阅读说明：本技术 基于人工表面等离子激元的高增益低剖面Vivaldi天线 (High-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton ) 是由 许锋 陈方君 于 2021-07-12 设计创作，主要内容包括：本发明提供一种基于人工表面等离子激元的高增益低剖面Vivaldi天线,包括介质基板,还包括馈电结构、金属辐射贴片和椭圆形金属引向器,馈电结构设于介质基板的下表面,馈电结构包括微带短截线和圆形金属片；金属辐射贴片和椭圆形金属引向器分别设于介质基板的上表面,金属辐射贴片分别设有圆形谐振腔、第一槽线、第二槽线、线性变化开口槽和指数渐变槽；椭圆形金属引向器的端部设于线性变化开口槽处,椭圆形金属引向器采用人工表面等离子激元椭圆形金属引向器,椭圆形金属引向器的两侧分别设有周期性排列的缺口；本发明能使得Vivaldi天线的增益获得显著提高,实现天线高增益高定向性,具有高方向性和高增益的优良辐射特性。(The invention provides a high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton, which comprises a dielectric substrate, a feed structure, a metal radiation patch and an elliptical metal director, wherein the feed structure is arranged on the lower surface of the dielectric substrate and comprises a micro-strip stub and a circular metal sheet; the metal radiation patch and the elliptical metal director are respectively arranged on the upper surface of the medium substrate, and the metal radiation patch is respectively provided with a circular resonant cavity, a first slot line, a second slot line, a linear change open slot and an index gradual change slot; the end part of the elliptical metal director is arranged at the linear change open slot, the elliptical metal director adopts an artificial surface plasmon polariton elliptical metal director, and two sides of the elliptical metal director are respectively provided with periodically arranged gaps; the invention can obviously improve the gain of the Vivaldi antenna, realizes high gain and high directionality of the antenna, and has excellent radiation characteristics of high directionality and high gain.)

1. A high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton comprises a dielectric substrate and is characterized in that: the feed structure is arranged on the lower surface of the dielectric substrate and comprises a micro-strip stub and a circular metal sheet, one end of the micro-strip stub is connected with the circular metal sheet, and the other end of the micro-strip stub extends to the side of the dielectric substrate; the metal radiation patch and the elliptical metal director are respectively arranged on the upper surface of the medium substrate, and the metal radiation patch is respectively provided with a circular resonant cavity, a first slot line, a second slot line, a linear change open slot and an index gradual change slot; the end part of the elliptical metal director is arranged at the linear change open slot, the elliptical metal director adopts an artificial surface plasmon polariton elliptical metal director, and notches which are periodically arranged are respectively arranged on two sides of the elliptical metal director.

2. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of claim 1, wherein: the elliptical metal director is formed by connecting half of two ellipses with the same width and different lengths.

3. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of claim 2, wherein: the elliptical metal director comprises a first semi-elliptical part and a second semi-elliptical part, wherein the first semi-elliptical part is connected with the second semi-elliptical part, the first semi-elliptical part is not provided with notches, and two sides of the second semi-elliptical part are respectively provided with notches which are periodically arranged.

4. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of claim 3, wherein: the depth of the gap of the second semi-elliptical part is gradually decreased from the middle part to the two ends.

5. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of claim 3, wherein: the length of the second semi-elliptical part is greater than that of the first semi-elliptical part, and the end part of the first semi-elliptical part is arranged at the linear change open slot.

6. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of any of claims 1-5, wherein: the circular resonant cavity, the first slot line, the second slot line, the linear change open slot and the index gradual change slot are sequentially communicated and arranged, and the width of the first slot line is different from that of the second slot line.

7. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of claim 6, wherein: the width of the second slot line is larger than that of the first slot line, and the width of the linearly-changed open slot is gradually increased from the end close to the second slot line to the end far away from the second slot line.

8. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of any of claims 1-5, wherein: the characteristic impedance formed by the feed structure is 50 omega.

9. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of any of claims 1-5, wherein: the microstrip stub is L-shaped.

10. The artificial surface plasmon based high-gain low-profile Vivaldi antenna of any of claims 1-5, wherein: the feed structure carries out coupling feed on the metal radiation patch, the metal radiation patch is used as a radiator of electromagnetic waves, and the artificial surface plasmon polariton elliptic metal director collects the electromagnetic waves and radiates the electromagnetic waves in an end-fire direction.

Technical Field

The invention relates to a high-gain low-profile Vivaldi antenna based on artificial surface plasmon polaritons, and belongs to the technical field of antennas.

