Ultra-wideband radar antenna unit and array

Abstract

The invention discloses an ultra wide band radar antenna unit and an array. The antenna unit comprises a dielectric substrate carrier, a rectangular printed antenna patch, an insertion type microstrip feed conduction band and a metal via hole. The upper surface of the dielectric substrate carrier is provided with a rectangular printed antenna patch and an inserted microstrip feed conduction band, the rectangular printed antenna patch is provided with a rectangular groove, and the inserted microstrip feed conduction band is electrically connected with the rectangular printed antenna patch in the rectangular groove. The antenna unit is divided into an antenna layer, a floor metal layer, a middle metal layer and a metal layer from top to bottom, the metal layer comprises a radio frequency wire, a chip and a peripheral circuit, and the insertion type microstrip feed conduction band is electrically connected with one end of the metal through hole; and the other end of the metal via hole penetrates through the floor metal layer and the middle metal layer and is electrically connected with the metal layer comprising the radio frequency wire, the chip and the peripheral circuit. According to the invention, the middle feed loading slot structure and the bias feed loading slot structure are arranged on the rectangular printed antenna patch, so that the Q value and the bandwidth broadening of the antenna are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-collision radar, and in particular to an ultra-wideband radar antenna unit and array. Background Art

[0002] With the development of industry and society, the per capita ownership of motor vehicles such as electric vehicles and cars has increased year by year. On the roads where motor vehicles are driving, coupled with factors such as road conditions, the influence of bad weather such as night and rain and snow, and the increased fatigue of drivers after long-term driving, drivers often have insufficient reaction time when they find something ahead. Therefore, it is urgent to develop a car anti-collision radar warning system to ensure driving safety when visibility is low and the driver is driving for a long time. Anti-collision radar is a detection device that can send audio-visual warning signals to the driver in advance. It is installed on the motor vehicle and can detect pedestrians, vehicles or surrounding obstacles that attempt to approach the vehicle body; it can send a signal of impending collision danger to the driver and passengers in advance, prompting the driver to take emergency measures to deal with special dangers and avoid losses.

[0003] Ultra Wideband (UWB) is applicable to a wide range of wireless systems. UWB radar signals are insensitive to channel fading, have low power spectrum density of transmitted signals, and the transmission system consumes much less power than existing traditional radio technologies. In particular, they have low interference characteristics to other wireless systems, and have strong anti-interference capabilities and high-precision distance resolution. The principle used by UWB radar is similar to Time Of Flight (TOF). A signal is sent through the transmitter, and the signal bounces back to the receiver after hitting an obstacle. The distance of signal transmission can be obtained by calculating the time difference between the transmitted and received signals and multiplying it by the speed of light. UWB radar uses the Doppler effect of wireless signals to detect changes in the surrounding electromagnetic environment. Moving objects will emit electromagnetic waves and apply frequency shifts to the electromagnetic waves. The presence of movement can be determined by the characteristics of changes in the battery environment.

[0004] The automobile anti-collision radar system based on ultra-wideband technology is a brand-new detection technology. It detects targets by emitting ultra-wideband signals of the GHz level, measures distance and speed using the radar principle, and determines the existence of targets by detecting the target's echo. The main design concept of the automobile radar anti-collision system is to take into account that traffic accidents often occur in complex road conditions, poor visibility, and driver fatigue. Therefore, its main design purpose is to detect potentially dangerous targets ahead as early as possible, provide a multimedia alarm display platform, and promptly remind the driver to take corresponding handling actions.

[0005] However, the automotive anti-collision radar system based on ultra-wideband technology still has certain defects and its accuracy and stability are not high.

[0006] Therefore, it is necessary to provide an ultra-wideband radar antenna unit and array to solve the above problems. Summary of the invention

[0007] In view of the problems and shortcomings of the prior art, the present invention provides an ultra-wideband radar antenna unit and array, which improves the Q value and bandwidth broadening of the antenna by arranging an intermediate feed loading slot structure and a bias feed loading slot structure on a rectangular printed antenna patch.

[0008] An embodiment of the present invention provides an ultra-wideband radar antenna unit, the antenna unit comprising a dielectric substrate carrier, a rectangular printed antenna patch, an inserted microstrip feeding conductor, and a metal via; A rectangular printed antenna patch and an inserted microstrip feeding conductive strip are provided on the upper surface of the dielectric substrate carrier, the rectangular printed antenna patch is provided with a rectangular groove, and the inserted microstrip feeding conductive strip 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, wherein the rectangular printed antenna patch is the first rectangular side along the length direction, and the rectangular printed antenna patch is the second rectangular side along the width direction, and the length of the first rectangular side and the length of the second rectangular side match the target center frequency of the antenna; A first gap and a second gap are symmetrically arranged between the inserted microstrip feed conductive strip and the rectangular printed antenna patch, the depth of the first gap and the second gap is less than or equal to half of the second rectangular side, and the width of the first gap and the second gap is less than or equal to the width of the inserted microstrip feed conductive strip; The antenna unit is divided into an antenna layer, a floor metal layer, an intermediate metal layer and a metal layer including RF routing, chips and peripheral circuits from top to bottom. The inserted microstrip feeding conductor is electrically connected to one end of the metal via, and the other end of the metal via passes through the floor metal layer and the intermediate metal layer and is electrically connected to the metal layer including RF routing, chips and peripheral circuits.

