Single-layer wide-beam patch antenna unit and wide-angle scanning phased array thereof

Abstract

The invention relates to a single-layer wide-beam patch antenna unit and a wide-angle scanning phased array thereof, the patch antenna unit comprises a single-layer dielectric substrate, a radiator and the ground, the radiator is formed by symmetrically loading two pairs of L-shaped branches with grounding via holes in the center, a plurality of grounding via holes with top loading U-shaped strips and a pair of no-load U-shaped strips on the periphery of an E surface of a U-shaped groove patch. The L-shaped branch widens the E-plane wave beam by prolonging the current path, reducing the patch size and coupling and exciting the center grounding through hole; ten grounding via holes of the top loading U-shaped strip adopt a parallel equivalent inverted F structure, a complementary conical wave beam is introduced through resonance under the height of a single-layer substrate, and an E-plane wave beam is broadened; the no-load U-shaped strip enhances the vertical current of the ten grounding through holes and guides the surface wave, so that the half-power beam width of the E surface reaches 182 degrees. According to the 1 * n phased array composed of the units, decoupling rectangular ring grooves are etched in a printing place, mutual coupling lower than-16dB and 3dB wave beam scanning with the width of + / -76 degrees are achieved, and the 1 * n phased array has the remarkable advantages of being easy to machine, low in profile, low in mutual coupling and wide in scanning range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar phased array antenna, and particularly relates to a single-layer low-profile wide-beam patch antenna unit and a wide-angle scanning phased array. BACKGROUND

[0002] The emergence of low-altitude economy promotes the research and development of various flying aircrafts including unmanned aerial vehicles, which also puts forward higher requirements for the performance of radar systems as key components. In order to realize high-precision positioning and path planning, the radar is required to have a wide-angle detection range. At the same time, the limited loading space and flight power of the aircraft limit the weight and structural size of the radar system, which requires the radar system to develop towards miniaturization and light weight.

[0003] Phased array antenna is one of the key elements that determines the performance of the radar system. In order to meet the above requirements of the radar system, it is required to integrate a small-sized low-profile wide-angle scanning phased array inside the radar hardware system. In the early years, a vertical electric wall, a super surface, a lens and other structures were mostly loaded to increase the unit beam so as to realize the wide-angle scanning phased array. In recent years, reconfigurable array antenna and conformal array are also researched to obtain the wide-angle scanning characteristics. These methods can effectively expand the wide-angle scanning range of the phased array, however, the loaded electromagnetic structures and the added elements are very easy to cause the increase of the mass or volume of the phased array, which is not conducive to the realization of miniaturization and light weight.

[0004] Wide-beam phased array technology based on super surface loading changes the wave front distribution of the antenna radiation field by adding one or more layers of super surface structure (such as artificial electromagnetic material patch array) to the surface of the traditional microstrip antenna unit array, using the phase control characteristics of super surface to electromagnetic wave, thereby expanding the scanning range of phased array. Typical applications are found in the phased array design of low-altitude detection radar, such as “IEEE Transactions on Antennas and Propagation” 2019, Vol. 67, No. 3 (article title: “Wide-Angle Scanning Phased Array Using Metasurface Loading for Low-Altitude Surveillance Radar”). The structure of this technology is complex and is prone to increase the weight: the super surface needs to be designed with multiple layers of periodic patch structure separately, and needs to be precisely aligned with the bottom antenna unit, resulting in an increase in the overall thickness and weight of the phased array; the gain loss of wide-angle scanning is significant: the regulation of super surface to electromagnetic wave depends on the electromagnetic coupling between units, when the scanning angle of phased array exceeds ±45°, the coupling efficiency of super surface unit decreases sharply, resulting in a gain attenuation of more than 5dB. Experimental data in the article show that at a working frequency of 10GHz, when the scanning angle increases from 0° to 60°, the gain decreases from 15dBi to 9.8dBi, which cannot meet the detection accuracy requirements of low-altitude radar for long-distance targets.

