Ultra-wideband antenna

Abstract

The present invention discloses an ultra-wideband antenna, comprising: a top loading plate and a metal floor facing each other, and a radiating part located between the top loading plate and the metal floor, and a short-circuit column and a parasitic vibrator arranged between the metal floor and the top loading plate, wherein the radiating part is an axisymmetric structure and the axis of symmetry passes through the center of the top loading plate and the metal floor respectively, and comprises a first radiator and a second radiator arranged axisymmetrically and located in the same plane, each radiator is knife-shaped and its inner side edges are connected back to back to each other, and the outer side edges are formed with grooves and side loading strips, and the side loading strips are parallel to the axis of symmetry and extend in the direction of the metal floor. In the present invention, the use of an elliptical disk-shaped top loading plate and a meander-designed groove and side loading strip structure effectively reduces the size of the antenna and widens the working bandwidth of the antenna. At the same time, the side loading strip can be grounded and / or the width of the side loading strip and the parasitic vibrator can be reasonably designed to adjust the high and low frequency radiation characteristics of the antenna and improve the gain.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, and in particular to an ultra-wideband antenna. Background Art

[0002] Very high frequency / ultra high frequency (VHF / UHF) is also called ultrashort wave, and its wireless communication frequency range is 30MHz-512MHz. Ultrashort wave communication has the advantages of wide available frequency, simple manufacturing, and small equipment size, which makes ultrashort wave communication widely used in military and civilian fields. Ultrashort wave frequency hopping communication is an important means of communication, especially in modern military communications. In order to achieve confidential communication and eliminate interference, multi-band, multi-functional radio stations and broadband frequency hopping radio stations are widely used. Ultrashort wave frequency hopping communication has strong data transmission and anti-interference capabilities. In addition, frequency hopping communication technology also has the advantages of high spectrum utilization, anti-multipath, anti-fading, and easy networking. In practice, most antennas used in this frequency band are whip antennas, which usually have a high height. There are very few ultrashort wave antennas that can meet the miniaturization of ultra-wideband. Therefore, research on high performance, wide bandwidth, and miniaturization of antennas has attracted more and more attention.

[0003] Traditional antennas are often limited in size and can only reach a narrow operating frequency band. Therefore, loading technology is widely used to broaden the antenna's operating bandwidth and reduce the size of the antenna. Since the current in an unloaded antenna is distributed as a standing wave, the change in the antenna's electrical length has a great impact on its input impedance. Antenna loading can avoid this problem. At the same time, loading technology can adjust the antenna's broadband matching, increase the antenna's operating bandwidth, and reduce the size of the antenna.

[0004] Loading technology refers to embedding appropriate loading elements such as reactance, impedance or dielectric materials into the antenna structure to improve the current distribution in the antenna, thereby changing the resonant frequency of the antenna. At the same time, at the same operating frequency, loading technology can also effectively reduce the height of the antenna and improve the radiation characteristics of the antenna. The loading element can be active or passive, distributed parameter element or lumped parameter element. Among them, the resistance-loaded antenna has the wideband characteristics of both impedance and radiation pattern, so suitable resistance loading can effectively broaden the working bandwidth of the antenna. However, although the well-known 506-3 antenna has a wider working bandwidth after resistance loading, the low-frequency gain of the antenna is very low, only about -9dBi.

[0005] In summary, the problems existing in the prior art are: the working frequency band that the existing antenna can achieve is relatively narrow under certain size restrictions, and the loading resistor used causes the low-frequency gain of the antenna to be relatively low. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides an ultra-wideband antenna, which can realize miniaturization and ultra-wideband of the antenna structure and also ensure excellent electrical performance as much as possible.

[0007] The ultra-wideband antenna provided by the present invention comprises:

[0008] A top loading plate and a metal floor disposed opposite and parallel to each other; and

[0009] The radiating part is located between the top loading plate and the metal floor, the radiating part is in an axisymmetric structure and the axis of symmetry passes through the center of the top loading plate and the center of the metal floor, the radiating part includes a first radiator and a second radiator arranged back to back, the first radiator and the second radiator are both located on the same surface and are both knife-shaped, the top end of each radiator is vertically connected to the top loading plate, and the bottom end of each radiator is vertically connected to the metal floor,

[0010] The inner sides of each radiator are connected back to back, a groove is formed in the outer side of each radiator, and a side loading bar is arranged on the outer side of each radiator, which is parallel to the symmetry axis and extends toward the metal floor.

