CN206962011U - Novel ultra wide band high-gain anti-pode Vivaldi antenna - Google Patents

Abstract

The utility model discloses a novel ultra-broadband high-gain antipodal Vivaldi antenna, which comprises a metal grounding plate and a metal microstrip feeder line respectively arranged on both sides of a dielectric plate, and the upper ends of the metal grounding plate and the metal microstrip feeder line are respectively about x The fan plate with axial rotation symmetry, the side of the fan plate is composed of the inner index gradient groove line, the outer index gradient groove line, and the semi-ellipse whose two ends are respectively connected to the end of the inner index gradient groove line and the outer index gradient groove line; the metal microstrip feeder The lower end of the metal ground plate is connected to the microstrip line, the lower end of the metal ground plate is connected to the wing plate, and the coaxial joint is fed through the microstrip line and the wing plate. The microstrip-slot line feeding method has the advantages of simple feeding, ultra-wideband, high gain, symmetric pattern, good radiation directionality, and low cross-polarization ratio. It has a simple structure, easy processing, and easy integration. Strong practicability and wide applicability, especially in the fields of mobile antennas, broadband antennas, MIMO antennas and array antennas, etc., have good application prospects.

Description

Novel Ultra Wideband High Gain Antipodal Vivaldi Antenna

technical field

The invention relates to an antenna, in particular to a novel ultra-wideband high-gain antipodal Vivaldi antenna.

Background technique

With the rapid development of communication technology at home and abroad, wireless communication systems put forward higher requirements on important parameters such as transmission rate, system capacity and transmission power. Antenna is an electronic device used to transmit or receive electromagnetic waves. It plays an important role in wireless communication systems. It can realize the mutual conversion between free space electromagnetic field and guided wave system electromagnetic field. It is used in radar systems, satellite navigation and medical equipment and other fields. has been widely used. At present, as a key technology in the field of wireless communication, ultra-wideband antennas have attracted much attention in the research field of wideband wireless communication systems.

As one of the UWB antennas, the Antipodal Vivaldi antenna has also received the attention of many scholars at home and abroad in recent years.

The antipodal Vivaldi antenna is an end-fire traveling wave antenna with a tapered slot line structure, which has good broadband and directional radiation characteristics, and is simple in structure, easy to process, and easy to integrate. Therefore, the antipodal Vivaldi antenna The design of the method has good application prospects in the research fields of broadband antenna, MIMO antenna, integrated antenna and array antenna.

Contents of the invention

In order to solve the deficiencies of the prior art, the object of the present invention is to provide a novel ultra-wideband high-gain antipodal Vivaldi antenna with simple feeding, ultra-wideband, high gain and good radiation directivity.

In order to achieve the above object, the present invention adopts the following technical solutions:

A new ultra-wideband high-gain antipodal Vivaldi antenna, including a metal ground plate and a metal microstrip feeder set on both sides of the dielectric plate,

The upper ends of the metal grounding plate and the metal microstrip feeder are respectively fan plates that are rotationally symmetrical about the x-axis, and the sides of the fan plates are composed of an inner index gradual change groove line, an outer index gradual change groove line, and two ends respectively connected to the inner index The gradient groove line and the semi-ellipse at the end of the outer exponential gradient groove line;

The lower end of the metal microstrip feeder is connected to the microstrip line,

The lower end of the metal ground plate is connected to the wing plate,

The coaxial connector is fed through the microstrip line and the wings.

The edge of the above-mentioned wing plate is composed of a gradient bar wheel connected to parallel double lines at the bottom, and the two sides of the gradient bar wheel are respectively symmetrical to the inner index gradient groove line about the Y axis and the origin;

Wherein, the width of the parallel double lines is T1, and the height is H4; the length of the major axis of the semi-ellipse is 2*T2, and the length of the minor axis is 2*H2.

The aforementioned microstrip line is rectangular, with a width of W and a height of H3+H4.

The starting point of the above inner exponential gradient groove line is end point is Line type is

The starting point of the outer exponential gradient groove line is end point is Line type is

Among them, x _i and y _i are the x coordinates and y coordinates of the inner exponential gradient line respectively, x _o and y _o are the x coordinates and y coordinates of the outer exponential gradient line respectively; W is the width of the microstrip line, is the Y-axis length of the outer index groove line, and H is the height of the outer index gradient groove line H1 is a variable, and H3 is the height of the inner exponential gradient groove.

The inner conductor of the coaxial joint is connected to the microstrip line, and the outer conductor is connected to the fan plate.

The above dielectric board is a rectangular substrate with a width of T1+2*T2, a height of H+H3+H4, and a thickness of thick.

The top of the above-mentioned dielectric board is provided with a trapezoidal substrate, and the two ends of the lower bottom are respectively with The upper bottom width is T, the lower bottom width is T1, the height is H5, and the thickness is thick.

