CN115441173A - Opposite extension Vivaldi antenna and design method - Google Patents

Abstract

The utility model provides a butt-rubbing Vivaldi antenna and a design method thereof, comprising a dielectric substrate, a dielectric substrate and a dielectric substrate, wherein the dielectric substrate comprises an arc-shaped dielectric substrate and a rectangular dielectric substrate, and the arc-shaped dielectric substrate is tightly connected with the rectangular dielectric substrate; the radiation patches are respectively positioned on the top layer and the bottom layer of the dielectric substrate; the grounding structure is positioned on the top layer of the dielectric substrate; the feeder line is positioned at the bottom layer of the dielectric substrate; loading a fan-shaped expanding structure at the opening of the radiation patch, wherein the fan-shaped expanding structure is symmetrical about a central axis in the vertical direction of the antenna; loading a plurality of fan-shaped directors on the two layers of surfaces of the medium substrate, wherein the fan-shaped radiuses of the fan-shaped directors are the same, the fan-shaped radians are the same, and the intervals between the adjacent fan-shaped directors are the same; effectively expanding the aperture of the antenna, enhancing the gain of the antenna and simultaneously not influencing the loss of the antenna.

Description

Opposite extension Vivaldi antenna and design method

Technical Field

The disclosure relates to the technical field of short-distance detection small-sized antenna design, in particular to a pair-extension Vivaldi antenna and a design method.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

Ultra-wideband wireless communication technology has begun to be investigated for applications such as detection, imaging and positioning due to its high pulse integration, fast communication speed and low cost. A typical ultra-wideband device generally includes an ultra-wideband signal generating and storing device, a radio frequency front end and a radio frequency terminal portion, and the required devices are simple and inexpensive. The radio frequency front end of the ultra-wideband terminal equipment generally needs ultra-wideband antenna matching, so the performance of the ultra-wideband antenna indirectly affects the function and efficiency of the ultra-wideband terminal equipment. Generally, an ultra-wideband antenna is classified into an omni-directional antenna and a directional antenna, wherein the directional antenna has a fixed direction and can emit energy toward a desired detection direction, so as to achieve ideal experimental results. Among the directional antennas, vivaldi antennas are widely used due to their low profile, low cross polarization, compact structure, etc. Vivaldi antennas were first proposed by Gibson in 1978. Later in 1988, based on the antenna proposed by Gibson, gait designed a modified Vivaldi antenna, also the earliest counterpropagate Vivaldi antenna. Compared with the original Vivaldi antenna, the radiation patches of the extension Vivaldi antenna are arranged on two sides of the antenna substrate, so that the feeding problem of the antenna can be solved, and the feeding efficiency is improved to a certain extent.

However, the original Vivaldi antenna still has a large improvement space in performance, especially in gain and directivity. The existing methods also improve gain and direction, but destroy the loss characteristics of the antenna.

Disclosure of Invention

In order to solve the above problems, the present disclosure provides an opposite extension Vivaldi antenna and a design method thereof, which can enlarge the aperture of the antenna, enhance the gain of the antenna, further guide the radiation beam of the antenna, and enhance the directivity and increase the gain of the antenna on the basis of ensuring the loss characteristic of the opposite extension Vivaldi antenna.

According to some embodiments, the following technical scheme is adopted in the disclosure:

a antipodal Vivaldi antenna, comprising:

the dielectric substrate comprises an arc-shaped dielectric substrate and a rectangular dielectric substrate, and the arc-shaped dielectric substrate is tightly connected with the rectangular dielectric substrate;

the radiation patches are respectively positioned on the top layer and the bottom layer of the dielectric substrate;

the grounding structure is positioned on the top layer of the dielectric substrate;

and the feed line is positioned at the bottom layer of the dielectric substrate.

Furthermore, the circular arc-shaped dielectric substrate and the rectangular dielectric substrate are made of the same material and have the same thickness, and the length of the rectangular dielectric substrate is twice the radius of the circular arc-shaped dielectric substrate.

Furthermore, the edge of the single patch of the radiation patch is enclosed by an outer exponential line, an inner exponential line and a circular arc line.

Furthermore, the slope of the outer index line is twice that of the inner index line, the abscissa of the outer index line is the same as that of the inner index line, and the end points are located on the arc lines forming the edge of the radiation patch.

Further, the circle center of the arc line is the same as that of the arc-shaped medium substrate, and the radius of the arc line is smaller than that of the arc line medium substrate.

Furthermore, the grounding structure is formed by closely connecting and combining an exponential type grounding structure and a rectangular grounding structure, and the length of the rectangular part of the rectangular grounding structure is the same as that of the rectangular dielectric substrate.

Furthermore, the planar shape of the feeder line is rectangular, the width of the feeder line is equal to the distance between the starting points of the two exponential lines at the edge of the radiation patch, a fan-shaped expanding structure is loaded at the opening of the radiation patch, and the fan-shaped expanding structure is symmetrical about the central axis in the vertical direction of the antenna.

Furthermore, a plurality of fan-shaped directors are loaded on the two-layer surface of the medium substrate, the fan-shaped radiuses of the fan-shaped directors are the same, the fan-shaped radians are the same, and the intervals between the adjacent fan-shaped directors are the same.

According to some embodiments, the following technical scheme is adopted in the disclosure:

a method of designing an extension Vivaldi antenna, comprising:

drawing the medium substrate, wherein the drawing of the circular arc medium substrate and the drawing of the rectangular medium substrate are included;

drawing the radiation patch, including drawing the exponential line edge of the patch and drawing the circular arc edge;

drawing a grounding structure for top-layer radiation patch balanced feed;

the feed line is designed for transferring energy to the radiating patch.

