Dual-polarization large-size ultra-wideband strong-coupling time domain antenna array

Abstract

The invention discloses a dual-polarization large-size ultra-wideband strong-coupling time domain antenna array, which comprises a metal floor, a metal grounding column, a resistive layer, a Marchand balun, a dipole layer and a wide-angle matching layer, the wide-angle matching layer is arranged above the dipole layer, the Marchand balun and the metal grounding column are vertically arranged between the dipole layer and the metal floor, and the metal grounding column is arranged above the Marchand balun. The resistive layer is horizontally placed between the dipole layer and the metal floor, and the resistive layer is hollowed out at the position where the Marchand Balun and the metal grounding column pass through; the resistive layer is used for absorbing electric field energy to destroy short-circuit resonance generated when the distance between the dipole and the floor is half wavelength; the Marchand Balun is used for connecting the coaxial connector for feeding and gradually changing the impedance of the feeder line to be matched with the antenna; the dipole layer is used for antenna radiation; the wide-angle matching layer is used for providing impedance transition between the dipole layer and air. The antenna has the performance of ultra wide band, large size, high gain and wide-angle scanning.

Description

Technical Field

[0001] The present invention belongs to the technical field of antenna engineering, and relates to a dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array, which has the advantages of dual polarization, ultra-wideband, high gain, wide-angle scanning, etc. Background Art

[0002] Compared with continuous-wave frequency-domain technology, ultra-wideband time-domain technology has stronger penetration ability and higher resolution. Devices designed based on this technology have stronger anti-interference ability and anti-stealth ability, and can achieve extremely high power peaks. The antenna forms of ultra-wideband time-domain antennas can be horn antennas, monopole antennas, slot antennas, array antennas, etc. Among them, the array antenna includes a strongly coupled time-domain antenna, which is a kind of ultra-wideband antenna proposed based on an infinite current sheet. By reducing the spacing between dipole elements to increase the element mutual coupling, and introducing capacitance between elements to cancel the inductance effect of the floor, a wider operating bandwidth is achieved.

[0003] The strongly coupled time-domain antenna has the advantages of ultra-wideband and large-angle scanning. However, in a two-dimensional array, problems such as short-circuit resonance points and common-mode resonance points often occur in ultra-wideband applications, resulting in the original operating bandwidth being divided into several discontinuous frequency bands, thus affecting the antenna performance. In addition, for better matching, a unit size of 0.5×0.5λ h 2 or smaller is generally adopted in the strongly coupled array, which limits the gain of the unit. Summary of the Invention

[0004] The object of the present invention is to provide a dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array with a unit size of 1×1λ h 2 After arraying, the antenna unit has the characteristics of dual polarization, ultra-wideband, and wide-angle scanning. In addition, the large unit size makes its gain significantly greater than that of ordinary strongly coupled antenna units, and it can be well applied to various scenarios.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array includes a metal floor, metal grounding posts, a resistive layer, a Marchand balun, a dipole layer, and a wide-angle matching layer. The wide-angle matching layer is placed above the dipole layer, the Marchand balun and the metal grounding posts are vertically placed between the dipole layer and the metal floor, the resistive layer is horizontally placed between the dipole layer and the metal floor, and the resistive layer is hollowed out at the passing positions of the Marchand balun and the metal grounding posts;

[0007] The resistive layer is used to absorb the electric field energy to break the short - circuit resonance generated when the distance between the dipole and the floor is half a wavelength, thereby broadening the working bandwidth;

[0008] The Marchand balun is used to connect the coaxial connector for feeding, and gradually changes the feeder impedance to match the antenna;

[0009] The dipole layer is used for antenna radiation;

[0010] The wide - angle matching layer is used to provide impedance transition between the dipole layer and the air.

[0011] Preferably, the resistive layer is composed of a first dielectric substrate, and a resistive copper foil is printed on the front side of the first dielectric substrate.

