Strongly supported ultra-wideband all-metal tightly coupled phased array antenna

Abstract

The present invention belongs to the technical field of microwave antennas, and specifically provides a strongly supported ultra-wideband all-metal tightly coupled phased array antenna to achieve the characteristics of high power resistance and stronger mechanical stability of the tightly coupled phased array antenna. The present invention includes: a radiation structure, namely, front and rear metal dipoles, and an opening structure loaded on the metal dipole; a support structure, namely, a metal support arm of the front metal dipole, and a metal support with a gradient structure of the rear metal dipole; a feeding structure, namely, a gradient metal feeding strip, a floor, and a coaxial line. The present invention divides a dipole into front and rear metal dipoles, and etches a symmetrical opening structure on the front and rear metal dipoles, which is equivalent to introducing multiple parallel capacitors to reduce the input impedance of the antenna, thereby expanding the working bandwidth and scanning angle of the antenna; the present invention loads a metal support structure under each dipole to achieve the function of strong support for the entire antenna. The invention can be used in electronic countermeasure systems and high-speed aircraft.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave antennas, and specifically provides a strongly supported ultra-wideband all-metal tightly coupled phased array antenna. Background Art

[0002] With the rapid development of wireless communication technology, electronic countermeasure systems have put forward more stringent requirements for wide-area coverage, miniaturization, integration, and support. Wide-area coverage includes wide-area coverage in frequency and wide-area coverage in space. Wide-area coverage in frequency requires that the antenna working bandwidth is wide enough, and wide-area coverage in space requires that the antenna scanning angle is wide enough. Miniaturization and integration require the antenna to have low profile and compact characteristics. At the same time, in order to ensure that the electronic countermeasure system still meets the working conditions in harsh environments, the antenna needs to have sufficient support capacity and interference suppression capabilities.

[0003] The tightly coupled phased array antenna utilizes the coupling between units to make the units that originally do not have broadband characteristics achieve ultra-wideband characteristics after being arrayed. It also has the characteristics of wide scanning angle, low profile and compactness.

[0004] At present, the radiating metal sheets of tightly coupled phased array antennas are usually printed on dielectric substrates, but this form of antenna often has weak support capabilities and is easily affected by external interference, causing it to fail to work. Compared with dielectric plate printed antennas, all-metal antennas have the advantages of high power resistance and stronger mechanical stability, which means that in some special fields, such as high-speed aircraft and bumpy sea surfaces, strongly supported all-metal tightly coupled phased arrays have greater application advantages. Therefore, it is of great significance to study strongly supported ultra-wideband all-metal tightly coupled phased array antennas. Summary of the invention

[0005] The present invention aims to solve the problem of the lack of external interference in the field of tightly coupled array antenna technology, and realize an all-metal tightly coupled phased array antenna with strong support, ultra-wide bandwidth and wide scanning angle.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows

[0007] The present invention is mainly composed of a radiation structure, a support structure and a feeding structure. The radiation structure adopts the form of two groups of crossed front metal dipoles and rear metal dipoles. The front metal dipole and the rear metal dipole are staggered and symmetrical. The front metal dipole and the rear metal dipole form an L-shaped structure, so that a part of the inductance is introduced at the radiation end to effectively reduce the overall antenna size. The front metal dipole and the rear metal dipole are loaded with opening structures with the same parameters. The opening structures on the front metal dipole and the rear metal dipole are also symmetrical in shape, and the opening structures are all designed in a semi-inverted trapezoid. In this way, the front metal dipole and the rear metal dipole are staggered, which is equivalent to introducing multiple parallel capacitors at the radiation structure to achieve better impedance matching, thereby expanding the actual working bandwidth of the antenna.

[0008] Since the overall stability of the antenna is relatively high in actual work, and adding too much metal structure will seriously affect the radiation performance of the antenna, the present invention uses a metal support arm for the front metal dipole, and the overall width of the metal support arm remains consistent, which can effectively reduce the impact of too much metal structure on the radiator while maintaining the stability of the overall structure. A metal support with a gradient structure is used under the rear metal dipole, and the width of the metal support with a gradient structure decreases from bottom to top, which can effectively prevent the impact of external electromagnetic waves on the feeding structure, as well as the mutual impact between the feeding structures, and also greatly enhance the stability of the overall antenna.

[0009] In order to ensure that the impedance matching capacity of the antenna is sufficient, the gradient metal feed strip is placed directly on the floor, and energy is fed through the coaxial line located below the floor. The structure of the gradient metal feed strip gradually narrows from bottom to top, which can meet a wide range of impedance transformation, thereby achieving ultra-wideband impedance matching.

[0010] The innovation of the present invention lies in:

[0011] 1. The introduction of multiple parallel capacitors is achieved through a special radiation structure, which reduces the cross-sectional height of the antenna and greatly expands the actual working bandwidth and actual scanning angle of the antenna.