Further, drawing a fan-shaped expanding structure loaded at the opening of the radiation patch, wherein the drawing comprises the design of the radius and the radian of the fan-shaped expanding structure;

and drawing the sector directors loaded on the two layers of surfaces of the dielectric substrate, wherein the sector directors comprise the radius and radian of a single sector director and the distribution design of a plurality of directors, and are used for guiding the radiation beams of the antenna at the opening.

Compared with the prior art, the beneficial effect of this disclosure is:

compared with a conventional single rectangular structure, the medium substrate for the extension Vivaldi antenna structure not only saves materials, but also has the advantages of miniaturization and simple structure;

according to the antenna, the fan-shaped expanding structure which is made of the same material as the dielectric substrate and has the same thickness with the dielectric substrate is additionally arranged at the opening of the radiation patch, so that the advantages that the aperture of the antenna is effectively expanded, the gain of the antenna is enhanced, and meanwhile, the loss of the antenna is not influenced are achieved;

the antenna disclosed by the invention is additionally provided with a plurality of fan-shaped directors which have the same size and are equally spaced along the central axis direction of radio frequency on the two sides of the dielectric substrate, so that the radiation beams of radio frequency signals are guided, and the stability of the directional radiation of the antenna is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to be construed as limiting the disclosure.

Fig. 1 is a front view of an original versus-extended Vivaldi antenna provided by the present disclosure;

fig. 2 is a back view of an original antipodal Vivaldi antenna provided by the present disclosure;

fig. 3 is a front view of a diversity Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 4 is a front view of a pair-wise Vivaldi antenna loaded with a sector extension structure and a plurality of sector directors in an embodiment provided by the present disclosure;

fig. 5 is a diagram S11 of an original versus-extended Vivaldi antenna provided by the present disclosure;

fig. 6 is a diagram of S11 for a diversity Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 7 is a diagram S11 of an opposite-topology Vivaldi antenna loaded with a sector extension structure and multiple sector directors designed in accordance with the present disclosure;

FIG. 8 is a plot of standing wave ratios for an original versus extended Vivaldi antenna provided by the present disclosure;

fig. 9 is a standing wave ratio diagram for extended Vivaldi antennas with sector extension structures loaded in an embodiment provided by the present disclosure;

fig. 10 is a standing wave ratio diagram for an opposite extension Vivaldi antenna with a sector extension structure and multiple sector directors loaded in an embodiment provided by the present disclosure;

fig. 11 is a gain diagram of an original para-extension Vivaldi antenna provided by the present disclosure;

fig. 12 is a gain diagram for a diversity Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 13 is a gain diagram for a twisted Vivaldi antenna loaded with a sector extension structure and multiple sector directors in an embodiment provided by the present disclosure;

FIG. 14 is a vertical pattern at 3GHz for the original twisted-pair Vivaldi antenna provided by the present disclosure;

fig. 15 is a vertical pattern at 3GHz for a twisted Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 16 is a vertical pattern at 3GHz for an opposite extension Vivaldi antenna with a sector extension structure and multiple sector directors loaded in an embodiment provided by the present disclosure;

FIG. 17 is a vertical pattern at 5GHz for the original twisted-pair Vivaldi antenna provided by the present disclosure;

FIG. 18 is a vertical pattern at 5GHz for a twisted pair Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 19 is a vertical pattern at 5GHz for a twisted Vivaldi antenna loaded with a sector extension structure and multiple sector directors in an embodiment provided by the present disclosure;

FIG. 20 is a vertical pattern at 7GHz for the original twisted-pair Vivaldi antenna provided by the present disclosure;

fig. 21 is a vertical pattern at 7GHz for a twisted pair Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 22 is a vertical pattern at 7GHz for a twisted pair Vivaldi antenna loaded with a sector extension structure and multiple sector directors in an embodiment provided by the present disclosure;

fig. 23 is the vertical pattern at 9GHz for the original antipodal Vivaldi antenna provided by the present disclosure;

fig. 24 is a vertical pattern at 9GHz for a twisted Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 25 is a vertical pattern at 9GHz for an opposite extension Vivaldi antenna with a sector extension structure and multiple sector directors loaded in an embodiment provided by the present disclosure;

fig. 26 is the horizontal pattern at 3GHz for the original antipodal Vivaldi antenna provided by the present disclosure;

fig. 27 is a horizontal pattern at 3GHz for a twisted pair Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 28 is a horizontal pattern at 3GHz for a butt-extension Vivaldi antenna with a sector extension structure and multiple sector directors loaded in an embodiment provided by the present disclosure;

fig. 29 is a horizontal pattern at 5GHz for the original diagonal Vivaldi antenna provided by the present disclosure;

FIG. 30 is a horizontal pattern at 5GHz for a twisted pair Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 31 is a horizontal pattern at 5GHz for a butt-extension Vivaldi antenna with a sector extension structure and multiple sector directors loaded in an embodiment provided by the present disclosure;

fig. 32 is a horizontal pattern at 7GHz for the original antipodal Vivaldi antenna provided by the present disclosure;

FIG. 33 is a horizontal pattern at 7GHz for a twisted pair Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 34 is a horizontal pattern at 7GHz for a butt-extension Vivaldi antenna with a sector extension structure and multiple sector directors loaded in an embodiment provided by the present disclosure;

FIG. 35 is the horizontal pattern at 9GHz for the original pairwise Vivaldi antenna provided by the present disclosure;

fig. 36 is a horizontal pattern at 9GHz for a twisted Vivaldi antenna loaded with a sector extension structure in an embodiment provided by the present disclosure;

fig. 37 is a horizontal pattern for a twisted Vivaldi antenna 9GHz loaded with a sector extension structure and multiple sector directors in an embodiment provided by the present disclosure.

