printed antenna patch 13. To improve polarization purity, this invention uses a metal via 14 for microstrip feeding, rather than directly exciting the metal patch through a via.

[0062] like Figure 2 and Figure 3 As shown, this utility model provides two antenna element designs 1, including a center-inserted microstrip-fed antenna element 2 and an offset-inserted microstrip-fed antenna element 3. It should be noted that... Figure 2 and Figure 3 The antenna elements in this paper omit the dielectric substrate carrier and metal layer, showing only the rectangular printed antenna patch and the inserted microstrip feed conductor to illustrate the different positions of the inserted microstrip feed conductor in the intermediate inserted microstrip feed antenna element 2 and the offset inserted microstrip feed antenna element 3. Unlike printed antennas with coaxial feeding, the transmission direction of the excitation current is along both the horizontal and vertical directions of the rectangle, resulting in a greater degree of cross-polarization. Both antenna elements 1 provided by this invention are inserted microstrip fed, which has better polarization purity compared to other feeding methods.

[0063] The center-inserted microstrip-fed antenna element 2 is a rectangular groove positioned at the midpoint of the opposite side of the first rectangular edge 131 of the rectangular printed antenna patch 13. The center-inserted microstrip-fed antenna element 2 is symmetrical from left to right, and the current flowing vertically to the center-inserted microstrip-fed conductor 21 cancels each other out. In this feeding method, the current flows primarily along the insertion direction of the center-inserted microstrip-fed conductor 21, concentrating on the left and right sides of the conductor 21 and the first rectangular edge 131. This results in a good Q value for the antenna near the center frequency; therefore, the center-inserted microstrip-fed antenna element 2 is used to improve the antenna's Q value.

[0064] The bias-insertion microstrip-fed antenna element 3 is a rectangular groove positioned on the opposite side of the first rectangular side 131 of the rectangular printed antenna patch 13. The bias feeding of the bias-insertion microstrip-fed antenna element 3 creates a difference in the current paths of the rectangular printed antenna patches 13 on the left and right sides of the bias-insertion microstrip-fed conductor 31, which can slightly perturb the original resonant frequency, obtaining two resonant points near the original center frequency, thereby achieving a larger bandwidth. Therefore, the bias-insertion microstrip-fed antenna element 3 is used to improve bandwidth expansion.

[0065] like Figures 4-8 As shown, this utility model provides an antenna array for an ultra-wideband radar antenna element. The antenna array includes a first antenna element 4, a second antenna element 5, and a third antenna element 6. The first antenna element 4 is used to transmit radio frequency signals, and the second antenna element 5 and the third antenna element 6 are used to receive radio frequency signals. The first antenna element 4, the second antenna element 5, and the third antenna element 6 are placed vertically, and the second antenna element 5 and the third antenna element 6 are symmetrical about the centerline of the first antenna element 4. It should be noted that... Figures 4-8The antenna elements in the diagram omit the dielectric substrate carrier and metal layer, showing only the rectangular printed antenna patch and the insert microstrip feed conductor to illustrate the different positions of the insert microstrip feed conductor in the intermediate insert microstrip feed antenna element and the offset insert microstrip feed antenna element.

[0066] In some embodiments, such as Figures 4-8 As shown, the antenna array consists of the first antenna element 4, the second antenna element 5, and the third antenna element 6, all of which are intermediate-insertion microstrip-fed antenna elements 2.

[0067] in Figure 4 A is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4 pointing to the lower end of the PCB board 7, and the ends of the middle insert microstrip feed conductor 21 of the second antenna unit 5 and the third antenna unit 6 pointing to the upper end of the PCB board 7 respectively.

[0068] in Figure 4 B is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6, which points to the upper end of the PCB board 7 respectively.

[0069] in Figure 4 C is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4 pointing to the upper end of the PCB board 7, and the ends of the middle insert microstrip feed conductor 21 of the second antenna unit 5 and the third antenna unit 6 pointing to the lower end of the PCB board 7, respectively.