[0009] Preferably, the antenna unit is a middle-insertion microstrip feeding antenna unit, and the rectangular groove is arranged at a middle position on opposite sides of the first rectangular side of the rectangular printed antenna patch.

[0010] Preferably, the antenna unit is an offset inserted microstrip fed antenna unit, and the rectangular groove is arranged at an offset position on the opposite side of the first rectangular side of the rectangular printed antenna patch.

[0011] Preferably, the metal via is a metal via-to-microstrip feed.

[0012] Preferably, the dielectric constant of the dielectric substrate carrier is greater than or equal to 2, and the loss tangent is less than or equal to 10-3 , its thickness is less than or equal to 3mm.

[0013] An embodiment of the present invention also provides an antenna array using the above-mentioned ultra-wideband radar antenna unit, wherein the antenna array includes a first antenna unit, a second antenna unit and a third antenna unit, wherein the first antenna unit is used to transmit radio frequency signals, and the second antenna unit and the third antenna unit are used to receive radio frequency signals, and the first antenna unit, the second antenna unit and the third antenna unit are respectively placed up and down, and the second antenna unit and the third antenna unit are symmetrical with respect to the midline of the first antenna unit.

[0014] Preferably, the first antenna unit, the second antenna unit and the third antenna unit are all antenna arrays of intermediate inserted microstrip feeding antenna units.

[0015] Alternatively, the first antenna unit is an intermediate inserted microstrip feeding antenna unit, the second antenna unit and the third antenna unit are offset inserted microstrip feeding antenna units, and the offset position is close to the edge of the PCB board to form an antenna array.

[0016] Alternatively, the first antenna unit is an intermediate inserted microstrip feeding antenna unit, the second antenna unit and the third antenna unit are offset inserted microstrip feeding antenna units, and the offset position is close to the middle line of the PCB board to form an antenna array.

[0017] Alternatively, the first antenna unit, the second antenna unit, and the third antenna unit are all offset inserted microstrip fed antenna units, and the offset 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.

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

[0019] Preferably, the end of the inserted microstrip feed conductor of the first antenna unit points to the lower end of the PCB board, and the ends of the inserted microstrip feed conductors 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 inserted microstrip feeding conductors of the first antenna unit, the second antenna unit, and the third antenna unit are respectively directed to the upper end of the PCB board.

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

[0022] Alternatively, the ends of the inserted microstrip feeding conductors of the first antenna unit, the second antenna unit, and the third antenna unit are respectively directed 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 split resonant ring periodic structure comprises a plurality of split resonant ring units; Each of the plurality of split resonant ring units is a polygonal structure including an open inner ring and an open outer ring, and the number of sides of each of the plurality of split resonant ring units is K, where K≥8; The multiple open resonant ring units form a T-shaped array, and the T-shaped array is used to isolate the first antenna unit, the second antenna unit and the third antenna unit; The number of the open resonant ring units between the first antenna unit and the second antenna unit is N1, N1≥4; the number of the open resonant ring units between the first antenna unit and the third antenna unit is N2, N2≥4; the number of the open resonant ring units between the second antenna unit and the third antenna unit is N3, N3≥6; The spacing between the inner ring and the outer ring is 0.1-0.5 mm, and the spacing between the multiple open resonant ring units is 0.2-0.8 mm.