The specific implementation mode is as follows:

the present disclosure is further illustrated by the following examples in conjunction with the accompanying drawings.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Example 1

In an embodiment of the present disclosure, a opposite topology Vivaldi antenna is provided, as shown in fig. 1, including a dielectric substrate, including an arc-shaped dielectric substrate 1 and a rectangular dielectric substrate 2, where the arc-shaped dielectric substrate 1 is tightly connected to the rectangular dielectric substrate 2; the circular arc-shaped dielectric substrate and the rectangular dielectric substrate are made of the same material and have the same thickness, and the length of the rectangular dielectric substrate is twice the radius of the circular arc-shaped dielectric substrate.

The radiation patches are respectively positioned on the top layer and the bottom layer of the dielectric substrate; the radiation patch is divided into two parts, which are respectively positioned on the top layer and the bottom layer of the dielectric substrate.

The grounding structure is positioned on the top layer of the dielectric substrate;

and the feeder line is positioned at the bottom layer of the dielectric substrate.

Specifically, the main outline edge of the radiation patch comprises two exponential lines and an arc line, the top radiation patch is connected with the grounding structure, and the bottom radiation patch is connected with the feeder line; the edge of a single patch of the radiating patch is enclosed by an outer exponential line, an inner exponential line and a circular arc line. The slope of the outer index line is twice that of the inner index line, the abscissa of the outer index line is the same as that of the inner index line, and the end points are located on the arc lines forming the edges of the radiation patches. The circular arc line is the same as the circular arc center of the circular arc-shaped dielectric substrate, and the radius of the circular arc line is smaller than that of the circular arc line dielectric substrate.

The grounding structure is formed by tightly connecting and combining an exponential type grounding structure and a rectangular grounding structure, and the length of the rectangular part of the rectangular grounding structure is the same as that of the rectangular dielectric substrate. The main outline of the exponential structure is two exponential lines, and the distance between the end points of the two exponential lines of the grounding structure is equal to the distance between the starting points of the two exponential lines of the radiation patch.

The planar shape of the feeder line is rectangular, the width of the feeder line is equal to the distance between the starting points of the two exponential lines at the edge of the radiation patch, and a fan-shaped expanding structure is loaded at the opening of the radiation patch so as to increase the aperture of the antenna and enhance the gain of the antenna. The fan-shaped expanding structure is symmetrical about a central axis in the vertical direction of the antenna. And a plurality of fan-shaped directors are loaded on the two layers of surfaces of the dielectric substrate to guide the radiation beams of the antenna and improve the directional radiation performance of the antenna. The radians of the fan-shaped directors are consistent, the radiuses of the fan-shaped directors are consistent, namely the fan-shaped radiuses of the fan-shaped directors are the same, the fan-shaped radians of the fan-shaped directors are the same, and the distances between the adjacent fan-shaped directors are the same.

As an example, the top radiating patch is symmetrical to the bottom radiating patch about the plane z = -0.5 × h, h is the thickness of the substrate. The gradient rates of the two exponential lines of the single-layer radiation patch of the dielectric substrate are different.

As an embodiment, the length of the rectangular substrate is the same as the diameter of the circular arc substrate.

The width of the rectangular substrate is slightly larger than that of the rectangular grounding structure.

As an embodiment, the feeder line plane shape is a rectangle. The width of the feeder line is the same as the distance between the starting points of the two exponential lines constituting the patch.

As an example, the width of the feed line is the same as the distance from the start of the two exponential lines that make up the patch.

As an example, the radius of the circular arc-shaped edge of the radiation patch is slightly smaller than the radius of the circular arc-shaped substrate.

As an embodiment, the fan-shaped expanding structure is in close connection with the substrate in a thickness consistent with the substrate. The width of a longitudinal opening of the fan-shaped expanding structure is the same as the diameter of the circular arc-shaped substrate. The fan-shaped expanding structure is made of the same material as the substrate, and the fan-shaped expanding structure and the substrate are made of FR-4 materials. The fan-shaped extension is symmetrical with respect to a line y = r, r being the radius of the circular arc shaped substrate. The fan-shaped circle of the fan-shaped expanding structure is not concentric with the circular arc edge of the patch and the circle center of the circular arc substrate.

In one embodiment, the number of the sector directors for loading the substrate in a single layer is multiple. The number of the fan-shaped directors loaded on the two layers of the substrate is the same. The substrate two-layer loaded single fan director is symmetric about a line y = r, r being the radius of the circular arc shaped substrate. The fan-shaped directors are of uniform size.

The dimensions of the fan-shaped directors include the radius of the fan-shaped of a single fan-shaped director, the arc of the fan-shaped, and the spacing between adjacent fan-shaped directors.

The directors of the top substrate layer are symmetrical to the directors of the bottom substrate layer about a plane z = -0.5 x h, h being the thickness of the substrate.

The material of the single fan-shaped director is consistent with the material of the patch, the grounding structure and the feeder line, and all are ideal electric conductors.

Example 2

An embodiment of the present disclosure provides a design method for a extension Vivaldi antenna, including:

drawing the medium substrate, wherein the drawing of the circular arc medium substrate and the drawing of the rectangular medium substrate are included;

drawing the radiation patch, including drawing the exponential line edge of the patch and drawing the circular arc edge;

drawing a grounding structure for top-layer radiation patch balanced feed;

the feed line is designed for transferring energy to the radiating patch.

Further, drawing a fan-shaped expanding structure loaded at the opening of the radiation patch, wherein the drawing comprises the design of the radius and the radian of the fan-shaped expanding structure;

and drawing the fan-shaped directors loaded on the two layers of surfaces of the dielectric substrate, wherein the fan-shaped directors comprise the radius and radian of a single fan-shaped director and the design of distribution of a plurality of directors, and are used for guiding the radiation beams of the antenna at the opening.