[0005] “IEEE Transactions on Antennas and Propagation” 2018, Vol. 66, No. 1 (article title: “Study on Wide-Angle Scanning Linear Phased Array Antenna”). The profile of this technology is high: the parasitic electric wall loaded near the antenna unit is as high as 0.21 wavelengths, resulting in a high profile and additional weight of the array. “IEEE Transactions on Antennas and Propagation” 2022, Vol. 70, No. 10 (article title: “Millimeter-Wave Wideband Dual-Polarized LTCC Antenna Array Based on Metasurfaces for Beam-Scanning Applications”). The number of layers of this technology is large and the structure is complex: the antenna structure contains 9 layers of LTT, the strip line structure contains 6 layers of LTT, and a total of 15 layers of substrate, which is prone to increase the weight and profile. The scanning range is limited: the maximum 3dB scanning range is only ±55°, and when it is higher than ±55°, the gain decreases sharply.

[0006] Therefore, magnetohydrodynamic antennas, which inherently possess wide beam characteristics, are also used to construct wide-angle scanning phased arrays. However, their commonly used coupled feeding structures often require the support of multilayer dielectric substrates, which easily results in high profiles and complex fabrication. Furthermore, wide-beam elements often lead to stronger element coupling during array formation, degrading element performance and consequently reducing array scanning performance. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention aims to propose a single-layer wide-beam patch antenna element for constructing a wide-angle scanning phased array. By sequentially loading L-shaped stubs, grounding vias, and unloaded U-shaped strips on both sides of the outer periphery of the E-plane of the U-shaped slot patch, and combining methods such as reducing the E-plane size, introducing resonant vertical current to form a complementary conical beam, and guiding surface waves, a wider beam can be obtained with a low profile single-layer substrate height. Simultaneously, by fully utilizing the limited space of the single-layer antenna and etching defective ground structures on the printed ground plane, without loading any additional decoupling structures, the mutual coupling between elements is effectively reduced, ensuring consistent and good element characteristics and achieving wide-angle scanning characteristics.

[0008] To achieve the above objectives, the technical means employed in this invention are as follows: A single-layer wide-beam patch antenna unit includes a single-layer dielectric substrate 2, a radiator 1 printed on the upper surface of the single-layer dielectric substrate 2, and a ground plane 3 printed on the lower surface of the single-layer dielectric substrate 2. The radiator 1 includes a U-shaped groove patch 101 disposed in the middle of a single-layer dielectric substrate 2. The two corners of the U-shaped groove patch 101 are respectively connected to two pairs of L-shaped branches 103, and each pair of L-shaped branches 103 is symmetrical about the center line. An unloaded grounding via 104 is provided in the middle of the opening of the two pairs of L-shaped branches 103 on the single-layer dielectric substrate 2. Multiple grounding vias 106 are symmetrically provided on the single-layer dielectric substrate 2 around the L-shaped branches 103 along the E-plane direction. A U-shaped strip 105 is loaded on the top of the grounding via 106. An unloaded U-shaped strip 1011 is symmetrically printed on the periphery of the U-shaped strip 105 along the E-plane direction.

[0009] The center of the U-shaped groove patch 101 is connected to the inner core of the 50-ohm coaxial line 102. The polarization direction is along the U-shaped groove opening direction of the U-shaped groove patch 101. After being connected to the L-shaped stub 103, the longitudinal dimension of the U-shaped groove patch 101 is reduced to be smaller than the transverse dimension. The longitudinal dimension is the E-plane direction, and the transverse dimension is the direction perpendicular to the E-plane direction. The E-plane beamwidth is slightly increased by 10°~15°.

[0010] The two pairs of L-shaped branches 103 are closely attached to the horizontal edge of the U-shaped groove patch 101, with the ends of the L-shaped branches 103 close to the center of the horizontal edge of the U-shaped groove patch 101. They are used to guide and converge the current on both sides of the U-shaped groove patch 101, thereby exciting the vertical current in the unloaded grounding via 104 at the center of the L-shaped branch 103. This causes the unloaded grounding via 104 to resonate at the height of the low-profile single-layer substrate, forming a conical beam that complements the beam of the U-shaped groove patch 101, thereby expanding the E-plane beamwidth.

