An ultra-wideband tightly coupled antenna and tightly coupled antenna array

Abstract

The application discloses a kind of ultra-wideband dual polarization tight coupling antennas and tight coupling antenna array, ultra-wideband dual polarization tight coupling antenna includes antenna radiator, open loop structure, metal shield, metal plate structure and fixed base: the antenna radiator, contains horizontal dipole, power divider and balun three parts;The open loop structure is arranged on horizontal dipole;The metal shield is set in the power divider outside for shielding power divider;The power divider and balun are printed on vertically orthogonal medium plate, and power divider is connected with balun by metallized via located on medium plate;The fixed base is used to fix the medium plate;The metal plate structure is located between power divider and horizontal dipole.This application is loaded with metal plate structure below horizontal dipole and above wilkinson strip line power divider, can suppress the common mode resonance of antenna, significantly expand the bandwidth of antenna, while not loss the radiation efficiency of antenna.

Description

Technical Field

[0001] This invention relates to the field of ultra-wideband antenna technology, and more particularly to an ultra-wideband low-profile tightly coupled antenna. Background Technology

[0002] With the rapid development of wireless communication technology, ultra-wideband, low-profile, and wide-scan angle antennas, as an indispensable and important component of communication systems, have gradually become a research hotspot. Traditional ultra-wideband antenna array design primarily begins with the design of broadband antenna elements, first ensuring broadband impedance matching of the antenna elements. When considering antenna element arrays, it is necessary to minimize the mutual coupling effect between antenna elements to ensure that the antenna impedance matching is not deteriorated. Early scanning antennas were mostly used in narrowband and small-scan angle applications. The design of such array antennas has matured; however, the electrical performance of antenna elements and array coupling effects greatly limit the expansion of the impedance bandwidth and phase scan angle of the array antenna. Based on the theory of connected arrays, Munk et al. proposed a strongly coupled ultra-wideband phased array antenna. This array antenna introduces capacitive mutual coupling effects between adjacent elements to counteract the inductive effects caused by the reflector, achieving the expansion of the array antenna's impedance bandwidth and low-profile design. Since then, tightly coupled array antennas have become one of the hot topics in antenna research, with excellent results continuously gaining public attention.

[0003] When the height of a tightly coupled antenna is increased, the bandwidth can be extended to lower frequencies; however, due to the effect of reflection from the metal short-circuit ground, in A common-mode resonance will occur at this point, thus affecting the bandwidth extension. In addition, conventional tightly coupled antennas often use dielectric substrates with different dielectric constants as wide-angle matching layers to improve the antenna's scanning angle performance and extend the bandwidth. However, such dielectric substrates are often expensive and heavy. Moreover, the higher the dielectric constant and the thicker the dielectric substrate, the easier it is to generate surface waves, which will worsen the matching performance. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide an ultra-wideband dual-polarized tightly coupled antenna that extends bandwidth while ensuring radiation efficiency. To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An ultra-wideband dual-polarized tightly coupled antenna, characterized in that it comprises: an antenna radiator, an open-loop structure, a metal shield, a metal plate structure, and a mounting base. The antenna radiator comprises three parts: a horizontal dipole, a power divider, and a balun. The open ring structure is disposed on the horizontal dipole; The metal shielding cover is disposed outside the power divider to cover the power divider; The power divider and balun are printed on a vertically orthogonally placed dielectric substrate, and the power divider and balun are connected through metallized vias located on the dielectric substrate. The mounting base is used to fix the medium plate; The metal plate structure is horizontally arranged on the dielectric plate and located between the power divider and the horizontal dipole.

[0005] This invention proposes an ultra-wideband, low-profile, tightly coupled antenna, which improves upon the structure of traditional TCDA (Transmitted Terminal Block) tightly coupled antennas. A horizontally arranged metal plate structure is loaded in the space below the antenna dipole and above the Wilkinson power divider. From the perspective of the equivalent circuit model, this is equivalent to connecting an equivalent inductor in parallel between the antenna array and the metal ground plane, shifting the common-mode resonance to higher frequencies and moving it out of the band. Simultaneously, the metal plate structure acts as a short-circuit ground plane, adding a metal shielding structure outside the power divider patch to shield the antenna array from radiated interference from the lower power divider patch. Compared to conventional tightly coupled antennas, the metal plate structure further extends the bandwidth, increasing the bandwidth of this TCDA tightly coupled antenna from 9:1 to 10:1 without sacrificing the antenna's radiation efficiency. Existing resistive patch loading methods for bandwidth extension suffer from radiation efficiency due to the lossy loading method, while the metal plate structure loading, acting as an equivalent capacitor, is a lossless loading method that extends the bandwidth without affecting the antenna's radiation efficiency.

