Lightweight coupled feeding ultra-wideband phased-array antenna

Abstract

The invention provides a light-weight coupling feed ultra-wideband phased-array antenna which is mainly divided into an upper metal radiation part and a lower printed board feed part. Wherein the metal radiation part is realized through machining, and the interior of the metal radiation part is hollowed out, so that the metal radiation part has relatively high consistency and can realize light weight. And the antenna feed part is formed by laminating a plurality of layers of printed boards and comprises a feed connector, a feed strip line, an antenna mounting hole, a coupling slot, a quasi-coaxial metallized hole and a metallized shielding hole. The feed strip line is excited through the feed connector, energy is transmitted to the metal radiation part through the coupling gap, and finally good matching with a free space is achieved. The metal radiation part is positioned and assembled with an antenna mounting hole in the feed printed board through a positioning pin, and is fixed by large-area welding on the ground, so that the grounding of the metal part is ensured, and good alignment precision is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and in particular relates to a lightweight coupled-fed ultra-wideband phased array antenna. Background Art

[0002] For antenna array systems, their basic function is to transmit and receive electromagnetic waves, and they are also considered to be spatial filters for the amplitude, phase, frequency and polarization characteristics of electromagnetic waves. In order to meet the requirements of low-profile and lightweight arrays, research on antenna radiation units with excellent performance of wide bandwidth and angle scanning and lightweight is gaining more and more attention, and their performance will directly affect the information processing capabilities of the system.

[0003] At present, many new detection requirements cannot be achieved by using mechanical scanning array antennas, so they are gradually replaced by phased array antennas with fast beam scanning capabilities. Wide scanning angle, broadband, and lightweight phased array technology are urgently needed in various application fields. Currently, common phased array antenna units mainly include printed vibrator antennas, patch antennas, slotted gradient line antennas, etc. Patch antennas are usually used as a selection method for high integration with the integrated layer, but the bandwidth of patch antennas is narrow and it is difficult to meet the use requirements of ultra-wideband. Common slotted gradient line antennas have problems such as poor integration with the integrated layer and heavy weight due to the high antenna profile.

[0004] In summary, existing lightweight, ultra-wideband phased array antennas have major technical difficulties: while meeting the requirements of ultra-wide bandwidth angular scanning performance, they must also take into account engineering feasibility, improve integration and reduce antenna weight. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a lightweight coupled-fed ultra-wideband phased array antenna. The radiating part of the antenna adopts a metal gradient slot line structure, has an ultra-wide bandwidth angle scanning characteristic, and uses a mature machining process to ensure that the antenna still has high consistency in the high frequency band, and hollows out the interior to achieve lightweight units. The ultra-wideband antenna feeding structure includes a feeding strip line and a broadband matching balun, which is implemented by printed circuit board lamination, and the energy excitation of the antenna radiating part is performed by slot coupling. The antenna radiating part and the feeding part are welded on the bottom surface, which is simple to implement and has high reliability. The antenna is easy to integrate with the network design and is suitable for the design of an integrated array system architecture.

[0006] The ultra-wideband phased array antenna of the present invention comprises a metal radiation part, a feed printed board, a support printed board and a radio frequency connector arranged from top to bottom; wherein the metal radiation part is an exponential gradient slot line structure with a weight reduction slot opened inside; the feed printed board comprises: a metallized shielding hole, a feed strip line, a unit mounting hole, a coupling slot and a quasi-coaxial metallized hole; the feed printed board is in a stepped shape, and the antennas are connected as one through the support printed board.

[0007] The excitation energy is input from the RF connector, transmitted along the feed stripline, and transmitted to the metal radiating part through the coupling gap. Finally, the exponential gradient slot line structure of the metal radiating part is used to achieve a good match with the free space. The metallized shielding holes in the feed printed circuit board constrain the path of energy transmission on the feed stripline, and the coaxial metallized holes constrain the energy from the RF connector to the feed stripline.

[0008] Furthermore, the feed printed board is formed by laminating multiple layers of printed boards, the upper and lower layers are both metal layers, the feed strip line is in the middle part of the feed printed board, the coupling gap is opened in the upper metal layer of the feed printed board, the metallized shielding hole and the coaxial metallized hole penetrate the feed printed board and ensure electrical continuity with the upper and lower metal layers, and the metal radiation part is connected to the feed printed board through the unit mounting hole.