[0012] Preferably, the thickness of the first dielectric substrate is 1.016 mm, the relative dielectric constant is 2.2, and the sheet resistance of the resistive copper foil is 50 Ω / m².

[0013] Preferably, the Marchand balun is composed of a second dielectric substrate and a third dielectric substrate. The second dielectric substrate and the third dielectric substrate are press - fitted and connected through a curing sheet; metal patches are printed on the outer sides of the second dielectric substrate and the third dielectric substrate to form the ground plane of the stripline. The metal patches on the second dielectric substrate and the third dielectric substrate are electrically connected through periodic metallized vias; the tapered stripline is printed on the inner side of the second dielectric substrate, and the starting point of the stripline is a coplanar waveguide - to - stripline structure for connecting the coaxial connector.

[0014] Preferably, the thickness of the second dielectric substrate and the third dielectric substrate is 0.508 mm, the relative dielectric constant is 2.2, and the thickness of the curing sheet is 0.101 mm.

[0015] Preferably, the dipole layer is composed of a fourth dielectric substrate. Two - polarized bow - tie dipoles are printed on the front side of the fourth dielectric substrate. The ends of the bow - tie dipoles adopt an interdigital structure, and the center of the two - polarized interdigital is a coupling patch, and the coupling patch is connected to the metal grounding post.

[0016] Preferably, the thickness of the fourth dielectric substrate is 0.508 mm, and the relative dielectric constant is 2.2.

[0017] Preferably, the wide - angle matching layer includes a fifth dielectric substrate and a sixth dielectric substrate, and rectangular metal patches arranged periodically are printed on both sides of the fifth dielectric substrate and the sixth dielectric substrate.

[0018] Preferably, first long - strip metal patches with a size of 0.22 * 0.14λ are printed periodically on the upper surface of the fifth dielectric substrate. The first long - strip metal patches are arranged periodically in the transverse and longitudinal directions, and the size of the periodic unit is 0.25 * 0.15λ h 2 ​h 2 ; The upper surface of the sixth dielectric substrate is periodically printed with second strip-shaped metal patches sized 0.17*0.12λ h 2 . The second strip-shaped metal patches are arranged periodically in the transverse and longitudinal directions, and the size of the periodic unit is 0.25*0.15λ h 2 ; The sixth dielectric substrate is placed 8 mm above the fifth dielectric substrate. The fifth and sixth dielectric substrates have a thickness of 1 mm and a relative dielectric constant of 2.2.

[0019] Preferably, the diameter of the metal ground posts is 1 mm.

[0020] The beneficial effects of the present invention are as follows:

[0021] The strongly coupled time-domain antenna array is composed of a wide-angle matching layer, a dipole layer, a Marchand balun, a resistive layer, and a metal floor, and operates at 0.6 - 6 GHz. The strongly coupled time-domain antenna array is improved from a traditional dipole antenna. The introduction of the wide-angle matching layer can improve impedance matching. Adding a resistive layer and shorting posts can suppress the short-circuit resonance point and the resonance that appears in the E-plane scan under large-size structures respectively. The large unit size of 1×1λ h 2 significantly reduces the number of units under the same aperture area (the number of units is reduced by 75%) and significantly increases the unit gain. The strongly coupled time-domain antenna array can achieve ±45° scanning within an ultra-wideband and can be applied to various scenarios. Description of the Drawings

[0022] Figure 1 is the overall structure diagram of a dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array of the present invention.

[0023] Figure 2 is the top view of the resistive layer in the present invention.

[0024] Figure 3 is the structure diagram of the Marchand balun in the present invention

[0025] Figure 4 is the top view of the dipole layer in the present invention.

[0026] Figure 5 is the top view of the lower-layer wide-angle matching layer in the present invention.

[0027] Figure 6 is the top view of the upper-layer wide-angle matching layer in the present invention.

[0028] Figure 7 is the schematic diagram of the voltage standing wave ratio varying with frequency at different E-plane scan angles in the present invention.

