阅读说明：本技术 一种宽带多极化平面反射阵天线 (Broadband multi-polarization plane reflective array antenna ) 是由 陈银言 陈西洋 李东明 于 2020-12-08 设计创作，主要内容包括：本发明公开了天线技术领域的一种宽带多极化平面反射阵天线,具有结构简单,设计参数少,同时具有良好的多极化特性和交叉极化特性。在平面介质基板的第一表面和第二表面按照设定规律设置多个无源微带谐振振子,多个无源微带谐振振子将平面介质基板划分为若干个天线单元,在每个天线单元中,包含一个位于第一表面的无源微带谐振振子和一个位于第二表面的无源微带谐振振子,位于第一表面的无源微带谐振振子和位于第二表面的无源微带谐振振子平行,且均位于天线单元的中心并呈中心对称,同时具有相同的微带宽度,位于第二表面的无源微带谐振振子具有固定的微带长度；在平面介质基板的一侧设有反射板,反射板与第二表面之间保持设定高度的空气层。(The invention discloses a broadband multi-polarization planar reflective array antenna in the technical field of antennas, which has the advantages of simple structure, less design parameters, and good multi-polarization characteristic and cross-polarization characteristic. The planar dielectric substrate is characterized in that a plurality of passive microstrip resonant vibrators are arranged on a first surface and a second surface of the planar dielectric substrate according to a set rule, the planar dielectric substrate is divided into a plurality of antenna units by the plurality of passive microstrip resonant vibrators, each antenna unit comprises a passive microstrip resonant vibrator positioned on the first surface and a passive microstrip resonant vibrator positioned on the second surface, the passive microstrip resonant vibrators positioned on the first surface and the passive microstrip resonant vibrators positioned on the second surface are parallel, are positioned at the centers of the antenna units and are centrosymmetric and have the same microstrip width, and the passive microstrip resonant vibrators positioned on the second surface have fixed microstrip length; a reflecting plate is arranged on one side of the planar medium substrate, and an air layer with a set height is kept between the reflecting plate and the second surface.)

1. A broadband multi-polarization planar reflective array antenna is characterized by comprising a planar dielectric substrate, wherein a plurality of passive microstrip resonant vibrators are arranged on a first surface and a second surface of the planar dielectric substrate according to a set rule, the planar dielectric substrate is divided into a plurality of antenna units by the plurality of passive microstrip resonant vibrators, each antenna unit comprises a passive microstrip resonant vibrator located on the first surface and a passive microstrip resonant vibrator located on the second surface, the passive microstrip resonant vibrators located on the first surface and the passive microstrip resonant vibrators located on the second surface are parallel, located in the centers of the antenna units, are centrosymmetric and have the same microstrip width, and the passive microstrip resonant vibrators located on the second surface have fixed microstrip length; and a reflecting plate is arranged on one side of the planar medium substrate, is opposite to the second surface and keeps an air layer with a set height with the second surface.

2. The broadband multi-polarization planar reflective array antenna according to claim 1, wherein the plurality of passive microstrip resonators are independently, alternately, and uniformly spaced along parallel lines parallel to the X-axis and parallel lines parallel to the Y-axis, respectively, and are disposed in a grid pattern on the first surface and the second surface.

3. The array antenna of claim 1, wherein the distance between two adjacent antenna elements does not exceed the half wavelength of free space corresponding to the highest operating frequency.

4. The broadband multi-polarization planar reflective array antenna according to claim 1, wherein a feed antenna is disposed on the other side of the planar dielectric substrate, and the feed antenna faces the first surface at a predetermined angle for transmitting or receiving electromagnetic wave signals.

5. The broadband multi-polarization planar reflective array antenna according to claim 4, wherein the passive microstrip resonator element located on the first surface has a plurality of microstrip lengths.

6. The array antenna of claim 1, wherein the reflector plate is made of a good metal conductor.

7. The broadband multi-polarization planar reflective array antenna according to claim 1, wherein the width W of the passive microstrip resonator element satisfies:

W＜0.125λ_f0 (3)

wherein λ is_f0The free space wavelength corresponding to the center operating frequency.

8. The broadband multi-polarization planar reflective array antenna according to claim 1, wherein the height h of the air layer satisfies:

h≤0.25λ_fh (4)

wherein λ is_fhThe free space wavelength corresponding to the highest operating frequency.

9. The broadband multi-polarization planar reflective array antenna according to claim 1, wherein the microstrip length Lb of the passive microstrip resonator element on the second surface satisfies:

Lb＜d-W (5)

wherein d is the antenna unit interval, and W is the microstrip width of the passive microstrip resonator.

