Ultra-wideband antipodal Vivaldi antenna of airborne radar

Abstract

The utility model provides an ultra-wideband antipodal Vivaldi antenna for an airborne radar, which is used for solving the technical problems of small detection range and low resolution of the airborne radar caused by low low-frequency gain, narrow working band and poor directivity of the conventional antipodal Vivaldi antenna. The antenna comprises a dielectric substrate and a radiation unit, the radiation unit comprises a first radiation arm and a second radiation arm which are symmetrically arranged, the first radiation arm is printed on one side of the front surface of the dielectric substrate, the second radiation arm is printed on one side of the back surface of the dielectric substrate, and a reflection floor is arranged at the line tail part of the back surface of the dielectric substrate. And the reflection floor is connected with the second radiation arm. According to the utility model, radiation current at the edge of the antenna is reduced through the slot at the edge of the antenna, so that the current can be spread along inner edge slot lines at two sides of the antenna all the time and mutually coupled to generate radiation; by adding the reflection floor at the tail part of the back surface of the dielectric substrate, electromagnetic waves can be reflected, and the antenna gain is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of antenna especially relates to a kind of airborne radar ultra wide band heel Vivaldi antenna. BACKGROUND

[0002] Antenna essentially plays the key role of conversion between guided electromagnetic wave and space electromagnetic wave, is indispensable in radar system, it can receive also can emit electromagnetic wave.For airborne system, airborne antenna is responsible for radiating and receiving high-frequency pulsed electromagnetic wave.Therefore, the performance of antenna directly determines the detection effect of airborne radar system.The gain of antenna and operating frequency determine the detection depth of system, when the operating frequency of antenna is lower and gain improves, system detection depth will increase accordingly.Meanwhile, the effective operating bandwidth of antenna is crucial to the azimuth resolution of airborne radar, the wider effective operating bandwidth, the higher longitudinal resolution of antenna, it means that radar system can more accurately distinguish the position of target in longitudinal.In addition, the 3dB beamwidth of antenna determines the lateral resolution of system, the narrower 3dB beamwidth of antenna, the more diffraction wave interference can be suppressed, the higher lateral resolution of system.

[0003] Heel Vivaldi antenna is a end-fire antenna, its maximum radiation direction is parallel with the plane where metal radiating arm is located.Because energy is radiated from exponential simple slot line to free space, the frequency of electromagnetic wave is from high to low along with slot line width, therefore, it has very wide operating bandwidth, and radiation direction is concentrated, anti-interference ability is strong, easy to integrate and wideband characteristics are widely used in airborne radar system.The traditional Vivaldi antenna structure is dielectric substrate and metal patch printed on both sides of dielectric substrate, the length and opening width of the tapered slot line of antenna are designed according to specific frequency, to realize good radiation characteristics.It can work in the frequency range of contribution, suitable for a variety of communication systems;Antenna has unidirectional, can realize higher gain radiation.But, because two metal patches are out of plane, cross polarization is easy to produce, influence radiation characteristics;With the increase of frequency, phase inversion phenomenon occurs in the process of electromagnetic wave propagation in bottom metal patch, leading to poor radiation performance at high frequency.

[0004] The application patent with the application number 202322293854.0 discloses an ultra-wideband high-gain Vivaldi antenna, which comprises a dielectric substrate and a metal conductor layer printed on the front and back surfaces of the dielectric substrate, wherein the metal conductor layer comprises a radiation arm, and the radiation arms on the front and back surfaces are the same in structure and rotationally symmetrical about the main radiation direction; the two sides of the radiation arm are respectively provided with an inner exponentially tapered slot line and an outer exponentially tapered slot line, and the radiation arm is provided with an exponential groove at the opposite open ends of the two slot lines, and the curvature of the exponential groove is the same as that of the inner exponentially tapered slot line / outer exponentially tapered slot line; the radiation arms on the front and back surfaces overlap at the opposite tight ends of the two slot lines. The ultra-wideband high-gain Vivaldi antenna improves the traditional Vivaldi antenna, adds an exponential groove on the radiation arm on both sides of the antenna, the curvature of the exponential groove is the same as that of the antenna radiation slot line, and the best groove length can be obtained through simulation to increase the current flow path distance, improve the performance of the antenna at low frequency, and increase the gain of the antenna. However, the above-mentioned patent has edge effect when the antenna radiates, and most of the current is at the edge of the radiation arm, so it is necessary to change the current path by slotting at the edge of the radiation arm to make the current flow along the inner slot line as much as possible to achieve better radiation performance. The two metal patches of the antenna are out of plane, and the electromagnetic wave of the bottom metal patch will be phase-inverted in the propagation process. Practical new type content