[0011] Preferably, the ultra-wideband antenna further includes:

[0012] A plurality of short-circuit posts are vertically connected between the metal floor and the top loading plate.

[0013] Preferably, the multiple short-circuit posts include a first short-circuit post, a second short-circuit post and a third short-circuit post, all of which are parallel to the plane where the radiating part is located, the first short-circuit post and the second short-circuit post are mirror-symmetrical structures with the plane where the radiating part is located as a mirror plane, the third short-circuit post is arranged between the first short-circuit post and the radiating part, and the width of the third short-circuit post is greater than the width of the first short-circuit post.

[0014] Preferably, the ultra-wideband antenna further includes:

[0015] A plurality of parasitic oscillators are vertically connected to the metal floor and arranged around the radiation part.

[0016] Preferably, the plurality of parasitic vibrators include a first parasitic vibrator and a second parasitic vibrator, the first parasitic vibrator and the second parasitic vibrator are parallel to each other and perpendicular to the plane where the radiation portion is located, and are respectively close to the outer side of the first radiator and the outer side of the second radiator.

[0017] Preferably, the plurality of parasitic vibrators further include a third parasitic vibrator and a fourth parasitic vibrator, the third parasitic vibrator and the fourth parasitic vibrator are parallel to each other and to the plane where the radiation portion is located, and are respectively arranged on two sides of the radiation portion and are asymmetrical.

[0018] Preferably, the width of the bottom end of the radiating portion gradually decreases, a feeding port is provided at the center of the metal floor, and the bottom end of the radiating portion is connected to a coaxial cable through the feeding port.

[0019] Preferably, two chamfers with gradually decreasing widths are formed at the bottom end of the radiation portion.

[0020] Preferably, the bottom width of the radiation portion changes gradually in a step-like manner.

[0021] Preferably, the top loading plate is in the shape of an elliptical disk, and the length of the major axis of the elliptical disk is greater than the length of the top end of the radiation portion.

[0022] Preferably, the groove opening shape is at least one of U-shape, semicircle, semi-ellipse, diamond shape and V-shape.

[0023] The beneficial effects of the present invention are:

[0024] 1. The ultra-wideband antenna designed in the present invention uses meander technology and short-circuit posts. The meander technology makes the current path longer by setting grooves and side loading strips, effectively reduces the antenna size and optimizes the standing wave. The short-circuit post is equivalent to introducing an inductive load, further optimizing the impedance characteristics of the antenna.

[0025] 2. The antenna structure has a low profile, and the top loading plate and parasitic oscillator used at the same time further reduce the cross-sectional size of the antenna and expand the impedance bandwidth of the antenna.

[0026] 3. The width of the lower end of the radiating part changes gradually, so that the structure of the antenna radiating part connected with the coaxial cable changes smoothly. This design is also beneficial to the impedance matching of the antenna, increasing the antenna bandwidth and realizing the ultra-wideband design of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0028] Figure 1 A schematic diagram of the structure of an ultra-wideband antenna according to an embodiment of the present invention is shown;

[0029] Figure 2 A front view showing an ultra-wideband antenna structure according to an embodiment of the present invention;

[0030] Figure 3 A rear view showing an ultra-wideband antenna structure according to an embodiment of the present invention;

[0031] Figure 4 A bottom view showing an ultra-wideband antenna structure according to an embodiment of the present invention;

[0032] Figure 5 An antenna gain simulation diagram of an embodiment of the present invention is shown;

[0033] Figure 6 The directional diagram of the horizontal gain of the antenna of the embodiment of the present invention at the center frequency is shown;

[0034] Figure 7 The broadside radiation gain diagram of the antenna according to the embodiment of the present invention is shown when θ=60° / 90° and φ=0° in the low frequency band;

[0035] Figure 8 The broadside radiation gain diagram of the antenna according to the embodiment of the present invention is shown when θ=60° / 90° and φ=0° in the high frequency band;

[0036] Fig. 9 A schematic diagram showing the structure of a groove in an ultra-wideband antenna according to an alternative embodiment of the present invention;

[0037] Fig.10 A schematic diagram showing the structure of a groove in an ultra-wideband antenna according to an alternative embodiment of the present invention;

[0038] Fig.11 A schematic diagram showing the structure of a radiation portion in an ultra-wideband antenna according to an alternative embodiment of the present invention;

[0039] Fig.12 A schematic structural diagram of a radiation portion in an ultra-wideband antenna according to an alternative embodiment of the present invention is shown. DETAILED DESCRIPTION