As an example, the specific process of mapping the diversity Vivaldi antennas is as follows:

the dielectric substrate for the extension Vivaldi antenna is drawn as shown in fig. 1. Firstly, drawing a circular arc-shaped medium substrate 1. As shown in the formula (1), the radius R of the circular arc-shaped dielectric substrate 1 is limited by the selection of the frequency, and in this embodiment, the frequency f _L Is the lowest operating frequency. In this embodiment, the radius R of the circular arc-shaped dielectric substrate 1 is 50mm. This dimension enables the antenna to operate at frequencies of 3GHz and above 3 GHz. In order to meet the miniaturization characteristic, the thickness of the circular arc-shaped dielectric substrate 1 is 0.8mm. On the basis of the circular arc-shaped dielectric substrate 1, a rectangular dielectric substrate 2 is drawn. The length of the rectangular dielectric substrate 2 is twice the radius of the circular arc dielectric substrate 1. In the present embodiment, the width of the rectangular dielectric substrate 2 is selected to be 20mm, and is closely connected with the circular arc-shaped dielectric substrate 1. The thickness of the rectangular dielectric substrate 2 is 0.8mm, and the feeding loss of the whole substrate is not too large.

R＝0.5*sqrt(2/ε _r +1))/f _L (1)

The patch is drawn on the top layer of the dielectric substrate 1. The inner exponential line 3 of the patch is drawn first. The inner exponential line 3 is determined by equation (2), where b _i Is the gradual change rate of the inner exponential line 3, determines the degree of inclination of the exponential line. In this embodiment, b is 0.05.a is _i And c _i Are two constants, determined by equation (3) and equation (4), respectively, where (x) ₁ ,y ₁ ) And (x) ₂ ,y ₂ ) Respectively, the start point coordinates and the end point coordinates of the index line. In this embodiment, the key to the design is to (x) ₂ ,y ₂ ) And (4) selecting. The coordinates of the start point of the inner exponential line 3 are set to (-20, -1). End abscissa x of inner exponential line 3 ₂ And ordinate y ₂ Determined by formula (5) and formula (6), respectively, r is the radius of the patch arc line 5, deg ₁ Is the sum (x) of the circle centers of the patch arc lines 5 ₂ ,y ₂ ) The included angle between the connecting line and the central axis of the antenna. In this embodiment, the radius of the patch arc line 5 is 50mm,the center of the circle is set as the origin (0, 0) of the coordinate system and the included angle deg ₁ Set to 20 degrees.

y _i ＝a _i *exp(b _i *x)+c _i (2)

a _i ＝(y ₂ -y ₁ )/(exp(b*x ₂ )-exp(b*x ₁ )) (3)

c _i ＝(y _1* exp(b _i *x ₂ )-y _2* exp(b ₁ *x ₁ ))/(exp(b _i *x ₂ )-exp(b _i *x ₁ )) (4)

x ₂ ＝x _c +r*cos(deg ₁ *pi/180) (5)

y ₂ ＝y _c +r*sin(deg ₁ *pi/180) (6)

Further, x ₂ Determined as 45.11,y ₂ The determination was 16.42. According to formula (3) and formula (4), a _i Was determined to be 1.89,c _i Was determined to be-1.69. Inner exponential line 3 equation of y =1.89 × e ^(0.05*x) -16.9。

The outer index line 4 of the patch is drawn. The outer exponential line 4 is determined by equation (7), b _o Is the gradual change of the outer exponential line 4. In this embodiment, b _o Is 0.1.a is a _o And c _o Are two constants, determined by equations (8) and (9). (x) ₃ ,y ₃ ) And (x) ₄ ,y ₄ ) Are the start and end points of the outer exponential line 4. To ensure symmetry of the overall structure of the antenna, x ₃ Value and x ₁ Same as-20,y ₃ The value is 0.1. End abscissa x of outer index line 4 ₄ And ordinate y ₄ Determined by the equations (10) and (11), where deg ₂ Is the sum (x) of the circle centers of the patch arc lines 5 ₂ ,y ₂ ) The included angle between the connecting line and the central axis of the antenna is more than deg ₁ . In this example, deg ₂ Set to 70 degrees.

y _o ＝a _o *exp(b _o *x)+c _o (7)

a _o ＝(y ₄ -y ₃ )/(exp(b _o *x ₄ )-exp(b*x ₃ )) (8)

c _o ＝(y _3* exp(b _o *x ₄ )-y ₄ *exp(b _o *x ₃ ))/(exp(b _o* x ₄ )-exp(b _o *x ₃ )) (9)

x ₄ ＝x _c +r*cos(deg ₂ *pi/180) (10)

y ₄ ＝y _c +r*sin(deg ₂ *pi/180) (11)

Further, x ₄ Determined as 16.4,y ₄ Was determined to be 45.1. According to formula (8) and formula (9), a _o Was determined to be 8.77,c _o Was determined to be-0.68. Inner exponential line 3 equation of y =8.77 × e ^(0.1*x) -0.68。

Further, according to r, deg ₁ And deg ₂ And drawing the circular arc line 5 at the edge of the patch.

Further, the patches on the bottom layer of the dielectric substrate 1 are drawn by sequentially performing symmetric transformation with y =0 (central axis of the antenna) and z = -0.5 × h.

