Low profile ultra-wideband antenna device based on double-sided helical wire and lossy open resonant loop loading

Abstract

The application discloses a kind of based on double-sided spiral wiring and low profile ultra-wideband antenna device of lossy open resonant ring loading, including double-sided spiral antenna structure, lossy open resonant ring structure, metal back cavity and balun, wherein the upper and lower surfaces of double-sided spiral antenna structure are respectively provided with Archimedes spiral arm, and are provided with the metal via hole that is connected with different levels spiral arm;The lossy open resonant ring structure is provided with annular dielectric substrate, and a circle of open resonant ring loaded with resistance is arranged on the upper surface thereof;Double-sided spiral antenna structure is located above the lossy open resonant ring structure, and both are arranged in the metal back cavity;Balun is vertically arranged in the center of metal back cavity, and the top end is respectively connected with the two spiral arms on the upper surface of circular dielectric substrate, and the bottom end is arranged on the bottom surface of metal back cavity and connected with external antenna interface through through-hole.The antenna device with improved structure has ultra-wideband, low profile, high gain, unidirectional radiation and good circular polarization characteristics.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wireless communication, and particularly relates to a low-profile ultra-wideband antenna device based on double-spiral wiring and lossy open resonant ring loading. BACKGROUND

[0002] An antenna is a key element indispensable to a radio communication system, which can complete the conversion between waveguide form energy and spatial electromagnetic field energy. With the development of modern wireless communication technology, the integration and miniaturization trend of many communication and detection systems puts forward higher and higher requirements for antenna design, such as wide frequency band, small size, low profile, unidirectional radiation, stable performance and the like, which have become a widely researched topic by scholars in recent years.

[0003] In existing wideband antennas, a planar spiral antenna has good impedance and radiation characteristics in a wide frequency band, and thus becomes one of main forms of wideband antennas. Common planar spiral antennas include Archimedes spiral antennas, equiangular spiral antennas and composite spiral antennas. Due to the similarity of their own frequencies, such antennas can maintain good circular polarization performance in a wide frequency band range, and linearly polarized waves in any polarization direction can be received by the circularly polarized antenna, which is particularly suitable for using circularly polarized antennas when reconnaissance and disturbing enemy communication.

[0004] A planar spiral antenna in free space can radiate circularly polarized waves in two directions perpendicular to the spiral plane, and thus in the design of a traditional spiral antenna, a metal back cavity is usually placed below the planar spiral antenna to achieve unidirectional radiation, generally at a quarter wavelength below the antenna. However, such a design has the disadvantage that when the antenna operates at a low frequency band, the profile of the overall antenna is difficult to reduce, and the radiation reflected from the metal back cavity will cause serious interference in some frequency bands, resulting in unstable performance of the antenna and serious limitation of the wide frequency band characteristics of the spiral antenna. Therefore, many scholars fill the back cavity with an absorbing material to absorb the back radiation of the spiral antenna and improve the low-frequency performance of the spiral antenna, but this will increase the overall weight of the antenna device, which is not conducive to the design goal of modern antenna miniaturization and lightness, and half of the energy radiated by the antenna is absorbed, which will also reduce the gain and efficiency of the antenna. At the same time, the design of using a traditional spiral antenna plus a metal back cavity requires both printing technology and mechanical part processing, and the processing is also relatively cumbersome.

[0005] In the field of modern wireless communication technology, ultra-wideband communication technology is widely used in ultra-wideband communication systems, military radars, biological engineering and other fields due to its high transmission rate, large system capacity, high resolution and other advantages. Therefore, it is necessary to design a planar spiral antenna with the advantages of ultra-wideband, low profile, one-way radiation, high gain and circular polarization characteristics, and the performance is relatively stable and easy to process, so as to meet the needs of more modern wireless communication systems. SUMMARY

[0006] The purpose of the present application is to provide a low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading, which is used to realize the circular polarization and one-way radiation performance of the antenna in the ultra-wideband, while realizing low profile and high gain.

