Cellular slant-polarized ultra-wideband rectangular grid array antenna

Abstract

The application provides a unit-level inclined polarization ultra-wideband rectangular grid array antenna. Each antenna unit adopts a two-dimensional symmetrical structure composed of a horizontal polarization plane and a vertical polarization plane, the structure of the horizontal polarization plane and the vertical polarization plane is consistent, and the horizontal polarization wave and the vertical polarization wave are self-synthesized through one port; each plane of the antenna unit is composed of a feeding matching part and a radiation cavity part, the structure is simple, the unit-level inclined polarization radiation characteristic can be realized, and the array is a regular rectangular grid. The array antenna of the application can cover more than 9 times of the frequency, and can realize two-dimensional ±45° beam scanning in the working frequency range under the premise of sufficient array scale.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of array antennas, and particularly relates to a unit-level oblique polarization ultra-wideband rectangular lattice array antenna. BACKGROUND

[0002] Phased array systems have been widely used in communication, radar, electronic countermeasure and other fields due to their rapid beam scanning, simultaneous multi-function, modularity and other characteristics. With the continuous widening of the functions of various products, ultra-wideband, wide-angle scanning, multi-polarization and the like have gradually become the design of array antennas.

[0003] Array antennas used in receiving systems such as reconnaissance equipment require circular polarization, dual polarization or oblique polarization radiation characteristics to cope with unknown polarized incoming waves. At present, the following methods are commonly used for ultra-wideband oblique polarization array antennas:

[0004] (1) Dual-polarized array antenna synthesizes oblique polarization;

[0005] (2) Linear polarization array antenna + polarization converter;

[0006] (3) Linear polarization array is rotated by a certain angle.

[0007] The first scheme above doubles the number of channels when used in a phased array system, and the cost is greatly increased. The second scheme greatly increases the antenna profile height due to the influence of the polarizer, and the conversion efficiency is not high and the power capacity is limited. The third scheme can control the cost and size, but the rectangular lattice is changed into a triangular lattice after rotation, and the complexity of the rear components is increased. SUMMARY

[0008] In order to overcome the deficiencies of the prior art, the application provides a unit-level oblique polarization ultra-wideband rectangular lattice array antenna. Each antenna unit adopts a two-dimensional symmetrical structure composed of a horizontal polarization surface and a vertical polarization surface, and the structures of the horizontal polarization surface and the vertical polarization surface are consistent, and are excited by one port to realize the self-synthesis of horizontal polarization waves and vertical polarization waves. Each surface of the antenna unit is composed of a feed matching part and a radiation cavity part, and the structure is simple, can realize the oblique polarization radiation characteristics at the unit level, and the array after the array is a regular rectangular lattice. The working frequency band of the array antenna of the application can cover more than 9 times the frequency, and under the premise of sufficient array scale, two-dimensional ±45° beam scanning in the working frequency band can be realized.

[0009] The utility model provides a unit level slant polarized ultra wide band rectangular grid array antenna, characterized by: adopt modularization design to take one slant polarized unit as a module, and all modules are arrayed into regular rectangular grid, wherein, each antenna unit adopts two-dimensional symmetry structure composed of horizontal polarization plane and vertical polarization plane, and the structure of horizontal polarization plane and vertical polarization plane is kept consistent, and is excited through one port, and each plane antenna unit is composed of feed matching part and radiation part, wherein, the feed matching part is composed of feed coaxial structure (1), gradually changing matching slot (2) and reflection cavity (3), and the radiation part (4) is gradually changing open slot adopting high order Bessel curve structure, compared with traditional exponential curve, the curve shape can be more flexibly adjusted.

[0010] The array antenna realizes self-combination of horizontal polarized wave and vertical polarized wave through structural design, realizes slant polarized radiation characteristics, adopts irregular module division, and the reflection cavity (3) spans adjacent modules.

[0011] The utility model has the advantages that: vertical and horizontal polarization self power division and polarization combination are realized through two-dimensional symmetry structure, the structure of two cross sections is same, equal amplitude and in phase transmission can be realized, the loss and amplitude and phase error caused by external power divider are avoided, and unit level slant polarized radiation characteristics are realized, high order Bessel curve structure is introduced in the gradually changing structure of the radiation part, more flexible and larger range of curve shape adjustment can be realized, the structure is better matched with free space, and better matching adjustment capacity is achieved, the modularization design is adopted, and processing and assembly are facilitated, the irregular module division is adopted, the problem that the reflection cavity spans adjacent modules is solved, and the structural stability can be increased. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is unit level slant polarized array antenna structure schematic diagram of the utility model;

[0013] Figure 2 It is unit level slant polarized array antenna bottom view;