And drawing the grounding structure. The first line plots the exponential portion 6 of the ground structure. The exponential line 6 of the ground structure is determined by equation (12). i is the slope of the index line 6, and in this embodiment, i takes on a value of-0.4. g and j are two constants determined by equation (13) and equation (14), respectively. (x) ₅ ,y ₅ ) And (x) ₆ ,y ₆ ) The start and end points of the exponential grounding structure 6. In this embodiment, y6 has the same value as y3, and x6 has a value of-30. The value of x5 is-45, the distance from y5 to the central axis of the antenna is the radius R of the circular arc-shaped substrate 1, and the value of the distance in a coordinate system is-50.

y _g ＝g*exp(i*x)+j(12)

g＝(y ₆ -y ₅ )/(exp(i*x ₆ )-exp(i*x ₅ )) (13)

j＝(y _5* exp(i*x ₆ )-y ₆ *exp(i*x ₅ ))/(exp(i _* x ₆ )-exp(i*x ₅ )) (14)

Further, g was determined to be 7.48 × 10 according to equations (13) and (14) ^-7 And f is determined to be-0.18. Finger of ground structure according to equation (12)Equation for the number line 6 is y =7.48 × 10 ^-7 *e ^(-0.4*x) -0.18。

Further, the lower half of the ground structure is plotted as an exponential line by performing a symmetric transformation with the straight line y = 0.

Further, a grounded rectangular structure 7 is drawn. The length of the rectangular grounding structure 7 is the same as that of the rectangular dielectric substrate 2, and is twice of the radius R of the circular arc-shaped dielectric substrate. In the present embodiment, in order to secure the overall connectivity of the ground structure, the width of the rectangular portion 7 of the ground structure is set to 5mm. One end of the ground rectangular portion 7 is closely connected to the ground index line 6.

Further, referring to fig. 2, the feeder line 8 at the bottom of the substrate is drawn. In the present embodiment, the planar shape of the power feeding line 8 is rectangular. The width of the feed line 8 is equal to the ordinate y of the origin of the off-chip index line 4 ₃ And the ordinate y of the start of the in-patch exponential line 3 ₁ The difference of (a). The length of the feeder line 8 is equal to the abscissa x of the origin of the exponential line 3 in the patch ₁ (or the origin of the outer index line 4. Abscissa x ₃ ) Distance to the edge of the rectangular dielectric substrate 2.

As an implementation manner, on the basis of the original opposite-extension Vivaldi antenna, the opposite-extension Vivaldi antenna loaded with the sector extension structure is designed.

Referring to fig. 3, a sector extension 9 to the Vivaldi antenna is designed. In this embodiment, the sector expanding structure 9 is used to expand the radiation aperture of the antenna at the opening of the patch, enhance the radiation energy of the antenna at the opening, and improve the gain of the antenna in the whole frequency band. The radius of the fan extension 9 is determined by the formula (15), (x) ₇ ,y ₇ ) Is the sector circle center of the sector expanding structure 9. In order to ensure the symmetry of the sector-shaped expanding structure 1 about the central axis of the antenna and ensure the same improvement effect on the left and right spherical beams of the antenna in the horizontal direction, the longitudinal coordinate y of the circle center of the sector-shaped expanding structure 9 is arranged in a rectangular coordinate system ₇ 0 is selected. In the present embodiment, the abscissa x of the circle center of the sector-shaped extension structure 9 ₇ And was selected to be 40. (x) ₈ ,y ₈ ) Is the sector starting point of the sector expanding structure. Wherein, the fanOrdinate y of the shape origin ₈ The width of the fan-shaped widening 9 is determined. For the sector expanding structure 9, if the width is too narrow, the expanded aperture of the antenna may increase the gain, but for the beam, especially for the beam at the high frequency, there is a bad influence on the directivity; if the width is too large, the half-power beam width of the antenna with the widened aperture is increased, and the directivity of the antenna is damaged. Therefore, in order to protect the radiation directivity of the antenna and to enlarge the antenna gain, the sector start ordinate y of the sector widening structure 9 ₈ Set to 50. Sector starting point abscissa x for sector extension 9 ₈ Which determines the length of the fan-shaped extension 9. If the length of the sector-shaped extension structure 9 is too long, then excessive losses will be incurred when feeding the antenna, especially at the top end of the substrate 1; if it is too short, the gain boosting effect of the antenna will not be significant. Therefore, in order to avoid unnecessary loss and at the same time to raise the antenna gain, in the present embodiment, the length of the sector extension structure 9 is set to 25mm.

rs＝sqrt((x ₈ -x ₇ )*(x ₈ -x ₇ )+(y ₈ -y ₇ )*(y ₈ -y ₇ )) (15)

deg _r ＝2*arctan((y ₈ -y ₇ )/(x ₈ -x ₇ )) (16)

Further, according to (x) ₇ ,y ₇ ) And (x) ₈ ,y ₈ ) The radius length of the fan-shaped expansion structure is determined using equation (15). Since it is necessary to ensure energy balance on both sides of the central axis of the antenna, the sector widening structure 9 is symmetrical with respect to the central axis of the antenna, and the sector angle can be determined by equation (16). According to the sector angle, the sector center and the sector radius of the sector structure 9, the sector line of the sector expansion structure 9 can be drawn.

Further, according to the sector line starting point (x) of the sector-shaped expanding structure 9 ₈ ,y ₈ ) And the end point (x) of the intra-patch exponential line 3 ₂ ,y ₂ ) The straight line portion on the upper side of the central axis of the antenna of the fan-shaped extension structure 9 is drawn. And drawing the lower side straight line of the fan-shaped expanding structure 9 by axial-axial symmetrical transformation of the axis in the antenna. To be made intoThe radiation beam of the antenna is not affected, and in this embodiment, the thickness of the fan-shaped expanding structure 9 is the same as that of the plate-making material, the arc-shaped substrate 1 and the rectangular substrate 2.

On the basis of loading the sector expansion structure 9, a plurality of sector directors 10 are loaded in an exponential open slot of the antenna. The sector director 10 can guide the radiation beam of the antenna at the opening of the antenna, weaken the level intensity of the side lobe of the radiation beam, weaken the half-power angular width of the antenna at the same time, and improve the directional radiation performance of the antenna.

