Dual-polarization tightly-coupled dipole ultra-wideband antenna loaded with resistive film

Abstract

The invention discloses a dual-polarization tight coupling dipole ultra-wideband antenna loaded with a resistive film. The antenna comprises a medium matching layer loaded with a metasurface, a dipole antenna, a coupling capacitor patch, a metal through hole, a curve-shaped gap, the resistive film, a coaxial line feeder, a metal floor, a first medium substrate, a second medium substrate and a third medium substrate. According to the invention, the dual-polarization, low-profile and wide-band design of the tightly coupled antenna can be realized. According to the invention, the provided frequency covers 0.8-12GHz, the active standing-wave ratios of the two ports of the dual-polarization unit are both below 3, and the isolation between the two ports is less than-15dB. The height of the antenna unit is 33 mm, and the antenna unit has good radiation characteristics. The antenna has the advantages of wide working frequency band, wide beam scanning range and low profile height, is convenient to process, can be conformal on a curved surface carrier, and has important significance in practical engineering application such as electronic reconnaissance and electronic countermeasure.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-wideband antennas, and in particular relates to a dual-polarization tightly coupled dipole ultra-wideband antenna loaded with a resistive film. Background Art

[0002] As the information transmission rate in modern society gradually increases and the signal coverage range becomes wider, the demand for broadband and even multi-band antennas is increasing. The bandwidth of traditional broadband antennas is mostly limited to the same frequency band, and it is difficult to achieve multi-band coverage. Traditional ultra-wideband antenna arrays such as Vivaldi antenna arrays can achieve ultra-wide working bandwidth, but their high profile and heavy weight often hinder the integrated and integrated design of electronic information systems. Unlike other ultra-wideband arrays, the planar ultra-wideband modular array (PUMA) is made of planar etched circuits and metal through holes, so it can be made into a simple multi-layer microwave PCB structure without the need for an external balun structure. In addition, the PUMA array has a low profile and can be constructed modularly. The adjacent unit oscillators of the tightly coupled array can generate capacitive coupling, which can offset the inductive coupling between the antenna and the floor, so the tightly coupled array has a natural technical advantage in ultra-wideband and low-profile applications. However, there are still many key technologies to be overcome in the tightly coupled phased array antenna array. At the same time, due to the characteristics of dipole antennas such as low profile, good polarization characteristics, wide bandwidth, and easy array formation, they are often used as tightly coupled antenna array elements. Summary of the invention

[0003] The object of the present invention is to provide a dual-polarization tightly coupled dipole ultra-wideband antenna loaded with a resistive film, which can be mass-produced by using printed circuit technology and has the advantages of small size, stable performance and low production cost.

[0004] The technical solution to achieve the purpose of the present invention is: a dual-polarized tightly coupled dipole ultra-wideband antenna loaded with a resistive film, the antenna unit comprising a dielectric matching layer loaded with a metasurface, a dipole antenna, a coupling capacitor patch, a metal through hole, a curved gap, a resistive film, a coaxial line feed, a metal floor, a first dielectric substrate, a second dielectric substrate and a third dielectric substrate; the dielectric matching layer loaded with a metasurface is placed on the top of the first dielectric substrate; the dipole antenna is symmetrically orthogonally placed and printed on the front and back of the first dielectric substrate; the coupling capacitor patch is printed on both sides of the first dielectric substrate; the coaxial line feed as the antenna feeding structure passes through the second dielectric substrate and the third dielectric substrate loaded with the resistive film and is connected to the dipole antenna; the curved gap is opened at the end of the dipole antenna, and the metal through hole is embedded in the first dielectric substrate; the metal floor and the dielectric matching layer and the resistive film are placed parallel to the antenna.

[0005] Compared with the prior art, the present invention has the following significant advantages: (1) a new reactance component is introduced by using a dipole, thereby replacing dielectric loading to achieve ultra-wideband impedance matching and obtaining stable gain at the same time; (2) the antenna unit is fed by direct coaxial feeding, which improves the feeding efficiency, reduces the complexity of model design, and avoids the loss of power divider components; (3) loading capacitor coupling, dielectric matching layer and curved gap improve some resonant frequencies of the antenna in the entire working frequency band, thereby improving the impedance matching of the antenna at low and high frequencies; (4) a layer of resistive film is added between the dipole antenna and the metal floor to absorb the reflected waves from the ground within the short-circuit resonant bandwidth of the dual-polarized antenna, thereby broadening the working bandwidth of the dual-polarized antenna; (5) it is produced by printed circuit technology, has a simple structure, and a low profile height, which is about one-fourth of the height of the antenna working in the same frequency band, is easy to conform to a curved carrier, and has a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0007] Figure 1 It is a schematic diagram of the overall structure of the dual-polarized tightly coupled dipole antenna loaded with a resistive film according to the present invention.

[0008] Figure 2 It is a front structural schematic diagram of two polarization units of the dual-polarization tightly coupled dipole antenna loaded with a resistive film according to the present invention.

