Ultra-wideband low-profile phased-array antenna

Abstract

The invention belongs to the technical field of antenna engineering, and particularly relates to an ultra-wide-band low-profile phased-array antenna, which realizes broadband impedance matching characteristics and effectively expands the working bandwidth of the antenna by optimizing a dipole arm structure and introducing a matching branch knot and linear tapered slot composite structure on a radiation unit layer; on the array architecture level, an electromagnetic metasurface technology is adopted, array current distribution is improved through a periodic artificial electromagnetic structure, the active standing-wave ratio is remarkably reduced, the scanning angle of an array is widened, and meanwhile high compression of a system profile is achieved; on the structural design level, a three-dimensional composite structure of a transverse metal floor, a longitudinal radiation layer and a transverse metasurface layer is innovatively constructed, and the overall section height is reduced to 0.137 lambda Low (lambda Low is the lowest working frequency wavelength) through electromagnetic coupling and space folding technologies; in conclusion, the ultra wide band (the relative bandwidth is greater than or equal to 90%) and the low profile (lt; and the method is suitable for a new generation of broadband phased array radar system.

Description

Technical Field

[0001] The present invention belongs to the technical field of antenna engineering, and in particular relates to an ultra-wideband low-profile phased array antenna. Background Art

[0002] The demand for high-performance antennas is growing in modern communications, radar, and electronic countermeasures. Phased array antennas, as an important antenna type, are widely used in various complex radar and communication systems because they can quickly change the beam direction by adjusting the excitation phase of each array antenna element. They offer advantages such as fast scanning speed, beam focusing, and excellent anti-interference capabilities.

[0003] However, traditional phased array antennas face many challenges in practical applications. On the one hand, with the rapid development of wireless communication technology, spectrum resources are becoming increasingly scarce, and the system has placed higher requirements on the bandwidth of antennas. Ultra-wideband characteristics can realize signal transmission within a wider frequency band, effectively improving spectrum utilization. However, combining ultra-wideband characteristics with phased arrays is not easy, and a series of problems need to be solved, such as mutual coupling between antenna units, broadband matching, and radiation performance stability. On the other hand, in order to achieve better electrical performance, traditional phased array antennas often adopt multi-layer structures or higher-profile radiating units, which makes it difficult to reduce the overall profile of the antenna and cannot meet the urgent needs for miniaturization and low profile in many scenarios. For example, in some strictly restricted application scenarios, such as in aerospace, vehicle-mounted and ship-mounted platforms, an excessively high antenna profile will affect the overall performance of the system, increase wind resistance, and reduce stealth.

[0004] In summary, traditional phased array antenna solutions are difficult to achieve both ultra-wideband performance and low-profile performance. Therefore, the development of a phased array antenna that can simultaneously possess ultra-wideband and low-profile characteristics has extremely important practical significance and broad application prospects for promoting the development of communication, radar and other technologies and meeting the usage needs of various modern platforms. Summary of the Invention

[0005] The purpose of the present invention is to provide an ultra-wideband low-profile phased array antenna. At the radiating element level, by optimizing the dipole arm structure and introducing a composite structure of matching branches and linear gradient slots, a wide-band impedance matching characteristic is achieved, effectively expanding the antenna operating bandwidth. At the array architecture level, electromagnetic metasurface technology is adopted to improve the array current distribution through a periodic artificial electromagnetic structure, which not only significantly reduces the active standing wave ratio and widens the array scanning angle, but also achieves a high compression of the system profile. At the structural design level, an innovative three-dimensional composite structure of a transverse metal floor-longitudinal radiation layer-transverse metasurface layer is constructed. Through electromagnetic coupling and space folding technology, the overall profile height is reduced to 0.137λ. Low (λ Lowis the lowest operating frequency wavelength); In summary, the present invention has both ultra-wideband (relative bandwidth ≥ 90%), low profile (<0.137λ Low ) characteristics, suitable for the new generation of broadband phased array radar systems.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An ultra-wideband, low-profile phased array antenna, comprising a periodically arranged plurality of antenna units; the antenna units comprising a transverse metasurface layer, a longitudinal radiating layer, a transverse metal floor layer, and a coaxial feeding element; the transverse metasurface layer being arranged parallel to the transverse metal floor layer, the longitudinal radiating layer being arranged perpendicularly between the transverse metasurface layer and the transverse metal floor layer, and the coaxial feeding element penetrating the transverse metal floor layer to feed the longitudinal radiating layer;