[0070] in Figure 4 D is the end of the interstitial microstrip feed conductor 21 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6, which points to the lower end of the PCB board 7.

[0071] In some embodiments, such as Figure 5 As shown, the first antenna element 4 is a center-inserted microstrip-fed antenna element 2, and the second antenna element 5 and the third antenna element 6 are both offset-inserted microstrip-fed antenna elements 3, with the offset position close to the edge of the PCB board 7, forming an antenna array:

[0072] in Figure 5 A is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4, which points to the lower end of the PCB board 7. The ends of the bias insert microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7, respectively.

[0073] in Figure 5B is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4, and the ends of the bias insert microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7, respectively.

[0074] in Figure 5 C is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4, and the ends of the bias insert microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 point to the lower end of the PCB board 7, respectively.

[0075] in Figure 5 D is the end of the middle insert microstrip feed conductor 21 of the first antenna unit 4 pointing to the upper end of the PCB board 7, and the ends of the bias insert microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 pointing to the lower end of the PCB board 7, respectively.

[0076] In some embodiments, such as Figure 6 As shown, the first antenna element 4 is a center-inserted microstrip-fed antenna element 2, and the second antenna element 5 and the third antenna element 6 are both offset-inserted microstrip-fed antenna elements 3, with the offset position close to the center line of the PCB board 7 forming an antenna array.

[0077] in Figure 6 A is the first antenna unit 4, and the end of the intermediate inserted microstrip feed conductor 21 points to the lower end of the PCB board 7. The ends of the bias inserted microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7, respectively.

[0078] in Figure 6 B is the end of the first antenna unit 4, which is the middle insertion microstrip feed conductor 21. The ends of the second antenna unit 5 and the third antenna unit 6, which are bias insertion microstrip feed conductors 31, point to the upper end of the PCB board 7, respectively.

[0079] in Figure 6 C is the end of the first antenna unit 4, which is the middle insertion microstrip feed conductor 21. The ends of the second antenna unit 5 and the third antenna unit 6, which are the bias insertion microstrip feed conductors 31, point to the lower end of the PCB board 7, respectively.

[0080] in Figure 6 D is the first antenna element 4, and the end of the intermediate inserted microstrip feed conductor 21 points to the upper end of the PCB board 7. The ends of the bias inserted microstrip feed conductor 31 of the second antenna element 5 and the third antenna element 6 point to the lower end of the PCB board 7, respectively.

[0081] In some embodiments, such as Figure 7As shown, the first antenna element 4, the second antenna element 5, and the third antenna element 6 are all biased insertion microstrip fed antenna elements 3, and the biased positions of the second antenna element 5 and the third antenna element 6 are close to the edge of the PCB board 7 to form an antenna array.

[0082] in Figure 7 In the first antenna unit 4, the end of the bias insertion microstrip feed conductor 31 points to the lower end of the PCB board 7, and the ends of the bias insertion microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7, respectively.

[0083] in Figure 7 B is the bias insertion microstrip feed conductor 31 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6, with the ends pointing to the upper end of the PCB board 7 respectively.

[0084] in Figure 7 C is the bias insertion microstrip feed conductor 31 of the first antenna unit 4, with the end pointing to the upper end of the PCB board 7. The ends of the bias insertion microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 respectively point to the lower end of the PCB board 7.

[0085] in Figure 7 D is the bias insertion microstrip feed conductor 31 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6, with the ends pointing to the lower end of the PCB board 7 respectively.

[0086] In some embodiments, such as Figure 8 As shown, the first antenna element 4, the second antenna element 5, and the third antenna element 6 are all biased insertion microstrip fed antenna elements 3, and the biased positions of the second antenna element 5 and the third antenna element 6 are close to the antenna array formed by the center line of the PCB board 7.