[0011] Of the plurality of grounding vias 106, one is located in the middle of the U-shaped strip 105, and the remaining grounding vias 106 are symmetrically distributed on both sides of the U-shaped strip 105, with the opening of the U-shaped strip 105 facing the U-shaped slot patch 101. The middle and left grounding vias 106, together with the left half of the U-shaped strip 105 loaded above them, constitute an equivalent inverted F patch antenna structure. The middle and right grounding vias 106, together with the U-shaped strip 101 loaded above them... The right half of section 5 constitutes another equivalent inverted-F patch antenna structure. The two equivalent inverted-F antenna structures are connected in parallel, so that the grounding via 106 resonates at a height of less than λ / 10 of a single-layer dielectric substrate, introducing a conical beam complementary to the normal beam of the U-shaped slot patch 101, where λ is the free-space wavelength corresponding to the center frequency of the U-shaped slot patch 101. The U-shaped strip 105 is wider than the U-shaped slot patch 101 and is spaced from the edge of the U-shaped slot patch 101 by a distance greater than 0 and less than λ / 4. Reducing the spacing distance and increasing the width of the U-shaped strip 105 adjusts the coupling current intensity from the U-shaped slot patch 101, thereby enhancing the vertical current on the grounding via, secondary exciting the complementary conical beam, and improving the beamwidth of the antenna E-plane.

[0012] The unloaded U-shaped strip 1011, with its opening facing the U-shaped slot patch 101, has a length and width greater than the U-shaped strip 105 loaded on the top of the grounding via 106. The edge of the unloaded U-shaped strip 1011 is spaced 0~λ / 4 apart from the edge of the U-shaped strip 105. By reducing this distance and increasing the width of the U-shaped strip 1011, the coupling current is enhanced, thereby expanding the E-plane beamwidth. This is because the coupling current on the unloaded U-shaped strip 1011 is in the opposite direction to the horizontal current on the U-shaped strip 105. Utilizing the coupling current on the unloaded U-shaped strip 1011, the horizontal current on the U-shaped strip 105 can be weakened, causing more current on the U-shaped strip 105 to converge on multiple grounding vias 106, enhancing the vertical current components on multiple grounding vias 106, thus forming a complementary conical beam for the second time. Combined with the effect of the unloaded U-shaped strip (1011) or the outward guiding surface wave, the E-plane beamwidth is further expanded. Further expand the beamwidth.

[0013] The phased array of single-layer wide-beam microstrip antenna elements consists of an array of 1×n single-layer wide-beam microstrip antenna elements connected along the polarization direction. The radiators 1 of adjacent elements do not overlap, and the spacing between elements is less than or equal to 0.5λ, where λ is the free space wavelength of the center frequency within the operating frequency band. The radiators 1 of all single-layer wide-beam patch antenna elements in the entire array share a dielectric substrate 2 and a ground plane 3.

[0014] A rectangular ring groove 4 is etched on the ground 3 between adjacent single-layer wide-beam patch antenna units to form a defective ground structure, which at the same time has the function of blocking and canceling coupling current, and can effectively suppress strong coupling between units.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention, based on the existing single-layer narrow-beam U-shaped slot patch 101, extends the current path and reduces the size of the U-shaped slot patch 101 in the E-plane direction by loading at the corners on both sides of the U-shaped slot patch 101, thereby effectively expanding the E-plane beamwidth. Simultaneously, the L-shaped stub 103 guides and converges the edge current of the U-shaped slot patch 101, coupling and exciting the vertical current on the unloaded ground via 104 at its center, forming a conical beam complementary to the U-shaped slot patch 101 beamwidth, thus further widening the E-plane beam. The surface beamwidth is achieved by using five grounding vias 106 in each of the ten grounding vias 106, which are top-loaded with U-shaped strips 105 to form two parallel equivalent inverted F patch structures. This allows for secondary resonance under a low-profile single-layer substrate, forming complementary conical beams to broaden the E-plane beam. The loading of the unloaded U-shaped strips 1011 weakens the horizontal current on the U-shaped strips 105 of the ten grounding vias, strengthens the vertical current of the grounding vias, and guides the surface coupling current of the radiator outward to further obtain the wide beamwidth coverage performance of the antenna element. The triple loading structure combines three methods: reducing antenna size, introducing resonant vertical current to form complementary conical beams, and guiding surface waves, thereby achieving coverage of the upper half-space on a single-layer substrate. Compared to most existing beambearing technologies, this technology does not require additional discrete structures or components, and has significant advantages such as lower profile, lighter weight, and easier processing.