Referring to fig. 4, the first fan-shaped director 10 is first designed. The radius of the fan director 10 is determined by equation (17), (x) ₉ ,y ₉ ) Is the center of the sector director 10. In order to ensure that the guiding effect of the director 10 on the beams on the upper side and the lower side of the central axis of the antenna is consistent and the symmetry of the original radiation beam is not damaged, in a rectangular coordinate system, the longitudinal coordinate y of the center of the sector of the first sector director 10 is ₉ Is determined to be 0. Circle center abscissa x of fan-shaped director ₉ Set to 40. (x) ₁₀ ,y ₁₀ ) Is the starting point of the sector line of the sector director if the point is away from the center of the sector (x) ₁₀ ,y ₁₀ ) Too far, this results in an excessively large radius of the sector and an overall oversized deflector, which may cause unexpected losses at the opening. In order not to destroy other characteristics while improving the beam of the antenna, especially the radiation beam at high frequencies, in this embodiment the point coordinate is set to (40, 4.5).

rs＝sqrt((x ₁₀ -x ₉ )*(x ₁₀ -x ₉ )+(y ₁₀ -y ₉ )*(y ₁₀ -y ₉ )) (17)

Further, the radius and arc of the fan of the single fan director 10 is determined based on the center of the fan and the start of the fan.

Further, according to the radius and the radian of the sector, the sector line and the straight line which enclose the single director 10 are determined.

Further, other fan directors are drawn from the single fan director 10. In this embodiment, the interval between adjacent fan-shaped directors is 2mm, and the number of directors for a single layer of the substrate is 5. And designing all the directors on the top layer of the substrate according to the interval of the fan-shaped directors and the number of the fan-shaped directors on the single-layer substrate. The directors at the bottom layer of the substrate are drawn using symmetry. In this embodiment, all of the directors are of the same material and thickness as the patch.

As an example, the antenna is modeled using CST2020, the process is as follows:

the circular arc-shaped substrate 1 is designed. A circle with a radius of 50mm is drawn on the xOy plane with the origin of the coordinate system as the original. The arc shape is expanded to a three-dimensional structure with the thickness of 0.8mm along the negative half axis of the z axis by taking the z axis as the extension direction. The three-dimensional structure is used as an arc-shaped substrate 1 and is made of FR-4.

A rectangular substrate 2 is drawn. A rectangular parallelepiped having a length of 100mm, a width of 20mm and a thickness of 0.8mm was drawn as a rectangular substrate 2 starting from (-50,50,0). The cuboid length, width and height extend along an x-axis positive semi-axis, a y-axis negative semi-axis and a z-axis negative semi-axis, respectively. The cuboid material is selected as FR-4. The circular arc-shaped substrate 1 and the rectangular substrate 2 are combined to form a complete substrate by using the addition function in the boolean operation in the CST.

And drawing the substrate top layer patch. According to the curve equation y =1.89 × e ^(0.05*x) -16.9, with (x) ₁ ,y ₁ 0) is a starting point, (x) ₂ ,y ₂ And 0) as an end point, drawing an inner exponential line 3 of the top layer patch of the substrate. According to the curve equation y =7.48 x 10 ^-7 *e ^(-0.4*x) -0.18, with (x) ₃ ,y ₃ 0) as a starting point, (x) ₄ ,y ₄ And 0) drawing an outer index line 4 of the top layer patch of the substrate as an end point. With (x) ₄ ,y ₄ 0) as the center of a circle, R as the radius, (x) ₄ ,y ₄ 0) is a starting point, (x) ₂ ,y ₂ And 0) as an end point, drawing an arc line 5. With (x) ₁ ,y ₁ 0) is a starting point, (x) ₃ ,y ₃ 0) as an end point, a straight line x = x is drawn ₁ . Using the addition function of the boolean operation, the inner index line 3, the outer index line 4, the circular arc line 5 and the straight line x = x ₁ And (4) combining. The combined curve was extended 0.035mm in the positive z-axis direction to form an index patch. The material of the index patch is configured as an ideal electrical conductor.

And drawing the substrate bottom layer patch. With the mirror function of boolean operations, with plane y =0 as the axis of symmetry, the top radiating patch is copied and the copied patch is mirrored. And (4) taking the plane z = -0.5 x h (h is the thickness of the substrate) as a symmetry axis, and mirroring the mirrored paster again to finish drawing the bottom paster of the substrate.

And drawing the grounding structure of the top layer of the substrate. According to the curve equation y =1.89 × e ^(0.05*x) -16.9, with (x) ₁ ,y ₁ 0) as a starting point, (x) ₂ ,y ₂ And 0) as an end point, an exponential line 6 of the grounded structure is drawn. With the mirror function, the exponential lines 6 are copied and the copied exponential lines are mirrored to the lower side of the central axis of the antenna according to plane y = 0. With (x) ₁ ,y ₁ 0) as a starting point, a rectangle 7 of 100mm in length and 5mm in width is drawn. The two exponential lines are joined with a rectangle 7. And expanding the combined line by 0.035mm along the positive direction of the z-axis to form a complete grounding structure. The material of the ground structure is arranged as an ideal electrical conductor.

The feed structure 8 of the bottom layer of the substrate is drawn. With (x) ₁ ,y ₁ And, -h) as a starting point, a rectangular parallelepiped having a length of 30mm, a width of 2mm, and a thickness of 0.035mm is drawn as the feeder line 8. The length, the width and the thickness of the cuboid are respectively expanded along an x-axis negative half shaft, a y-axis positive half shaft and a z-axis negative half shaft. The material of the cuboid is selected as an ideal electric conductor.