[0007] To achieve the above technical purpose, the technical scheme provided by the present application is:

[0008] The low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading is characterized in that it comprises a double-sided spiral antenna structure, a lossy open resonant ring structure, a metal back cavity, a balun and a plurality of support columns.

[0009] The double-sided spiral antenna structure is provided with a circular dielectric substrate, the upper and lower surfaces of the circular dielectric substrate are respectively provided with two identical Archimedes spiral arms, and a plurality of metal vias are arranged along each Archimedes spiral arm, the metal vias being used to connect the Archimedes spiral arms at different levels;

[0010] The lossy open resonant ring structure is provided with an annular dielectric substrate, and the upper surface of the annular dielectric substrate is provided with a ring-shaped open resonant ring loaded with resistors;

[0011] The double-sided spiral antenna structure and the lossy open resonant ring structure are both arranged in the metal back cavity, and the double-sided spiral antenna structure is located above the lossy open resonant ring structure;

[0012] The support columns are used to support the dielectric substrates of the double-sided spiral antenna structure and the lossy open resonant ring structure, and to control the distance between the bottom surfaces of the double-sided spiral antenna structure, the lossy open resonant ring structure and the metal back cavity;

[0013] The metal back cavity is a cylindrical groove arranged on a metal back plate, and a through hole for wiring is arranged in the middle of the cylindrical groove;

[0014] The balun is vertically arranged at the center of the metal back cavity, the top end of the balun passes through the middle part of the dielectric substrates of the lossy open resonant ring structure and the double-sided spiral antenna structure, the microstrip line and the ground plate of the balun are connected to the starting points of the two Archimedes spiral arms on the upper surface of the circular dielectric substrate from the top end of the balun, and the bottom end of the balun is arranged on the bottom cavity surface of the metal back cavity and connected to the external antenna interface through the through hole for wiring.

[0015] Further improved or preferred solutions based on the above technical solutions further include:

[0016] Further, the two Archimedes spiral arms on the same plane of the circular dielectric substrate are arranged at 180 degrees, and the two Archimedes spiral arms are connected by a resistor; the double-sided spiral antenna structure is provided with two groups of resistors, which are composed of a plurality of resistors respectively arranged at the ends of the two Archimedes spiral arms, and the plurality of resistors are arranged in sequence along the spiral direction of the Archimedes spiral arm.

[0017] Further, the one-turn open resonant ring of the lossy open resonant ring structure is arranged on the surface of the annular dielectric substrate in clockwise or counterclockwise order.

[0018] Further, the lossy open resonant ring structure is provided with twice as many resistors as the number of open resonant rings, two resistors are loaded on each open resonant ring, and the two resistors are symmetrically arranged on both sides of the opening of the open resonant ring.

[0019] Further, the surface of the metal via is coated with copper, and the Archimedes spiral arm of the double-sided spiral antenna structure, the open resonant ring of the lossy open resonant ring structure, and the microstrip line and ground plate of the balun are all formed by etching the copper material coated on the corresponding dielectric substrate.

[0020] Further, the balun is an exponential tapered balun, and the tapered microstrip line and the tapered ground plate are provided on the dielectric substrate of the balun, and the tapered microstrip line and the tapered ground plate both have an exponential tapered line.

[0021] Further, the support column is a stepped column provided with an annular stepped surface, the diameter of the upper column body is smaller than the diameter of the lower column body; the annular dielectric substrate is provided with a mounting hole at a position corresponding to each support column, and the dielectric substrate is sleeved on the upper column body of the support column through the mounting hole and is held by the annular stepped surface; the dielectric substrate supporting the double-sided spiral antenna structure and the lossy open resonant ring structure is spaced by a gasket, and the gasket is sleeved on the upper column body of the support column.

[0022] As a preferred solution, the dielectric substrate of the double-sided spiral antenna structure, the lossy open resonant ring structure, and the balun is made of Rogers RO4003C plate material with a dielectric constant ε r = 3.55 and a loss tangent tanδ = 0.0027.