[0016] This invention constructs a 1×n phased array based on the aforementioned single-layer wide-beam patch antenna elements. The element spacing is smaller than the antenna element size and less than or equal to 0.5λ (λ being the free-space wavelength of the highest frequency within the operating band), with n elements arranged along the E-plane. Despite limited space and a low profile, the impact of mutual coupling between adjacent elements on the phased array's scanning performance is still considered. By fully utilizing the printed ground plane 3, rectangular ring grooves are etched on the ground plane 3 at the center of adjacent elements, constructing a defective ground structure. Mutual coupling between elements is suppressed through two methods: limiting and blocking coupling current and introducing opposite paths to cancel out coupling current, thus enabling each element to maintain stable and consistent good performance.

[0017] Compared to methods such as isolation barriers, metasurface loading, and electromagnetic band gaps, this invention can effectively suppress strong coupling between units in a simpler way without adding extra structures, thereby obtaining higher quality wide-angle scanning characteristics on existing low-profile, lightweight structures. Attached Figure Description

[0018] Figure 1 This is an overall structural diagram of the wide-beam patch antenna unit of the present invention.

[0019] Figure 2 This is a top view of the wide-beam patch antenna unit of the present invention.

[0020] Figure 3 This is an overall structural diagram of the wide-beam wide-angle scanning patch phased array of the present invention.

[0021] Figure 4 This is a top view of the wide-beam wide-angle scanning patch phased array of the present invention.

[0022] Figure 5 This is a bottom view of the wide-beam wide-angle scanning patch phased array of the present invention.

[0023] Figure 6 The port voltage standing wave ratio (VSWR) diagram of the wide-beam patch antenna element of this invention (17.23~17.87GHz) is shown.

[0024] Figure 7 The images show the E-plane and H-plane radiation patterns of the wide-beam patch antenna element of the present invention at three frequencies, where (a) is 17.2 GHz. Z (a) E-plane and H-plane radiation patterns; (b) 17.5GH Z The radiation patterns of the E-plane and H-plane; (c) is at 17.8 GH. Z The radiation patterns of the E-plane and H-plane.

[0025] Figure 8 The images show a comparison of the standing wave ratios (SWR) of each unit before and after etching the rectangular ring decoupling groove in the wide-beam wide-angle scanning patch phased array of the present invention. (a) is a comparison of the SWR of each adjacent unit before adding the rectangular ring groove, and (b) is a comparison of the SWR of each adjacent unit after adding the rectangular ring groove.

[0026] Figure 9 The diagram shows a comparison of the coupling coefficients of adjacent units before and after etching the rectangular ring decoupling groove in the wide-beam wide-angle scanning patch phased array of the present invention. (a) is a comparison of the coupling coefficients of adjacent units before adding the rectangular ring groove, and (b) is a comparison of the coupling coefficients of adjacent units after adding the rectangular ring groove.

[0027] Figure 10The images show the scanning patterns of the wide-beam, wide-angle scanning patch phased array of the present invention at three different frequencies, where (a) is 17.2 GHz. Z (a) is the scan pattern; (b) is 17.5 GH. Z The scan pattern; (c) is 17.8 GH. Z The scanning direction pattern. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings.

[0029] See Figure 1 and Figure 2 A single-layer wide-beam patch antenna unit includes a single-layer dielectric substrate 2, a radiator 1 printed on the upper surface of the single-layer dielectric substrate 2, and a ground plane 3 printed on the lower surface of the single-layer dielectric substrate 2. The substrate thickness is 1.524 mm, and the profile height corresponding to 17.5 GHz is 0.089 wavelengths. It has the significant characteristics of simple structure and low profile.

[0030] The radiator 1 includes a U-shaped groove patch 101 disposed in the middle of a single-layer dielectric substrate 2. The two corners of the U-shaped groove patch 101 are respectively connected to two pairs of L-shaped branches 103, and each pair of L-shaped branches 103 is symmetrical about the center line. An unloaded grounding via 104 is provided in the middle of the opening of the two pairs of L-shaped branches 103 on the single-layer dielectric substrate 2. Five grounding vias 106 are symmetrically provided on the periphery of the L-shaped branches 103 along the E-plane direction. A U-shaped strip 105 is loaded on the top of the grounding via 106. An unloaded U-shaped strip 1011 is symmetrically printed on the periphery of the U-shaped strip 105 along the E-plane direction.

