Matching layer loaded large-size ultra-wideband phased-array antenna

Abstract

The invention discloses a light-weight large-size ultra-wideband phased-array antenna with a loaded matching layer, and belongs to the technical field of antenna engineering. The antenna provided by the invention adopts the strong coupling dipole antenna unit, and has the characteristic of ultra wide band; a novel wide-angle impedance matching layer is adopted to suppress surface waves introduced due to increase of unit spacing, and the unit spacing is increased under the condition that no grating lobe is met; and the antenna standing wave is optimized by adopting a coplanar strip line and leaf-shaped dipole form. And the wide-angle impedance matching layer and the antenna layer are printed on the single-layer dielectric plate, so that the processing is convenient, and the assembly is simple. Simulation results show that when the antenna unit is used in a phased array, grating lobes do not appear in H-plane scanning of + / -45 degrees within the frequency band of f0-6.1 f0, and the active standing-wave ratio is lower than 3.

Description

Technical Field

[0001] The invention belongs to the technical field of antenna engineering, and in particular relates to a novel matching layer loaded ultra-wideband phased array antenna, which has the characteristics of large size, ultra-wideband and wide-angle scanning. Background Art

[0002] Phased arrays are widely used in radar detection, satellite communications and other fields due to their advantages such as flexible beam scheduling, large airspace coverage, and the ability to search and track multiple targets. At the same time, in order to meet the phased array system's requirements for broadband and wide-angle scanning of antennas while saving system costs, phased array antennas with large size, ultra-wideband and wide-angle scanning characteristics have become a research hotspot. Strongly coupled dipole arrays usually have ultra-wideband characteristics. For example, in the paper "Dual-Polarized Tightly CoupledDipole Array for UHF–X-Band Satellite Applications", a bandwidth of 10.5:1 was achieved, with an E-plane, D-plane and H-plane scanning range of ±60° and a unit size of 0.23λ. h ×0.23λ h ; In the paper “A Wideband, Wide Scanning Tightly Coupled Dipole Array With Integrated Balun (TCDA-IB)”, a bandwidth of 7.35:1 was achieved, the E-plane, D-plane and H-plane scanning range was ±45°, and the unit size was 0.23λ h ×0.47λ h In the above paper, two small strongly coupled antenna units are connected in parallel to form an array unit to improve impedance matching and achieve wide bandwidth angle scanning performance. However, this method requires more units to achieve high gain, which will inevitably increase the overall cost of the system. Summary of the invention

[0003] Based on the background technology, the present invention proposes a novel matching layer loaded strongly coupled ultra-wideband phased array antenna, which has the characteristics of large size, ultra-wideband and wide-angle scanning. In addition, the antenna adopts a single-layer PCB board structure, which is easy to process and assemble, and can be used in various scenarios such as radar and navigation.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A matching layer-loaded lightweight large-size ultra-wideband phased array antenna, the antenna is formed by splicing antenna units arranged in an array, each antenna unit comprises: a wide-angle impedance matching layer, an antenna layer, a resistive grid layer and a metal floor; the wide-angle impedance matching layer is arranged in parallel with the metal floor; the antenna layer is arranged in parallel with the resistive grid layer and is located between the wide-angle impedance matching layer and the metal floor; the antenna layer is perpendicular to the metal floor, and the projection of the antenna layer on the metal floor and the wide-angle impedance matching layer is the central axis of the metal floor and the wide-angle impedance matching layer; the resistive grid layer is located at the edge of the metal floor and the wide-angle impedance matching layer;

[0006] The wide-angle impedance matching layer comprises a substrate, wherein a row of rectangular metal patches are arranged in parallel along the central axis on the upper surface of the substrate, and the long sides of the rectangular metal patches are perpendicularly bisected by the central axis; rectangular grooves are symmetrically provided on the two sides of each rectangular metal patch divided by the central axis; a narrow metal strip is led out from each end of each rectangular metal patch, and the narrow metal strip is perpendicular to the central axis and extends to the edge of the substrate;

[0007] The antenna layer includes a dielectric substrate, two dipole arms are arranged on one side of the dielectric substrate, each dipole arm extends a coplanar strip line toward the metal floor, and the coplanar strip line is located in the middle of the dielectric substrate; a coupling patch is arranged on each of the two edges of the other side, and each coupling patch is connected to the metal floor through a metal short-circuit column;

[0008] The resistive grid layer comprises a dielectric substrate and a plurality of resistive grid bars arranged on the dielectric substrate.