Technical Field

The invention belongs to the technical field of antennas, and particularly relates to a broadband multi-polarization planar reflective array antenna.

Background

In the traditional plane reflection array antenna, linear polarization waves incident from a linear polarization feed antenna are subjected to specific reflection phase compensation along two orthogonal directions through a reflection array surface rectangular unit, a T-shaped unit, a cross micro-strip resonance unit and the like, and then linear-circular polarization conversion is realized. However, the antenna units have complex structures and more design parameters, and the conventional antenna unit distribution mode makes the planar reflective array have single polarization and poor cross polarization suppression.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a broadband multi-polarization planar reflective array antenna which has the advantages of simple structure, less design parameters, good multi-polarization characteristic and low cross-polarization characteristic.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a broadband multi-polarization planar reflective array antenna comprises a planar dielectric substrate, wherein a plurality of passive microstrip resonant vibrators are arranged on a first surface and a second surface of the planar dielectric substrate according to a set rule, the planar dielectric substrate is divided into a plurality of antenna units by the plurality of passive microstrip resonant vibrators, each antenna unit comprises a passive microstrip resonant vibrator located on the first surface and a passive microstrip resonant vibrator located on the second surface, the passive microstrip resonant vibrators located on the first surface and the passive microstrip resonant vibrators located on the second surface are parallel, located in the centers of the antenna units, are in central symmetry and have the same microstrip width, and the passive microstrip resonant vibrators located on the second surface have fixed microstrip length; and a reflecting plate is arranged on one side of the planar medium substrate, is opposite to the second surface and keeps an air layer with a set height with the second surface.

Furthermore, the plurality of passive microstrip resonance oscillators are independently, alternately and uniformly arranged at equal intervals along a plurality of parallel lines parallel to the X axis and a plurality of parallel lines parallel to the Y axis, and are distributed in a grid manner on the first surface and the second surface.

Further, the distance between two adjacent antenna units does not exceed the half wavelength of the free space corresponding to the highest working frequency.

Furthermore, a feed antenna is arranged on the other side of the planar dielectric substrate, and the feed antenna faces the first surface at a set angle and is used for transmitting or receiving electromagnetic wave signals.

Further, the passive microstrip resonator at the first surface has a plurality of microstrip lengths.

Furthermore, the reflecting plate is made of a good metal conductor.

Further, the width W of the passive microstrip resonator satisfies:

W＜0.125λ_f0 (3)

wherein λ is_f0The free space wavelength corresponding to the center operating frequency.

Further, the height h of the air layer satisfies:

h≤0.25λ_fh (4)

wherein λ is_fhThe free space wavelength corresponding to the highest operating frequency.

Further, the microstrip length Lb of the passive microstrip resonator at the second surface satisfies:

Lb＜d-W (5)

wherein d is the antenna unit interval, and W is the microstrip width of the passive microstrip resonator.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention effectively simplifies the complex unit structure by adopting the single-layer plane dielectric substrate with simple structure and the double-layer vibrator structure stacked on the upper and lower surfaces of the plane dielectric substrate; the length of the lower passive microstrip resonator is fixed, the length of the upper passive microstrip resonator is changed, unit design parameters are effectively simplified, the unit simulation and optimization period is shortened, and reflection phase compensation values of all units can be conveniently obtained by using commercial simulation software;

(2) according to the invention, the plurality of passive microstrip resonant vibrators are independently, alternately and uniformly arranged at equal intervals along the parallel lines parallel to the X axis and the parallel lines parallel to the Y axis respectively, and grid distribution is formed on the first surface and the second surface, so that the influence of the coupling effect between adjacent orthogonal antenna units on the reflection phase is comprehensively analyzed, and the antenna has good multi-polarization characteristics and good low cross-polarization characteristics; the reflection phase of the antenna unit and the unit parameters have approximate linear relation, a reflection array meeting the circular polarization requirement can be designed only by designing a group of phase shift curves, and the design method is simplified.