[0008] The transverse metasurface layer is composed of a transverse dielectric plate and circular metal patches periodically arranged on its upper surface;

[0009] The longitudinal radiation layer is composed of a longitudinal dielectric plate and a front metal layer and a back metal layer respectively arranged on the front and back sides thereof;

[0010] The back metal layer has a left-right mirror-symmetrical structure along the longitudinal midline, including: a rectangular metal ground, a dipole radiator, a rectangular metal matching branch, and a strip metal matching branch; in order from bottom to top, the rectangular metal ground, the dipole radiator, the rectangular metal matching branch, and the strip loading structure are sequentially connected to form a back metal layer, covering the back of the longitudinal dielectric plate; a circular groove is provided in the middle of the rectangular metal ground, a linear gradient groove is formed between the two dipole arms, and the groove width linearly widens from bottom to top, each dipole arm is correspondingly loaded with a rectangular metal matching branch and a strip metal matching branch, a rectangular groove is correspondingly formed between the two rectangular metal matching branches, and a strip groove is correspondingly formed between the two strip metal matching branches, and in order from bottom to top, the circular groove, the linear gradient groove, the rectangular groove, and the strip groove are sequentially connected; each dipole arm is correspondingly provided with an L-shaped gap, which is provided along the edge of the longitudinal dielectric layer and extends upward to the rectangular metal matching branch;

[0011] The front metal layer includes: an L-shaped tapered microstrip feed line, a fan-shaped open-circuit patch, a rectangular coupling metal sheet, and a metal short-circuit line. One end of the L-shaped tapered microstrip feed line is connected to the inner conductor of the coaxial feeding element, and the other end is connected to the center position of the fan-shaped open-circuit patch. The fan-shaped open-circuit patch couples energy into the linear tapered slot of the back metal layer. Two rectangular coupling metal sheets are arranged along the edge of the longitudinal dielectric layer and correspond to the dipole arms of the back metal layer respectively. Each rectangular coupling metal sheet is connected to the transverse metal floor layer via a metal short-circuit line, and the metal short-circuit line is arranged along the edge of the longitudinal dielectric layer.

[0012] Furthermore, the array size of the circular metal patches is 15×15.

[0013] Furthermore, the operating frequency band of the ultra-wideband low-profile phased array antenna is 0.63 GHz to 1.88 GHz, and the profile height is 0.137λ. Low ,λ Low Low frequency wavelength.

[0014] Furthermore, the L-shaped tapered microstrip feed line is composed of a longitudinal step-tapered microstrip line and a transverse step-tapered microstrip line. The starting end of the longitudinal step-tapered microstrip line is connected to the inner conductor of the coaxial feeding element, and the end of the transverse step-tapered microstrip line is connected to the fan-shaped open patch.

[0015] Based on the above technical solution, the beneficial effects of the present invention are:

[0016] 1. The present invention further improves the impedance matching of wide-angle scanning by setting a circular electromagnetic metasurface, effectively reducing the active standing wave ratio within the operating frequency band.

[0017] 2. Through design optimization, the antenna unit can achieve a standing wave ratio of less than 3.3 in the entire working frequency band, with a relative bandwidth of 99.6%, and has the advantages of ultra-wideband, low profile, and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the three-dimensional structure of the ultra-wideband low-profile phased array antenna in the present invention.

[0019] Figure 2 Schematic diagram of the unit structure of the ultra-wideband low-profile phased array antenna in the present invention.

[0020] Figure 3 Schematic diagram of the top view of the transverse dielectric plate of the ultra-wideband low-profile phased array antenna unit in the present invention.

[0021] Figure 4 This is a schematic front view of the longitudinal dielectric plate of the ultra-wideband low-profile phased array antenna unit of the present invention.