[0009] Figure 3 It is a top view of the resistive film of the dual-polarized tightly coupled dipole antenna loaded with the resistive film according to the present invention.

[0010] Figure 4 It is the active standing wave ratio of the dual-polarization tightly coupled dipole antenna loaded with a resistive film according to the present invention.

[0011] Figure 5 It is the two-port isolation of the dual-polarization tightly coupled dipole antenna loaded with a resistive film of the present invention.

[0012] Figure 6 It is a comparison diagram of the single polarization gain and dual polarization gain of the dual polarization tightly coupled dipole antenna loaded with a resistive film according to the present invention.

[0013] Figure 7 The directional diagram results of the dual-polarization tightly coupled dipole antenna loaded with a resistive film of the present invention when operating at 2 GHz, 6 GHz, 10 GHz and 12 GHz. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0015] The present invention proposes a dual-polarized tightly coupled dipole antenna loaded with a resistive film. By loading a resistive film under the dipole and the coupling patch, a resonant structure is introduced in the 9GHz to 12GHz frequency band, and the operating bandwidth is expanded by using multiple resonant frequency points. Through direct feeding of the coaxial line, a 15:1 (0.8-12GHz) operating bandwidth is achieved.

[0016] Combination Figure 1 The dual-polarized tightly coupled dipole antenna loaded with a resistive film, the antenna unit includes a dielectric matching layer 1, a dipole antenna 2, a coupling capacitor 3, a metal through hole 4, a curved gap 5, a resistive film 6, a coaxial feed 7, a metal floor 8, a first dielectric substrate 9, a second dielectric substrate 10 and a third dielectric substrate 11. The antenna dipole 2 is symmetrically orthogonally placed and printed on the front and back of the first dielectric substrate 9. The coupling capacitor patch 3 is printed on both sides of the first dielectric substrate. The coaxial feed 7, as the feeding structure of the antenna, passes through the second dielectric substrate 10 and the third dielectric substrate 11 loaded with the resistive film 6 and is connected to the dipole antenna 2. The curved gap 5 is opened at the end of the dipole antenna 2, and the metal through hole 4 is embedded in the first dielectric substrate 9. The dielectric matching layer 1 loaded with a metasurface is placed on the top of the dipole antenna 2. The metal floor 8 is placed parallel to the antenna with the dielectric matching layer 1 and the resistive film 6. The present invention can realize the dual-polarization, low-profile, and wide-band design of the tightly coupled antenna.

[0017] Furthermore, the dielectric matching layer 1 , the first dielectric substrate 9 , the second dielectric substrate 10 and the third dielectric substrate 11 are made of FR4.

[0018] Furthermore, the dipole antenna 2 and the coupling capacitor patch 3 are made of metal copper.

[0019] Furthermore, the dipole antenna 2, the coupling capacitor patch 3 and the metal through hole 4 are printed on a RogersRO4003 microwave substrate.

[0020] Furthermore, the material of the resistive film 6 is high-resistance carbon paste.

[0021] Furthermore, the metal through hole 4 and the metal floor 8 are made of copper.

[0022] Furthermore, the frequency coverage provided by the antenna is 0.8 to 12 GHz, the active standing wave ratios of the two ports of the dual-polarization unit are both below 3, the isolation between the two ports is less than -15 dB, and it has good radiation characteristics.

[0023] The dielectric substrate is 0.508mm thick Rogers RO4003 (ε r=3.55). The front and back sides of the first dielectric substrate are both equipped with two dipole antennas 2 and two coupling capacitor patches 3, and a row of metal through holes are punched at the ends of the dipoles. The metal through holes and coupling capacitor patches introduced here are to strengthen the capacitive coupling. The voltage standing wave ratio of this antenna unit deteriorates in the low frequency band, especially the impedance mismatch at 2GHz is serious. By punching metal through holes on the dipole radiating arm, part of the dipole radiating arm is introduced into the back side of the dielectric substrate, and a metal patch is loaded on the front side of the dielectric substrate. The metal patch on the front side of the dielectric substrate forms a capacitive coupling with the metal patch on the back side of the dielectric substrate, which effectively extends the length of the dipole radiating arm, thereby improving the voltage standing wave ratio in the low frequency band. A 2mm thick FR4 (ε r =4.4) The substrate is placed on the array antenna aperture plane and parallel to the array antenna's dielectric coating as a dielectric matching layer. It can play the role of impedance transformation, improve the impedance matching of the array antenna's input impedance to the free space wave impedance, and reduce the unit's active reflection coefficient. However, the voltage standing wave ratio is still high at certain frequencies, so a curved slot is introduced on the antenna's radiating arm to improve some of the antenna's resonant frequencies in the entire operating frequency band. In order to solve the problem of severe mismatch of the dual-polarized antenna unit in the high frequency band (9GHz~12GHz), a layer of FR4 (ε r =4.4) with a dielectric substrate having a size of 12.5 mm × 12.5 mm × 0.44 mm. Square and circular rings of high-resistance carbon paste with a width of 0.825 mm are printed on the dielectric substrate to absorb the reflected waves from the ground within the short-circuit resonance bandwidth of the antenna, thereby widening the working bandwidth of the antenna.