The fan-shaped extension 9 is drawn. With (x) ₇ ,y ₇ 0) is a sector circle, (x) ₈ ,y ₈ And 0) is the starting point of the sector, and the arc segment of the sector with the radius of 40mm and the angle of 130 degrees is drawn. Connection point (x) ₂ ,y ₂ 0) and (x) ₈ ,y ₈ And 0) drawing a fan-shaped straight line part on the upper side of the central axis of the antenna. And drawing a fan-shaped straight line part on the lower side of the central axis of the antenna by using a mirror symmetry function and taking y =0 as a symmetry axis. Connection point (x) ₂ ,y ₂ 0) and (x) ₂ ,-y ₂ 0), forming another straight line. And expanding the four curves by 0.8mm along a negative half shaft of a z axis to form a fan-shaped expanding structure 9. The material of the fan-shaped expanding structure is selected to be FR-4. The fan-shaped extension structure 9 and the substrate 1 are combined to form a complete structure by utilizing a boolean operation addition function.

Drawing sector guideA device 10. With (x) ₉ ,y ₉ 0) is the center of the sector, 5mm is the sector radius, and is expressed by (x) ₁₀ ,y ₁₀ And 0) as a starting point, drawing a 130-degree sector arc. Connecting (x) ₉ ,y ₉ 0) and (x) ₁₀ ,y ₁₀ And 0), drawing the sector radius on the upper side of the central axis of the antenna. And drawing the sector radius of the lower side of the central axis of the antenna by using a mirror image function and taking the plane y =0 as a symmetry axis. The three lines are joined using boolean operations. The combined curve was extended 0.035mm along the positive z-axis half to form a single fan-shaped director 10. The material of the single director 10 is arranged as a perfect electrical conductor. And (3) translating the single director along the positive half axis of the x axis by using a translation transformation function. The translation times are 4 times, and 5 directors are ensured to be arranged on the single-side substrate; the distance of each translation is 68mm to ensure that the distance between adjacent fan directors is 5mm. And copying all the fan-shaped directors on the top layer of the substrate, and mirroring the copied fan-shaped directors to the bottom layer of the substrate by using a mirroring function to finish drawing all the fan-shaped directors on the surface of the antenna substrate.

The antenna is simulated by using a CST2020 time domain solver. The simulation results are analyzed with reference to fig. 5 to 37.

Fig. 5 to 7 are simulation results of S11 of three antennas. It can be seen from fig. 5 that the original butt-up Vivaldi antenna based on the new substrate has S11 below-10 dB in the 3-10GHz band, and the first resonance frequency occurs at 3.25 GHz. In fig. 6, the first resonant frequency of the opposite extension Vivaldi antenna loaded with the sector extension structure is slightly decreased, and S11 within 3-10GHz does not have deterioration phenomena such as obvious rise, fluctuation and the like. In FIG. 8, the first resonant frequency is slightly increased after the sector directors are loaded, but still remains near 3.25GHz and S11 still does not deteriorate within 3-10 GHz. In summary, the antenna based on the novel substrate, loaded with the sector expansion structure and the sector director, provided by the embodiment, has a good return loss characteristic within 3-10GHz, the radiated energy can be well radiated into the space and is not absorbed by the antenna, the fluctuation range of the S11 curve of the antenna is stable, and the stable frequency domain characteristic of the antenna is indicated; in addition, the resonant frequency of the antenna is low, indicating that the antenna can obtain good impedance matching characteristics at low frequencies.

Fig. 8 to 10 are simulation results of standing wave ratios of three antennas varying with frequency. The standing wave ratio reflects the case where the antenna energy radiation is impedance matched to the feed line. As can be seen from FIG. 8, the standing wave ratios of the novel substrate-based antipodal Vivaldi antenna are less than 1.8 in 3-10 GHz. After the sector expanding structure is loaded, the standing wave ratio of the antenna shown in fig. 9 is still less than 1.8. The standing wave ratios in the vicinity of 4.5GHz and 7.5GHz are simultaneously reduced, approaching 1.6. After loading the sector directors, as shown in fig. 10, the standing wave ratio of the antenna is still below 1.8, and the standing wave ratio of the antenna has dropped below 1.6 near 7.5GHz and again near 4.5 GHz. In a comprehensive view, after the sector expansion structure and the sector director are loaded, the standing-wave ratio of the antenna is still lower than 2, the requirements of ultra-wideband on detection and other applications are met, and in addition, the standing-wave ratio of the antenna in most frequency bands is lower than 1.6, which shows that the antenna has good impedance matching and high energy radiation rate.

Fig. 11-13 are the results of the gain variation with frequency for the three antennas. In fig. 11, the new substrate based paradox Vivaldi antenna has good gain in 3-10 GHz. Within 5-7GHz, the gain of the antenna fluctuates at 6 dBi; after 8GHz, the gain of the antenna exceeds 7dBi, with a peak gain of 7.7dBi at 9GHz. In fig. 12, the gain of the antenna loaded with the sector extension structure is improved in the whole frequency band. After 5GHz, the gain was increased by more than 1dBi. After 7.8GHz, the gain of the antenna is always above 8dBi, higher than the peak gain in the original antenna. At 9GHz, the antenna loaded with the fan-shaped expansion structure reaches 9.2dBi, and is improved by 1.5dBi compared with the original antenna. In fig. 13, on the basis of loading the sector spreading structure, the antenna gain loaded with multiple sector directors is increased within 3-10 GHz. After 5GHz the gain of the antenna is higher than 7dBi at each frequency, in particular after 8GHz the gain of the antenna is always higher than 9dBi. At 9GHz, the peak gain of the antenna reached 10.2dBi, which is 1dBi higher than the peak gain in fig. 12. In a comprehensive view, the loading sector expansion structure and the plurality of sector directors can effectively improve the gain and weaken the signal distortion of the antenna in practical application.