[0025] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects: An ultra-wideband radar antenna unit and array according to an embodiment of the present invention, the antenna unit comprises a dielectric substrate carrier, a rectangular printed antenna patch, an inserted microstrip feeding conductive strip, and a metal via; a rectangular printed antenna patch and an inserted microstrip feeding conductive strip are arranged on the upper surface of the dielectric substrate carrier, the rectangular printed antenna patch is provided with a rectangular groove, and the inserted microstrip feeding conductive strip is electrically connected to the rectangular printed antenna patch in the rectangular groove; the rectangular printed antenna patch comprises a first rectangular side and a second rectangular side, the rectangular printed antenna patch is a first rectangular side along the length direction, and the rectangular printed antenna patch is a second rectangular side along the width direction, and the length of the first rectangular side and the length of the second rectangular side match the target center frequency of the antenna; the inserted microstrip feeding conductive strip is a first rectangular side and a second rectangular side, and the length of the inserted microstrip feeding conductive strip matches the target center frequency of the antenna; the inserted microstrip feeding conductive strip is a first rectangular side and a second rectangular side, and the length of the inserted microstrip feeding conductive strip matches the target center frequency of the antenna; the inserted microstrip feeding conductive strip is a first rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a second rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a second rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a first ... first rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a A first gap and a second gap are symmetrically arranged between the strip and the rectangular printed antenna patch, the depth of the first gap and the second gap is less than or equal to half of the second rectangular side, and the width of the first gap and the second gap is less than or equal to the width of the inserted microstrip feeding conductive strip; the antenna unit is divided into an antenna layer, a floor metal layer, an intermediate metal layer, and a metal layer containing radio frequency wiring, a chip, and a peripheral circuit from top to bottom, the inserted microstrip feeding conductive strip is electrically connected to one end of the metal via, and the other end of the metal via passes through the floor metal layer and the intermediate metal layer and is electrically connected to the chip containing radio frequency wiring, a chip, and a peripheral circuit and the metal layer of the peripheral circuit, thereby solving the problem of large antenna space occupation and effectively realizing the transceiver function of the ultra-wideband radar system under a compact structure; Furthermore, by providing a middle feed loading slot structure and a bias feed loading slot structure on the rectangular printed antenna patch, the Q value and bandwidth broadening of the antenna are improved; Furthermore, the polarization purity of the antenna is improved by adopting a method of transferring metal vias to microstrip feeding instead of directly exciting the metal patch with vias. Furthermore, by placing the transmitting antenna unit and the two receiving antenna units one above the other, the problem of antenna space occupation is further optimized; Furthermore, by arranging the two receiving antennas symmetrically about the midline of the transmitting antenna, it is ensured that the receiving antenna receives a signal with a similar signal amplitude which is emitted by the transmitting antenna and then reflected by an object; Furthermore, by designing a periodic metamaterial structure based on a nested split resonant ring unit, the isolation between the transmitted signal and the received signal can be effectively improved, and the coupling between the two receiving antennas can also be improved; Furthermore, on the basis of ensuring compact space, the design of effective bandwidth and isolation between units is achieved, realizing the ranging and angle measurement functions of the one-transmit, two-receive ultra-wideband radar, with an angle measurement range of ±70°. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present invention, not all embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0027] Figure 1 Schematic diagram of the structure of an ultra-wideband radar antenna unit of a preferred embodiment.

[0028] Figure 2 It is a schematic structural diagram of a middle insertion type microstrip feeding antenna unit of a preferred embodiment.

[0029] Figure 3 It is a schematic structural diagram of a biased inserted microstrip fed antenna unit of a preferred embodiment.

[0030] Figure 4 The first antenna unit, the second antenna unit and the third antenna unit of the preferred embodiment are all schematic diagrams of an antenna array with intermediate inserted microstrip feeding antenna units.

[0031] Figure 5 A schematic diagram of an antenna array in which the first antenna unit of a preferred embodiment is an intermediate inserted microstrip fed antenna unit, the second antenna unit and the third antenna unit are offset inserted microstrip fed antenna units, and the offset position is close to the edge of the PCB board.

[0032] Figure 6 A schematic diagram of an antenna array in which the first antenna unit of a preferred embodiment is a middle inserted microstrip fed antenna unit, the second antenna unit and the third antenna unit are offset inserted microstrip fed antenna units, and the offset position is close to the middle line of the PCB board.

[0033] Figure 7 A schematic diagram of an antenna array in which the first antenna unit, the second antenna unit and the third antenna unit of a preferred embodiment are all offset inserted microstrip fed antenna units, and the offset positions of the second antenna unit and the third antenna unit are close to the edge of the PCB board.

[0034] Figure 8 A schematic diagram of an antenna array in which the first antenna unit, the second antenna unit and the third antenna unit of a preferred embodiment are all offset inserted microstrip fed antenna units, and the offset positions of the second antenna unit and the third antenna unit are close to the middle line of the PCB board.

[0035] Fig. 9 It is a schematic structural diagram of an antenna array with a nested open resonant ring periodic structure according to a preferred embodiment.