[0005] In view of the technical problems of the existing Vivaldi antenna with low low-frequency gain, narrow working frequency band and poor directivity, which leads to small detection range and low resolution of the airborne radar, the utility model provides an airborne radar ultra-wideband Vivaldi antenna, which slots the two radiation arms of the traditional Vivaldi antenna, optimizes the slot line structure and adds a reflection floor at the tail of the antenna to realize the demand of the airborne radar for ultra-wideband and high gain.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is as follows: an airborne radar ultra-wideband Vivaldi antenna, which comprises a dielectric substrate and a radiation unit, the radiation unit comprises a first radiation arm and a second radiation arm arranged symmetrically, the first radiation arm is printed on the front side of the dielectric substrate, the second radiation arm is printed on the back side of the dielectric substrate, a reflection floor is arranged at the tail of the back side of the dielectric substrate, and the reflection floor is connected with the second radiation arm.

[0007] Preferably, the first radiation arm and the second radiation arm are both slotted at the edge, and a plurality of tail slots are arranged circumferentially around the slot.

[0008] Preferably, the slot is a circular slot.

[0009] Preferably, the number of the circular slots is 2, including a semicircular slot and a quarter circular slot, and a plurality of tail grooves are uniformly distributed on the circumferences of the semicircular slot and the quarter circular slot.

[0010] Preferably, the distance between the semicircular slot and the line tail of the medium substrate is greater than the distance between the quarter circular slot and the line tail of the medium substrate.

[0011] Preferably, the tail grooves are in the shape of a rectangle.

[0012] Preferably, the first radiation arm and the second radiation arm are spread in opposite directions; the first radiation arm is a metal patch printed on the front surface of the medium substrate, and the second radiation arm and the reflecting floor are metal patches printed on the back surface of the medium substrate.

[0013] Preferably, the reflecting floor is in the shape of a parabola and is symmetric about the central axis of the vertical direction of the medium substrate.

[0014] Preferably, the medium substrate is provided with a feeding end, the feeding end includes a microstrip line and a ground plane, the microstrip line is printed on the front surface of the medium substrate, the ground plane is printed on the back surface of the medium substrate, the microstrip line is connected with the first radiation arm, and the ground plane is connected with the second radiation arm.

[0015] Preferably, the feeding end is connected with the dipole antenna for feeding through an SMA radio frequency connector, and the microstrip line is in the shape of a rectangle.

[0016] Compared with the prior art, the utility model has the beneficial effects of:

[0017] 1. The antenna edge grooves reduce the antenna edge radiation current, the current can propagate along the inner edge groove lines on both sides of the antenna all the time, and the current is coupled to generate radiation.

[0018] 2. The metal patch tail on the back surface of the medium substrate is provided with a reflecting floor, electromagnetic waves are reflected, and the antenna gain is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained according to these drawings without the creative labor of the person skilled in the art.

[0020] Figure 1 It is a structural schematic diagram of the utility model.

[0021] Figure 2 Fig. 1 is a schematic diagram of a front structure of a dielectric substrate. Figure 1

[0022] Figure 3 Fig. 2 is a schematic diagram of a back structure of a dielectric substrate. Figure 1

[0023] Figure 4 Fig. 3 is a simulation result of a reflection coefficient of an antenna.

[0024] Figure 5 Fig. 4 is a simulation result of a current distribution of an antenna.

[0025] Figure 6 Fig. 5 is a simulation result of a radiation pattern of an antenna.

[0026] In the figure, 1 is a first radiation arm, 2 is a dielectric substrate, 3 is a second radiation arm, and 4 is a reflecting ground plate. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] Embodiment 1

[0029] As Figure 1 , Figure 2 and Figure 3 ​​The utility model provides a kind of airborne ultra-wideband against heel Vivaldi antenna, including dielectric substrate 2 and the radiation unit two parts obtained by metal patch printed on the front and back of dielectric substrate 2, wherein the radiation unit is to the external radiation electromagnetic wave.The radiation unit is composed of symmetrical first radiation arm 1, second radiation arm 3 and reflection floor part, the shape of first radiation arm 1 and second radiation arm 3 is identical, first radiation arm 1 is printed on the front side of dielectric substrate 2, second radiation arm 3 is printed on the back side of dielectric substrate 2, the first radiation arm 1 of front and the second radiation arm 3 of back open to opposite direction, and first radiation arm 1 and second radiation arm 3 two radiation arms are in edge open circular slot and tail slot, the number of circular slot is 2, one is semicircular slot, one is four circular slot, tail slot is evenly distributed on the circumference of semicircular slot and four circular slot, and tail slot is rectangular, reflection floor 4 is added in line tail on the back of dielectric substrate 2, reflection floor 4 is connected with second radiation arm 3, and the effect of reflection floor 4 is to reflect electromagnetic wave and increase gain.The shape of reflection floor 4 is parabola, and reflection floor 4 is symmetrical about the vertical central axis of dielectric substrate 2, keeps symmetry, and increases reflection gain.