[0031] The center of the U-shaped slot patch 101 is connected to the inner core of the 50-ohm coaxial line 102. The polarization direction is along the opening direction of the U-shaped slot of the U-shaped slot patch 101. After connecting the L-shaped stubs, its longitudinal (along the E-plane direction) dimension is reduced to be smaller than its transverse (orthogonal to the E-plane direction) dimension, and the E-plane beamwidth increases slightly by about 10°. The two pairs of L-shaped stubs 103 are close to the transverse side of the U-shaped slot patch 101, with their ends close to the center of the transverse side. They are used to guide the current on both sides of the U-shaped slot patch 101 to converge and excite the vertical current at its center, so that the unloaded grounding via 104 resonates at the height of the low-profile single-layer substrate, thereby forming a conical beam that is complementary to the beam of the U-shaped slot patch 101, thus expanding the E-plane beamwidth.

[0032] Of the ten grounding vias 106, one via is located in the middle of the U-shaped strip 105, and the remaining vias are located on both sides of the U-shaped strip 105. The grounding via 106 and the left half of the U-shaped strip 105 above it form an equivalent inverted-F patch antenna structure, wherein the middle via of the grounding via 106 is equivalent to a feed structure, and the vias on both sides are equivalent to parallel inductors; similarly, the grounding via 106 and the right half of the U-shaped strip 105 above it form another equivalent inverted-F patch antenna structure. The two equivalent inverted-F antenna structures are connected in parallel, allowing the grounding vias to resonate in a single-layer dielectric with a lower profile. The U-shaped strip 105 is wider than the U-shaped slot patch 101 and is spaced a certain distance from the edge of the U-shaped slot patch 101. Reducing this distance and increasing the width of the U-shaped strip 105 can adjust the coupling current intensity from the U-shaped slot patch 101, thereby enhancing the vertical current on the grounding via, secondary excitation of complementary conical beams, and significantly improving the beamwidth of the antenna's E-plane.

[0033] The horizontal and vertical sides of the unloaded U-shaped strip 1011 are both longer than those of the U-shaped strip 105, and are spaced a certain distance from the edge of the U-shaped strip (105). By reducing this distance and increasing the width of the U-shaped strip 1011, the coupling current can be enhanced. By utilizing the strong reverse current of the unloaded U-shaped strip 1011 to weaken the horizontal current on the U-shaped strip 105, more current can be concentrated on the grounding via 106 to enhance the vertical current component, thus forming a complementary conical beam. In addition, the unloaded U-shaped strip 1011 can also guide surface waves outward, and these designs can further extend the E-plane beamwidth.

[0034] A linear phased array consisting of eight single-layer wide-beam wide-angle scanning patch antenna elements, see Figures 3-5 The spacing between the centers of adjacent units is equal to 0.5λ (λ is the free-space wavelength of the center frequency 17.5GHz). All radiators in the entire array share a single dielectric substrate 2 and ground plane 3. Wide-beam units are prone to large coupling. To reduce the coupling between units, rectangular annular grooves 4 are etched on the ground plane 3 at the center of adjacent units to construct a defective ground structure. This structure not only blocks the coupling current between adjacent units but also weakens the coupling by utilizing the opposite coupling paths of adjacent units, thereby effectively suppressing strong coupling between units without adding additional structures.

[0035] The combined implementation of multiple technologies enables the single-layer patch antenna to achieve a wide beam, while effectively suppressing mutual coupling between elements in the linear phased array. This results in stable impedance characteristics and excellent wide-beam performance for the array elements, allowing for a 3dB scan range of ±76° within the operating frequency band. The antenna element in this invention combines wide beam, low profile, miniaturization, lightweight, and ease of fabrication and integration. The constructed linear phased array exhibits low mutual coupling and wide-angle scanning characteristics, making it suitable for radar systems in aircraft, enabling wide-angle detection and sensing.

[0036] 1. Simulation Content Simulation experiments were conducted on the antenna element and its phased array in the above embodiments using simulation software. The voltage standing wave ratio, radiation pattern of the antenna element, and the characteristics of the element ports and the array scanning pattern in the phased array before and after etching the rectangular ring slot are shown in [the figure]. Figures 6-10 .

[0037] 2. Simulation Results Figure 6 This is a curve showing the voltage standing wave ratio (VSWR) as a function of operating frequency, obtained from simulation of the single-layer wide-beam patch antenna element in the embodiment. When the VSWR < 2, the antenna operates at 17.23–17.87 GHz.