[0036] Description of reference numerals: 1. Antenna unit; 11. Dielectric substrate carrier; 12. Inserted microstrip feed conductor; 13. Rectangular printed antenna patch; 131. First rectangular edge; 132. Second rectangular edge; 14. Metal via; 15. First gap; 16. Second gap; 17. Floor metal layer; 18. Intermediate metal layer; 19. Metal layer including RF traces, chips and peripheral circuits; 2. Intermediate insertion type microstrip feeding antenna unit; 21. Intermediate insertion type microstrip feeding conductor strip; 3. Biased inserted microstrip fed antenna unit; 31. Biased inserted microstrip fed conductor strip; 4. A first antenna unit; 5. Second antenna unit; 6. The third antenna unit; 7. PCB board; 8. Nested open resonant ring periodic structure. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0039] Based on the problems existing in the prior art, an embodiment of the present invention provides an ultra-wideband radar antenna unit and array, which improves the Q value and bandwidth broadening of the antenna by arranging an intermediate feed loading slot structure and a bias feed loading slot structure on a rectangular printed antenna patch.

[0040] Based on the problems existing in the prior art, an embodiment of the present invention provides an ultra-wideband radar antenna unit. The antenna unit 1 includes a dielectric substrate carrier 11, an inserted microstrip feeding conductor 12, a rectangular printed antenna patch 13, and a metal via 14.

[0041] The dielectric substrate carrier 11 is a carrier for carrying the rectangular printed antenna patch 13, and its dielectric constant is greater than or equal to 2, and its loss tangent is less than or equal to 10 -3 , its thickness is less than or equal to 3mm.

[0042] like Figure 1 As shown, a rectangular printed antenna patch 13 and an inserted microstrip feeding conductor 12 are provided on the upper surface of the dielectric substrate carrier 11. The rectangular printed antenna patch 13 is provided with a rectangular groove. The inserted microstrip feeding conductor 12 is electrically connected to the rectangular printed antenna patch 13 in the rectangular groove.

[0043] The rectangular printed antenna patch 13 includes a first rectangular side 131 along the length direction of the rectangular printed antenna patch 13 and a second rectangular side 132 along the width direction of the rectangular printed antenna patch 13. The length of the first rectangular side 131 and the length of the second rectangular side 132 match 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.

[0044] A first slot 15 and a second slot 16 are symmetrically arranged between the inserted microstrip feed strip 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 of the second rectangular side 132, and the width of the first slot 15 and the second slot 16 is less than or equal to the width of the inserted microstrip feed strip 12. The depth of the first slot 15 and the second slot 16 can match the feeding of the inserted microstrip feed strip 12 to the target input impedance, and the width of the first slot 15 and the second slot 16 can adjust the bandwidth of the antenna after matching.

[0045] The antenna unit 1 is divided into an antenna layer, a floor metal layer 17, an intermediate metal layer 18, and a metal layer 19 including RF traces, chips, and peripheral circuits from top to bottom. The inserted microstrip feeding conductor 12 is electrically connected to one end of the metal via 14, and the other end of the metal via 14 is electrically connected to the metal layer 19 including RF traces, chips, and peripheral circuits through the floor metal layer 17 and the intermediate metal layer 18. The floor of the floor metal layer 17 serves as a signal isolation floor, which matches the rectangular printed antenna patch 13, so that the electromagnetic wave is effectively radiated. The radar signal is connected from the chip port through the intermediate metal layer 18 and the RF traces on the metal layer 19 including RF traces, chips, and peripheral circuits. Then the signal current is connected to the rectangular printed antenna patch 13 through the metal via 14 and the inserted microstrip feeding conductor 12. In order to improve the polarization purity, the present invention adopts the method of converting metal vias 14 to microstrip feeding, rather than directly exciting the metal patch by vias.

[0046] like Figure 2 and Figure 3 As shown, the present invention provides two antenna unit 1 designs, including a middle insertion type microstrip feeding antenna unit 2 and a bias insertion type microstrip feeding antenna unit 3. It should be noted that: Figure 2 and Figure 3 The antenna unit omits the dielectric substrate carrier and the metal layer, and only shows the rectangular printed antenna patch and the inserted microstrip feeding conductor to illustrate the different positions of the inserted microstrip feeding conductor in the middle inserted microstrip feeding antenna unit 2 and the offset inserted microstrip feeding antenna unit 3. Different from the printed antenna with coaxial feeding, the transmission direction of the excited current is along the horizontal and vertical directions of the rectangle, and a large degree of cross-polarization occurs. The two antenna units 1 provided by the present invention are both inserted microstrip fed, and have better polarization purity compared with other feeding methods.

[0047] Among them, the middle insertion microstrip feeding antenna unit 2 is a rectangular groove set in the middle position of the opposite side of the first rectangular side 131 of the rectangular printed antenna patch 13. The middle insertion microstrip feeding antenna unit 2 is symmetrical, and the current in the vertical direction of the middle insertion microstrip feeding conductive strip 21 cancels each other out. Under this feeding mode, the current flows mainly along the insertion direction of the middle insertion microstrip feeding conductive strip 21, and the current is concentrated on the left and right sides of the middle insertion microstrip feeding conductive strip 21 and the first rectangular side 131. The antenna has a good Q value near the center frequency, so the middle insertion microstrip feeding antenna unit 2 is used to improve the Q value of the antenna.