[0087] in Figure 8 In the first antenna unit 4, the end of the bias insertion microstrip feed conductor 31 points to the lower end of the PCB board 7, and the ends of the bias insertion microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7, respectively.

[0088] in Figure 8 B is the bias insertion microstrip feed conductor 31 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6, with the ends pointing to the upper end of the PCB board 7 respectively.

[0089] in Figure 8 The C of the bias insertion microstrip feed conductor 31 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6 points to the lower end of the PCB board 7 respectively.

[0090] in Figure 8 D is the bias insertion microstrip feed conductor 31 of the first antenna unit 4, which points to the upper end of the PCB board 7. The bias insertion microstrip feed conductor 31 of the second antenna unit 5 and the third antenna unit 6 respectively point to the lower end of the PCB board 7.

[0091] Metamaterials are artificially synthesized materials whose physical properties differ from those of naturally occurring materials due to altered material arrangement or structure. One characteristic of metamaterials is their negative refractive index, which prevents radio waves from penetrating them. This provides shielding protection, avoids interference from nearby conductive surfaces, and improves isolation between antennas.

[0092] Negative refractive index metamaterials can be designed and constructed into concentric arrays of subwavelength open-circuit resonators at microwave frequencies, with nested open-circuit resonators placed opposite each other. The capacitance of each element is generated by the close spacing between these concentric rings, while the inductance is formed by the length enclosed by each ring. Compared to transmission line metamaterials, nested open-circuit resonator-based metamaterials are suitable for constructing two-dimensional or three-dimensional left-handed materials, are easy to integrate, are suitable for operation at high frequencies, and can realize most of the extraordinary electromagnetic properties of metamaterials.

[0093] like Figure 9 As shown, nested open-loop resonant ring periodic structures 8 for decoupling are provided in the gaps between the first antenna element 4, the second antenna element 5, and the third antenna element 6. In ultra-wideband radar systems, the transmit and receive frequency bands are the same and used simultaneously, placing high demands on the isolation between the receiving and transmitting systems. Insufficient transmit-receive isolation leads to excessively strong signal leakage from the transmitted signal into the receiving system, resulting in increased noise floor, system saturation, and performance degradation. This invention effectively utilizes the gaps between the antennas by adding nested open-loop resonant ring periodic structures 8 between the first antenna element 4, the second antenna element 5, and the third antenna element 6. Within these gaps, the propagation of surface waves in the dielectric substrate carrier 11 is effectively suppressed, creating a high-resistivity surface between the first antenna element 4, the second antenna element 5, and the third antenna element 6, thereby reducing mutual coupling between the antenna elements 1.

[0094] The nested open-ring resonant periodic structure 8 includes multiple open-ring resonant units; each of the multiple open-ring resonant units is a polygonal structure including an inner ring and an outer ring with an opening, and the wavelength of the resonant frequency is 1 / 8 to 1 / 30 of the wavelength.

[0095] Each of the plurality of open-ended resonant ring units has K sides, where K ≥ 8. Compared to ordinary quadrilateral rectangular open-ended resonant rings, the polygonal resonant ring proposed in this invention provides better isolation at specific frequencies. The plurality of open-ended resonant ring units form a T-shaped array, which is used to isolate the first antenna unit, the second antenna unit, and the third antenna unit, thereby improving the isolation between the three antennas.

[0096] The number of open-loop resonant ring isolation units between the edges of the two antenna monopole plates is m, where m ≥ 2, and the isolation increases with the value of n. The number of isolation units in the other direction is determined by the antenna width. In this embodiment, the number of open-loop resonant ring units between the first antenna unit and the second antenna unit is N1, where N1 ≥ 4; the number of open-loop resonant ring units between the first antenna unit and the third antenna unit is N2, where N2 ≥ 4; the number of open-loop resonant ring units between the second antenna unit and the third antenna unit is N3, where N3 ≥ 6; the spacing between the inner and outer rings is 0.1-0.5 mm, and the spacing between the plurality of open-loop resonant ring units is 0.2-0.8 mm.