[0023] Advantages:

[0024] 1) The low profile ultra-wideband antenna device of the present application can effectively reduce the characteristic impedance of the spiral antenna, realize the low impedance ultra-wideband planar spiral antenna, and greatly reduce the height of the balun, thereby providing favorable conditions for realizing the low profile of the whole antenna device;

[0025] 2) The low profile ultra-wideband antenna device of the present application can effectively expand the impedance bandwidth and axial ratio bandwidth of the low frequency, improve the axial ratio performance of the low frequency, and avoid the shortcomings of increasing the weight of the antenna device and reducing the gain and efficiency of the antenna device by the traditional method of filling the wave-absorbing material;

[0026] 3) In the low profile ultra-wideband antenna device of the present application, one circle of the lossy open resonant ring structure is distributed below the outer circle of the double-sided spiral wiring structure, and the metal back cavity below the center part of the double-sided spiral wiring structure can reflect the back radiation of the medium and high frequency in the spiral antenna, realize the one-way radiation of the antenna, and improve the gain, so that the whole antenna device can improve the impedance characteristics and axial ratio characteristics in the low frequency band of the spiral antenna, and also maintain the high gain performance in the medium and high frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a split state structure diagram of the low profile ultra-wideband antenna device of the present application;

[0028] Figure 2 is an assembled state side view structure diagram of the low profile ultra-wideband antenna device of the present application;

[0029] Figure 3 is a top view of the double-sided spiral antenna structure;

[0030] Figure 4 is a side view of the double-sided spiral antenna structure;

[0031] Figure 5 is a top view of the lossy open resonant ring;

[0032] Figure 6 is a cross-sectional structure diagram of the exponential gradient balun;

[0033] Figure 7 is an S 11 simulation result diagram;

[0034] Figure 8 is a simulation result diagram of the actual gain of the low profile ultra-wideband antenna device of the present application;

[0035] Figure 9 A simulation result diagram of the axial ratio of the low-profile ultra-wideband antenna device of the present application;

[0036] Figure 10 A radiation pattern of the present application at a frequency point of 2GHz when phi=0°;

[0037] Figure 11 A radiation pattern of the present application at a frequency point of 2GHz when phi=90°;

[0038] Figure 12 A radiation pattern of the present application at a frequency point of 10GHz when phi=0°;

[0039] Figure 13 A radiation pattern of the present application at a frequency point of 10GHz when phi=90°;

[0040] Figure 14 A radiation pattern of the present application at a frequency point of 18GHz when phi=0°;

[0041] Figure 15 A radiation pattern of the present application at a frequency point of 18GHz when phi=90°. DETAILED DESCRIPTION

[0042] The low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading provided by the present application will be described in more detail below in combination with the accompanying drawings and specific embodiments.

[0043] A low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading, as shown in Figure 1 It is provided with a double-sided spiral antenna structure, a lossy open resonant ring structure, a metal back cavity 8 and an exponential tapered balun 9 and other parts.

[0044] The double-sided spiral antenna structure includes a circular dielectric substrate 1, four Archimedes spiral arms 2, a series of metal vias 3 and ten resistors.

[0045] The upper and lower surfaces of the circular dielectric substrate 1 are covered with copper, and two Archimedes spiral arms 2 are respectively formed on both surfaces by etching the copper layer, and the two Archimedes spiral arms 2 on the same surface are arranged at 180 degrees. A series of circular metal vias 3 are punched on the Archimedes spiral arms 2 of the circular dielectric substrate 1, the surfaces of the metal vias 3 are covered with copper, and the Archimedes spiral arms 2 on the upper and lower surfaces are connected from the starting end to the end through the series of metal vias 3. At the same time, the two Archimedes spiral arms 2 on the upper surface of the circular dielectric substrate 1 are respectively loaded with five resistors 4 at the end. The five resistors 4 are arranged in sequence along the extension direction of the spiral arm, one end of each resistor 4 is connected to the end of the outermost Archimedes spiral arm, and the other end is connected to the end of the next Archimedes spiral arm on the same surface.

[0046] The lossy open resonant ring structure is located below the double-sided spiral antenna structure, and includes a ring-shaped dielectric substrate 5, ten open resonant rings 6, and twenty resistors 7.