[0048] Among them, the offset insertion type microstrip feeding antenna unit 3 is a rectangular groove set at an offset position on the opposite side of the first rectangular side 131 of the rectangular printed antenna patch 13. The offset feeding of the offset insertion type microstrip feeding antenna unit 3 makes the current paths of the rectangular printed antenna patch 13 on the left and right sides of the offset insertion type microstrip feeding conductive strip 31 different, which can cause perturbations to the original resonant frequency, obtain two resonance points near the original center frequency, and thus achieve a larger bandwidth. Therefore, the offset insertion type microstrip feeding antenna unit 3 is used to improve the bandwidth broadening.

[0049] like Figure 4-Figure 8 As shown, the present invention provides an antenna array of an ultra-wideband radar antenna unit, the antenna array includes a first antenna unit 4, a second antenna unit 5 and a third antenna unit 6, the first antenna unit 4 is used to transmit radio frequency signals, the second antenna unit 5 and the third antenna unit 6 are used to receive radio frequency signals, the first antenna unit 4 and the second antenna unit 5 and the third antenna unit 6 are placed up and down respectively, and the second antenna unit 5 and the third antenna unit 6 are symmetrical with the midline of the first antenna unit 4. It should be noted that Figure 4-Figure 8 The antenna unit omits the dielectric substrate carrier and the metal layer, and only shows the rectangular printed antenna patch and the inserted microstrip feeding conductor to illustrate the different positions of the inserted microstrip feeding conductor in the middle inserted microstrip feeding antenna unit and the offset inserted microstrip feeding antenna unit.

[0050] In some embodiments, Figure 4-Figure 8As shown, the antenna array is an antenna array in which the first antenna unit 4, the second antenna unit 5, and the third antenna unit 6 are all intermediate inserted microstrip feeding antenna units 2: in Figure 4 A is that the end of the middle inserted microstrip feeding conductive tape 21 of the first antenna unit 4 points to the lower end of the PCB board 7, and the ends of the middle inserted microstrip feeding conductive tape 21 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7 respectively.

[0051] in Figure 4 B is the end of the intermediate inserted microstrip feeding conductive strip 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.

[0052] in Figure 4 C is that the end of the middle inserted microstrip feeding conductive tape 21 of the first antenna unit 4 points to the upper end of the PCB board 7, and the ends of the middle inserted microstrip feeding conductive tape 21 of the second antenna unit 5 and the third antenna unit 6 point to the lower end of the PCB board 7 respectively.

[0053] in Figure 4 D is the end of the intermediate inserted microstrip feeding conductive strip 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 respectively.

[0054] In some embodiments, Figure 5 As shown, the first antenna unit 4 is an intermediate inserted microstrip feeding antenna unit 2, the second antenna unit 5 and the third antenna unit 6 are both offset inserted microstrip feeding antenna units 3, and the offset position is close to the edge of the PCB board 7 to form an antenna array: in Figure 5 A is that the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4 points to the lower end of the PCB board 7, and the ends of the offset inserted microstrip feeding conductors 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7 respectively.

[0055] in Figure 5 B is the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4, and the ends of the offset inserted microstrip feeding conductors 31 of the second antenna unit 5 and the third antenna unit 6 respectively point to the upper end of the PCB board 7.

[0056] in Figure 5 C is the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4, and the ends of the offset inserted microstrip feeding conductors 31 of the second antenna unit 5 and the third antenna unit 6 respectively point to the lower end of the PCB board 7.

[0057] in Figure 5D is that the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4 points to the upper end of the PCB board 7, and the ends of the offset inserted microstrip feeding conductors 31 of the second antenna unit 5 and the third antenna unit 6 point to the lower end of the PCB board 7 respectively.

[0058] In some embodiments, Figure 6 As shown, the first antenna unit 4 is an intermediate inserted microstrip feeding antenna unit 2, the second antenna unit 5 and the third antenna unit 6 are both offset inserted microstrip feeding antenna units 3, and the offset position is close to the middle line of the PCB board 7 to form an antenna array.

[0059] in Figure 6 A is the first antenna unit 4, and the end of the middle inserted microstrip feeding conductive tape 21 points to the lower end of the PCB board 7, and the ends of the offset inserted microstrip feeding conductive tapes 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7 respectively.

[0060] in Figure 6 B represents the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4, and the ends of the offset inserted microstrip feeding conductor 31 of the second antenna unit 5 and the third antenna unit 6 respectively point to the upper end of the PCB board 7.