[0006] The open-ring structure of this invention replaces the conventional wide-angle matching layer, which significantly reduces the antenna profile height and overall weight while ensuring antenna scanning performance. It can also avoid the generation of surface waves caused by the increase in dielectric layer thickness.

[0007] The metal plate structure of this invention eliminates the metal short-circuit ground plane structure used in conventional TCDA type tightly coupled antennas. At the same time, a metal shield is added to the outside of the Wilkinson microstrip power divider to eliminate the matching degradation caused by the radiation of this patch to the space above, thus ensuring the antenna bandwidth.

[0008] The optimized design of the metal plate structure is a multi-layer plate structure. Compared with a single-layer metal plate, a multi-layer metal plate can be regarded as multiple parallel inductors, reducing the inductance value of the equivalent inductance and thus increasing the resonance suppression effect. On the other hand, since each metal plate is at a different height from the ground, it is equivalent to introducing resonance points at different frequency points corresponding to its height, thereby further expanding the overall bandwidth of the antenna on the basis of a single-layer metal plate structure.

[0009] Furthermore, an open-loop structure of a V-shaped patch printed on a dielectric substrate is used in the space above the horizontal dipole patch to replace the wide-angle matching layer, thereby optimizing the scan angle and extending the impedance bandwidth. From the perspective of the equivalent circuit, the loading of this open-loop structure is equivalent to connecting an LC stub in parallel between free space and the ground plane, which can serve as impedance matching. Attached Figure Description

[0010] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is an overall view of the ultra-wideband low-profile tightly coupled antenna unit of the present invention.

[0012] Figure 2 This is a schematic diagram of the tightly coupled antenna array proposed in this invention.

[0013] Figure 3 This is a schematic diagram of the horizontal conical patch dipole structure of the present invention, where a is a side view and b is a top view.

[0014] Figure 4 This is a schematic diagram of the open ring structure of the present invention.

[0015] Figure 5 This is a schematic diagram of the multi-layer metal plate structure of the present invention, where a is a three-dimensional view of the multi-layer structure and b is a top view of the metal plate structure.

[0016] Figure 6 This is a schematic diagram of the metal shield structure of the present invention, where a is a rear side view of the metal shield structure and b is a front view of the metal shield structure.

[0017] Figure 7 This is a schematic diagram of the Wilkinson microstrip power divider and the three-layer stripline Machand balun structure of the present invention. In the diagram, a is a front view of the front dielectric substrate, b is an enlarged schematic diagram of the metallized via structure at the connection between the Wilkinson power divider and the Machand balun, c is a rear view of the front layer of the dielectric substrate, d is a schematic diagram of the middle layer dielectric substrate structure, and e and f are the front and rear views of the rear layer dielectric substrate structure, respectively.

[0018] Figure 8 This is a schematic diagram of another polarized upper dielectric plate interlocking slotted structure of the present invention.

[0019] Figure 9 This is a schematic diagram of the fixed base structure of the present invention, where a is a side view of the fixed base and b is a top view of the fixed base.

[0020] Figure 10 This invention provides an active standing wave at the normal phase angle and at scanning angles of 0° and 60° on the E plane when loading a single-layer metal plate structure and a multi-layer metal plate structure.

[0021] Figure 11 This invention provides an active standing wave at the normal phase angle and at scanning angles of 0° and 60° on the E plane when loading an open ring structure and a 4mm wide-angle matching layer.

[0022] Figure 12 This invention provides an active standing wave at the normal phase angle and at scanning angles of 0° and 60° on the E plane before and after loading the metal shield structure.