Fig. 14 to 25 show vertical patterns of three antennas at 3GHz, 5GHz, 7GHz, and 9GHz. As seen from fig. 14 to 17, the pair-topology Vivaldi antenna based on the novel substrate satisfies the directional radiation characteristics at each frequency point. As seen in fig. 18 to 21, the main lobe level strength of the antenna pattern loaded with the extended structure is improved at all four selected frequency points, particularly at 7GHz and 9GHz, by more than 1dBi; the strength of the side lobe is reduced, and the reduction amplitude is about 1dBi; in addition, the half-power beam angle of the antenna is reduced. It can be seen from fig. 22 to 25 that the main lobe intensity of the antenna beam is again increased at all frequency points, and is again increased by 1.3dBi at 7GHz, because the beam of the antenna is guided by loading the sector director at the opening of the antenna; the strength of the side lobes of the antenna beam decreases again, the decreasing amplitude exceeds 1dBi, and particularly exceeds 3dBi at 7 GHz. After loading the sector directors, the half-power beam angle of the antenna is reduced again. The reduction of the half-power angle means that the directivity of the antenna is enhanced. In a comprehensive view, the loading of the fan-shaped expanding structure and the fan-shaped director can effectively enhance the main lobe level intensity of the vertical radiation beam, weaken the energy intensity of the side lobe, simultaneously reduce the half-power beam angle and improve the directional radiation characteristic of the antenna.

Fig. 26 to 37 show horizontal patterns of three antennas at 3GHz, 5GHz, 7GHz, and 9GHz. From fig. 26 to 29, it can be seen that the original antenna also satisfies the directional radiation characteristic in the horizontal direction. After the expansion expanding structure is loaded, as shown in fig. 30 to 33, the main lobe of the horizontal directional pattern of the antenna is increased, particularly at 5GHz, 7GHz and 9GHz. In addition, the sidelobe of the antenna is weakened and the half-power beam angle is reduced. After the sector director is loaded, as shown in fig. 34-37, the main lobe level intensity of the horizontal directional diagram of the antenna increases again, the side lobe intensity decreases, and the main lobe intensity increase amplitude and the side lobe energy weakening intensity are obvious at 7 GHz. The half-power beam angle of the antenna drops again at each frequency due to the steering of the sector directors. In summary, the optimization result of the horizontal directional diagram simulation of the antenna is substantially the same as the optimization result of the vertical directional diagram shown in fig. 14 to 25, after the sector extension structure and the plurality of directors are loaded, the main lobe level strength of the horizontal directional diagram of the antenna is increased, the secondary lobe strength of the horizontal directional diagram of the antenna is weakened, the half-power angle of the antenna is reduced, the symmetry of the directional diagram is not damaged, and the directional radiation characteristic of the antenna is enhanced

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Although the present disclosure has been described with reference to specific embodiments, it should be understood that the scope of the present disclosure is not limited thereto, and those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the present disclosure.

Claims (10)

1. An antipodal Vivaldi antenna, comprising:

the dielectric substrate comprises an arc-shaped dielectric substrate and a rectangular dielectric substrate, and the arc-shaped dielectric substrate is tightly connected with the rectangular dielectric substrate;

the radiation patches are respectively positioned on the top layer and the bottom layer of the dielectric substrate;

the grounding structure is positioned on the top layer of the dielectric substrate;

and the feeder line is positioned at the bottom layer of the dielectric substrate.

2. The opposite-topology Vivaldi antenna as claimed in claim 1, wherein said circular arc-shaped dielectric substrate is made of the same material and the same thickness as said rectangular dielectric substrate, and the length of said rectangular dielectric substrate is twice the radius of said circular arc-shaped dielectric substrate.

3. A para-topology Vivaldi antenna as claimed in claim 1, wherein the edge of the individual patches of said radiating patch is defined by an outer and inner exponential line and a circular arc.

4. A antipodal Vivaldi antenna as claimed in claim 3, wherein the slope of said outer index line is twice the slope of the inner index line, the abscissa of said outer and inner index lines being the same, and the end points being located on the circular arc lines forming the edges of said radiating patches.

5. The opposite topology Vivaldi antenna as recited in claim 4, wherein the circular arc line has the same center as the circular arc of the circular arc dielectric substrate, and the radius of the circular arc line is smaller than that of the circular arc dielectric substrate.

6. The antipodal Vivaldi antenna as claimed in claim 1, wherein said ground structure is formed by closely connecting and combining an exponential ground structure and a rectangular ground structure, and the length of the rectangular portion of said rectangular ground structure is the same as the length of said rectangular dielectric substrate.

7. A p-topology Vivaldi antenna according to claim 1, characterized in that said feed line has a rectangular plan shape with a width equal to the distance between the start of the two exponential lines at the edge of said radiating patch, at the opening of said radiating patch a fan-shaped extension is applied, said fan-shaped extension being symmetrical with respect to the axis in the vertical direction of the antenna.

8. The opposite-topology Vivaldi antenna as claimed in claim 1, wherein a plurality of sector directors are loaded on the two-layer surface of said dielectric substrate, the sectors of said plurality of sector directors have the same radius, the same radian and the same distance between adjacent sector directors.

9. A method for designing a extended Vivaldi antenna, comprising:

drawing the medium substrate, including drawing the arc-shaped medium substrate and drawing the rectangular medium substrate;

drawing the radiation patch, including drawing the exponential line edge of the patch and drawing the circular arc edge;

drawing a grounding structure for top-layer radiation patch balanced feed;

the feed line is designed to transfer energy to the radiating patch.

10. A method of designing a rubbing Vivaldi antenna as claimed in claim 9,

drawing a fan-shaped expanding structure loaded at the opening of the radiation patch, wherein the drawing comprises the design of the radius and the radian of the fan-shaped expanding structure;

and drawing the fan-shaped directors loaded on the two layers of surfaces of the dielectric substrate, wherein the fan-shaped directors comprise the radius and radian of a single fan-shaped director and the design of distribution of a plurality of directors, and are used for guiding the radiation beams of the antenna at the opening.

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