[0040] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0042] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0043] Figure 1 FIG. 2 shows a schematic diagram of the structure of an ultra-wideband antenna according to an embodiment of the present invention. Figure 1As shown, the present invention provides an ultra-wideband antenna 10, comprising: a radiating portion 12, a top loading plate 11, a parasitic vibrator 13, a short-circuit column 14 and a metal floor 15, wherein the radiating portion 12 is an axisymmetric structure and the axis of symmetry passes through the center of the top loading plate 11 and the center of the metal floor 15, the radiating portion 12 comprises a first radiator 1241 and a second radiator 1242 arranged back to back, further, the top loading plate 11 and the metal floor 15 are arranged opposite to each other and in parallel, the first radiator 1241 and the second radiator 1242 are both located on the same surface and have a knife-shaped longitudinal cross-section, the top ends of the first radiator 1241 and the second radiator 1242 are both vertically connected to the top loading plate 11, the bottom ends of the first radiator 1241 and the second radiator 1242 are both vertically connected to the metal floor 15, and the radiating portion 12 is connected to the coaxial cable with its bottom end 123 as a feeding point. Among them, the inner sides of the first radiator 1241 and the second radiator 1242 are connected back to back to each other, and the outer sides of the first radiator 1241 and the second radiator 1242 are formed with grooves. Furthermore, side loading bars 122 are provided on the outer sides of the first radiator 1241 and the second radiator 1242, and the side loading bars 122 are parallel to the above-mentioned symmetry axis and extend in the direction of the metal floor 15.

[0044] In this embodiment, a plurality of short-circuit posts 14 of the ultra-wideband antenna 10 are vertically connected between the metal floor 15 and the top loading plate 11. Furthermore, a plurality of parasitic oscillators 13 are vertically connected to the metal floor 15 and are disposed around the radiation portion 12.

[0045] Further, the top loading plate 11 is a polyhedron with at least one pair of parallel planes. Further, the top loading plate 11 is an elliptical disk-shaped loading plate in this embodiment, and the parasitic vibrator 13 is arranged around the radiating portion 12. Further, the lateral openings of the plurality of grooves 121 face outward, and the shape is generally U-shaped. Further, two pairs of grooves 121 and a pair of side loading bars 122 are symmetrically arranged on both sides of the radiating portion, and the adjacent grooves 121 located on a single side are not connected to each other, and the side loading bars 122 located on the same side are connected to the radiating portion 12 only through their top ends in the horizontal direction, and their connecting ends are located between two adjacent grooves 121 in the vertical direction. Further, the depth of the groove close to the top end is less than the depth of the groove below it, and the length of the major axis of the elliptical disk-shaped top loading plate 11 is greater than the length of the top end of the radiating portion 12.

[0046] Furthermore, the width of the lower end of the radiation portion 12 gradually decreases to the bottom end 123 , and the central area of ​​the metal floor 15 has a feeding port, through which the bottom end 123 of the radiation portion 12 is connected to a coaxial cable for ultra-short waveband signal transmission.

[0047] In this embodiment, the antenna uses meander technology to implement the bending structure of the groove 121 and the side loading bar 122 on the side of the radiating portion 12, which effectively reduces the height of the antenna and makes the current path longer, thereby reducing the overall size of the antenna. Furthermore, by reasonably selecting the number and positions of the grooves 121 and the side loading bar 122, the low-frequency resonance can be adjusted, the low-frequency electrical performance can be improved, and the antenna bandwidth can be expanded. At the same time, the voltage standing wave ratio of the antenna radiating portion 12 can be reduced to a certain extent.

[0048] Figure 2 , Figure 3 and Figure 4 The front view, rear view and bottom view of the ultra-wideband antenna structure of the embodiment of the present invention are respectively shown, which can further illustrate the antenna structure in the embodiment of the present invention, as shown in FIG. Figure 4 As shown, further, the elliptical disk-shaped top loading plate 11 is arranged parallel to the metal floor 15, each parasitic vibrator 13 is perpendicular to the plane where the metal floor 15 is located, the first radiator 1241 and the second radiator 1242 are located on the same surface, and further, the multiple parasitic vibrators 13 include the first parasitic vibrator 131 and the second parasitic vibrator 132, the first parasitic vibrator 131 and the second parasitic vibrator 132 are parallel to each other and perpendicular to the plane where the radiation part 12 is located, and are respectively close to the outer side edge of the first radiator 1241 and the outer side edge of the second radiator 1242. Further, the multiple parasitic vibrators 13 also include the third parasitic vibrator 133 and the fourth parasitic vibrator 134, the third parasitic vibrator 133 and the fourth parasitic vibrator 134 are parallel to each other and parallel to the plane where the radiation part 12 is located, and are respectively arranged on both sides of the radiation part and are asymmetrical.