The width W of the above-mentioned microstrip line is 1.4mm, the opening width T1 of the outer index groove line is 23.2mm, the height H of the outer index gradual groove line is 41.0mm, and the height H3 of the inner index gradual groove line is 11.6mm; parallel double lines The width of T1 is 23.2mm, the height H4 of parallel double lines is 8.0mm; the major axis length of the semi-ellipse structure 2*T2 is 2*20.0mm, the minor axis length is 2*H2 is 2*29.4mm, and the internal and external indices The slots are connected. The width of the rectangular substrate is 63.2mm, the height is 60.6mm, and the thickness is 1mm; the height H5 of the isosceles trapezoidal substrate is 30mm, the upper bottom T of the trapezoidal substrate is 10mm, and the lower bottom T1 of the trapezoidal substrate is 23.2mm.

The benefits of the present invention are: a novel ultra-broadband high-gain antipodal Vivaldi antenna of the present invention is a Vivaldi antenna of the microstrip line-slot line feeding mode, and adopts an antipodal structure. It is implemented on a 1mm FR4 substrate, and is mainly composed of three parts: a dielectric board, a metal grounding board, and a metal microstrip feeder. The metal grounding board and the metal microstrip feeder are printed on both sides of the dielectric board.

The gradient balun structure is used to achieve a better transition between the exponentially variable slot line and the parallel double line, which improves the impedance bandwidth of the antenna; the semi-elliptical structure is loaded at the left and right ends of the antenna, which improves the low-frequency standing wave ratio characteristics; in the direction of the antenna axis The trapezoidal substrate is loaded, and the surface current of the antenna is constrained in the direction of the main axis of the antenna, which not only eliminates the offset problem of the peak gain of the antenna, but also improves the gain value of the antenna.

A novel ultra-wideband high-gain antipodal Vivaldi antenna of the present invention has the advantages of simple feeding, ultra-wideband, high gain, symmetrical pattern, good radiation directivity, small gain peak offset angle, low cross-polarization ratio, It has the advantages of high front-to-back ratio, simple structure, easy processing, and easy integration. It has strong practicability and wide applicability, especially in the research fields of mobile antennas, broadband antennas, MIMO antennas, and array antennas. It has a good application prospect.

Description of drawings

Fig. 1 is the front view of structural representation of the present invention;

Fig. 2 is the simulation graph of standing wave ratio of the present invention;

Fig. 3 is the gain simulation graph of the present invention;

Fig. 4 is the measured curve figure of standing wave ratio of the present invention;

Fig. 5 is the measured curve diagram of gain of the present invention;

Fig. 6 is the direction diagram of the present invention at the 2GHz frequency point;

Fig. 7 is the pattern of the present invention at the 14GHz frequency point;

FIG. 8 is a directional diagram of the present invention at a frequency of 22 GHz.

The meanings of the marks in the attached drawings are as follows: 1. Inner index gradient groove line, 2. Outer index gradient groove line, 3. Semi-ellipse, 4. Microstrip line, 5. Gradient bar wheel, 6. Parallel double lines, 7. Medium Plate, 8, trapezoidal base plate, 9, fan plate.

Detailed ways

The present invention will be specifically introduced below in conjunction with the accompanying drawings and specific embodiments.

Embodiments of the novel ultra-broadband high-gain antipodal Vivaldi antenna of the present invention,

Based on the HFSS electromagnetic simulation software (based on the finite element method), the antenna is simulated and optimized to determine the overall size of the antenna;

Based on AutoCAD software, the PCB processing layout of the antenna was drawn, and the actual object was processed; the antenna standing wave ratio was measured with an Agilent E8361-000009 vector network analyzer, and the antenna pattern and gain were measured in a microwave anechoic chamber.

Fig. 1 is the front view of the structure diagram of the present invention.

The novel ultra-broadband high-gain antipodal Vivaldi antenna of the present invention adopts a microstrip line 4-slot line feeding mode, and the slot line is an exponential gradient structure that radiates electromagnetic waves outward and is horn-shaped.

It is mainly composed of a dielectric board 7 , a metal grounding board and a metal microstrip feeder; the metal grounding board and the metal microstrip feeder are printed on both sides of the dielectric board 7 respectively.

The metal microstrip feeder on the front is composed of a fan plate 9 connected to the rectangular microstrip line 4 at the bottom. The end points are respectively the end points of the inner index gradient groove line 1 and the outer index gradient groove line 2.

The metal grounding plate on the back is composed of the fan plate 9 connected to the wing plate at the bottom, and the edge of the wing plate is composed of the gradient bar wheel 5 connected to the parallel double line 6 at the end, wherein the two sides forming the gradient bar wheel 5 are respectively connected to the inner index gradient groove line 1 Symmetric about the Y axis and about the origin.