[0029] Figure 8 This is a schematic diagram showing the variation of voltage standing wave ratio with frequency at different scanning angles of the present invention in the H plane.

[0030] Figure 9 These are the radiation patterns of the present invention in the E plane and H plane at 6 GHz broadside. Detailed implementation manners

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] Refer to Figure 1 As shown, a dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array shown in this embodiment is used as a dual-polarized antenna array unit, and the size of the antenna unit is 1×1λ. h 2 . The antenna unit mainly consists of a metal floor 1, metal grounding posts 2, a resistive layer 3, a Marchand balun 4, a dipole layer 5, and wide-angle matching layers 6 and 7. The wide-angle matching layers are placed above the dipole layer 5, the Marchand balun 4 and the metal grounding posts 2 are vertically placed between the dipole layer 5 and the metal floor 1, the resistive layer 3 is horizontally placed between the dipole layer 5 and the metal floor 1, and the resistive layer is hollowed out at specific positions to allow the vertically placed Marchand balun 4 and metal grounding posts 2 to pass through.

[0033] Refer to Figure 2 As shown in the detailed structure diagram of the resistive layer 3, the resistive layer consists of a first dielectric substrate 8, and a resistive copper foil 9 is printed on the front surface of the first dielectric substrate 8. The resistive layer is horizontally placed between the dipole layer and the metal floor layer, and can broaden the operating bandwidth by absorbing the electric field energy to destroy the short-circuit resonance generated when the distance between the dipole and the floor is half a wavelength. In this embodiment, the thickness of the first dielectric substrate 8 is 1.016 mm, the relative dielectric constant is 2.2, and the sheet resistance of the resistive copper foil 9 is 50 Ω / m2. The first dielectric substrate is hollowed out at specific positions to allow the vertically placed metal grounding posts 2 and Marchand balun 4 to pass through.

[0034] Refer to Figure 3Detailed structural diagram of the Marchand balun 4 shown. The Marchand balun is composed of a second dielectric substrate 10 and a third dielectric substrate 11. The second dielectric substrate 10 and the third dielectric substrate 11 are press-connected through a curing sheet 14. Metal patches 12 and 13 printed on the outer sides of the second dielectric substrate 10 and the third dielectric substrate 11 constitute the ground plane of the stripline. The tapered stripline 15 is printed on the inner side of the second dielectric substrate 10. In addition, the starting point of the stripline 15 is a coplanar waveguide-to-stripline structure for connecting a coaxial connector. The metal patches 12 and 13 are electrically connected through periodic metallized vias 16. The metallized vias play a shielding role and at the same time suppress the parallel plate mode between the two metal ground planes. In this embodiment, the thickness of the second dielectric substrate 10 and the third dielectric substrate 11 is 0.508 mm, and the relative dielectric constant is 2.2. The thickness of the curing sheet 14 is 0.101 mm

[0035] See Figure 4 Detailed structural diagram of the dipole layer 5 shown. The dipole layer 5 is mainly composed of a fourth dielectric substrate 17. Two types of polarized bow-tie dipoles 18 are printed on the front surface of the fourth dielectric substrate 17. The ends of the bow-tie dipoles 18 adopt an interdigital structure to enhance the coupling capacitance between the units. The center of the two polarized interdigital parts is a coupling patch 19. The coupling patch is connected to the metal ground post 2, which can solve the resonance problem that occurs when the antenna scans in the E-plane. In this embodiment, the thickness of the fourth dielectric substrate 17 is 0.508 mm, and the relative dielectric constant is 2.2. The diameter of the metal ground post 2 is 1 mm.