[0038] Figure 7 The above describes the E-plane and H-plane radiation patterns of the single-layer microstrip antenna element of the embodiment at three frequency points (17.2 GHz, 17.5 GHz, and 17.8 GHz) obtained through simulation. In the E-plane, the lower half-power beamwidths at the three frequency points are 182°, 185°, and 189°, respectively; in the H-plane, the beamwidths at the three frequency points are 107°, 106°, and 106°, respectively. This result demonstrates that the single-layer patch antenna element of the present invention can cover the upper half of the space within its operating frequency band.

[0039] Figures 8-10 The voltage standing wave ratio (VSWR) and coupling coefficient of the array elements were simulated before and after etching rectangular ring decoupling slots on the ground between adjacent elements in Example 1×8 phased array. After etching the rectangular ring slots on the ground, the VSWR and coupling coefficient of the eight elements showed good consistency and could all operate in the range of 17.2~17.8GHz. The coupling coefficient between elements also decreased from -9dB to -16.8dB. Figure 10 The E-plane scanning pattern obtained from the simulation embodiment 1×8 phased array shows that the 3dB scanning range can reach ±76° at three frequencies: 17.2GHz, 17.5GHz, and 17.8GHz.

[0040] In summary, the single-layer patch antenna unit of the present invention includes a single-layer dielectric substrate 2, a radiator 1 on the upper surface of the substrate, and a ground plane 3 on the lower surface of the substrate. The radiator 1 consists of a U-shaped patch (101) arranged along the E-plane direction with two pairs of L-shaped branches 103 with unloaded grounding vias 104 at the center, ten grounding vias (106) with a top-loaded pair of U-shaped strips 105, and a pair of unloaded U-shaped strips (1011). These designs achieve full-space coverage beams at all frequencies under the low profile single-layer substrate height by reducing the antenna unit size, introducing complementary conical beams, and guiding surface waves outward. Based on the single-layer wide-beam patch antenna element, a 1×8 linear phased array is constructed with an element spacing greater than the element size and less than 0.5λ. The negative impact of mutual coupling between array elements on scanning performance is considered. The limited space and the ground under the low profile (3) are fully utilized to etch a defective decoupling structure of a rectangular ring groove (4), reducing mutual coupling to below -16.8dB, obtaining consistent and good impedance and radiation performance, and finally enabling the entire linear phased array to achieve a 3dB wide-angle domain scanning range above ±76°.

[0041] The above are merely the preferred embodiments of the present invention under such unit matching and beamwidth, and do not constitute any limitation on the present invention. Obviously, under the concept of the present invention, the structure, parameters and frequency of the present invention can be modified to obtain a wider beamwidth and a wider array scanning range of the antenna of the present invention, as well as to achieve further compactness and low profile of the antenna, but these are all within the scope of protection of the present invention.

Claims

1. A single-layer wide-beam patch antenna element, characterized in that, It includes a single-layer dielectric substrate (2), a radiator (1) printed on the upper surface of the single-layer dielectric substrate (2), and a ground plane (3) printed on the lower surface of the single-layer dielectric substrate (2); The radiator (1) includes a U-shaped groove patch (101) disposed in the middle of a single-layer dielectric substrate (2). The two sides of the U-shaped groove patch (101) are connected to two pairs of L-shaped branches (103), and each pair of L-shaped branches (103) is symmetrical about the center line. An unloaded grounding via (104) is provided in the middle of the opening of the two pairs of L-shaped branches (103) on the single-layer dielectric substrate (2). Multiple grounding vias (106) are symmetrically provided on the single-layer dielectric substrate (2) around the L-shaped branches (103) along the E-plane direction. A U-shaped strip (105) is loaded on the top of the grounding via (106). An unloaded U-shaped strip (1011) is symmetrically printed on the periphery of the U-shaped strip (105) along the E-plane direction.

2. The single-layer wide-beam patch antenna element according to claim 1, characterized in that, The center of the U-shaped groove patch (101) is connected to the inner core of the 50-ohm coaxial line (102). The polarization direction is along the U-shaped groove opening direction of the U-shaped groove patch (101). After being connected to the L-shaped stub (103), the longitudinal dimension of the U-shaped groove patch (101) is reduced to be smaller than the transverse dimension. The longitudinal direction is the E-plane direction, and the transverse direction is perpendicular to the E-plane direction. The E-plane beamwidth is slightly increased by 10°~15°.