The fan plate 9 of the back metal ground plate and the fan plate 9 of the front metal microstrip feeder are rotationally symmetrical about the x-axis.

The antenna is fed by a 50 ohm SMA coaxial connector, the inner conductor is connected to the microstrip line 4 , and the outer conductor is connected to the fan board 9 .

In the Cartesian coordinate system shown in Figure 1, the coordinates of the starting point of the outer exponential gradient groove line 2 are The coordinates of the end point are The coordinates of the starting point of inner exponential gradient groove line 1 are The coordinates of the end point are The line types of the inner index gradient groove line 1 and the outer index gradient groove line 2 are expressed by formulas (1) and (2) respectively:

Wherein, x _i and y _i are the x coordinates and y coordinates of the inner index gradient line respectively, x _o and y _o are the x coordinates and y coordinates of the outer index gradient line respectively; W is the width of the microstrip line 4, is the Y-axis length of the outer index groove line, and H is the height of the outer index gradient groove line 2 H3 is the height of the inner exponential gradient groove line 1, and the unit is mm.

The width of the parallel double line 6 is T1, and the height is H4; the length of the major axis of the semi-ellipse 3 is 2*T2, and the length of the minor axis is 2*H2, which are connected with the inner and outer index groove lines.

The substrate plate of the antenna is FR4, the width of the rectangular substrate is T1+2*T2, the height is H+H3+H4, and the thickness is thick; a trapezoidal substrate 8 with an isosceles structure is loaded in the radiation direction of the main axis of the antenna, thereby improving the radiation of the antenna The characteristics and the symmetry of the direction diagram, the upper base of the isosceles trapezoidal substrate 8 is T, the lower base is T1, the height is H5, and the thickness is thick.

Based on the HFSS electromagnetic simulation software, the radiation patch structure, the microstrip feeder structure and the size parameters of the trapezoidal substrate 8 structure of the new antipodal Vivaldi antenna were optimized and designed, and the overall structure of the new antipodal Vivaldi antenna was finally determined. structure.

The width W of the microstrip line 4 is 1.4 mm, the opening width T1 of the outer index groove line is 23.2 mm, the height H of the outer index gradual groove line 2 is 41.0 mm, and the height H3 of the inner index gradual groove line 1 is 11.6 mm; parallel The width of the double line 6 is T1 is 23.2mm, the height H4 of the parallel double line 6 is 8.0mm; the length of the major axis 2*T2 of the semi-ellipse 3 structure is 2*20.0mm, and the length of the minor axis is 2*H2 is 2*29.4 mm, connected with the inner and outer index groove lines. The width of the rectangular substrate is 63.2mm, the height is 60.6mm, and the thickness is 1mm; the height H5 of the isosceles trapezoidal substrate 8 is 30mm, the upper bottom T of the trapezoidal substrate 8 is 10mm, and the lower bottom T1 of the trapezoidal substrate 8 is 23.2mm.

Fig. 2 is the simulation graph of the standing wave ratio of this patent, the antenna has good standing wave characteristics in the frequency band of 1.5-22GHz, and the average standing wave ratio is less than 3; in the range of 1.6-22GHz, the standing wave ratio is less than 2.

Fig. 3 is a gain simulation curve diagram of this patent, it can be seen from the figure that the gain in the low frequency band is relatively low, and the gain in the high frequency band is relatively high. In the frequency range of 2-22GHz, the highest gain of the antenna is 10.8dB, and the lowest gain is 1.2dB.

Fig. 4 is the actual measurement curve of the standing wave ratio of this patent. The standing wave ratio of the antenna is measured by using the Aglient E8361-000009 vector network analyzer, and the test result of the standing wave ratio of 1.5-22GHz shown in Fig. 4 is obtained. It can be seen from the actual measurement results that the VWR of the new ultra-wideband Vivaldi antenna is less than 2 in the frequency range of 1.6-22GHz, and the octave bandwidth is 13.75. Combining the simulation results of the standing wave ratio in Figure 2, it can be seen that the simulation results of the standing wave ratio at low frequencies are basically consistent with the measured results, while the measured results of the standing wave ratio above 10 GHz are inferior to the simulation results. This is due to processing errors and high SMA connectors. due to frequency loss. However, it can be seen from the variation trend of the VSWR measurement results at high frequencies that the bandwidth of the antenna is still scalable in the high frequency band above 22 GHz.

Figure 5 is the measured gain curve of this patent. The gain of the antenna was measured in a microwave anechoic room. In the frequency range of 2-22 GHz, the measured gain value was 1.5-11.1 dB, and at the 14 GHz frequency point, the gain reached the highest value of 11.1 dB. . Because the high-frequency loss of the dielectric substrate and the SMA connector is large, the measured performance of the antenna in the high-frequency band gain is slightly lower than the simulation result, but the change trend of the two is basically consistent.