[0049] Further, the plurality of short-circuit posts 14 include a first short-circuit post 141, a second short-circuit post 143 and a third short-circuit post 142, all of which are parallel to the plane where the radiation portion 12 is located. The first short-circuit post 141 and the second short-circuit post 143 are mirror-symmetrical structures with the plane where the radiation portion 12 is located as a mirror surface, and the third short-circuit post 142 is arranged between the first short-circuit post 141 and the radiation portion 12. Further, in combination Figure 2 and Figure 3 The sizes of the short-circuit pillars 14 at different positions are also different. Specifically, the width of the third short-circuit pillar 142 is greater than the width of the first short-circuit pillar.

[0050] In this embodiment, the sizes of different short-circuit posts can be reasonably designed and the positions of the short-circuit posts can be adjusted according to the gain requirements of the antenna 10. It should be noted that the short-circuit posts can increase the inductive load of the antenna. The elliptical disc-shaped top loading plate 11 connected to the top of the radiating portion 12 and the side loading strip 122 arranged on the side of the radiating portion 12 can extend the height of the antenna by extending the current path in places where the frequency gain is poor, and control the movement of the resonance point to correct the frequency, which is equivalent to the effect of resistance. The different sizes and positions of the short-circuit posts are equivalent to the size and position of the loading inductor. By selecting a reasonable position, better impedance matching parameters can be obtained, which is conducive to the improvement of the standing wave of the antenna and further obtaining a higher radiation gain.

[0051] Figure 5 FIG. 2 shows a simulation diagram of antenna gain according to an embodiment of the present invention. Figure 5 As shown, overall, except for a few frequency points near 2500MHz, the voltage standing wave ratio (VSWR) of the antenna radiator within the working bandwidth is generally less than 3, which meets the design requirements. Specifically, the voltage standing wave ratio of the antenna radiation is lower than 2 in the working frequency range of 200-400MHz, and when the working frequency is near 1200MHz, the voltage standing wave ratio also reaches 1.9. In the simulation results, especially when the working frequency is close to 400MHz, its voltage standing wave is close to 1, that is, the impedance matching effect between the feeder and the antenna is good, the antenna radiation rate is high, and the gain is high, which shows that the antenna in the embodiment of the present invention has a very high low-frequency gain.

[0052] Figure 6 The directional diagram of the horizontal gain of the antenna of the embodiment of the present invention at the center frequency is shown. It can be seen from the figure that the side lobes and back lobes in the vertical direction of the directional diagram are small, so the directional receiving performance of the antenna working at the center frequency is higher and the gain is higher.

[0053] Figure 7 and Figure 8 The broadside radiation gain diagrams of the antenna according to the embodiment of the present invention are shown in the low frequency band and the high frequency band when θ=60° / 90° and φ=0°, respectively. Figure 7 and Figure 8As shown, the antenna radiation gain of the antenna in the low frequency band θ=90° is greater than -2dBi except for a few frequency bands of 200~225MHz where the antenna gain is slightly less than -2dBi. The antenna radiation gain of the antenna in the low frequency band θ=60° is greater than -1dBi, and at the frequency point of 400MHz, the gain is greater than 4.5dBi. The antenna gain of the antenna in the high frequency band θ=90° is greater than -6dBi, and when the antenna works near 1.2MHz, the antenna radiation gain can reach 15dBi. The antenna radiation gain of the antenna in the high frequency band θ=60° is greater than -8dBi, and when the antenna works near 1.2MHz, the antenna radiation gain can reach 15dBi, which can meet the design requirements as a whole.

[0054] In the embodiment of the present invention, the radiation part material is optionally one of ferrite, single metal, alloy magnetic material, and other conductive dielectric materials. In addition, in the radiation part 12 of the present embodiment, the U-shaped grooves 121 with lateral openings facing outwards and symmetrically distributed on the outer sides of the first radiator 1241 and the second radiator 1242 can be replaced by one or more combinations of semicircular grooves, semi-elliptical grooves, diamond grooves, and V-shaped grooves. The grooves 121 of the above-mentioned partial shapes are as follows: Fig. 9 and Fig.10 As shown. Furthermore, the shape of the side loading strip can be optionally prism-shaped or cylindrical. In a preferred embodiment of the present invention, the position of the side loading strip and the width of the parasitic vibrator are not fixed, and the side loading strip can also be grounded, or the number and position of the side loading strip and the width of the parasitic vibrator can be reasonably designed to adjust the high and low frequency radiation characteristics of the antenna.