3. The single-layer wide-beam patch antenna element according to claim 1, characterized in that, The two pairs of L-shaped stubs (103) are closely attached to the horizontal edge of the U-shaped groove patch (101). The ends of the L-shaped stubs (103) are close to the center of the horizontal edge of the U-shaped groove patch (101). They are used to guide and converge the current on both sides of the U-shaped groove patch (101) and excite the vertical current of the unloaded grounding via (104) at the center of the L-shaped stub (103). This causes the unloaded grounding via (104) to resonate at the height of the low-profile single-layer substrate, forming a conical beam that is complementary to the beam of the U-shaped groove patch (101), thereby expanding the E-plane beamwidth.

4. A single-layer wide-beam patch antenna element according to claim 1, characterized in that, Of the plurality of grounding vias (106), one is located in the middle of the U-shaped strip (105), and the remaining grounding vias (106) are symmetrically distributed on both sides of the U-shaped strip (105), wherein the opening of the U-shaped strip (105) faces the U-shaped slot patch (101); the middle and left grounding vias (106) together with the left half of the U-shaped strip (105) loaded above them constitute an equivalent inverted F patch antenna structure, and the middle and right grounding vias (106) together with the U-shaped strip loaded above them constitute an equivalent inverted F patch antenna structure. 105) The right half constitutes another equivalent inverted F patch antenna structure. The two equivalent inverted F antenna structures are connected in parallel, so that the grounding via (106) resonates at a height of less than λ / 10 of a single-layer dielectric substrate and introduces a conical beam that is complementary to the normal beam of the U-shaped slot patch (101), where λ is the free space wavelength corresponding to the center frequency of the U-shaped slot patch (101). The U-shaped strip (105) is wider than the U-shaped slot patch (101) and the distance between it and the edge of the U-shaped slot patch (101) is greater than 0 and less than λ / 4. The adjustment of the spacing distance and the width of the U-shaped strip (105) are adjusted from the coupling current intensity of the U-shaped slot patch (101), thereby enhancing the vertical current on the grounding via, secondary exciting of the complementary conical beam, and improving the beam width of the antenna E-plane.

5. A single-layer wide-beam patch antenna element according to claim 1, characterized in that, The unloaded U-shaped strip (1011) has its opening facing the U-shaped slot patch (101), and its length and width are both greater than the U-shaped strip (105) loaded on top of the grounding via (106). The edge of the unloaded U-shaped strip (1011) is spaced 0~λ / 4 away from the edge of the U-shaped strip (105). By reducing this distance and increasing the width of the U-shaped strip (1011), the coupling current is enhanced to expand the E-plane beamwidth. This is because the coupling current on the unloaded U-shaped strip (1011) is oriented... The direction of the horizontal current on the U-shaped strip (105) is opposite to that on the U-shaped strip (1011). The coupling current on the unloaded U-shaped strip (1011) can weaken the horizontal current on the U-shaped strip (105), so that more current on the U-shaped strip (105) can be concentrated on multiple grounding vias (106), and the vertical current component on multiple grounding vias (106) can be enhanced, thereby forming a complementary conical beam for the second time. Combined with the effect of the unloaded U-shaped strip (1011) guiding surface waves outward, the E-plane beam can be further extended.

6. A phased array based on the single-layer wide-beam microstrip antenna element described in any one of 1 to 5, characterized in that: The array consists of 1×n single-layer wide-beam microstrip antenna elements connected along the polarization direction. The radiators (1) of adjacent elements do not overlap, and the spacing between elements is less than or equal to 0.5λ, where λ is the free space wavelength of the center frequency within the operating frequency band. All the radiators (1) of the single-layer wide-beam patch antenna elements in the entire array share a dielectric substrate (2) and a ground plane (3).

7. The wide-angle scanning phased array composed of single-layer wide-beam patch antenna elements according to claim 6, characterized in that: A rectangular ring groove (4) is etched on the ground (3) between adjacent single-layer wide-beam patch antenna units to form a defective ground structure, which at the same time has the function of blocking and canceling coupling current, and can effectively suppress strong coupling between units.

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