Background

The research on wireless communication, especially for 5G communication, microwave and millimeter wave communication, has increasingly strict requirements on antenna performance. Vivaldi antennas are widely used in many applications such as Ultra Wideband (UWB), radar, 5G communication devices, etc. because they have the advantages of simple structure, light weight, large bandwidth, operating frequency at higher frequencies, and providing stable radiation patterns.

Current wireless devices require wide bandwidth, high data rates, and greater capacity. The Vivaldi antenna is used as a traveling wave end-fire planar antenna and has the advantages of high gain, high efficiency, low return loss and the like. However, the directivity of the conventional Vivaldi antenna is low, and when the Vivaldi antenna is etched on a thick dielectric substrate, the main beam of high frequency is split. In order to solve the above problems, chinese patent application CN202011170766.6 discloses a multi-octave ultra-wideband antenna and a conformal array antenna, which includes a dielectric substrate, a feeding structure, and metal radiation patches attached to the front and back of the dielectric substrate. However, the antenna of the application has a large volume, the gain and the directivity of the antenna are still to be improved, and in addition, the chip resistor is added, so that certain processing difficulty is increased.

Therefore, the research significance of the Vivaldi antenna with high gain and low profile is very large. The above-mentioned problems are problems that should be considered and solved in the design process of the high-gain low-profile Vivaldi antenna.

Disclosure of Invention

The invention aims to provide a high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton, wherein an artificial surface plasmon polariton elliptic metal director is used at an open slot of a metal radiation patch, the director can concentrate energy in an end-fire direction and improve directivity, the gain of the antenna is improved, and the problems that the volume of the antenna is large and the gain and the directivity need to be improved in the prior art are solved.

The technical solution of the invention is as follows:

a high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton comprises a dielectric substrate, a feed structure, a metal radiation patch and an elliptical metal director, wherein the feed structure is arranged on the lower surface of the dielectric substrate and comprises a micro-strip stub line and a circular metal sheet, one end of the micro-strip stub line is connected with the circular metal sheet, and the other end of the micro-strip stub line extends to the side part of the dielectric substrate; the metal radiation patch and the elliptical metal director are respectively arranged on the upper surface of the medium substrate, and the metal radiation patch is respectively provided with a circular resonant cavity, a first slot line, a second slot line, a linear change open slot and an index gradual change slot; the end part of the elliptical metal director is arranged at the linear change open slot, the elliptical metal director adopts an artificial surface plasmon polariton elliptical metal director, and notches which are periodically arranged are respectively arranged on two sides of the elliptical metal director.

Furthermore, the oval metal director is formed by connecting half of two kinds of ovals with the same width and different lengths.

Furthermore, the oval metal director comprises a first semi-oval part and a second semi-oval part, the first semi-oval part is connected with the second semi-oval part, the first semi-oval part is not provided with notches, and two sides of the second semi-oval part are respectively provided with notches which are periodically arranged.

Furthermore, the depth of the notch of the second semi-elliptical part decreases from the middle part to the two ends.

Further, the length of the second semi-elliptical part is larger than that of the first semi-elliptical part, and the end part of the first semi-elliptical part is arranged at the linear change open slot.

Furthermore, the circular resonant cavity, the first slot line, the second slot line, the linear change open slot and the index gradual change slot are sequentially communicated and arranged, and the width of the first slot line is different from that of the second slot line.

Further, the width of the second slot line is larger than that of the first slot line, and the width of the linearly-changed open slot is gradually increased from the end close to the second slot line to the end far from the second slot line.

Further, the characteristic impedance formed by the feed structure is 50 Ω.

Further, the microstrip stub is in an L shape.

Further, the feed structure carries out coupling feed on the metal radiation patch, the metal radiation patch is used as a radiator of electromagnetic waves, and the artificial surface plasmon polariton elliptic metal director collects the electromagnetic waves and radiates the electromagnetic waves in an end-fire direction.

The invention has the beneficial effects that: compared with the prior art, the high-gain low-profile Vivaldi antenna based on the artificial surface plasmon polariton has the advantages that firstly, compared with a common microstrip transmission line, the high-gain low-profile Vivaldi antenna based on the artificial surface plasmon polariton adopts a microstrip-slot line feed structure, and can realize broadband design; secondly, the artificial surface plasmon polariton elliptical metal director can gather electromagnetic waves, and high gain and high directionality of the antenna are realized; compared with the traditional Vivaldi antenna, the director with the periodic notch is introduced at the tail end of the opening of the radiating metal patch, so that high gain of the antenna is guaranteed, and the gain of the antenna is remarkably improved. The high-gain low-profile Vivaldi antenna based on the artificial surface plasmon polaritons has the advantages that after the artificial surface plasmon polariton director is introduced, the directionality is obviously improved, the maximum gain is improved, the low-profile Vivaldi antenna is low in profile, small in size, free of chip resistance and easy to process, and has excellent radiation characteristics of high directionality and high gain.