[0055] In the embodiment, the width of the lower end of the antenna radiating portion 12 gradually changes to the bottom end 123, and the outer sides of the first radiator 1241 and the second radiator 1242 gradually decrease to the same extent, so that the structure of the antenna radiating portion 12 connected to the feeding port changes smoothly, or the lower end of the antenna radiating portion is set to a chamfered width gradient or an arc width gradient, or is designed to be a stepped width gradient, such as Fig.11 and Fig.12 As shown, this design is also beneficial to antenna impedance matching, increasing the working bandwidth of the antenna and achieving ultra-wideband antenna.

[0056] In the present invention, the elliptical disk-shaped top loading with appropriate resistance value (size) and the meander design of the groove and side loading strip structure on the side of the radiating part effectively reduce the size of the antenna and expand the working bandwidth of the antenna. At the same time, by reasonably designing short-circuit posts of different sizes and their positions, it is further ensured that the antenna has good impedance matching within a wide bandwidth.

[0057] In addition, the antenna structure has a higher low-frequency gain, thereby increasing the communication distance of the airborne system.

[0058] It should be noted that in the description of the present invention, it is necessary to understand that the terms "upper", "lower", "inner" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limitations on the present invention.

[0059] In addition, in this article, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0060] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. An ultra-wideband antenna, It is characterized in that The ultra-wideband antenna comprises: a top loading plate and a metal floor disposed opposite and parallel to each other; a plurality of short-circuit posts vertically connected between the metal floor and the top loading plate; and The radiating part is located between the top loading plate and the metal floor, the radiating part is in an axially symmetrical structure and the axis of symmetry passes through the center of the top loading plate and the center of the metal floor, the radiating part includes a first radiator and a second radiator arranged back to back, the first radiator and the second radiator are both located on the same surface and are both knife-shaped, the top end of each radiator is vertically connected to the top loading plate, and the bottom end of each radiator is vertically connected to the metal floor, The inner sides of each radiator are connected back to back, the outer sides of each radiator are formed with a groove, and a side loading bar is arranged on the outer side of each radiator, and the side loading bar is parallel to the symmetry axis and extends in the direction of the metal floor. The multiple short-circuit posts include a first short-circuit post, a second short-circuit post, and a third short-circuit post, all of which are parallel to the plane where the radiating part is located. The first short-circuit post and the second short-circuit post are in a mirror-symmetrical structure with the plane where the radiating part is located as a mirror plane. The third short-circuit post is arranged between the first short-circuit post and the radiating part, and the width of the third short-circuit post is greater than the width of the first short-circuit post.

2. The ultra-wideband antenna according to claim 1, It is characterized in that The ultra-wideband antenna also includes: A plurality of parasitic oscillators are vertically connected to the metal floor and arranged around the radiation part.

3. The ultra-wideband antenna according to claim 2, It is characterized in that The plurality of parasitic oscillators include a first parasitic oscillator and a second parasitic oscillator. The first parasitic oscillator and the second parasitic oscillator are parallel to each other and perpendicular to the plane where the radiation portion is located, and are respectively close to the outer side of the first radiator and the outer side of the second radiator.

4. The ultra-wideband antenna according to claim 3, It is characterized in that The plurality of parasitic vibrators further include a third parasitic vibrator and a fourth parasitic vibrator. The third parasitic vibrator and the fourth parasitic vibrator are parallel to each other and to the plane where the radiation part is located, and are respectively arranged on two sides of the radiation part and are asymmetrical.

5. The ultra-wideband antenna according to claim 1, It is characterized in that The width of the bottom end of the radiation part gradually decreases, a feeding port is arranged at the center of the metal floor, and the bottom end of the radiation part is connected to a coaxial cable through the feeding port.

6. The ultra-wideband antenna according to claim 5, It is characterized in that Two chamfers with gradually decreasing widths are formed at the bottom end of the radiation portion.

7. The ultra-wideband antenna according to claim 5, It is characterized in that The bottom width of the radiation portion changes gradually in a step-like manner.

8. The ultra-wideband antenna according to claim 1, It is characterized in that The top loading plate is in the shape of an elliptical disk, and the length of the major axis of the elliptical disk is greater than the length of the top end of the radiation portion.

9. The ultra-wideband antenna according to claim 1, It is characterized in that The groove opening shape is at least one of U-shape, semicircle, semi-ellipse, diamond shape and V-shape.

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