[0061] in Figure 6 C is the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4, and the ends of the offset inserted microstrip feeding 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.

[0062] in Figure 6 D is that the end of the middle inserted microstrip feeding conductor 21 of the first antenna unit 4 points to the upper end of the PCB board 7, and the ends of the offset inserted microstrip feeding conductors 31 of the second antenna unit 5 and the third antenna unit 6 point to the lower end of the PCB board 7 respectively.

[0063] In some embodiments, Figure 7 As shown, the first antenna unit 4, the second antenna unit 5, and the third antenna unit 6 are all offset inserted microstrip fed antenna units 3, and the offset positions of the second antenna unit 5 and the third antenna unit 6 are close to the edge of the PCB board 7 to form an antenna array.

[0064] in Figure 7 A is that the end of the biased inserted microstrip feeding conductive tape 31 of the first antenna unit 4 points to the lower end of the PCB board 7, and the ends of the biased inserted microstrip feeding conductive tape 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7 respectively.

[0065] in Figure 7B is the end of the biased inserted microstrip feeding conductive strip 31 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.

[0066] in Figure 7 C is that the end of the biased inserted microstrip feeding conductor 31 of the first antenna unit 4 points to the upper end of the PCB board 7, and the ends of the biased inserted microstrip feeding 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.

[0067] in Figure 7 D is the end of the biased inserted microstrip feeding conductive strip 31 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 respectively.

[0068] In some embodiments, Figure 8 As shown, the first antenna unit 4, the second antenna unit 5, and the third antenna unit 6 are all offset inserted microstrip fed antenna units 3, and the offset positions of the second antenna unit 5 and the third antenna unit 6 are close to the middle line of the PCB board 7 to form an antenna array.

[0069] in Figure 8 A is that the end of the biased inserted microstrip feeding conductive tape 31 of the first antenna unit 4 points to the lower end of the PCB board 7, and the ends of the biased inserted microstrip feeding conductive tape 31 of the second antenna unit 5 and the third antenna unit 6 point to the upper end of the PCB board 7 respectively.

[0070] in Figure 8 B is the end of the biased inserted microstrip feeding conductive strip 31 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.

[0071] in Figure 8 C is the end of the biased inserted microstrip feeding conductive tape 31 of the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6 pointing to the lower end of the PCB board 7 respectively.

[0072] in Figure 8 D is that the end of the biased inserted microstrip feeding conductor 31 of the first antenna unit 4 points to the upper end of the PCB board 7, and the ends of the biased inserted microstrip feeding 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.

[0073] Metamaterials are artificial materials that change the arrangement or physical structure of materials to present physical properties that are different from those of natural substances. One of the characteristics of metamaterials is that they have a negative refractive index, which makes radio waves impenetrable. This has the effect of shielding, avoiding interference from nearby conductive surfaces, and improving isolation between antennas.

[0074] Negative refractive index metamaterials can be designed and constructed with concentric sub-wavelength split resonant ring arrays at microwave frequencies, with nested split resonant rings placed opposite to each other. The capacitance of each element is generated by the close spacing between the concentric rings, while the inductance comes from the length surrounded by each ring. Compared with transmission line metamaterials, metamaterials based on nested split resonant rings are suitable for constructing two-dimensional or three-dimensional left-handed materials, are easy to integrate, suitable for working in high-frequency bands, and can realize most of the extraordinary electromagnetic properties of metamaterials.

[0075] like Fig. 9 As shown, the gaps between the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6 are all provided with a nested open resonant ring periodic structure 8 for decoupling. In an ultra-wideband radar system, the transmitting and receiving frequency bands are the same and are used simultaneously, which places high demands on the isolation of the receiving and transmitting systems. If the transmitting and receiving isolation is not enough, the signal strength of the transmitted signal leaking into the receiving system is too large, which will lead to an increase in the background noise of the receiving system, system saturation, and performance degradation. The present invention effectively utilizes the gaps between the antennas, and adds a nested open resonant ring periodic structure 8 between the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6. The propagation of surface waves in the dielectric substrate carrier 11 can be effectively suppressed in the gaps therebetween, and a high-resistance surface is generated between the first antenna unit 4, the second antenna unit 5 and the third antenna unit 6 to reduce the mutual coupling between the antenna units 1.

[0076] The nested split resonant ring periodic structure 8 includes a plurality of split resonant ring units; each of the plurality of split resonant ring units is a polygonal structure including an open inner ring and an open outer ring, and is 1 / 8 to 1 / 30 of the wavelength corresponding to the resonant frequency.