[0030] Embodiment 2

[0031] A kind of airborne ultra-wideband against heel Vivaldi antenna, the feed end of Vivaldi antenna includes microstrip line and ground plane, microstrip line is printed on the front of dielectric substrate 2, and ground plane is printed on the back of dielectric substrate 2, wherein microstrip line is rectangular structure, and microstrip line is connected with first radiation arm 1.Ground plane is connected with second radiation arm 3, and feed end is connected with dipole antenna by SMA radio frequency connector and is fed, and signal wave is propagated along the inner edge groove line of first radiation arm 1 and second radiation arm 3 of both sides of antenna, and is coupled to generate radiation mutually.Under the condition of not coupling, antenna has no effect basically, and will not produce radiation performance.

[0032] Other structures are same with embodiment 1.

[0033] Embodiment 3

[0034] A kind of airborne ultra-wideband against heel Vivaldi antenna, other structures are same with embodiment 2, the airborne ultra-wideband against heel Vivaldi antenna of the present application is tested, and simulation calculation is carried out with electromagnetic simulation software HFSS, obtains Figure 4S11 is a standard for measuring the goodness of the impedance matching of the antenna, when S11 <-10dB, the antenna is in a good matching condition, and the antenna can work in the bandwidth, when the impedance bandwidth of the antenna is less than -10dB, the frequency is 1-6GHz, and the relative bandwidth of the antenna is 142.8%, so the bandwidth of the antenna is wide, and the requirement of the ultra-wideband is achieved.

[0035] In addition, when the frequency is 2.2GHz, simulation calculation is carried out by using an electromagnetic simulation software HFSS, and the result is as follows: Figure 5 As shown in Fig. 6, the current distribution of the antenna is shown, and it can be seen that the current is mostly concentrated on the slot line of the antenna, propagates along the inner edge of the exponential taper to the opening of the antenna, and then the energy on the two metal patches is coupled to generate radiation, and the radiation in the opening direction is the largest.

[0036] Figure 6 As shown in Fig. 7, the two-dimensional radiation pattern of the antenna is shown, and the text in the figure represents the goodness of the radiation performance of the antenna, and it can be seen that when the angle is 0°, the antenna has the strongest radiation at 2.2GHz, and the gain is 8.7dBi.

[0037] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An airborne radar ultra-wideband (UWB) toehold Vivaldi antenna comprising a dielectric substrate (2) and a radiating element, characterized in that, The radiation unit comprises a first radiation arm (1) and a second radiation arm (3) symmetrically arranged, the first radiation arm (1) is printed on the front side of the medium substrate (2), the second radiation arm (3) is printed on the back side of the medium substrate (2), the back side of the medium substrate (2) is provided with a reflection floor (4) at the tail end, and the reflection floor (4) is connected with the second radiation arm (3).

2. The airborne radar ultra-wideband (UWB) Tusk Vivaldi antenna of claim 1, wherein, The first radiation arm (1) and the second radiation arm (3) are both provided with slits at the edges, and a plurality of tail grooves are arranged on the circumference of the slits.

3. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna of claim 2, wherein, The slit is a circular slit.

4. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna of claim 3, wherein, The number of the circular slits is two, including a semicircular slit and a quarter circular slit, and a plurality of tail grooves are uniformly distributed on the circumferences of the semicircular slit and the quarter circular slit.

5. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna of claim 4, wherein, The distance between the semicircular slit and the tail end of the medium substrate (2) is greater than the distance between the quarter circular slit and the tail end of the medium substrate (2).

6. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna according to claim 4 or 5, wherein, The shape of the tail groove is rectangular.

7. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna of claim 6, wherein, The first radiation arm (1) and the second radiation arm (3) are spread in opposite directions; the first radiation arm (1) is a metal patch printed on the front side of the medium substrate (2), and the second radiation arm (3) and the reflection floor (4) are metal patches printed on the back side of the medium substrate (2).

8. The airborne radar ultra-wide band (UWB) Tusked Vivaldi antenna according to any one of claims 1-5, 7, wherein, The shape of the reflection floor (4) is a parabola, and the reflection floor (4) is symmetric about the central axis of the vertical direction of the medium substrate (2).

9. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna of claim 8, wherein, The medium substrate (2) is provided with a feeding end, the feeding end comprises a microstrip line and a ground plane, the microstrip line is printed on the front side of the medium substrate (2), the ground plane is printed on the back side of the medium substrate (2), the microstrip line is connected with the first radiation arm (1), and the ground plane is connected with the second radiation arm (3).

10. The airborne radar ultra-wideband (UWB) notch Vivaldi antenna of claim 9, wherein, The feeding end is connected with the dipole antenna through an SMA radio frequency connector for feeding, and the microstrip line is a rectangular structure.

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