Drawings

FIG. 1 is a schematic structural diagram of a high-gain low-profile Vivaldi antenna based on artificial surface plasmons according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a front structure of an embodiment of a high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton;

FIG. 3 is a schematic diagram of a back structure of an embodiment of a high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton;

FIG. 4 is a schematic structural diagram of a processed object of the high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton in the embodiment; wherein (a) is a schematic diagram of the front structure of the object, and (b) is a schematic diagram of the back structure of the object;

FIG. 5 is a schematic diagram of simulated and actually measured S parameters of a high-gain low-profile Vivaldi antenna based on artificial surface plasmons according to an embodiment;

FIG. 6 is a simulated and measured gain diagram of an embodiment of an artificial surface plasmon based high-gain low-profile Vivaldi antenna;

FIG. 7 is a simulated and actually measured E-plane directional diagram of the high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton of the embodiment, wherein (a), (b) and (c) are respectively the measured and simulated E-plane directional diagrams of the antenna at frequency points of 7GHz, 9GHz and 11 GHz;

FIG. 8 is a simulated and measured H-plane directional pattern of the high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton of the embodiment, wherein (a), (b), and (c) are measured and simulated H-plane directional patterns of the antenna at frequency points of 7GHz, 9GHz, and 11GHz, respectively;

wherein: 1-a dielectric substrate, 2-a metal radiation patch, 3-a circular resonant cavity, 4-a first slot line, 5-a linear change open slot, 6-an exponential gradient slot, 7-an elliptical metal director, 8-a microstrip stub, 9-a circular metal patch and 10-a second slot line;

71-first semi-elliptical portion, 72-second semi-elliptical portion, 73-notch.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Examples

A high-gain low-profile Vivaldi antenna based on artificial surface plasmon polariton, as shown in figure 1, figure 2 and figure 3, comprises a dielectric substrate 1, a feed structure, a metal radiation patch 2 and an elliptical metal director 7, wherein the feed structure is arranged on the lower surface of the dielectric substrate 1 and comprises a micro-strip stub line 8 and a circular metal sheet, one end of the micro-strip stub line 8 is connected with the circular metal sheet, and the other end of the micro-strip stub line 8 extends to the side part of the dielectric substrate 1; the metal radiation patch 2 and the elliptical metal director 7 are respectively arranged on the upper surface of the medium substrate 1, and the metal radiation patch 2 is respectively provided with a circular resonant cavity 3, a first slot line 4, a second slot line 10, a linear change open slot 5 and an index gradual change slot 6; the end part of the elliptical metal guider 7 is arranged at the linear change open slot 5, the elliptical metal guider 7 adopts an artificial surface plasmon polariton elliptical metal guider 7, and notches 73 which are periodically arranged are respectively arranged at two sides of the elliptical metal guider 7.

Compared with the prior art, the high-gain low-profile Vivaldi antenna based on the artificial surface plasmon polariton has the advantages that firstly, compared with a common microstrip transmission line, the high-gain low-profile Vivaldi antenna based on the artificial surface plasmon polariton adopts a microstrip-slot line feed structure, and can realize broadband design; secondly, the artificial surface plasmon polariton elliptical metal director 7 can gather electromagnetic waves, and high gain and high directionality of the antenna are realized; compared with the traditional Vivaldi antenna, the director of the periodic notch 73 is introduced at the tail end of the opening of the radiating metal patch, so that the high gain of the antenna is ensured, the gain of the antenna is obviously improved, and the antenna has a low section, small volume, no patch resistance and easy processing.

In the embodiment, the elliptical metal director 7 is formed by connecting half of two ellipses with the same width and different lengths. The elliptical metal director 7 comprises a first semi-elliptical part 71 and a second semi-elliptical part 72, wherein the first semi-elliptical part 71 is connected with the second semi-elliptical part 72, the first semi-elliptical part 71 is not provided with notches, notches 73 which are periodically arranged are respectively arranged on two sides of the second semi-elliptical part 72, and the first semi-elliptical part 71 enables electromagnetic energy to be smoothly coupled to the director. The second semi-elliptical portion 72 excites artificial surface plasmons to achieve focused electromagnetic waves to improve antenna directivity and gain.

The depth of the notch 73 of the second semi-elliptical portion 72 decreases from the middle portion to both ends, so that the wave number of the artificial surface plasmon polariton matches the wave number of the free space, and the electromagnetic wave is smoothly radiated into the free space. The length of the second semi-elliptical portion 72 is greater than the length of the first semi-elliptical portion 71, and the end of the first semi-elliptical portion 71 is disposed at the linearly changing open slot 5.