[0009] Furthermore, a plurality of rectangular grooves are provided on both sides of the rectangular metal patch divided by the central axis in the wide-angle impedance matching layer, and all the rectangular grooves in one rectangular metal patch are arranged in a row, and the long side of each rectangular groove is parallel to the central axis of the substrate.

[0010] Furthermore, each dipole arm in the antenna layer is petal-shaped and symmetrically arranged with respect to the midline of the dielectric substrate. The two dipole arms form the shape of a whale's tail, but each dipole arm is independent; the tail tip of the left dipole arm is located at the upper left corner of the dielectric substrate, the tail tip of the right dipole arm is located at the upper right corner of the dielectric substrate, and the tail roots of the two dipole arms are located at the center of the dielectric substrate; and a coplanar strip line is derived from the tail root of each dipole arm.

[0011] Furthermore, all the resistive bars in the resistive grid layer are evenly spaced, and the axis direction of each resistive bar is perpendicular to the metal floor.

[0012] The antenna of the present invention adopts a strongly coupled dipole antenna unit and has the characteristics of ultra-wideband. The surface wave introduced by the expansion of the unit spacing is suppressed by loading a new wide-angle impedance matching layer, and the unit spacing is increased under the condition of no grating lobe, and the impedance matching of the antenna unit during H-plane wide-angle scanning is significantly improved. In addition, the antenna adopts a single-layer PCB board structure, which has the advantages of easy processing, simple assembly and stable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural diagram of a lightweight, large-size, ultra-wideband phased array antenna unit loaded with a novel matching layer of the present invention.

[0014] Figure 2 It is a structural diagram of the antenna layer of the antenna unit of the present invention.

[0015] Figure 3 2 are diagrams of matching layer structures, wherein (a) is a diagram of a novel matching layer structure in which a surface wave suppression structure is added to the antenna unit of the present invention, and (b) is a diagram of a matching layer structure in which a surface wave suppression structure is not added.

[0016] Figure 4 It is a schematic diagram showing the variation of the active standing wave ratio of the antenna unit at different scanning angles with frequency according to the present invention.

[0017] Figure 5 It is the active standing wave ratio of the antenna unit of the present invention when different matching layers are loaded when the antenna unit scans 45° on the H plane.

[0018] Figure 6 The side-ray radiation patterns of the E-plane and H-plane of the antenna unit of the present invention at different frequencies, where (a), (b), and (c) are the results of f0, 3.6f0, and 6.1f0, respectively. DETAILED DESCRIPTION

[0019] The 3D view of the lightweight large-size ultra-wideband phased array antenna unit loaded with the new matching layer in this embodiment is as follows Figure 1 As shown, the overall structure includes a wide-angle impedance matching layer 1, an antenna layer 2, a resistive grid layer 3 and a metal floor 4. The antenna works at f0~6.1f0, and the unit size is 0.61λ h ×0.58λ h ×0.63λ h (λ h The wavelength corresponds to 6.1f0), and the beam scanning of ±45° on the H plane can be achieved within the working bandwidth.

[0020] In this embodiment, the structure of the antenna layer 2 in the antenna unit is as follows Figure 2 As shown, all structures are printed on the dielectric board. Structure 5 is a coupling patch with a width of 0.041λ h , the length is 0.081λ h, located between adjacent unit dipole arms 7 to provide capacitive coupling to broaden the bandwidth, structure 6 is a metal short-circuit column with a width of 0.01λ h , length 0.49λ h The coupling plate 5 and the metal floor 4 are connected by a short-circuit column to suppress the common mode resonance. The dipole arm 7 is leaf-shaped with a height of 0.33λ h , with a width of 0.29λ h The coplanar strip line 8 consists of two strips with a width of 0.02λ h The parallel double wires and the dipole arms are on the same side of the dielectric substrate.