[0014] Figure 3 It is unit level slant polarized unit antenna structure schematic diagram of the utility model;

[0015] Wherein, (a) - front view, (b) - rear view, (c) - top view, (d) - bottom view;

[0016] Figure 4 It is unit level slant polarized array antenna array unit active standing wave;

[0017] Wherein, (a) - normal active standing wave, (b) - Phi=0, 90 degree section scanning active standing wave;

[0018] Figure 5Radiation pattern of the unit-level slant polarized array antenna of the application at the reference frequency;

[0019] Wherein, (a) -Phi=0° cross-section pattern, (b) -Phi=45° cross-section pattern, (c) -Phi=90° cross-section pattern, (d) -Phi=135° cross-section pattern.

[0020] Figure 6 ±45° scanning pattern of the unit-level slant polarized array antenna beam of the application at 2GHz;

[0021] Wherein, (a) -Phi=0° cross-section pattern, (b) -Phi=45° cross-section pattern, (c) -Phi=90° cross-section pattern, (d) -Phi=135° cross-section pattern.

[0022] Figure 7 ±45° scanning pattern of the unit-level slant polarized array antenna beam of the application at 10GHz;

[0023] Wherein, (a) -Phi=0° cross-section pattern, (b) -Phi=45° cross-section pattern, (c) -Phi=90° cross-section pattern, (d) -Phi=135° cross-section pattern.

[0024] Figure 8 ±45° scanning pattern of the unit-level slant polarized array antenna beam of the application at 18GHz;

[0025] Wherein, (a) -Phi=0° cross-section pattern, (b) -Phi=45° cross-section pattern, (c) -Phi=90° cross-section pattern, (d) -Phi=135° cross-section pattern.

[0026] Figure 9 Polarization pattern of the unit-level slant polarized array antenna of the application at the reference frequency;

[0027] Wherein, (a) polarization pattern at 2GHz, (b) polarization pattern at 10GHz, (c) polarization pattern at 18GHz. DETAILED DESCRIPTION

[0028] The application will be further described in conjunction with the drawings and examples, and the application includes but is not limited to the following examples.

[0029] The application proposes a unit-level slant polarized ultra-wideband rectangular grid array antenna, which realizes self-synthesis of horizontal polarization wave and vertical polarization wave by adopting the same structure design in horizontal polarization plane and vertical polarization plane, and through a set of feeding structure of two-dimensional structure, and is excited through a port, finally presents slant polarization radiation characteristics, and is a regular rectangular grid after arraying.

[0030] like Figure 1 and 2 As shown, the unit-level slanted polarization ultrawideband rectangular grid array antenna adopts a modular design, with each slanted polarization unit constituting a module. All modules are mounted on a single, solid metal base plate and are fixed together by sintering.

[0031] like Figure 1 and 3 As shown, each antenna element adopts a two-dimensional symmetrical structure composed of a horizontal polarization surface and a vertical polarization surface, and the structures of the horizontal polarization surface and the vertical polarization surface are consistent. Each antenna element consists of a feeding matching part and a radiating part. The feeding matching part consists of a feeding coaxial structure (1), a gradient matching slot (2), and a reflective cavity (3). Specifically, the antenna element is a metal structure. The reflective cavity (3), the gradient matching slot (2), and the functional opening radiating structure (4) of the antenna are formed by directly cutting the metal block through wire cutting process. The coaxial structure (1) directly feeds the gradient matching slot (2). The coaxial connector interface is located at the bottom of the antenna and is installed on the antenna ground plane by screws or its own threads.

[0032] When the antenna is in operation, energy is fed into the tapered matching slot (2) through the coaxial probe, inducing current on the metal walls of the horizontal and vertical polarization surfaces. This current flows to both sides along the two matching slots, with the two sides of the slot line connected to the reflective cavity (3) and the functional open-aperture radiating structure (4), respectively. The current transmitted to the reflective cavity (3) is conducted to the other side of the tapered matching slot (2) through the reflection of the rectangular cavity. Ultimately, most of the energy is transferred to the functional open-aperture radiating structure (4) and continues to radiate into free space along the edge.

[0033] Because the antenna element adopts a two-dimensional symmetrical structure, it can achieve self-synthesis of vertical and horizontal polarization through a general feeding structure, thus realizing the slant polarization radiation characteristics at the element level.

[0034] This invention also introduces a higher-order Bézier curve structure into the gradient structure of the radiating structure (4) to replace the traditional exponential linear gradient structure. The curve equation is as follows:

[0035] (1)

[0036] in, By controlling the two endpoints of the curve (( x 1, z 1), ( x 5, z 5) This allows for coarse adjustment of the curve curvature, while controlling the intermediate point (( x 2, z 2), (x 3, z 3), ( x 4, z 4) The bending position and angle of the curve can be finely adjusted to achieve more flexible and wider range of curve shape adjustment, and better match with free space.