[0077] The number of sides of each of the multiple open resonant ring units is K, K≥8; compared with the ordinary quadrilateral rectangular open resonant ring, the polygonal resonant ring proposed in the present invention has a better isolation effect for a specific frequency. The multiple open resonant ring units form a T-shaped array, and the T-shaped array is used to isolate the first antenna unit, the second antenna unit and the third antenna unit, respectively improving the isolation between the three antennas.

[0078] The number of open resonant ring isolation units between the edges of the two antenna monopoles is m, m≥2, and the isolation increases with the increase of the value of n. The number of isolation units in the other direction is determined by the width of the antenna. In this embodiment, the number of open resonant ring units between the first antenna unit and the second antenna unit is N1, N1≥4; the number of open resonant ring units between the first antenna unit and the third antenna unit is N2, N2≥4; the number of open resonant ring units between the second antenna unit and the third antenna unit is N3, N3≥6; the spacing between the inner ring and the outer ring is 0.1-0.5mm, and the spacing between the multiple open resonant ring units is 0.2-0.8mm. An ultra-wideband radar antenna unit and array according to an embodiment of the present invention, the antenna unit comprises a dielectric substrate carrier, a rectangular printed antenna patch, an inserted microstrip feeding conductive strip, and a metal via; a rectangular printed antenna patch and an inserted microstrip feeding conductive strip are arranged on the upper surface of the dielectric substrate carrier, the rectangular printed antenna patch is provided with a rectangular groove, and the inserted microstrip feeding conductive strip is electrically connected to the rectangular printed antenna patch in the rectangular groove; the rectangular printed antenna patch comprises a first rectangular side and a second rectangular side, the rectangular printed antenna patch is a first rectangular side along the length direction, and the rectangular printed antenna patch is a second rectangular side along the width direction, and the length of the first rectangular side and the length of the second rectangular side match the target center frequency of the antenna; the inserted microstrip feeding conductive strip is a first rectangular side and a second rectangular side, and the length of the inserted microstrip feeding conductive strip matches the target center frequency of the antenna; the inserted microstrip feeding conductive strip is a first rectangular side and a second rectangular side, and the length of the inserted microstrip feeding conductive strip matches the target center frequency of the antenna; the inserted microstrip feeding conductive strip is a first rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a second rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a second rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a first ... first rectangular side and a second rectangular side, and the inserted microstrip feeding conductive strip is a A first gap and a second gap are symmetrically arranged between the strip and the rectangular printed antenna patch, the depth of the first gap and the second gap is less than or equal to half of the second rectangular side, and the width of the first gap and the second gap is less than or equal to the width of the inserted microstrip feeding conductive strip; the antenna unit is divided into an antenna layer, a floor metal layer, an intermediate metal layer, and a metal layer containing radio frequency wiring, a chip, and a peripheral circuit from top to bottom, the inserted microstrip feeding conductive strip is electrically connected to one end of the metal via, and the other end of the metal via passes through the floor metal layer and the intermediate metal layer and is electrically connected to the chip containing radio frequency wiring, a chip, and a peripheral circuit and the metal layer of the peripheral circuit, thereby solving the problem of large antenna space occupation and effectively realizing the transceiver function of the ultra-wideband radar system under a compact structure; Furthermore, by providing a middle feed loading slot structure and a bias feed loading slot structure on the rectangular printed antenna patch, the Q value and bandwidth broadening of the antenna are improved; Furthermore, the polarization purity of the antenna is improved by adopting a method of transferring metal vias to microstrip feeding instead of directly exciting the metal patch with vias. Furthermore, by placing the transmitting antenna unit and the two receiving antenna units one above the other, the problem of antenna space occupation is further optimized; Furthermore, by arranging the two receiving antennas symmetrically about the midline of the transmitting antenna, it is ensured that the receiving antenna receives a signal with a similar signal amplitude which is emitted by the transmitting antenna and then reflected by an object; Furthermore, by designing a periodic metamaterial structure based on a nested split resonant ring unit, the isolation between the transmitted signal and the received signal can be effectively improved, and the coupling between the two receiving antennas can also be improved; Furthermore, on the basis of ensuring compact space, the design of effective bandwidth and isolation between units is achieved, realizing the ranging and angle measurement functions of the one-transmit, two-receive ultra-wideband radar, with an angle measurement range of ±70°.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-wideband radar antenna unit, characterized in that: The antenna unit includes a dielectric substrate carrier, a rectangular printed antenna patch, an inserted microstrip feeding conductor, and a metal via; A rectangular printed antenna patch and an inserted microstrip feeding conductive strip are provided on the upper surface of the dielectric substrate carrier, the rectangular printed antenna patch is provided with a rectangular groove, and the inserted microstrip feeding conductive strip 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, wherein the rectangular printed antenna patch is the first rectangular side along the length direction, and the rectangular printed antenna patch is the second rectangular side along the width direction, and the length of the first rectangular side and the length of the second rectangular side match the target center frequency of the antenna; A first gap and a second gap are symmetrically arranged between the inserted microstrip feed conductive strip and the rectangular printed antenna patch, the depth of the first gap and the second gap is less than or equal to half of the second rectangular side, and the width of the first gap and the second gap is less than or equal to the width of the inserted microstrip feed conductive strip; The antenna unit is divided into an antenna layer, a floor metal layer, an intermediate metal layer and a metal layer including RF routing, chips and peripheral circuits from top to bottom. The inserted microstrip feeding conductor is electrically connected to one end of the metal via, and the other end of the metal via passes through the floor metal layer and the intermediate metal layer and is electrically connected to the metal layer including RF routing, chips and peripheral circuits.

