A large-size ultra-wideband phased array antenna with a matching layer loaded

Abstract

The present invention discloses a lightweight large-size ultra-wideband phased array antenna with a matching layer loaded, belonging to the technical field of antenna engineering. The antenna of the present invention adopts a strongly coupled dipole antenna element, which has the characteristics of ultra-wideband; a novel wide-angle impedance matching layer is adopted to suppress the surface wave introduced by increasing the element spacing, and the element spacing is increased under the condition of no grating lobes; the coplanar strip line and the leaf-shaped dipole form are adopted to optimize the antenna standing wave. The wide-angle impedance matching layer and the antenna layer are both printed on a single-layer dielectric board, which is convenient for processing and simple for assembly. The simulation results show that when the antenna element is used in a phased array, it can achieve no grating lobes in the H-plane scan of ±45° within the frequency band of f0 to 6.1f0, and the active standing wave ratio is lower than 3.

Description

Technical Field

[0001] The present invention belongs to the technical field of antenna engineering, and particularly 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 have been widely used in radar detection, satellite communication and other fields due to their advantages such as flexible beam scheduling, large coverage airspace, and the ability to search and track multiple targets. At the same time, in order to meet the requirements of phased array systems for antenna broadband and wide-angle scanning, and to save system costs, phased array antennas with the characteristics of large size, ultra-wideband and wide-angle scanning have become a research hotspot. Strongly coupled dipole arrays usually have ultra-wideband characteristics. For example, in the paper "Dual-Polarized Tightly Coupled Dipole Array for UHF–X-Band Satellite Applications", a bandwidth of 10.5:1 was achieved, with E-plane, D-plane and H-plane scanning ranges of ±60°, and the element size was 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, with E-plane, D-plane and H-plane scanning ranges of ±45°, and the element size was 0.23λ h ×0.47λ h . In the above papers, by combining two small strongly coupled antenna elements in parallel to form an array element to improve impedance matching, the performance of broadband wide-angle scanning was achieved. However, this method requires more element numbers to achieve high gain, which will inevitably increase the overall cost of the system. Summary of the Invention

[0003] Based on the background art, 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 convenient for processing and simple to assemble, and can be applied in various scenarios such as radar and navigation.

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

[0005] A lightweight large-size ultra-wideband phased array antenna with a matching layer loaded, which is composed of antenna units arranged in an array. Each antenna unit includes: 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 parallel to the metal floor; the antenna layer is arranged parallel to 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 projections of the antenna layer on the metal floor and the wide-angle impedance matching layer are the central axes of the metal floor and the wide-angle impedance matching layer; the resistive grid layer is located at the edges of the metal floor and the wide-angle impedance matching layer.

[0006] The wide-angle impedance matching layer includes a substrate. Along the central axis on the upper surface of the substrate, a row of rectangular metal patches is arranged side by side. The long sides of the rectangular metal patches are vertically bisected by the central axis; on both sides of each rectangular metal patch divided by the central axis, rectangular slots are symmetrically opened; at both ends of each rectangular metal patch, a metal narrow strip is led out, and the metal narrow strip is perpendicular to the central axis and extends to the edge of the substrate.

[0007] The antenna layer includes a dielectric substrate. On one side of the dielectric substrate, two dipole arms are arranged. Each dipole arm extends a coplanar strip line towards the metal floor, and the coplanar strip line is located in the middle of the dielectric substrate; on the two edges of the other side, a coupling patch is arranged respectively, and each coupling patch is connected to the metal floor through a metal shorting post.

[0008] The resistive grid layer includes a dielectric substrate and multiple resistive grid bars arranged on the dielectric substrate.

[0009] Further, on both sides of each rectangular metal patch in the wide-angle impedance matching layer divided by the central axis, a plurality of rectangular slots are opened. All the rectangular slots in one rectangular metal patch are arranged in a row, and the long sides of each rectangular slot are parallel to the central axis of the substrate.

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

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

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

[0013] Figure 1 FIG. is a structural diagram of a lightweight large-size ultra-wideband phased array antenna element with a new type of matching layer loaded according to the present invention.

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

[0015] Figure 3 FIG. is a structural diagram of the matching layer, where (a) is a structural diagram of a new type of matching layer with a surface wave suppression structure added to the antenna element of the present invention, and (b) is a structural diagram of the matching layer without the surface wave suppression structure added.

[0016] Figure 4 FIG. is a schematic diagram of the active standing wave ratio of the antenna element of the present invention varying with frequency at different scanning angles.

[0017] Figure 5 FIG. is the active standing wave ratio of the antenna element of the present invention with different matching layers loaded when scanning 45° in the H-plane.