[0023] Figure label: 1-Open ring structure; 2-Horizontal dipole; 3-Markand balun; 4-Metal plate structure; 5-Wilkinson power divider; 6-Metal shield; 7-Fixing base; 8-Conical dipole patch; 9-Parasitic patch; 10-Pad; 11-Metalized via; 12-Dielectric substrate 1; 13-V-type patch; 14-Dielectric substrate 2; 15-Copper cladding; 16-Dielectric substrate 3; 17-Fixing screw hole; 18-Dielectric substrate mounting slot; 19-Square slot; 20-Markand balun outer patch 1; 21-Wilkinson power divider patch; 22-Surface mount resistor; 23-Dielectric substrate 4; 24-Markand balun power supply patch; 25-Dielectric substrate 5; 26-Dielectric substrate 6; 27-Markand balun outer patch 2; 28-Metalized via. Detailed Implementation

[0024] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0025] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] In the description of this application, it should be understood that the terms "horizontal", "vertical", "up", "down", "front", "back", "X-axis", "Y-axis", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0027] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined. In this application, unless otherwise expressly specified and limited, the terms "connected," "linked," "inserted," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] like Figure 1 As shown, the ultra-wideband low-profile tightly coupled antenna provided by this invention includes an open-loop structure 1, a horizontal dipole 2, a Machandle balun 3, a metal plate structure 4, a Wilkinson power divider 5, a metal shield 6, and a mounting base 7. The Machandle balun 3 and the Wilkinson power divider 5 are printed on a vertically orthogonally placed three-layer dielectric substrate 23. The mounting base 7 has slots to fix the vertical dielectric substrate 23 and limit the connector position. The Wilkinson power divider 5 is connected to the Machandle balun 3 through a metallized via 11. The upper part of the Machandle balun 3 is soldered to a conical dipole patch 8. The open-loop structure 1 is placed above the horizontal dipole 2.

[0029] Figure 2 This is a schematic diagram of an array structure composed of the array elements proposed in this invention.

[0030] Figure 3 The diagram shows a partial structure of the horizontal dipole 2 of the present invention. There is a parasitic patch 9 on the opposite side of the dielectric substrate 12 of the two conical dipole patches 8. The parasitic patch 9 can further increase the coupling between the two array elements, thereby improving the impedance matching.

[0031] Figure 4 This is a schematic diagram of the open ring structure proposed in this invention, with a V-shaped patch printed on the dielectric substrate 14.

[0032] Figure 5 This is a schematic diagram of the metal plate structure 4 of the present invention. The metal plate structure 4 is a multi-layer plate structure with 2-5 layers. Figure 4 In the embodiment shown, the metal plate structure 4 is a 3-layer structure, with each layer having the same structure. The copper cladding layer 15 is printed on the dielectric substrate 16. To facilitate installation and fixation, the metal plate has fixing screw holes 17 and dielectric substrate fixing grooves 18. To facilitate soldering, square slots 19 are provided.

[0033] Figure 6To facilitate the welding of the resistor patch 22 on the Wilkinson power divider 5 that it shields, the metal shield 6 of the present invention has a square opening at the corresponding position.

[0034] Figure 7 This is a schematic diagram of the various structures on the vertical dielectric substrate 23 of the present invention. The dielectric substrate 23 has a three-layer structure, wherein the Wilkinson power divider 5 and the outer patch 20 of the Machandler Baron are printed on the front side of the front layer of the dielectric substrate 23, and the Machandler Baron feed patch 24 is printed on the back side of the dielectric substrate 23. The front layer of the dielectric substrate 23 has a metallized via 11 for connecting the Wilkinson power divider 5 and the Machandler Baron feed patch 24. The middle layer is an adhesive PP layer used to bond the front and back dielectric substrates. The back side of the rear layer 26 of the dielectric substrate has the second outer patch 27 of the Machandler Baron printed on it.

[0035] Figure 8 This is a schematic diagram of another polarized dielectric substrate structure of the present invention, on which the Chandler Baron 3 and Wilkinson power divider 5 are structured similarly to... Figure 7 The same as in the middle, except that the slots are cut into the interlocking structure. Figure 7 The opposite is true for the dielectric substrate.

[0036] Figure 9 This is a schematic diagram of the fixing base 7 of the present invention. In order to fix the two vertically orthogonal dielectric substrates and the antenna feed interface, a square groove and a circular through hole are opened on it.