[0022] Figure 5 This is a schematic diagram of the back structure of the longitudinal dielectric plate of the ultra-wideband low-profile phased array antenna unit in the present invention.

[0023] Figure 6 This is a diagram showing the active standing wave simulation results of the ultra-wideband low-profile phased array antenna unit in the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0025] This embodiment provides an ultra-wideband low-profile phased array antenna that operates in the 0.63GHz to 1.88GHz frequency range. The specific structure is as follows: Figure 1 As shown, the array size is 5×5; the antenna units are as follows Figure 2 As shown, it includes: a transverse metasurface layer, a longitudinal radiation layer, a transverse metal floor layer, and a coaxial feeding element; the transverse metasurface layer is arranged parallel to the transverse metal floor layer, the longitudinal radiation layer is arranged perpendicularly between the transverse metasurface layer and the transverse metal floor layer, and the coaxial feeding element passes through the transverse metal floor layer to feed the longitudinal radiation layer;

[0026] The transverse super surface layer is composed of a transverse dielectric plate and circular metal patches periodically arranged on its upper surface, such as Figure 3 As shown, the array scale of the circular metal patches is 15×15, the period is 5.6 mm×5.6 mm, and the radius of the circular metal patches is 2.2 mm, forming an electromagnetic metasurface structure with improved wide-angle scanning performance;

[0027] The longitudinal radiation layer is composed of a longitudinal dielectric plate and a front metal layer and a back metal layer respectively arranged on the front and back sides thereof;

[0028] The back metal layer has a left-right mirror-symmetrical structure along the longitudinal midline, such as Figure 4 As shown, it includes: a rectangular metal ground, a dipole radiator, a rectangular metal matching branch and a strip metal matching branch; in order from bottom to top, the rectangular metal ground, the dipole radiator, the rectangular metal matching branch and the strip loading structure are connected in sequence to form a back metal layer, covering the back of the longitudinal dielectric plate; a circular groove is opened in the middle of the rectangular metal ground, a linear gradient groove is formed between the two dipole arms, and the groove width is linearly widened from bottom to top, each dipole arm is correspondingly loaded with a rectangular metal matching branch and a strip metal matching branch, a rectangular groove is correspondingly formed between the two rectangular metal matching branches, and a strip groove is correspondingly formed between the two strip metal matching branches, and in order from bottom to top, the circular groove, the linear gradient groove, the rectangular groove and the strip groove are connected in sequence; each dipole arm is correspondingly opened with an L-shaped gap, which is set along the edge of the longitudinal dielectric layer and extends upward to the rectangular metal matching branch;

[0029] The front metal layer is as follows Figure 5As shown, it includes: an L-shaped tapered microstrip feed line, a fan-shaped open-circuit patch, a rectangular coupling metal sheet and a metal short-circuit line, wherein the L-shaped tapered microstrip feed line is composed of a longitudinal step-graded microstrip line and a transverse step-graded microstrip line, one end of the L-shaped tapered microstrip feed line is connected to the inner conductor of the coaxial feeding element, and the other end is connected to the center position of the fan-shaped open-circuit patch; the fan-shaped open-circuit patch is used to couple energy to the linear tapered groove of the back metal layer; two rectangular coupling metal sheets are arranged along the edge of the longitudinal dielectric layer and correspond to the dipole arms respectively; each rectangular coupling metal sheet is connected to the transverse metal floor layer through a metal short-circuit line, and the metal short-circuit line is arranged along the edge of the longitudinal dielectric layer.

[0030] Furthermore, the thickness of the transverse metasurface layer is 10 mm, and the transverse dimensions are 84 mm (length) × 84 mm (width); the thickness of the transverse metal floor layer is 6 mm, and the transverse dimensions are 84 mm (length) × 84 mm (width); the thickness of the longitudinal radiation layer is 2.5 mm, and the longitudinal dimensions are 84 mm (length) × 49.6 mm (width); based on this, the overall dimensions of the ultra-wideband low-profile phased array antenna unit are 84 mm (length) × 84 mm (width) × 65.6 mm (height), and the cross-sectional height is only 65.6 mm (0.137λ Low ,λ Low is a low-frequency wavelength).