[0009] Furthermore, the metal radiation part is formed by machining a magnesium alloy material, and both sides of the metal radiation part are hollowed out to form weight-reducing grooves, thereby achieving lightweighting of the antenna unit.

[0010] The beneficial effects of the present invention are

[0011] The radiating part of the antenna unit is made of magnesium alloy material and is realized through machining. It has the advantages of light weight, high processing precision and high consistency. The feed structure adopts mature printed circuit board processing technology, which is convenient for network integration design and suitable for integrated array system architecture design. The antenna has ultra-wide bandwidth angle scanning characteristics, simple engineering implementation, and is suitable for phased array radar systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a side view of the ultra-wideband phased array antenna of the present invention.

[0013] Figure 2 Schematic diagram of the metal radiation part.

[0014] Figure 3 This is a schematic diagram of the power feeding part of the printed circuit board.

[0015] Figure 4 is the normal standing wave curve of the antenna unit.

[0016] Figure 5It is the standing wave curve when the antenna unit scans 15° in two dimensions.

[0017] Figure 6 It is the standing wave curve when the antenna unit scans 60° in two dimensions.

[0018] Among them, 1-metal radiation part, 2-feed printed circuit board, 3-support printed circuit board, 4-shielding hole, 5-RF connector, 6-weight reduction groove 6, 7-feed strip line, 8-mounting hole, 9-coupling gap, 10-metallized hole. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The lightweight coupled-fed ultra-wideband phased array antenna of the present invention is mainly composed of three parts, namely: a metal radiation part 1, a feed printed board 2, and a support printed board 3. The metal radiation part 1 is an exponential gradient slot line structure, and a weight reduction slot 6 is opened inside; the printed board feed part 2 includes: a metallized shielding hole 4, a feed strip line 7, a unit mounting hole 8, a coupling slot 9, and a quasi-coaxial metallized hole 10; since the feed printed board 2 is in a stepped shape, it is necessary to ensure that the antennas are connected as one through the support printed board 3. The excitation energy is input from the RF connector 5, transmitted along the feed strip line 7, and transmitted to the metal radiation part 1 through the coupling slot 9, and finally the exponential slot line gradient part of the metal radiation part 1 is used to achieve a good match with the free space; the metallized shielding hole 4 constrains the path of energy transmission on the feed strip line 7, and the quasi-coaxial metallized hole 10 constrains and matches the energy excited from the RF connector 5 to the feed strip line 7. Figure 1 A side view of the overall structure of the antenna is given. Figure 2 A schematic diagram of the metal radiation part is given. Figure 3 A schematic diagram of the printed circuit board feeding section is given.

[0021] The feed printed board 2 is formed by laminating multiple layers of printed boards, and the upper and lower layers are both metal layers. The feed strip line 7 is in the middle part of the feed printed board 2, and the coupling gap 9 is opened in the upper metal layer of the feed printed board 2; the metallized shielding hole 4 and the quasi-coaxial metallized hole 10 penetrate the feed printed board 2 and ensure electrical continuity with the upper and lower metal layers; the unit installation hole 8 does not penetrate the feed printed board 2, and the depth can be controlled to a certain depth.

[0022] The metal radiation part 1 is formed by machining a magnesium alloy material, and weight-reducing grooves 6 are dug out at both sides of the metal radiation part 1 to achieve lightweighting of the antenna unit.

[0023] For conventional exponential gradient slot line ultra-wideband phased array antenna units, whether in printed circuit board or metal form, RF connectors are generally welded, and fixed and installed by metal structural plates, and interconnected with the RF connectors at the rear end. Although this interconnection method has high structural stability, it introduces the loss of two sections of RF connectors and increases the weight. In the present invention, feeding through coupling slots 9 effectively realizes the high integration of metal radiation part 1 and feeding printed circuit board 2, and further lightweighting is achieved by digging weight reduction grooves 6 in metal radiation part 1 and digging out half of feeding printed circuit board 2.

[0024] In order to meet the broadband and wide-angle scanning performance of the antenna, the electromagnetic field numerical algorithm is combined with simulation technology, and the purpose of improving the antenna radiation characteristics and S parameters is achieved through optimization design and performance comparison. In the design optimization stage, the unit spacing is a fixed parameter, and the overall height and thickness of the metal radiation part 1, the line width of each part of the feed strip line 7, the width of the coupling gap 9, the curvature of the exponential gradient slot line part of the metal radiation part 1, and the width of the upper and lower parts are adjusted and optimized. Through the optimization of these parameters, the antenna performance requirements of broadband and wide-angle scanning are finally achieved.