[0036] The wide-angle matching layers 6 and 7 are composed of two dielectric substrates. The same long strip patterns are printed on both sides of the dielectric substrates. The loading of the wide-angle matching layers can provide impedance transition between the dipole and the air, improving the impedance matching performance of the antenna. See Figure 5 Detailed structural diagram of the upper wide-angle matching layer 6 shown, mainly composed of opposite fifth dielectric substrates 20. First long strip metal patches 21 with a size of 0.22 * 0.14λ are periodically printed on the upper surface of the fifth dielectric substrate 20 h 2 The first long strip metal patches 21 are arranged periodically in the transverse and longitudinal directions, and the size of the periodic unit is 0.25 * 0.15λ h 2 See Figure 6 Detailed structural diagram of the lower wide-angle matching layer 7 shown, mainly composed of a sixth dielectric substrate 22. Second long strip metal patches 23 with a size of 0.17 * 0.12λ are periodically printed on the upper surface of the sixth dielectric substrate 22 h 2 The second long strip metal patches 23 are arranged periodically in the transverse and longitudinal directions, and the size of the periodic unit is 0.25 * 0.15λ h2 。In this embodiment, the wide-angle matching layer 7 is placed 8 mm above the wide-angle matching layer 6. The fifth dielectric substrate 20 and the sixth dielectric substrate 22 have a thickness of 1 mm and a relative dielectric constant of 2.2.

[0037] The overall working principle of the dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array is as follows: The dual-polarized antenna is fed through a 50Ω coaxial connector. The Marchand balun gradually changes the feeder impedance from 50Ω to 150Ω which is easier to match with the antenna, and at the same time realizes the conversion from unbalanced to balanced feeding. The bow-tie dual-polarized dipole is the main radiation structure of the antenna. The end of the bow-tie dipole adopts an interdigital structure, which significantly increases the capacitive coupling between the units, so as to offset the inductive effect caused by the floor reflection and expand the bandwidth of the antenna operation. When the antenna operates in an ultra-wide frequency band, common-mode resonance and short-circuit resonance will occur within the operating frequency band. In this example, the path of the common-mode resonance is shortened by loading metal grounding posts, and the common-mode resonance is removed outside the band. The resistive layer is loaded to absorb the electric field energy at the short-circuit resonance point and eliminate the resonance at the short-circuit point. Based on the above two points, the dual-polarized large-size ultra-wideband strongly coupled time-domain antenna element can achieve ultra-wideband operation. The loading of the wide-angle matching layers 6 and 7 above the dipole layer is used to improve the wide-angle scanning characteristics of the antenna element.

[0038] Figure 7 Figure 8 The schematic diagrams of the curves of the voltage standing wave ratio varying with frequency of the E-plane and H-plane of this antenna array at different scanning angles are given. At 0°, the antenna can satisfy that the voltage standing wave ratio is less than 2.5 within 0.6 - 6 GHz; when scanning at 30° and 45°, except for the resonance frequency points of the antenna, the antenna can basically satisfy that the voltage standing wave ratio is less than 3 within the bandwidth. The resonance frequency points are caused by the surface wave resonance of the large element size when scanning, which cannot be solved. And for the time-domain antenna, the far-field time-domain waveform of the antenna is the superposition of sine waves at all frequency points, and the anomalies at several frequency points will not have too much impact on the time-domain performance.

[0039] Figure 9 They are the E-plane and H-plane radiation patterns of the antenna array at broadside at 6 GHz.

[0040] By Figures 7 to 9 , it can be proved that this embodiment has the performance of ultra-wideband, large-size, high-gain, and wide-angle scanning. On the premise that the element size is one high-frequency wavelength, the short-circuit point is destroyed by introducing a resistive layer, and the E-plane resonance point is solved by using a short-circuit post, thus broadening the working bandwidth and ensuring a relatively large element gain.