Drawings

Fig. 1 is a schematic structural diagram of a broadband multi-polarization planar reflective array antenna according to an embodiment of the present invention;

fig. 2 is a schematic plane structure diagram of an antenna unit of a broadband multi-polarization planar reflective array antenna according to an embodiment of the present invention;

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a schematic diagram of the distribution of passive microstrip resonators along the axis X, Y in the embodiment of the present invention;

FIG. 5 is a graph of reflection phase of a unit analysis model according to the length of a passive microstrip resonator on a first surface in an embodiment of the present invention;

FIG. 6 is a normalized E-plane pattern for left-handed circular polarization of a reflective array antenna when the feed antenna is polarized at 135 degrees according to the present invention;

FIG. 7 is a normalized H-plane pattern for left-handed circular polarization of a reflective array antenna when the feed antenna is polarized at 135 degrees according to the present invention;

FIG. 8 is a normalized E-plane pattern for right hand circular polarization of a reflectarray antenna when the feed antenna is polarized at 45 degrees in accordance with the present invention;

FIG. 9 is a right-hand circularly polarized H-plane normalized directional diagram of a reflectarray antenna when the feed antenna is polarized at 45 degrees according to the present invention;

FIG. 10 is an E-plane normalized directional diagram of the horizontal polarization of a reflective array antenna when the feed antenna is horizontally polarized according to an embodiment of the present invention;

FIG. 11 is an H-plane normalized directional diagram of the horizontal polarization of a reflective array antenna when the feed antenna is horizontally polarized according to an embodiment of the present invention;

FIG. 12 is an E-plane normalized directional diagram of the vertical polarization of the reflective array antenna when the feed antenna is vertically polarized according to the embodiment of the present invention;

fig. 13 is an H-plane normalized directional diagram of vertical polarization of a reflective array antenna when the feed antenna is vertically polarized according to the embodiment of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1 to 4, a broadband multi-polarization planar reflective array antenna includes a planar dielectric substrate 2, a plurality of passive microstrip resonators are arranged on a first surface and a second surface of the planar dielectric substrate 2 according to a predetermined rule, the planar dielectric substrate 2 is divided into a plurality of antenna units by the plurality of passive microstrip resonators, each antenna unit includes a passive microstrip resonator 3a (or 4a) located on the first surface and a passive microstrip resonator 3b (or 4b) located on the second surface, the passive microstrip resonators located on the first surface and the passive microstrip resonators located on the second surface are parallel and are both located at the center of the antenna unit and are in central symmetry, and have the same microstrip width W, and the passive microstrip resonators located on the second surface have a fixed microstrip length Lb; a reflecting plate 6 is provided on one side of the planar dielectric substrate 2, and the reflecting plate 6 faces the second surface and maintains an air layer 5 of a predetermined height with respect to the second surface.

In this embodiment, a plurality of passive microstrip resonator elements are respectively arranged independently, alternately, and uniformly at equal intervals along a plurality of parallel lines parallel to the X axis and a plurality of parallel lines parallel to the Y axis, and are distributed in a grid pattern on the first surface and the second surface to form a planar reflection array, the dual-polarized feed antenna 1 faces the first surface at a set angle, and is configured to transmit or receive electromagnetic wave signals, and the planar reflection array is configured to reflect the electromagnetic wave signals transmitted by the feed antenna 1 to a target area, or reflect the electromagnetic wave signals from the target area to the feed antenna 1.

The passive microstrip resonator oscillator on the first surface has various microstrip lengths, and a reflection phase compensation range meeting design requirements can be obtained by adjusting the microstrip length of the passive microstrip resonator oscillator on the first surface; the reflection phase is compensated by fixing the length of the passive microstrip resonant oscillator on the second surface and changing the length of the passive microstrip resonant oscillator on the first surface, so that after the feed source antenna 1 irradiates, the planar reflection array can generate an equiphase plane on a plane vertical to the direction of a designed wave beam. The phase difference between each antenna unit and the central array element caused by the electromagnetic wave path difference is further compensated by calculating the electromagnetic wave path difference between the phase center of the feed source antenna 1 and each antenna unit; independently adjusting the length of the passive microstrip resonator along the X axis to compensate the X axis reflection phase value; independently adjusting the length compensation Y axial reflection phase value of the passive microstrip resonator along the Y axis; adjusting X, Y reflection phase difference between the axially adjacent passive microstrip resonant vibrator units to realize multiple polarization modes of the planar reflective array antenna; when the polarization direction of the linear polarization feed antenna is along the X axis, linear polarization and the like which are plane wave fronts can be generated along the X axis direction; when the polarization direction of the linear polarization feed antenna is along the Y axis, linear polarization and the like along the Y axis can be generated to be a plane wave front; when the polarization of the feed antenna is parallel to the 45 DEG or 135 DEG diagonal of the planar reflection array, and the +90 DEG or-90 DEG fixed reflection phase difference exists between the antenna units along the X axis and the Y axis, left-handed or right-handed (or conversely, depending on the + or-90 DEG reflection phase difference) circular polarization and the like can be generated as a planar wavefront.