[0021] The structure of the wide-angle impedance matching layer in the antenna unit in this embodiment is as follows: Figure 3 The main part of the wide-angle impedance matching layer is composed of rectangular metal patches 9 arranged in an array, each with a width of 0.15λ h , length 0.35λ h A groove with a width of 0.12λ is cut at the end position 10 on both sides of the metal patch in the length direction. h rectangular slot with a width of 0.01λ h The metal strip 11 is electrically connected to the antenna, thereby cutting off the reverse propagation current introduced by the expansion of the unit spacing to suppress the surface wave. The middle area of ​​the metal patch 9 is cut with rectangular slots 12 arranged in an array to further reduce the weight of the antenna unit. The width of each rectangular slot is 0.041λ. h , length 0.1λ h .

[0022] The structure of the resistive grid layer single layer 3 in the antenna unit in this embodiment is as follows: Figure 1 Each unit has 16 lengths of 0.61λ h 、Width 0.041λ h , square resistance is 50Ω / m 2 of resistive bars.

[0023] Figure 4 A schematic diagram of the variation of the active standing wave ratio of this antenna unit with frequency at different scanning angles is given. The antenna can achieve an active standing wave ratio less than 3 in the range of f0 to 6.1f0 at scanning angles of 0°, 30° and 45° on the H plane.

[0024] Figure 5 The active standing wave ratio of this antenna unit loaded with different matching layers when scanning 45° on the H-plane is given. The image shows that the designed new matching layer has an obvious and reliable suppression effect on high-frequency surface waves.

[0025] Figure 6 The E-plane and H-plane radiation patterns of this antenna unit at different frequencies are given, where (a), (b), and (c) are the results of f0, 3.6f0, and 6.1f0, respectively.

Claims

1. A matching layer loaded lightweight large-size ultra-wideband phased array antenna, the antenna is composed of antenna units arranged in an array, each antenna unit includes: Wide angle impedance matching layer, antenna layer, resistive grid layer and metal floor; The wide-angle impedance matching layer is arranged parallel to the metal floor; The antenna layer is arranged in parallel with the resistive grid layer and is located between the wide-angle impedance matching layer and the metal floor; the antenna layer is perpendicular to the metal floor, and the projection of the antenna layer on the metal floor and the wide-angle impedance matching layer is the central axis of the metal floor and the wide-angle impedance matching layer; the resistive grid layer is located at the edge of the metal floor and the wide-angle impedance matching layer; The wide-angle impedance matching layer comprises a substrate, wherein a row of rectangular metal patches are arranged in parallel along the central axis on the upper surface of the substrate, and the long sides of the rectangular metal patches are perpendicularly bisected by the central axis; rectangular grooves are symmetrically provided on the two sides of each rectangular metal patch divided by the central axis; a narrow metal strip is led out from each end of each rectangular metal patch, and the narrow metal strip is perpendicular to the central axis and extends to the edge of the substrate; The antenna layer includes a dielectric substrate, two dipole arms are arranged on one side of the dielectric substrate, each dipole arm extends a coplanar strip line toward the metal floor, and the coplanar strip line is located in the middle of the dielectric substrate; a coupling patch is arranged on each of the two edges of the other side, and each coupling patch is connected to the metal floor through a metal short-circuit column; The resistive grid layer comprises a dielectric substrate and a plurality of resistive grid bars arranged on the dielectric substrate.

2. A matching layer loaded lightweight large-size ultra-wideband phased array antenna as claimed in claim 1, characterized in that: A plurality of rectangular grooves are respectively provided on both sides of the rectangular metal patch divided by the central axis in the wide-angle impedance matching layer. All rectangular grooves in one rectangular metal patch are arranged in a row, and the long side of each rectangular groove is parallel to the central axis of the substrate.

3. The matching layer loaded lightweight large-size ultra-wideband phased array antenna according to claim 1, characterized in that: Each dipole arm in the antenna layer is petal-shaped and symmetrically arranged with respect to the midline of the dielectric substrate. The two dipole arms form the shape of a whale's tail, but each dipole arm is independent; the tail tip of the left dipole arm is located at the upper left corner of the dielectric substrate, the tail tip of the right dipole arm is located at the upper right corner of the dielectric substrate, and the tail roots of the two dipole arms are located at the center of the dielectric substrate; the tail root of each dipole arm derives a coplanar strip line.

4. The matching layer loaded lightweight large-size ultra-wideband phased array antenna according to claim 1, characterized in that: All the resistive bars in the resistive grid layer are evenly spaced, and the axis direction of each resistive bar is perpendicular to the metal floor.

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