[0047] The upper surface of the ring-shaped dielectric substrate 5 is covered with copper, and ten rotationally distributed open resonant rings 6 are formed by etching the copper layer. The ten open resonant rings 6 are located below the outer part of the double-sided spiral antenna structure, and the center part of the double-sided spiral antenna structure is below a metal back cavity 8.

[0048] Each open resonant ring 6 is loaded with two resistors 7, and the two resistors 7 are symmetrically arranged on both sides of the opening of the open resonant ring 6. The ten open resonant rings 6 are uniformly distributed on the ring-shaped dielectric substrate 5, as shown in Figure 5 The rotation of each open resonant ring 6 compared to the previous open resonant ring 6 is in a clockwise direction, and the position of the opening of each open resonant ring 6 can be referred to for the regular change.

[0049] The metal back cavity 8 is a cylindrical recess opened in a metal back plate, and a small hole is formed in the middle of the metal back cavity 8 for connecting the center conductor in the antenna SMA interface to the exponential tapered balun 9.

[0050] The exponential tapered balun 9 includes a balun dielectric substrate 9-1, a tapered microstrip line 9-2, and a tapered ground plate 9-3.

[0051] The front and back sides of the balun dielectric substrate 9-1 are double-sided copper, and the tapered microstrip line 9-2 and the tapered ground plate 9-3 are respectively etched on both sides. The tapered microstrip line 9-2 and the tapered ground plate 9-3 both have an exponential tapered line, which is established by different exponential tapered equations. As shown in Figure 6As shown, the exponential tapered balun 9 is gradually transitioned from the unbalanced microstrip structure to the balanced parallel two-way structure from bottom to top. When installed, the exponential tapered balun 9 is vertically placed, the top balanced end penetrates the circular dielectric substrate 1 of the antenna, and the tapered microstrip line 9-2 and the tapered ground plane 9-3 are respectively connected to the starting points of the two spiral arms on the upper layer of the circular dielectric substrate 1 by soldering. The bottom of the exponential tapered balun 9 is placed on the bottom cavity surface of the metal back cavity 8, and the center conductor of the SMA interface is connected to the bottom of the tapered microstrip line 9-2 through the small hole in the center of the metal back cavity 8.

[0052] In this embodiment:

[0053] The structural parameters of the double-sided spiral antenna structure include: the radius of the circular dielectric substrate 1 is 32.6 mm; the maximum radius of the Archimedean spiral arm is r = 29.3 mm, and the spiral arm width w = 0.785 mm; the resistance of the ten resistors 4 is 150 Ω; the diameter of the metal via 3 is 0.35 mm, and the height is 0.508 mm;

[0054] The structural parameters of the lossy open resonant ring include: the outer radius of the annular dielectric plate 5 is 32.6 mm, and the inner radius is 17.5 mm; the outer radius of the open resonant ring 6 is r1 = 7 mm, and the ring width w1 = 0.6 mm; the resistance of the resistor 7 is 150 Ω;

[0055] The structural parameters of the exponential tapered balun 9 include: the height of the exponential tapered part is 5 mm, and the height of the extended parallel two-wire part is 1 mm, which facilitates the insertion of the exponential tapered balun 9 into the circular dielectric substrate 1 of the double-sided spiral antenna structure for balanced feeding; the line width of the balanced end is 0.83 mm, the microstrip line width of the unbalanced end is 1.15 mm, and the ground plane width is 3 mm.

[0056] The board materials used for the circular dielectric substrate 1, the annular dielectric substrate 5, and the balun dielectric substrate 9-1 are all Rogers RO4003C, and the board thickness is 0.508 mm. The related electrical parameters are: dielectric constant ε r = 3.55, loss tangent tan δ = 0.0027.