[0018] Figure 6 FIG. is the side radiation patterns in the E-plane and H-plane of the antenna element of the present invention at different frequencies, where (a), (b), and (c) are the results at f0, 3.6f0, and 6.1f0 respectively. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In this embodiment, the 3D view of the lightweight large-size ultra-wideband phased array antenna element with a new type of matching layer loaded is as shown in Figure 1 FIG., and 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 operates at f0 to 6.1f0, and the element size is 0.61λ h ×0.58λ h ×0.63λ h (λ h is the wavelength corresponding to 6.1f0), and beam scanning of ±45° in the H-plane can be achieved within the operating bandwidth.

[0020] In this embodiment, the structure of the antenna layer 2 in the antenna element is as shown in Figure 2 FIG., where all structures are printed on a dielectric board. Structure 5 is a coupled patch, with a width of 0.041λ h , and a length of 0.081λ h, providing capacitive coupling between adjacent unit dipole arms 7 to broaden the bandwidth. Structure 6 is a metal shorting post with a width of 0.01λ h , and a length of 0.49λ h , connecting the coupling patch 5 and the metal ground plane 4 through the shorting post to suppress common-mode resonance. The dipole arm 7 is leaf-shaped, with a height of 0.33λ h , and a width of 0.29λ h . The coplanar strip 8 consists of two metal strips with a width of 0.02λ h , and the parallel double lines are on the same side of the dielectric substrate as the dipole arm.

[0021] In this embodiment, the structure of the wide-angle impedance matching layer in the antenna unit is as Figure 3 shown. The main part of the wide-angle impedance matching layer consists of rectangular metal patches 9 arranged in an array. Each patch has a width of 0.15λ h , and a length of 0.35λ h . Slots with a width of 0.12λ h are cut at both end positions 10 in the length direction of the metal patch, and are electrically connected through metal narrow strips 11 with a width of 0.01λ h to cut off the backward-propagating current introduced by expanding the unit spacing and suppress surface waves. Rectangular slots 12 arranged in an array are cut in the middle area of the metal patch 9 to further reduce the weight of the antenna unit. Each rectangular slot has a width of 0.041λ h , and a length of 0.1λ h .

[0022] In this embodiment, the structure of the resistive grid layer single layer 3 in the antenna unit is as Figure 1 shown. Each unit has 16 resistive grid bars with a length of 0.61λ h , a width of 0.041λ h , and a sheet resistance of 50 Ω / m 2 .

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

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

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

Claims

1. A lightweight large-size ultra-wideband phased array antenna with matching layer loading, which is spliced by antenna elements arranged in an array. Each antenna element 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 parallel to 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 projections of the antenna layer on the metal floor and the wide-angle impedance matching layer are the central axes of the metal floor and the wide-angle impedance matching layer; the resistive grid layer is located at the edges of the metal floor and the wide-angle impedance matching layer; The wide-angle impedance matching layer includes a substrate. Along the central axis on the upper surface of the substrate, a row of rectangular metal patches is arranged side by side. The long sides of the rectangular metal patches are vertically bisected by the central axis; on both sides of each rectangular metal patch divided by the central axis, rectangular slots are symmetrically opened; at each end of each rectangular metal patch, a metal narrow strip is led out, and the metal narrow strip is perpendicular to the central axis and extends to the edge of the substrate; The antenna layer includes a dielectric substrate. On one side of the dielectric substrate, two dipole arms are provided. Each dipole arm extends a coplanar strip line towards the metal floor, and the coplanar strip line is located in the middle of the dielectric substrate; on the other two edges, a coupling patch is provided respectively, and each coupling patch is connected to the metal floor through a metal shorting post; The resistive grid layer includes a dielectric substrate and multiple resistive grid bars arranged on the dielectric substrate.

2. The lightweight large-sized ultra-wideband phased array antenna with matching layer loading according to claim 1, wherein On both sides of each rectangular metal patch in the wide-angle impedance matching layer divided by the central axis, multiple rectangular slots are opened. All the rectangular slots in one rectangular metal patch are arranged in a row, and the long sides of each rectangular slot are parallel to the central axis of the substrate.

3. A lightweight large-size ultra-wideband phased array antenna with matching layer loading as claimed in claim 1, wherein Each dipole arm in the antenna layer is petal-shaped, symmetrically arranged with respect to the midline of the dielectric substrate. The two dipole arms form the shape of a whale tail, but each dipole arm is independent; the tip of the left dipole arm is located at the upper left corner of the dielectric substrate, the tip of the right dipole arm is located at the upper right corner of the dielectric substrate, and the roots of the two dipole arms are located at the central part of the dielectric substrate; a coplanar strip line is derived from the root of each dipole arm.

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

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