[0031] like Figure 6 The figure shows the active standing wave simulation results of the ultra-wideband low-profile phased array antenna unit in this embodiment. It can be seen from the figure that the active standing wave of the antenna unit is less than 3.3 under a relative bandwidth greater than 90%, with low reflection loss and high efficiency; and the profile height is only 65.6mm (0.137λ Low ,λ Low is a low-frequency wavelength), and has a low-profile physical structure; in summary, the present invention provides an ultra-wideband low-profile phased array antenna with good performance such as ultra-wideband, low profile, and high efficiency.

[0032] The above description is only a specific embodiment of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. An ultra-wideband, low-profile phased array antenna, comprising a plurality of antenna elements arranged periodically; characterized in that: The antenna unit includes: a transverse metasurface layer, a longitudinal radiating layer, a transverse metal floor layer, and a coaxial feeding element; the transverse metasurface layer is arranged parallel to the transverse metal floor layer, the longitudinal radiating layer is arranged perpendicularly between the transverse metasurface layer and the transverse metal floor layer, and the coaxial feeding element passes through the transverse metal floor layer to feed the longitudinal radiating layer; The transverse metasurface layer is composed of a transverse dielectric plate and circular metal patches periodically arranged on its upper surface; The longitudinal radiation layer is composed of a longitudinal dielectric plate and a front metal layer and a back metal layer respectively arranged on the front and back sides thereof; The back metal layer has a left-right mirror-symmetrical structure along the longitudinal midline, including: a rectangular metal ground, a dipole radiator, a rectangular metal matching branch, and a strip metal matching branch; in order from bottom to top, the rectangular metal ground, the dipole radiator, the rectangular metal matching branch, and the strip loading structure are sequentially connected to form a back metal layer, covering the back of the longitudinal dielectric plate; a circular groove is provided in the middle of the rectangular metal ground, a linear gradient groove is formed between the two dipole arms, and the groove width linearly widens from bottom to top, each dipole arm is correspondingly loaded with a rectangular metal matching branch and a strip metal matching branch, a rectangular groove is correspondingly formed between the two rectangular metal matching branches, and a strip groove is correspondingly formed between the two strip metal matching branches, and in order from bottom to top, the circular groove, the linear gradient groove, the rectangular groove, and the strip groove are sequentially connected; each dipole arm is correspondingly provided with an L-shaped gap, which is provided along the edge of the longitudinal dielectric layer and extends upward to the rectangular metal matching branch; The front metal layer includes: an L-shaped tapered microstrip feed line, a fan-shaped open-circuit patch, a rectangular coupling metal sheet, and a metal short-circuit line. One end of the L-shaped tapered microstrip feed line is connected to the inner conductor of the coaxial feeding element, and the other end is connected to the center position of the fan-shaped open-circuit patch. The fan-shaped open-circuit patch couples energy into the linear tapered slot of the back metal layer. Two rectangular coupling metal sheets are arranged along the edge of the longitudinal dielectric layer and correspond to the dipole arms of the back metal layer respectively. Each rectangular coupling metal sheet is connected to the transverse metal floor layer via a metal short-circuit line, and the metal short-circuit line is arranged along the edge of the longitudinal dielectric layer.

2. The ultra-wideband low-profile phased array antenna according to claim 1, characterized in that: The array size of the circular metal patches is 15×15.

3. The ultra-wideband low-profile phased array antenna according to claim 1, characterized in that: The operating frequency band of the ultra-wideband low-profile phased array antenna is 0.63 GHz to 1.88 GHz, and the profile height is 0.137λ. Low ,λ Low For low frequency wavelength.

4. The ultra-wideband low-profile phased array antenna according to claim 1, characterized in that: The L-shaped gradient microstrip feed line is composed of a longitudinal step gradient microstrip line and a transverse step gradient microstrip line. The starting end of the longitudinal step gradient microstrip line is connected to the inner conductor of the coaxial feeding element, and the end of the transverse step gradient microstrip line is connected to the fan-shaped open patch.

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