[0037] In addition, for structural stability, irregular module division can be adopted. Each module is not a regular cubic space, and the reflective cavity (3) spans the adjacent modules.

[0038] Figures 4-6 The simulation results are for an example of a 45° slanted polarized array antenna operating in the 2GHz~18GHz frequency band under the structure of this invention.

[0039] Figure 4 The active standing wave ratio (VSWR) of the element in the unit-level oblique polarization array antenna of this invention is presented. Figure (a) shows the normal active VSWR, and Figure (b) shows the active VSWR in the cross-sectional scan at Phi=0° and 90°. The horizontal axis represents the frequency range, and the vertical axis represents the active VSWR value. As can be seen from the figures, the normal active VSWR of the element in the array is less than 2.3, and it is less than 3 in more than 98% of the frequencies within the ±45° scanning range, and less than 5 across the entire frequency band.

[0040] Figure 5 The radiation patterns of the reference frequency unit-level slanted polarization array antenna of the present invention are given. Figure (a) is the radiation pattern of the Phi=0° section, Figure (b) is the radiation pattern of the Phi=45° section, Figure (c) is the radiation pattern of the Phi=90° section, and Figure (d) is the radiation pattern of the Phi=135° section. The horizontal axis represents the angle range, and the vertical axis represents the gain value. As can be seen from the figures, the radiation patterns are good and there are no split lobes, distortions, or other phenomena.

[0041] Figure 6 The beam pattern of the unit-level oblique polarized array antenna of the present invention at ±45° at 2GHz is given. Figure (a) is the beam pattern of the Phi=0° section, Figure (b) is the beam pattern of the Phi=45° section, Figure (c) is the beam pattern of the Phi=90° section, and Figure (d) is the beam pattern of the Phi=135° section. The horizontal axis represents the angle range, and the vertical axis represents the gain value. As can be seen from the figure, there are no abnormal phenomena such as grating lobes in the beam scanning pattern.

[0042] Figure 7 The beam pattern of the unit-level oblique polarized array antenna of the present invention at ±45° at 10 GHz is given. Figure (a) is the beam pattern of the Phi=0° section, Figure (b) is the beam pattern of the Phi=45° section, Figure (c) is the beam pattern of the Phi=90° section, and Figure (d) is the beam pattern of the Phi=135° section. The horizontal axis represents the angle range, and the vertical axis represents the gain value. As can be seen from the figures, there are no abnormal phenomena such as grating lobes in the beam scanning pattern.

[0043] Figure 8 The unit-level slant polarized array antenna beam of the present application at 18GHz is given, Fig. (a) is the Phi=0° cross-section pattern, Fig. (b) is the Phi=45° cross-section pattern, Fig. (c) is the Phi=90° cross-section pattern, and Fig. (d) is the Phi=135° cross-section pattern, the horizontal coordinate is the angle range, and the vertical coordinate is the gain value, from the figures, it can be seen that the beam scanning pattern has no abnormal phenomenon such as grating lobes;

[0044] Figure 9 The polarization pattern of the unit-level slant polarized array antenna of the present application at the reference frequency point is given, Fig. (a) is the polarization pattern at 2GHz, Fig. (b) is the polarization pattern at 10GHz, and Fig. (c) is the polarization pattern at 18GHz, the horizontal coordinate is the angle range, and the vertical coordinate is the gain value, it can be seen that in any cross-section of the pattern, the vertical and horizontal polarization components are basically consistent, and the slant polarization performance is good.

[0045] The 2GHz~18GHz array antenna exemplified is only a preferred embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A unit-level slanted polarization ultrawideband rectangular grid array antenna, characterized in that: The design adopts a modular approach, with each oblique polarization unit as a module. All modules are arrayed into a regular rectangular grid. Each antenna unit adopts a two-dimensional symmetrical structure composed of a horizontal polarization surface and a vertical polarization surface. The structures of the horizontal polarization surface and the vertical polarization surface are consistent and are excited through a port. Each antenna unit consists of a feed matching part and a radiation part. The feed matching part consists of a feed coaxial structure (1), a gradient matching slot (2), and a reflective cavity (3). The radiation part (4) is a gradient opening slot with a high-order Bezier curve structure, which can adjust the curve shape more flexibly. The array antenna achieves self-synthesis of horizontally polarized waves and vertically polarized waves through structural design, realizing oblique polarization radiation characteristics; it adopts irregular module division, in which the reflective cavity (3) spans the adjacent modules.

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