[0037] Figure 10 This invention relates to active standing waves (VSWRs) at normal angles and E-plane scanning angles of 0° and 60° when loading single-layer and multi-layer metal plate structures. The use of a multi-layer structure significantly increases the bandwidth of the loaded parallel equivalent inductor, resulting in more pronounced common-mode resonance suppression and effectively expanding the bandwidth.

[0038] Figure 11 This invention demonstrates active standing waves at normal angles and E-plane scanning angles of 0° and 60° when using an open-ring structure and a 4mm wide-angle matching layer. While the performance of open-ring loading and traditional wide-angle matching layer loading is similar at E-plane angles of 0° and 60°, the open-ring structure offers significant advantages due to its lower height, lighter weight, and lower overall cost.

[0039] Figure 12 This invention provides information on active standing waves (VSWRs) before and after the addition of the metal shielding structure, at normal angles and E-plane scanning angles of 0° and 60°. The metal shielding effectively suppresses the impedance mismatch caused by radiation from the Wilkinson power divider's microstrip line section to the space above, thus ensuring the overall bandwidth of the antenna.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-wideband dual-polarized tightly coupled antenna, characterized in that, include: Antenna radiator, open ring structure, metal shield, metal plate structure, and mounting base: The antenna radiator comprises three parts: a horizontal dipole, a power divider, and a balun. The open ring structure is disposed on the horizontal dipole; The metal shielding cover is disposed outside the power divider to cover the power divider; The power divider and balun are printed on a vertically orthogonally placed dielectric substrate, and the power divider and balun are connected through metallized vias located on the dielectric substrate. The mounting base is used to fix the medium plate; The metal plate structure is horizontally arranged on the dielectric plate and located between the power divider and the horizontal dipole; The metal plate structure is a multilayer plate structure, with each metal plate consisting of a dielectric substrate and a copper cladding layer. The multilayer plate structure can be regarded as multiple parallel inductors, which reduces the inductance value of the equivalent inductance and thus increases the resonance suppression effect. On the other hand, since each metal plate is at a different height from the ground, it is equivalent to introducing resonance points at different frequency points corresponding to its height, thereby expanding the overall bandwidth of the antenna.

2. The ultra-wideband dual-polarized tightly coupled antenna according to claim 1, characterized in that, The open ring structure consists of a V-shaped metal patch printed on a dielectric substrate, with a small notch inside the V-shaped patch to extend the current path and remove high-frequency resonance.

3. The ultra-wideband dual-polarized tightly coupled antenna according to claim 1, characterized in that, The multi-layered board structure has a square notch in the center.

4. The ultra-wideband dual-polarized tightly coupled antenna according to claim 3, characterized in that, The metal plate structure has 2-5 layers.

5. The ultra-wideband dual-polarized tightly coupled antenna according to claim 3, characterized in that, The horizontal dipole is a conical dipole patch. Antennas with different polarization directions are printed on the upper and lower sides of the dielectric substrate, respectively. A rectangular parasitic patch is printed on the opposite side of the dielectric substrate of adjacent dipole patches with the same polarization.

6. The ultra-wideband dual-polarized tightly coupled antenna according to claim 5, characterized in that, The balun is a Machand balun, and the power divider is a Wilkinson power divider. The Machand balun adopts a three-layer board structure, wherein the internal feed patch at the lower end of the Machand balun is connected to the output terminal of the Wilkinson power divider through a metallized via, and the external patch at the upper end of the Machand balun is connected to a horizontal conical dipole.

7. The ultra-wideband dual-polarized tightly coupled antenna according to claim 6, characterized in that, The outer portion of the Mahendra Baron has a cutout for optimizing antenna impedance matching.

8. The ultra-wideband dual-polarized tightly coupled antenna according to claim 6, characterized in that, The Wilkinson power divider is a 1-to-2 power divider that performs impedance transformation. It is printed on a vertically placed dielectric substrate in the form of a microstrip patch and uses a resistor loading method.

9. A tightly coupled antenna array, comprising an arrangement of ultra-wideband low-profile dual-polarized tightly coupled antennas as described in any one of claims 1-8.

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