[0097] This utility model discloses an ultra-wideband radar antenna unit and array. The antenna unit includes a dielectric substrate carrier, a rectangular printed antenna patch, an insertable microstrip feed strip, and metal vias. The upper surface of the dielectric substrate carrier is provided with a rectangular printed antenna patch and an insertable microstrip feed strip. The rectangular printed antenna patch has a rectangular groove, and the insertable microstrip feed strip is electrically connected to the rectangular printed antenna patch within the rectangular groove. The rectangular printed antenna patch includes a first rectangular side and a second rectangular side. The first rectangular side is located along the length direction, and the second rectangular side is located along the width direction. The lengths of the first and second rectangular sides match the target center frequency of the antenna. The insertable microstrip feed strip... A first gap and a second gap are symmetrically arranged between the conductor strip and the rectangular printed antenna patch. The depth of the first gap and the second gap is less than or equal to half the side of the second rectangle, and the width of the first gap and the second gap is less than or equal to the width of the insert-type microstrip feed conductor strip. The antenna unit is divided into an antenna layer, a ground metal layer, an intermediate metal layer, and a metal layer containing RF traces, chips, and peripheral circuits from top to bottom. The insert-type microstrip feed conductor strip is electrically connected to one end of the metal via. The other end of the metal via passes through the ground metal layer and the intermediate metal layer and is electrically connected to the chip and peripheral circuit metal layer containing RF traces, chips, and peripheral circuits. This solves the problem of large antenna space occupation and effectively realizes the transceiver function of an ultra-wideband radar system in a compact structure.

[0098] Furthermore, by setting an intermediate feed loading slot structure and an offset feed loading slot structure on the rectangular printed antenna patch, the Q value and bandwidth of the antenna are improved.

[0099] Furthermore, by using metal vias to feed microstrip data instead of directly exciting the metal patch vias, the polarization purity of the antenna is improved.

[0100] Furthermore, by placing the transmitting antenna unit and the two receiving antenna units one above the other, the antenna space occupancy problem is further optimized.

[0101] Furthermore, by symmetrically setting the two receiving antennas to the centerline of the transmitting antenna, it is ensured that the receiving antennas receive signals with similar amplitudes after being emitted by the transmitting antenna and reflected by objects.

[0102] Furthermore, by designing a periodic metamaterial structure based on nested open resonant ring units, the isolation between the transmitted and received signals can be effectively improved, and the coupling between the two receiving antennas can also be improved.

[0103] Furthermore, while ensuring a compact space, the design achieves effective bandwidth and inter-unit isolation, realizing the ranging and angle measurement functions of a single-transmitter dual-receiver ultra-wideband radar, with an angle measurement range of ±70°.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this utility model.

Claims

1. An ultra-wideband radar antenna array, characterized in that, The antenna array includes a first antenna unit, a second antenna unit, and a third antenna unit. The first antenna unit is used to transmit radio frequency signals, and the second and third antenna units are used to receive radio frequency signals. The first antenna unit, the second antenna unit, and the third antenna unit are placed vertically, and the second and third antenna units are symmetrical about the center line of the first antenna unit.