[0012] 2. The present invention adopts an extremely simple feeding structure and supporting structure, which not only satisfies a wide range of impedance transformation but also improves the stability and out-of-band anti-interference performance of the overall antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the ultra-wideband all-metal tightly coupled phased array antenna with strong support of the present invention, which includes the radiation structure indicated by Ⅰ, the support structure indicated by Ⅱ and the feeding structure indicated by Ⅲ;

[0014] Figure 2 It is a schematic diagram of the radiation structure, support structure and feeding structure of the ultra-wideband all-metal tightly coupled phased array antenna with strong support of the present invention;

[0015] Figure 3 It is a front view of the radiation structure, support structure and feeding structure of the strongly supported ultra-wideband all-metal tightly coupled phased array antenna of the present invention;

[0016] Figure 4 It is a side view of the radiation structure, support structure and feeding structure of the strongly supported ultra-wideband all-metal tightly coupled phased array antenna of the present invention;

[0017] Figure 5 It is a top view of the radiation structure, support structure and feeding structure of the ultra-wideband all-metal tightly coupled phased array antenna with strong support of the present invention;

[0018] Figure 6 It is a bottom view of the radiation structure, support structure and feeding structure of the ultra-wideband all-metal tightly coupled phased array antenna with strong support of the present invention;

[0019] Figure 7 It is an active standing wave with strong support of the ultra-wideband all-metal tightly coupled phased array antenna with side-firing, E-plane 45-degree scanning and H-plane 45-degree scanning;

[0020] Figure 8 The scanning pattern of the E-plane beam within the range of ±45 degrees at 1.4 GHz of the ultra-wideband all-metal tightly coupled phased array antenna strongly supported by the present invention when forming a 10×10 array;

[0021] Fig. 9 It is the scanning pattern of the H-plane beam within the range of ±45 degrees at 1.4 GHz when the ultra-wideband all-metal tightly coupled phased array antenna with strong support of the present invention is formed into a 10×10 array. Specific implementation plan

[0022] In order to make the objectives, technical solutions and innovative points of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0023] Figure 1 It is the overall structure of the present invention, and the structure of the present invention comprises, from top to bottom, a radiation structure I, a support structure II and a feeding structure III.

[0024] Figure 2 The specific structural features of the radiation structure, support structure and feed structure of the present invention are shown. Figure 3 is its front view, Figure 4 is its side view, Figure 5 This is its top view. Figure 6 1 is the front metal dipole, the length of the front metal dipole 1 is L1 = 27.8mm, the height is h1 = 29.1mm, the shortest thickness is W5 = 2mm, the longest thickness is W4 = 2.4mm, the tail end L structure length is L10 =4mm, L structure width W6 = 2mm; 2 is the rear metal dipole, the length of the rear metal dipole 2 is L1 = 27.8mm, the height h1 = 29.1mm, the shortest thickness W5 = 2mm, the longest thickness W4 = 2.4mm, the tail end L structure length L 10 =4mm, L structure width W6 =2mm, the size parameters of the front metal dipole 1 and the rear metal dipole 2 are consistent, the farthest distance between the front metal dipole 1 and the rear metal dipole 2 is W7 =1.6mm, and the closest distance is W8 =0.8mm; 3 is an opening structure loaded on the front and rear metal dipoles, and the opening structure 3 can be realized by etching and other processing methods. The long side L2 of the upper half inverted trapezoid is 13.5mm, the short side L3 =10.5mm, and the height h2 =5.8mm. The long side L4 of the lower half inverted trapezoid is 7.1mm, The short side L5=8mm, the height h3=5.8mm, the distance between the lower half inverted trapezoid and the upper half inverted trapezoid is h7=5.8mm; 4 is the metal support of the gradient structure of the rear metal dipole 2, the width of the metal support 4 of the gradient structure decreases from bottom to top, its height h4=45.9mm, lower width L7=34mm, upper width L6=2mm, thickness W3=2mm; 5 is the metal support arm of the front metal dipole 1, which consists of two sections, the first section is a horizontally extended metal arm, the length of the horizontally extended metal arm is L 11 =3.24mm, extended height h8=2mm, width L9=2mm, the second section is a vertical metal arm, the vertical metal arm length L9=2mm, height h4=45.9mm, width W1=2mm; 6 is a gradient metal feeding strip, the gradient metal feeding strip 6 decreases in width from bottom to top, the lower width L8=8mm, the upper width L6=2mm, the height h4=45.9mm, adjusting the upper and lower widths of the feeding strip can change the relevant impedance transformation range; 7 is the floor of the antenna, the length and width of the floor are both L 12 =57mm, the function of the floor 7 is to suppress back radiation and improve the antenna gain; 8 is the coaxial port of the antenna, which is used to feed energy to the antenna.