[0041] It will be understood that those of ordinary skill in the art can make equivalent substitutions or changes based on the technical solutions of the present invention and its inventive concept, and all such changes or substitutions should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array, characterized in that It includes a metal floor, metal grounding posts, a resistive layer, a Marchand balun, a dipole layer, and a wide-angle matching layer. The wide-angle matching layer is placed above the dipole layer. The Marchand balun and the metal grounding posts are vertically placed between the dipole layer and the metal floor. The resistive layer is horizontally placed between the dipole layer and the metal floor, and the resistive layer is hollowed out at the passing positions of the Marchand balun and the metal grounding posts; The resistive layer is used to absorb the electric field energy to break the short-circuit resonance generated when the distance from the dipole to the floor is half a wavelength, thereby broadening the working bandwidth; The Marchand balun is used to connect the coaxial connector for feeding, and gradually changes the feeder impedance to match the antenna; The dipole layer is used for antenna radiation; The wide-angle matching layer is used to provide impedance transition between the dipole layer and the air.

2. The dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array according to claim 1, characterized in that The resistive layer is composed of a first dielectric substrate, and a resistive copper foil is printed on the front surface of the first dielectric substrate.

3. A dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array according to claim 2, characterized in that The thickness of the first dielectric substrate is 1.016 mm, the relative dielectric constant is 2.2, and the sheet resistance of the resistive copper foil is 50 Ω / m2.

4. A dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array according to claim 1, characterized in that The Marchand balun is composed of a second dielectric substrate and a third dielectric substrate. The second dielectric substrate and the third dielectric substrate are press-fitted and connected through a curing sheet; Metal patches are printed on the outer sides of the second dielectric substrate and the third dielectric substrate to form the floor of the stripline. The metal patches on the second dielectric substrate and the third dielectric substrate are electrically connected through periodic metallized vias; The tapered stripline is printed on the inner side of the second dielectric substrate, and the starting point of the stripline is a coplanar waveguide-to-stripline structure for connecting the coaxial connector.

5. A dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array according to claim 4, characterized in that The thickness of the second dielectric substrate and the third dielectric substrate is 0.508 mm, the relative dielectric constant is 2.2, and the thickness of the curing sheet is 0.101 mm.

6. The dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array according to claim 1, wherein The dipole layer is composed of a fourth dielectric substrate. Two-polarized bowtie dipoles are printed on the front surface of the fourth dielectric substrate. The ends of the bowtie dipoles adopt an interdigital structure. The center of the two polarized interdigital parts is a coupling patch, and the coupling patch is connected to the metal grounding post.

7. A dual-polarized large-size ultra-wideband strongly-coupled time-domain antenna array according to claim 6, characterized in that The thickness of the fourth dielectric substrate is 0.508 mm, and the relative dielectric constant is 2.

2.

8. A dual-polarized large-size ultra-wideband strongly coupled time-domain antenna array according to claim 1, characterized in that The wide-angle matching layer includes a fifth dielectric substrate and a sixth dielectric substrate, and rectangular metal patches arranged periodically are printed on both sides of the fifth dielectric substrate and the sixth dielectric substrate.

9. A dual-polarized large-size ultra-wideband strongly-coupled time-domain antenna array according to claim 8, characterized in that The first long strip-shaped metal patch with a size of 0.22*0.14λ is periodically printed on the upper surface of the fifth dielectric substrate. The first long strip-shaped metal patches are arranged periodically along the horizontal and vertical directions, and the size of the periodic unit is 0.25*0.15λ h 2 ; The second long strip-shaped metal patch with a size of 0.17*0.12λ is periodically printed on the upper surface of the sixth dielectric substrate. The second long strip-shaped metal patches are arranged periodically along the horizontal and vertical directions, and the size of the periodic unit is 0.25*0.15λ h 2 ; h 2 ; h 2 ; The sixth dielectric substrate is placed 8 mm above the fifth dielectric substrate. The thickness of the fifth dielectric substrate and the sixth dielectric substrate is 1 mm, and the relative dielectric constant is 2.

2.

10. A dual-polarized large-size ultra-wideband strongly-coupled time-domain antenna array according to claim 1, characterized in that The diameter of the metal grounding post is 1 mm.

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