2. The ultra-wideband radar antenna array as described in claim 1, characterized in that, The first antenna unit, the second antenna unit, and the third antenna unit each include a dielectric substrate carrier, a rectangular printed antenna patch, an insert-type microstrip feed conductor, and a metal via. The upper surface of the dielectric substrate carrier is provided with a rectangular printed antenna patch and an insertable microstrip feed conductor. The rectangular printed antenna patch is provided with a rectangular groove, and the insertable microstrip feed conductor is electrically connected to the rectangular printed antenna patch in the rectangular groove. The rectangular printed antenna patch includes a first rectangular side and a second rectangular side. The first rectangular side is located along the length direction of the rectangular printed antenna patch, and the second rectangular side is located along the width direction of the rectangular printed antenna patch. The length of the first rectangular side and the length of the second rectangular side are matched with the target center frequency of the antenna. A first gap and a second gap are symmetrically arranged between the insertable microstrip feed conductor and the rectangular printed antenna patch. The depth of the first gap and the second gap is less than or equal to half the side of the second rectangle, and the width of the first gap and the second gap is less than or equal to the width of the insertable microstrip feed conductor. The antenna unit is divided into an antenna layer, a ground metal layer, an intermediate metal layer, and a metal layer containing radio frequency traces, chips, and peripheral circuits from top to bottom. The insert-type microstrip feed conductor is electrically connected to one end of the metal via. The other end of the metal via passes through the ground metal layer and the intermediate metal layer and is electrically connected to the metal layer containing radio frequency traces, chips, and peripheral circuits.

3. The ultra-wideband radar antenna array as described in claim 1, characterized in that, The first antenna element, the second antenna element, and the third antenna element are all antenna arrays of mid-insertion microstrip-fed antenna elements; Alternatively, the first antenna element is a center-inserted microstrip-fed antenna element, and the second and third antenna elements are both offset-inserted microstrip-fed antenna elements, with the offset position close to the edge of the PCB board, forming an antenna array. Alternatively, the first antenna element is a center-inserted microstrip-fed antenna element, and the second and third antenna elements are both offset-inserted microstrip-fed antenna elements, with the offset position close to the center line of the PCB board forming an antenna array. Alternatively, the first antenna unit, the second antenna unit, and the third antenna unit are all biased insertion microstrip fed antenna units, and the biased positions of the second antenna unit and the third antenna unit are close to the edge of the PCB board to form an antenna array. Alternatively, the first antenna unit, the second antenna unit, and the third antenna unit are all biased insertion microstrip fed antenna units, and the biased positions of the second antenna unit and the third antenna unit are close to the center line of the PCB board to form an antenna array.

4. The ultra-wideband radar antenna array as described in claim 3, characterized in that, The end of the insert-type microstrip feed conductive strip of the first antenna unit points to the lower end of the PCB board, and the ends of the insert-type microstrip feed conductive strips of the second antenna unit and the third antenna unit respectively point to the upper end of the PCB board; Alternatively, the ends of the insert-type microstrip feed conductors of the first antenna unit, the second antenna unit, and the third antenna unit respectively point to the upper end of the PCB board; Alternatively, the end of the insertable microstrip feed conductor of the first antenna unit points to the upper end of the PCB board, and the ends of the insertable microstrip feed conductors of the second antenna unit and the third antenna unit respectively point to the lower end of the PCB board. Alternatively, the ends of the insert-type microstrip feed conductors of the first antenna unit, the second antenna unit, and the third antenna unit respectively point to the lower end of the PCB board.

5. The ultra-wideband radar antenna array as described in claim 1, characterized in that, The gaps between the first antenna unit, the second antenna unit, and the third antenna unit are all provided with nested open resonant ring periodic structures for decoupling.

6. The ultra-wideband radar antenna array as described in claim 5, characterized in that, The nested open resonant ring periodic structure includes multiple open resonant ring units; Each of the plurality of open resonant ring units is a polygonal structure including an inner ring and an outer ring with an opening, and the number of sides of each of the plurality of open resonant ring units is K, where K≥8; The plurality of open resonant ring units form a T-shaped array, which is used to isolate the first antenna unit, the second antenna unit and the third antenna unit; The number of open-loop resonant units between the first antenna unit and the second antenna unit is N1, N1≥4; the number of open-loop resonant units between the first antenna unit and the third antenna unit is N2, N2≥4; and the number of open-loop resonant units between the second antenna unit and the third antenna unit is N3, N3≥6. The spacing between the inner and outer rings is 0.1-0.5 mm, and the spacing between the plurality of open resonant ring units is 0.2-0.8 mm.

Images