[0025] Figure 7 The active standing waves of the side-firing, E-plane 45-degree scanning and H-plane 45-degree scanning of the low-profile ultra-wideband metal tightly coupled phased array antenna under infinite boundary conditions are demonstrated. It can be seen that in the frequency band of 0.4GHz-2.24GHz, the active standing waves of the present invention in the side-firing and E-plane scanning of 45 degrees are less than 3, reaching a 5.6:1 octave bandwidth; in the frequency band of 0.4GHz-2.28GHz, the active standing waves of the present invention in the H-plane scanning of 45 degrees are less than 3.2, reaching a 5.7:1 octave bandwidth; it also meets the requirements for active standing waves of tightly coupled phased array antennas in engineering.

[0026] Figure 8The present invention shows a 10×10 array, at a frequency of 1.4 GHz, the E-plane beam scanning pattern within the range of ±45 degrees, Fig. 9 The scanning pattern of the H-plane beam within the range of ±45 degrees at the same frequency is shown. It can be seen that after the present invention forms a 10×10 array, it can achieve ±45-degree beam scanning on the E-plane and H-plane, while only introducing low gain loss. The profile height of the present invention is 0.1 times the low-frequency wavelength, which achieves an extremely low profile level compared to the traditional all-metal Vivaldi antenna.

[0027] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A strongly supported ultra-wideband all-metal tightly coupled phased array antenna, comprising a radiation structure, a support structure and a feeding structure, characterized in that: The radiation structure comprises two front metal dipoles (1) for achieving outward radiation and reception, two rear metal dipoles (2) for assisting transmission and reception and expanding the scanning angle, and an opening structure (3) loaded on the front and rear metal dipoles; the support structure comprises a metal support (4) with a gradient structure below the rear metal dipole and a metal support arm (5) of the front metal dipole; the feeding structure comprises a gradient metal feeding strip (6) connected to the metal dipole, a floor (7) located below the structure for suppressing back radiation, and a coaxial line (8) passing through the floor to feed the metal feeding strip; The front metal dipole (1) and the rear metal dipole (2) are staggered and symmetrical, which can expand the scanning angle of the antenna. The front metal dipole (1) and the rear metal dipole (2) are both loaded with an opening structure (3). The opening structure (3) on the front metal dipole (1) and the opening structure (3) on the rear metal dipole (2) are also symmetrical. The opening structure (3) loaded on the front and rear metal dipoles is designed in a semi-inverted trapezoidal shape, which is equivalent to introducing multiple parallel capacitors in the radiation structure to achieve better impedance matching.

2. The supporting structure of the strongly supported ultra-wideband all-metal tightly coupled phased array antenna according to claim 1 is characterized in that: The overall width of the metal support (4) with a gradient structure below the rear metal dipole decreases from bottom to top, which can effectively prevent the influence of external electromagnetic waves on the feeding structure and the mutual influence between feeding structures. The overall width of the metal support arm (5) of the front metal dipole remains straight, which can effectively reduce the influence of excessive metal structure on the radiator, while maintaining the stability of the overall structure.

3. The feeding structure of the strongly supported ultra-wideband all-metal tightly coupled phased array antenna according to claim 1 is characterized in that: The width of the gradient metal feeding strip (6) decreases from bottom to top, which can achieve a certain impedance transformation and thus impedance matching. The coaxial line (8) is connected to the gradient metal feeding strip (6) to achieve energy feeding. The floor (7) is used to suppress back radiation and improve gain.

4. The strongly supported ultra-wideband all-metal tightly coupled phased array antenna according to claim 1, characterized in that: The antenna unit has a lateral dimension of 57 mm×57 mm and a cross-sectional height of 75 mm.

5. The radiation structure of the strongly supported ultra-wideband all-metal tightly coupled phased array antenna according to claim 1 is characterized in that: The front metal dipole (1) and the rear metal dipole (2) are both L-shaped, so as to introduce a portion of inductance into the radiation structure and thereby reduce the size of the antenna radiator, wherein the difference in distance between the front metal dipole and the rear metal dipole is at least 0.8 mm and at most 1.6 mm.

6. The radiation structure of the strongly supported ultra-wideband all-metal tightly coupled phased array antenna according to claim 1 is characterized in that: The opening structure (3) loaded on the front and rear metal dipoles is designed in a semi-inverted trapezoidal shape and is symmetrically structured on the front metal dipole and the rear metal dipole, wherein the short side structure of the lower semi-inverted trapezoid is of full length, the long side length of the upper semi-inverted trapezoid is 13.5 mm, the short side length is 10.5 mm, and the height is 5.8 mm, and the long side length of the lower semi-inverted trapezoid is 7.1 mm, the short side length is 8 mm, and the height is 5.8 mm.

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