Figure 6-8 is the E-plane (xoy plane) pattern of this patent at three frequency points of 2GHz, 14GHz and 22GHz, where the solid line is the actual measurement result of the pattern, and the dotted line is the simulation result of the pattern. It can be clearly seen that the measured results of the antenna pattern are basically consistent with the simulation results, and the antenna has good symmetry and directivity.

As can be seen from the above, the actual measurement results and the simulation results of the embodiment of the novel ultra-wideband high-gain anti-Vivaldi antenna of the present invention are basically consistent, and the impedance of the novel ultra-wide-band high-gain anti-Vivaldi antenna with a standing wave ratio less than 2 The bandwidth is 1.6-22GHz, the octave bandwidth is 13.75, and the maximum gain within the impedance bandwidth is 11.1dB.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the above-mentioned embodiments do not limit the present invention in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (8)

1. Novel ultra wide band high-gain anti-pode Vivaldi antenna, it is characterised in that including being separately positioned on dielectric-slab two sides Metal ground plate and metal micro-strip feeder line,

Fan plate of the upper end of the metal ground plate and metal micro-strip feeder line respectively on x-axis rotational symmetry, the fan plate Side connect the interior exponential fade line of rabbet joint and outer exponential fade groove respectively by the interior exponential fade line of rabbet joint, the outer exponential fade line of rabbet joint and both ends The semiellipse of line end is formed；

The bottom of the metal micro-strip feeder line connects microstrip line,

The bottom of the metal ground plate connects wing plate,

Coaxial fitting is fed by microstrip line and wing plate.

2. Novel ultra wide band high-gain anti-pode Vivaldi antenna according to claim 1, it is characterised in that the wing plate Side the gradual change bar wheel of parallel wire connect by bottom form, the both sides of the gradual change bar wheel respectively with the interior exponential fade line of rabbet joint on Y-axis is symmetrical and origin symmetry；

Wherein, the width of parallel wire is T1, is highly H4；The long axis length of semiellipse is 2*T2, minor axis length 2*H2.

3. Novel ultra wide band high-gain anti-pode Vivaldi antenna according to claim 1, it is characterised in that the micro-strip Line is rectangle, a width of W, a height of H3+H4.

4. Novel ultra wide band high-gain anti-pode Vivaldi antenna according to claim 1, it is characterised in that the interior finger Number tapered slots starting point beTerminal isLine style is

The starting point of the outer exponential fade line of rabbet joint isTerminal isLine style is

Wherein, x_iAnd y_iThe x coordinate and y-coordinate of respectively interior exposure, x_oAnd y_oThe x coordinate of respectively outer exposure And y-coordinate；W is the width of microstrip line,For the Y-axis length of the outer index line of rabbet joint, H is the height of the outer exponential fade line of rabbet jointH1 is variable, and H3 is the height of the interior exponential fade line of rabbet joint.

5. Novel ultra wide band high-gain anti-pode Vivaldi antenna according to claim 1, it is characterised in that described coaxial The inner wire of joint connects microstrip line, and outer conductor connects fan plate.

6. Novel ultra wide band high-gain anti-pode Vivaldi antenna according to claim 1, it is characterised in that the medium Plate is rectangular substrate, width T1+2*T2, is highly H+H3+H4, thickness thick.

7. Novel ultra wide band high-gain anti-pode Vivaldi antenna according to claim 1, it is characterised in that the medium The top of plate is provided with trapezoidal substrate, and bottom two-end-point is respectivelyWithUpper bottom width is T, and go to the bottom a width of T1, Highly it is H5, thickness thick.

8. according to any described Novel ultra wide band high-gain anti-pode Vivaldi antennas of claim 1-7, it is characterised in that institute The width W for stating microstrip line is 1.4mm, and the A/F T1 of the outer index line of rabbet joint is 23.2mm, and the height H of the outer exponential fade line of rabbet joint is 41.0mm, the height H3 of the interior exponential fade line of rabbet joint is 11.6mm；The width of parallel wire is that T1 is 23.2mm, the height of parallel wire Degree H4 is 8.0mm；The long axis length 2*T2 of semiellipse structure is 2*20.0mm, and minor axis length is that 2*H2 is 2*29.4mm, and interior The outer index line of rabbet joint is connected；The width of rectangular substrate is 63.2mm, is highly 60.6mm, thickness 1mm；The height of isosceles trapezoid substrate Degree H5 is 30mm, and the upper bottom T of trapezoidal substrate is 10mm, and the bottom T1 of trapezoidal substrate is 23.2mm.