[0024] Example

[0025] Combination Figure 1 to Figure 3 , an ultra-wideband low-profile dual-polarized antenna with a range of 0.8 GHz to 12 GHz, comprising a dielectric matching layer 1, a dipole 2, a coupling capacitor 3, a metal through hole 4, a curved slot 5, a resistive film 6, a coaxial line feed 7, a metal floor 8, a first dielectric substrate 9, a second dielectric substrate 10, and a third dielectric substrate 11. The antenna unit size is 12.5 mm × 12.5 mm (0.033 λ L ×0.033λ L ), the antenna section height is 33mm (0.088λ L ,λ L The FR4 dielectric substrate of the resistive film has a size of 12.5 mm × 12.5 mm and a thickness of 0.44 mm. A square ring of high-resistance carbon paste with a side length of 12.5 mm and a width of 0.825 mm is printed on the dielectric substrate.

[0026] like Figure 4 , Figure 5 As shown, the active standing wave ratio of the antenna unit is less than 3 in the frequency band of 0.8 to 12 GHz, and the isolation between the two ports of the unit is less than -15 dB in the frequency band of 0.8 to 12 GHz.

[0027] like Figure 6 As shown, a comparison diagram of the single-line polarization gain and dual-polarization gain of a dual-polarization tightly coupled dipole antenna loaded with a semi-resistive frequency selective surface is shown.

[0028] like Figure 7 As shown, they are the active radiation patterns of the antenna unit at 2 GHz, 6 GHz, 10 GHz and 12 GHz respectively.

[0029] In summary, the present invention designs an ultra-wideband low-profile dual-polarization dipole antenna based on the tight coupling principle, and innovatively loads a resistive film. The antenna can provide a frequency coverage of 0.8 to 12 GHz. The results show that the active standing wave ratio of the two ports of the dual-polarization unit is less than 3, the isolation between the two ports is less than -15dB, it has good radiation characteristics, and the profile height is only 33mm (0.088λ L ). This antenna has the advantages of wide working frequency band, wide beam scanning range, low profile height, easy processing and can be conformally mounted on a curved carrier, which is of great significance in practical engineering applications such as electronic reconnaissance and electronic countermeasures.

Claims

1. A dual-polarized tightly coupled dipole ultra-wideband antenna loaded with a resistive film, characterized in that: The antenna unit comprises a metasurface-loaded dielectric matching layer (1), a dipole antenna (2), a coupling capacitor patch (3), a metal through hole (4), a curved gap (5), a resistive film (6), a coaxial line feed (7), a metal floor (8), a first dielectric substrate (9), a second dielectric substrate (10) and a third dielectric substrate (11); the metasurface-loaded dielectric matching layer (1) is placed on top of the first dielectric substrate (9); the dipole antenna (2) is symmetrically orthogonally placed and printed on the front and back surfaces of the first dielectric substrate (9); The coupling capacitor patch (3) is printed on both sides of the first dielectric substrate (9); The coaxial line feed (7) as the feeding structure of the antenna passes through the second dielectric substrate (10) and the third dielectric substrate (11) loaded with the resistive film (6) to connect with the dipole antenna (2); a curved slot (5) is opened at the end of the dipole antenna (2); a metal through hole (4) is embedded in the first dielectric substrate (9); and a metal floor (8) and a dielectric matching layer (1) and the resistive film (6) are placed parallel to the antenna.

2. The dual-polarized tightly coupled dipole antenna loaded with a resistive film according to claim 1, characterized in that: The material of the dielectric matching layer (1), the first dielectric substrate (9), the second dielectric substrate (10) and the third dielectric substrate (11) is FR4.

3. The dual-polarized tightly coupled dipole antenna loaded with a resistive film according to claim 1, characterized in that: The materials of the dipole antenna (2) and the coupling capacitor patch (3) are metal copper.

4. The dual-polarized tightly coupled dipole antenna loaded with a resistive film according to claim 1, characterized in that: The dipole antenna (2), coupling capacitor patch (3) and metal through hole (4) are printed on a Rogers RO4003 microwave substrate.

5. The dual-polarized tightly coupled dipole antenna loaded with a resistive film according to claim 1, characterized in that: The material of the resistive film (6) is high-resistance carbon paste.

6. The dual-polarized tightly coupled dipole antenna loaded with a resistive film according to claim 1, characterized in that: The metal through hole (4) and the metal floor (8) are made of copper.

7. The dual-polarized tightly coupled dipole antenna loaded with a resistive film according to claim 1, characterized in that: The frequency coverage provided by the antenna is 0.8 to 12 GHz. The active standing wave ratios of the two ports of the dual-polarization unit are both below 3, and the isolation between the two ports is less than -15 dB.

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