[0025] The main size selection range of this antenna unit is as follows: the triangular periodic arrangement spacing of the antenna unit is 0.77λ*0.88λ, and the thickness of the feed printed board 2 is 0.239mm, 0.239mm, and 1.624mm respectively. For the metal radiation part 1, the overall height is 1.8λ~1.9λ, the width is the same as the longer one-dimensional spacing of the antenna unit arrangement, and the thickness is 0.3λ~0.33λ; the starting height of the exponential gradient part in the metal radiation part 1 is 0.2λ~0.23λ, the width of the starting position at the bottom is 0.03λ~0.035λ, the width of the ending position at the top is 0.75λ~0.8λ, and the curvature of the index is 0.06~0.07.

[0026] For the feed printed board 2, the hole diameter of the metallized shielding hole 4 is in the range of 0.012λ~0.03λ; the diameter of the unit mounting hole 8 is 0.05λ~0.06λ; the diameter of the quasi-coaxial metallized hole 10 is 0.03λ~0.035λ; the feed stripline 7 is composed of five parts, the line width of the initial part is 0.01λ~0.014λ, and the line length is 0.022λ~0.026λ; the line width of the second section of the feed stripline 7 is 0.02λ~0.024λ, and the line length is 0. 19λ~0.21λ; the third section of the feed stripline 7 has a line width of 0.035λ~0.04λ, and a line length of 0.028λ~0.031λ; the fourth section of the feed stripline 7 has a line width of 0.1λ~0.12λ, and a line length of 0.1λ~0.12λ; the fifth section of the feed stripline 7 has a line width of 0.12λ~0.15λ, and a line length of 0.07λ~0.09λ; the width of the coupling slot 9 is 0.018λ~0.021λ, and the length is 0.35λ~0.4λ. The above λ is the working wavelength corresponding to the high frequency.

[0027] Specific embodiments according to the above-mentioned design, assembly and fixing methods and dimensional requirements are given below.

[0028] The antenna unit spacing is 16mm×18.2mm. The thickness of the multi-layer feed printed circuit board is 0.239mm, 0.239mm, and 1.624mm respectively, and it is laminated by 0.1mm prepreg. The material of the antenna printed circuit board is ROGERS6002.

[0029] The metal radiation part of the antenna has an overall height of 37.5mm, a width of 18.2mm and a thickness of 6.5mm. The starting height of the exponential gradient part of the metal radiation part is 4.5mm, the width at the bottom is 0.7mm, the width at the top is 16mm, and the exponential curvature is 0.066.

[0030] For the feed printed circuit board part, the diameters of the metallized shielding holes are 0.3mm, 0.4mm, and 0.6mm respectively; the diameter of the unit mounting hole is 1.2mm, and the hole depth is 1.8mm; the diameter of the quasi-coaxial metallized hole is 0.7mm; the line width of the starting part of the feed stripline is 0.25mm, and the line length is 0.5mm; the line width of the second section of the feed stripline is 0.46mm, and the line length is 4mm; the line width of the third section of the feed stripline is 0.75mm, and the line length is 0.62mm; the line width of the fourth section of the feed stripline is 2.2mm, and the line length is 2.4mm; the line width of the fifth section of the feed stripline is 2.7mm, and the line length is 1.7mm; the width of the coupling gap is 0.4mm, and the length is 8mm.

[0031] The antenna radiation part and the feeding part are welded over a large area, which makes the engineering implementation simple and the processing implementation cost low. The antenna is easy to integrate with the network design and is suitable for the integrated array system architecture design.

[0032] The main performance indicators achieved by the antenna unit are:

[0033] Working frequency: relative bandwidth 131%;

[0034] Scanning range: ±60°;

[0035] Standing wave characteristics: The standing wave in the normal full frequency band is less than 1.8, and the standing wave in the frequency band scan used in the entire airspace is less than 3.1.