[0057] In the installed low-profile ultra-wideband antenna device, a circular dielectric substrate 1 is placed horizontally, with an annular dielectric substrate 5 and a metal backplate parallel to it. The metal backplate has five mounting holes evenly distributed around its circumference for mounting nylon support columns. Each nylon support column is a stepped column with an annular stepped surface, the diameter of the upper column being smaller than the diameter of the lower column. The annular dielectric substrate 5 has mounting holes corresponding to each nylon support column, and the annular dielectric substrate 5 is fitted onto the upper column of the nylon support column through these mounting holes, supported by the annular stepped surface. A spacer 11 separates the double-sided helical antenna structure and the lossy open resonant ring structure, and the spacer 11 is fitted onto the upper column of the nylon support column. Figure 2 As shown, the combination of the double-sided helical antenna structure, the lossy open-ring resonator structure, and five nylon support pillars is placed in the metal back cavity 8. The diameter of the substrate of the helical antenna structure and the lossy open-ring resonator structure is adapted to the inner diameter of the metal back cavity 8. The distance between the lower surface of the circular dielectric substrate 1 and the upper surface of the annular dielectric substrate 5 is 0.6 mm, the distance between the lower surface of the annular dielectric substrate 5 and the bottom surface of the metal back cavity 8 is 4 mm, and the cross-sectional height of the metal back cavity 8 is 5.6 mm.

[0058] In this embodiment, ten open resonant rings 6 are located below the outer spiral of the double-sided spiral antenna structure and are spaced a distance from the spiral arm in the vertical direction. They can absorb the back radiation of the double-sided spiral antenna structure in the low-frequency band. The metal back cavity 8 is located a distance below the open resonant rings and can reflect the back radiation of the high-frequency band of the double-sided spiral antenna structure, thereby realizing unidirectional radiation of the antenna and improving the gain.

[0059] Figure 7 This embodiment describes a low-profile ultrawideband antenna device based on double-sided spiral wiring and a lossy open-loop resonator. 11 The simulation results show that the antenna in the embodiment has good impedance matching in the 2-18 GHz frequency band. 11 The result was no more than -10dB, which verifies the effectiveness of the low profile design.

[0060] Figure 8 The figure shows the simulation results of the actual gain of the low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading in this embodiment. It can be observed that the actual gain of the antenna is high in the operating frequency band, with an average actual gain of 6.06 dBi.

[0061] Figure 9 The figure shows the simulation results of the axial ratio of the low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading in this embodiment. It can be observed that the axial ratio of the antenna is less than 3dB in the operating frequency band, indicating that the overall circular polarization performance of the antenna is good.

[0062] Figures 10 to 13 The radiation patterns of the application at 2GHz and 10GHz, phi=0° and phi=90°, respectively, can be observed, and the antenna has good radiation pattern performance in the operating frequency band.

[0063] As shown in Figure 14 , Figure 15 The radiation patterns of the application at 18GHz, phi=0° and phi=90°, respectively, can be observed, and due to the height of the antenna profile being slightly higher than the quarter wavelength at 18GHz, the axial gain of the pattern is slightly reduced due to the partial cancellation of the axial radiation energy.

[0064] The low-profile ultra-wideband antenna device based on double-sided spiral wiring and lossy open resonant ring loading has the advantages of ultra-wideband, low profile, high gain, unidirectional radiation and good circular polarization characteristics.

[0065] The above is only the preferred embodiment of the application, and the protection scope of the application is not limited to the above-mentioned embodiments, and any technical solution falling within the concept of the application shall fall within the protection scope of the application. For ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the application shall be considered as the protection scope of the application.