2. An ultra-wideband radar antenna unit as claimed in claim 1, characterized in that: The antenna unit is a middle-insertion type microstrip feeding antenna unit, and the rectangular groove is arranged at a middle position on opposite sides of the first rectangular side of the rectangular printed antenna patch.

3. An ultra-wideband radar antenna unit as claimed in claim 1, characterized in that: The antenna unit is an offset inserted microstrip fed antenna unit, and the rectangular groove is arranged at an offset position on the opposite side of the first rectangular side of the rectangular printed antenna patch.

4. An ultra-wideband radar antenna unit as claimed in claim 1, characterized in that: The metal via is a metal via to microstrip feeding.

5. The ultra-wideband radar antenna unit according to claim 1, characterized in that: The dielectric constant of the dielectric substrate carrier is greater than or equal to 2, and the tangent of its loss angle is less than or equal to 10 -3 , its thickness is less than or equal to 3mm.

6. An antenna array using the ultra-wideband radar antenna unit according to any one of claims 1 to 5, 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 antenna unit and the third antenna unit are used to receive radio frequency signals. The first antenna unit, the second antenna unit and the third antenna unit are placed up and down respectively, and the second antenna unit and the third antenna unit are symmetrical with respect to the midline of the first antenna unit.

7. The antenna array according to claim 6, characterized in that: The first antenna unit, the second antenna unit, and the third antenna unit are all antenna arrays of intermediate inserted microstrip feeding antenna units; Alternatively, the first antenna unit is an intermediate inserted microstrip feeding antenna unit, the second antenna unit and the third antenna unit are offset inserted microstrip feeding antenna units, and the offset position is close to the edge of the PCB board to form an antenna array; Alternatively, the first antenna unit is an intermediate inserted microstrip feeding antenna unit, the second antenna unit and the third antenna unit are offset inserted microstrip feeding antenna units, and the offset position is close to the antenna array formed by the middle line of the PCB board; Alternatively, the first antenna unit, the second antenna unit, and the third antenna unit are all offset plug-in microstrip fed antenna units, and the offset 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 offset inserted microstrip fed antenna units, and the offset positions of the second antenna unit and the third antenna unit are close to the middle line of the PCB board to form an antenna array.

8. The antenna array according to claim 7, characterized in that: The end of the inserted microstrip feeding conductor of the first antenna unit points to the lower end of the PCB board, and the ends of the inserted microstrip feeding conductors of the second antenna unit and the third antenna unit point to the upper end of the PCB board respectively; Alternatively, the ends of the inserted microstrip feeding conductors of the first antenna unit, the second antenna unit, and the third antenna unit are respectively directed toward the upper end of the PCB board; Alternatively, the end of the inserted microstrip feeding conductor of the first antenna unit points to the upper end of the PCB board, and the ends of the inserted microstrip feeding 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 inserted microstrip feeding conductors of the first antenna unit, the second antenna unit, and the third antenna unit are respectively directed to the lower end of the PCB board.

9. The antenna array according to claim 6, characterized in that: 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.

10. The antenna array according to claim 9, characterized in that: The nested split resonant ring periodic structure includes a plurality of split resonant ring units; Each of the plurality of split resonant ring units is a polygonal structure including an open inner ring and an open outer ring, and the number of sides of each of the plurality of split resonant ring units is K, where K≥8; The multiple open resonant ring units form a T-shaped array, and the T-shaped array is used to isolate the first antenna unit, the second antenna unit and the third antenna unit; The number of the open resonant ring units between the first antenna unit and the second antenna unit is N1, N1≥4; the number of the open resonant ring units between the first antenna unit and the third antenna unit is N2, N2≥4; the number of the open resonant ring units between the second antenna unit and the third antenna unit is N3, N3≥6; The spacing between the inner ring and the outer ring is 0.1-0.5 mm, and the spacing between the multiple open resonant ring units is 0.2-0.8 mm.

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