In order to further expand the working bandwidth, an air layer 5 with a certain height is designed and introduced between the planar medium substrate 2 and the reflecting plate made of metal materials; in conjunction with the basic design principle of the planar reflective array, the reflection phase required to compensate for the array antenna element can be obtained by equation (1):

wherein: phi is a_cCompensating for the antenna element reflection phase; m is an arbitrary integer due to the periodicity of the transmission phase;represents the propagation constant of the electromagnetic wave in space;the position vector from the phase center of the feed source antenna to any unit of the array surface;a position vector representing an arbitrary unit of the array surface to the center of the array surface;the unit vector of the antenna array main beam pointing direction of the design embodiment is shown.

According to the basic design principle of the plane reflection array, in order to avoid the occurrence of grating lobes of the array antenna, the antenna unit spacing d should satisfy:

d≤0.5λ_fh (2)

wherein λ is_fhThe free space wavelength corresponding to the highest working frequency, namely the distance between two adjacent antenna units does not exceed the half free space wavelength corresponding to the highest working frequency.

Because the phase shift curve of the antenna unit directly influences the working bandwidth of the plane reflection antenna, in the embodiment, the antenna unit is formed by a stacked resonator with a double-layer passive microstrip structure, and the antenna unit is Printed on the first surface and the second surface of the single-layer plane medium substrate 2 by adopting a Printed Circuit Board (PCB) etching process, so that the induced current parasitic effect of the passive microstrip structure caused by electromagnetic waves transmitted by a feed source or received by a front surface is avoided, the cross polarization level is further improved, and the width W of the passive microstrip resonator satisfies the following requirements:

W＜0.125λ_f0 (3)

wherein λ is_f0The free space wavelength corresponding to the center operating frequency.

To further extend the phase shift bandwidth of the antenna element, an air layer of height h, which may be equivalent to another dielectric layer, i.e. ε, is introduced between the planar dielectric substrate 2 and the reflector plate 6_r＝ε₀The air layer has smaller dielectric loss and smaller Q value (1), so that the phase shift bandwidth of the antenna unit can be effectively expanded, and the height h of the air layer is fullFoot:

h≤0.25λ_fh (4)

wherein λ is_fhThe free space wavelength corresponding to the highest operating frequency.

In this embodiment, the reflection phase is compensated by fixing the microstrip length Lb of the parasitic microstrip resonator located on the second surface of the antenna unit and adjusting the size Lt of the first surface stacked resonator. Fig. 5 analyzes the influence of different lengths Lb of the microstrip resonators on the second surface on the change curve of the reflection phase along with the length Lt of the microstrip resonator on the first surface at the working center frequency, and it can be seen that the phase shift range of the antenna unit is larger than 360 degrees, and the design requirement of the planar reflective array antenna is met. In this embodiment, in order to ensure that the units do not interfere with each other structurally, the microstrip length Lb of the passive microstrip resonator on the second surface satisfies:

Lb＜d-W (5)

wherein d is the antenna unit interval, and W is the microstrip width of the passive microstrip resonator.

In order to ensure that the dual-polarized feed antenna in this embodiment excites the planar elements with equal amplitude and realize the multi-polarization function, as shown in fig. 4, the direction of the horizontal linear polarization electric field of the feed antenna is parallel to the axial direction of the array X; the direction of the feed source antenna vertical polarization electric field is parallel to the Y axis of the array; the direction of a feed source antenna synthesized 45-degree linearly polarized electric field is parallel to the 45-degree diagonal of the array; the direction of the 135-degree linear polarization electric field synthesized by the feed antenna is parallel to the 135-degree diagonal of the array. By independently compensating X, Y axial array element reflection phases and X, Y axial array element phase differences, equal phase horizontal, vertical and circular polarization (including left and right hand circular polarization) beam reflections in the design direction are achieved.

The antenna unit compensation phase is in linear relation with the parameters of the passive microstrip resonant vibrator, the array reflection phase is calculated by a reflection array antenna phase compensation formula, and the parameters of the unit vibrator can be adjusted after the phase of each unit is obtained. Because the paths of the electromagnetic waves radiated by the feed antenna to the units of the reflection array are different, phase differences caused by path differences exist among the units. When designing a planar reflective array, in order to keep each unit of the planar reflective array antenna in-phase radiation in the design direction, the variable polarization reflective array antenna independently decomposes in-phase circularly polarized reflected waves into two equal-amplitude orthogonal linear polarization reflective array designs with a phase difference of 90 degrees based on the principle. While adjusting parameters of stacked element units respectively according to the distribution of X, Y axial elements to compensate reflection phase, the technical requirement is that the compensation phase difference along the X and Y axial directions is 90 degrees, namely, the reflection phase relation between the antenna unit at any position of the plane front along the X axial direction and the adjacent antenna unit along the Y axial direction to be compensated is satisfied:

wherein phi is_xc，φ_ycRespectively reflecting phase compensation values of the antenna units along the x axial direction at any position of the array surface and the adjacent antenna units along the y axial direction; m is any integer;represents the propagation constant of the electromagnetic wave in space;respectively is a position vector from the phase center of the feed source antenna to the array surface along the x axial direction antenna unit and the adjacent y axial direction antenna unit;representing the position vector of any antenna unit along the x-axis of the array surface and the adjacent antenna unit along the y-axis to the center of the array surface;the unit vector of the antenna array main beam pointing direction of the design embodiment is shown.