[0036] Figure 4 It is a normal standing wave curve diagram of an embodiment of the present invention, wherein the abscissa represents frequency and the ordinate represents normal standing wave (VSWR). It can be seen that the matching performance is good within a relative bandwidth of 131%, and the standing wave is less than 1.8; Figure 5 The two-dimensional ±15° scanning standing wave curve diagram of the embodiment of the present invention, the two test curves respectively represent the standing wave conditions when scanning along the two main sections. Due to the unit spacing limitation, the relative bandwidth of the 15° scan is 123%, and the standing waves in the frequency band are all less than 1.8; Figure 6 The two-dimensional ±60° scanning standing wave curve of the embodiment of the present invention shows that as the scanning angle increases, the unit spacing has a more obvious restriction on the scanning bandwidth. The scanning bandwidth of the antenna of the present invention at 60° is 105%, and the large-angle scanning standing wave is below 3.1. Compared with the conventional ultra-wideband tightly coupled antenna, it has certain advantages in large-angle scanning standing wave. According to the scanning standing wave results, the ultra-wide bandwidth angle scanning matching of ±60° can be effectively achieved by the means of the present invention.

[0037] It can be seen from the figure that the performance indicators of the lightweight coupled-fed ultra-wideband phased array antenna provided by the present invention have met the expected design requirements.

[0038] The present invention is not limited to the above specific implementations, and the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made to the above implementations based on the technical essence of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lightweight coupled-fed ultra-wideband phased array antenna, characterized in that: It includes a metal radiation part, a feed printed board, a support printed board and a radio frequency connector arranged from top to bottom; wherein the metal radiation part is an exponential gradient slot line structure with a weight reduction slot opened inside; the feed printed board includes: a metallized shielding hole, a feed strip line, a unit mounting hole, a coupling gap and a quasi-coaxial metallized hole; the feed printed board is in a stepped shape, and the antennas are connected as one through the support printed board; The excitation energy is input from the RF connector, transmitted along the feed stripline, and transmitted to the metal radiating part through the coupling gap. Finally, the exponential gradient slot line structure of the metal radiating part is used to achieve a good match with the free space. The metallized shielding holes in the feed printed circuit board constrain the path of energy transmission on the feed stripline, and the coaxial metallized holes constrain the energy from the RF connector to the feed stripline.

2. The lightweight coupled-fed ultra-wideband phased array antenna according to claim 1, characterized in that: The feed printed board is formed by laminating multiple layers of printed boards, the upper and lower layers are both metal layers, the feed strip line is in the middle part of the feed printed board, the coupling gap is opened in the upper metal layer of the feed printed board, the metallized shielding hole and the quasi-coaxial metallized hole penetrate the feed printed board and ensure electrical continuity with the upper and lower metal layers, and the metal radiation part is connected to the feed printed board through the unit installation hole.

3. The lightweight coupled-fed ultra-wideband phased array antenna according to claim 2, characterized in that: The metal radiation part is formed by machining a magnesium alloy material, and both sides of the metal radiation part are hollowed out to form weight-reducing grooves, thereby achieving lightweighting of the antenna unit.

4. The lightweight coupled-fed ultra-wideband phased array antenna according to claim 1 or 2, characterized in that: The triangular periodic arrangement spacing of the antenna unit is 0.77λ*0.88λ, and the thicknesses of the feed printed circuit board are 0.239mm, 0.239mm, and 1.624mm respectively.

5. The lightweight coupled-fed ultra-wideband phased array antenna according to claim 1 or 2, characterized in that: The overall height of the metal radiation part is 1.8λ~1.9λ, the width is the same as the longer one-dimensional spacing of the antenna unit arrangement, and the thickness is 0.3λ~0.33λ; the starting height of the exponential gradient slot line structure in the metal radiation part is 0.2λ~0.23λ, the width at the starting position at the bottom is 0.03λ~0.035λ, the width at the ending position at the top is 0.75λ~0.8λ, and the exponential curvature is 0.06~0.

07.

6. A lightweight coupled-fed ultra-wideband phased array antenna according to claim 1 or 2, characterized in that: The diameter of the metallized shielding hole is 0.012λ~0.03λ; the diameter of the unit installation hole is 0.05λ~0.06λ; the diameter of the quasi-coaxial metallized hole is 0.03λ~0.035λ; the feed strip line consists of five parts, the line width of the initial part is 0.01λ~0.014λ, the line length is 0.022λ~0.026λ; the line width of the second section is 0.02λ~0.024λ, and the line length is 0.19λ~0. 21λ; the line width of the third section is 0.035λ~0.04λ, and the line length is 0.028λ~0.031λ; the line width of the fourth section is 0.1λ~0.12λ, and the line length is 0.1λ~0.12λ; the line width of the fifth section is 0.12λ~0.15λ, and the line length is 0.07λ~0.09λ; the width of the coupling gap is 0.018λ~0.021λ, and the length is 0.35λ~0.4λ, where λ is the operating wavelength.

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