Claims

1. A low profile ultra-wideband antenna device based on double helix wire and lossy aperture loaded resonant ring, characterized in that, The low profile ultra-wideband antenna device based on double spiral wiring and lossy open resonant ring loading comprises a double spiral antenna structure, a lossy open resonant ring structure, a metal back cavity (8), a balun and a plurality of support columns. The double spiral antenna structure is provided with a circular dielectric substrate (1), the upper and lower surfaces of the circular dielectric substrate (1) are respectively provided with two identical Archimedes spiral arms (2), and a plurality of metal vias (3) are arranged along each Archimedes spiral arm (2) for connecting the Archimedes spiral arms (2) at different levels. The lossy open resonant ring structure is provided with a ring-shaped dielectric substrate (5), and the upper surface of the ring-shaped dielectric substrate (5) is provided with a ring of open resonant rings (6) loaded with resistors (7). The double spiral antenna structure and the lossy open resonant ring structure are arranged in the metal back cavity (8), and the double spiral antenna structure is located above the lossy open resonant ring structure. The support columns are used for supporting the dielectric substrates of the double spiral antenna structure and the lossy open resonant ring structure and controlling the distance between the double spiral antenna structure, the lossy open resonant ring structure and the bottom surface of the metal back cavity (8). The metal back cavity (8) is a cylindrical groove provided on a metal back plate, and a through hole for wiring is arranged in the middle. The balun is vertically arranged at the center of the metal back cavity (8), the top end of the balun penetrates the middle part of the dielectric substrates of the lossy open resonant ring structure and the double spiral antenna structure, the balun microstrip line and the ground plate are respectively connected to the starting points of the two Archimedes spiral arms (2) on the upper surface of the circular dielectric substrate (1) from the top end of the balun, and the bottom end of the balun is arranged on the bottom cavity surface of the metal back cavity (8) and connected to the external antenna interface through the through hole for wiring.

2. The low profile ultra-wideband antenna device based on double spiral wiring and lossy open resonant ring loading according to claim 1, wherein the two Archimedes spiral arms (2) at the same level of the circular dielectric substrate (1) are arranged at 180 degrees, and the two Archimedes spiral arms (2) are connected through resistors (4). The double spiral antenna structure is provided with two groups of resistors (4) composed of a plurality of resistors (4) arranged at the ends of the two Archimedes spiral arms (2), and the plurality of resistors (4) are arranged in sequence along the spiral direction of the Archimedes spiral arm.

3. The low profile ultra-wideband antenna device based on double spiral wiring and lossy open resonant ring loading according to claim 1, wherein the ring of open resonant rings (6) of the lossy open resonant ring structure is arranged in sequence in clockwise or counterclockwise direction on the surface of the ring-shaped dielectric substrate (5).

4. The low profile ultra-wideband antenna device based on double spiral wiring and lossy open resonant ring loading according to claim 2 or 3, wherein the lossy open resonant ring structure is provided with twice as many resistors (7) as the number of open resonant rings, two resistors (7) are loaded on each open resonant ring (6), and the two resistors (7) are symmetrically arranged on the two sides of the opening of the open resonant ring (6). ​ ​ ​ 5. The low profile ultra-wideband antenna device based on double-sided spiral wire and loaded with lossy open resonant ring according to claim 1, characterized in that: The metal via (3) is covered with copper, and the Archimedes spiral arm (2) on the double-sided spiral antenna structure, the open resonant ring (6) of the lossy open resonant ring structure, and the microstrip line and ground plate of the balun are all made of copper material etched on the corresponding dielectric substrate.

6. The low profile ultra-wideband antenna device based on double-sided spiral wire and loaded with lossy open resonant ring according to claim 1, characterized in that: The balun is an exponential tapered balun (9), and the tapered microstrip line and the tapered ground plate are provided on the dielectric substrate of the balun, and the tapered microstrip line and the tapered ground plate both have exponential tapered lines.

7. The low profile ultra-wideband antenna device based on double-sided spiral wire and loaded with lossy open resonant ring according to claim 1, characterized in that: The support column is a stepped column with an annular stepped surface, and the diameter of the upper column is smaller than that of the lower column; The annular dielectric substrate (5) is provided with a mounting hole at a position corresponding to each support column, and the annular dielectric substrate (5) is sleeved on the upper column of the support column through the mounting hole and is supported by the annular stepped surface; The dielectric substrates supporting the double-sided spiral antenna structure and the lossy open resonant ring structure are spaced apart by a gasket (11) sleeved on the upper column of the support column.

8. The low profile ultra-wideband antenna device based on double-sided spiral wire and loaded with lossy open resonant ring according to claim 1, characterized in that: The dielectric substrate of the double-sided helical antenna structure, the lossy open resonant ring structure and the balun is made of Rogers RO4003C plate material with dielectric constant ε r = 3.55 and loss tangent tan δ = 0.0027.

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