In the embodiment, the single-layer planar dielectric substrate with a simple structure and the double-layer vibrator structure stacked on the upper surface and the lower surface of the planar dielectric substrate are adopted, so that the complex unit structure is effectively simplified; the length of the lower passive microstrip resonator is fixed, the length of the upper passive microstrip resonator is changed, unit design parameters are effectively simplified, the unit simulation and optimization period is shortened, and reflection phase compensation values of all units can be conveniently obtained by using commercial simulation software; the plurality of passive microstrip resonance oscillators are independently, alternately and uniformly arranged at equal intervals along a plurality of parallel lines parallel to an X axis and a plurality of parallel lines parallel to a Y axis respectively, and grid distribution is formed on the first surface and the second surface, so that the influence of the coupling effect between adjacent orthogonal antenna units on the reflection phase is comprehensively analyzed, and the antenna has good multi-polarization characteristics and good cross-polarization characteristics; the reflection phase of the antenna unit and the unit parameters have approximate linear relation, a reflection array meeting the circular polarization requirement can be designed only by designing a group of phase shift curves, and the design method is simplified.

Because the linearly polarized feed source horn antenna has simple structure, stable radiation wave beams and more actual products. In order to avoid the shielding effect of the feed horn, the design adopts a bias feed 15-degree design, and the radiation pattern of the antenna is shown in figures 6-13.

Fig. 6 and 7 show normalized directional diagrams of an E plane and an H plane of the antenna when the polarization direction of the center frequency feed source is 135 degrees; fig. 8 and 9 show normalized E-plane and H-plane directional diagrams of the antenna when the central frequency feed polarization direction is 45 °. It can be seen from the figure that the antenna pattern is stable, the half power lobe width is around 6.5 deg., and the first side lobe level is about-20 dB. The circularly polarized radiation pattern of the antenna in a wide frequency band range realizes high gain and low side lobe. The antenna can realize the conversion from linear polarization to left-hand circular polarization and from linear polarization to right-hand circular polarization respectively.

Fig. 10 and 11 show normalized directional diagrams of an E plane and an H plane of the antenna when the polarization direction of the central frequency feed source is located in the X axis direction; fig. 12 and 13 show normalized E-plane and H-plane directional diagrams of the antenna when the polarization direction of the center frequency feed is located in the Y-axis direction. It can be seen from the figure that the antenna pattern is stable, the half power lobe width is around 6 deg., and the first side lobe level is about-18 dB. The linear polarization radiation pattern of the antenna in a wide frequency band range realizes high gain and low side lobe. The antenna can realize horizontal polarization and vertical polarization respectively.

According to the scheme of the design embodiment, the gain bandwidths of the antenna for left-hand and right-hand circular polarization 1dB can reach 30.3% and 29.2% respectively; the axial ratio bandwidth of the left-hand circular polarization 3dB and the right-hand circular polarization 3dB respectively reaches 44% and 41.2%. The linear-circular polarization conversion performance is good. Meanwhile, the gain bandwidth of the 1dB linearly polarized horizontally (X axial direction) and vertically (Y axial direction) of the design example reaches 28% and 23.5%, respectively.

Through the technical scheme, a novel grid type line-circular variable polarization broadband planar reflective array antenna is designed. Compared with the traditional design method and thought, the method has the advantages that the unit structure and the analysis process are effectively simplified, and the coupling between units is reduced. The units are all subjected to phase compensation in a mode of adjusting the size of the upper-layer stacked oscillator, in order to ensure that the linear polarization feed source constant-amplitude excitation reflection array unit is ensured, the direction of a linear polarization electric field of the feed source is parallel to the diagonal line of the array, and the reflection of a constant-phase circularly polarized beam in the design direction is realized by independently compensating X, Y axial reflection phases of the array unit and X, Y phase differences of each unit of the axial array. The unit compensation phase is in linear relation with the oscillator parameters, the array reflection phase is calculated by a reflection array antenna phase compensation formula, and the parameters of the unit oscillator can be adjusted after the phase of each unit is obtained.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.