In the embodiment, the circular resonant cavity 3, the first slot line 4, the second slot line 10, the linear variation open slot 5 and the index gradient slot 6 are sequentially communicated, and the widths of the first slot line 4 and the second slot line 10 are different. The arrangement of the circular resonant cavity 3, the first slot line 4, the second slot line 10, the linear change open slot 5 and the index gradual change slot 6 can smoothly couple electromagnetic energy on the microstrip line onto the radiation patch, and more efficient radiation of electromagnetic waves is realized. Moreover, the impedance matching is better due to the different widths of the first slot line 4 and the second slot line 10. The width of the second slot line 10 is greater than the width of the first slot line 4, and the width of the linearly varying open slot 5 increases from the end near the second slot line to the end far from the second slot line.

In the embodiment, the feed structure performs coupling feed on the metal radiation patch 2, the metal radiation patch 2 is used as a radiator of electromagnetic waves, and the artificial surface plasmon elliptic metal director 7 collects the electromagnetic waves and radiates the electromagnetic waves in an end-fire direction. The antenna gain is increased, and the antenna directivity is improved.

In fig. 2, an artificial surface plasmon elliptical metal director 7 having periodic notches 73 is provided at the open end of the metal radiation patch 2. The width of the opening of the metal radiating patch 2 is determined according to the wavelength required by the design. The elliptical metal director 7 having a periodic gap 73 is located at the open end of the metal radiation patch 2 on the upper surface of the dielectric substrate 1, the gap 73 being present at a fixed period value, forming an artificial surface plasmon on which electromagnetic waves propagate at a speed less than vacuum. The cut-off frequency of the artificial surface plasmons containing the notch 73 is greater than the designed highest frequency, i.e., the maximum operating frequency of the antenna.

In fig. 3, the microstrip stub 8 and the circular metal patch 9 are connected to form a feed structure, which couples and feeds the metal radiating patch 2 to enable the antenna to operate. Can realize 50 omega impedance matching and can be connected with an external measuring instrument. The microstrip stub 8 is L-shaped to reduce the reflection coefficient. The circular metal patch 9 and the circular resonant cavity 3 need to satisfy the microstrip-slot line feed structure setting principle, that is, the diameter of the circular resonant cavity 3 should be similar to a quarter of the wavelength of the electromagnetic wave in the slot line, and the diameter of the circular metal patch 9 should also be similar to a quarter of the wavelength of the electromagnetic wave on the microstrip line.

The key parameters in the examples are: the dielectric substrate 1 used was Rogers4003C (relative permittivity 3.55, loss tangent 0.002), 0.508mm thick with a size of 40.6mm 119.4 mm. The remaining parameters are marked on figures 1 and 3 with the values: rs 5mm, ls 1mm 7mm, ls 2mm 4mm, s 1mm 0.2mm, s 2mm 0.6mm, ld 12mm, wd 4.2mm, L2 mm 14.4mm, W2 mm 7.2mm, L3 mm 58.3mm, h 1mm 0.5mm, h 2mm 1mm, h 3mm 1.5mm, h 4mm 2mm, h 5mm 2.5mm, h 6mm 3mm, Rm mm 4.4mm, wm mm 1.2mm, ws 0.6 mm.

Simulation and measurement results of the embodiment, as shown in fig. 5 to 8:

fig. 5 is a simulation and measured S-parameter result. The bandwidth of the S parameter simulation is 5GHz-12GHz (82.3%) which is less than-10 dB, and the bandwidth of the S parameter simulation is 5GHz-12GHz (82.3%) which is less than-10 dB. The bandwidths of the two are basically consistent, and the impedance matching of the antenna is good.

FIG. 6 is a graph of simulated and measured gain, with measured gain of the antenna greater than 5.2dBi and a maximum gain of 13.4dBi over a frequency range of 5GHz-12 GHz; the simulated gain variation range of the antenna is 6dBi-13.6 dBi. The simulated and measured gain errors are mainly due to machining and measurement.

In fig. 7, (a), (b), and (c) are measured and simulated E-plane patterns of the antenna at frequencies of 7GHz, 9GHz, and 11GHz, respectively. In fig. 8, (a), (b), and (c) are measured and simulated H-plane patterns of the antenna at frequencies of 7GHz, 9GHz, and 11GHz, respectively. In the directional diagram at the frequency points, the curve is smooth, the main lobe is obvious, and the directional radiation performance is good. The antenna designed by the invention has excellent radiation characteristics of high directivity and high gain.

The above embodiments are merely illustrative of the technical idea of the present invention, and the technical idea of the present invention is not limited thereto, and any modifications and decorations made on the technical scheme according to the technical idea of the present invention are within the scope of the present invention.