CN111403921A - Linear polarized wave arbitrary polarization angle converter - Google Patents

Abstract

The invention discloses a converter for randomly polarizing linearly polarized waves of a planar artificial electromagnetic structure, which is used for realizing angle deflection of linearly polarized electromagnetic waves polarized in any direction. The resonance unit is formed by compounding three parts: the dielectric ceramic comprises four rectangular copper patches, two insulating F4B dielectric substrates and a copper metal ground substrate pressed between the two dielectric substrates. Two holes are drilled in the dielectric substrate and copper is plated on the edges of the holes. The polarization switching mechanism is: when linearly polarized waves polarized in any direction of 5.8GHz are normally incident to the front surface of the structure, the planar monopole antenna is coupled to generate resonance, energy received by the front monopole antenna is coupled to the back monopole antenna through the copper-plated hole, and orthogonal decomposition of incident electric fields and synthesis of transmission orthogonal electric fields are performed, so that incident linearly polarized waves are realized

Description

Linear polarized wave arbitrary polarization angle converter

Technical Field

The invention belongs to the electromagnetic technology, adopts a planar artificial electromagnetic structure, and particularly relates to an arbitrary polarization angle converter for linearly polarized waves.

Background

In the information age, a polarization converter is generally applied to the front end of the radiation aperture of an antenna as an important device for controlling the propagation state of electromagnetic waves, and the polarization converter switches and controls the polarization state of the electromagnetic waves radiated by the antenna. The polarization converter is widely applied to the fields of wireless communication and microwave imaging. An artificial electromagnetic structure is a periodic or aperiodic array structure constructed by artificially designing cells with special electromagnetic properties. These particular electromagnetic functions are difficult or impossible to achieve with conventional materials in nature. Therefore, artificial electromagnetic structures have been widely used in the design of frequency selective surfaces, artificial absorbers, stealth functional materials, and polarization converters.

When linearly polarized electromagnetic waves propagate in free space, due to the complexity of the space environment, effects such as scattering, refraction, diffraction and the like can be generated, so that the polarization direction of the electromagnetic waves is changed. When the polarization direction of the electromagnetic wave is not the same as that of the receiving antenna, the receiving efficiency is lowered, and when the polarization directions of the electromagnetic wave and the receiving antenna are orthogonal, the antenna receives almost no electromagnetic signal. The polarization direction of the received signal is deflected to the polarization direction of the receiving antenna, so that the antenna has the best receiving efficiency. Most of the linearly polarized wave polarization converters designed based on the artificial electromagnetic structure have polarization selection characteristics, namely, the incident wave must be consistent with the polarization direction of the artificial electromagnetic structure unit, otherwise, the incident wave is reflected, and the polarization conversion efficiency is reduced. Therefore, it is increasingly important to design a polarization converter suitable for polarization conversion at any incident angle and having high efficiency.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects of the prior art, the linear polarized wave arbitrary polarization angle converter is provided and is suitable for arbitrary angle conversion of linear polarized waves.

The technical scheme is as follows: the invention provides a linearly polarized wave arbitrary polarization angle converter, which adopts a planar artificial electromagnetic structure and comprises an array formed by resonance units, wherein each resonance unit comprises three parts, the first part is formed by four rectangular copper patches, the second part is two F4B dielectric substrates, and the third part is a copper metal ground substrate which is pressed between the two dielectric substrates; each unit structure in the array comprises a copper patch, a copper plated through hole, a copper metal ground substrate and an F4B dielectric substrate; the copper patches are attached to the outer surface of the medium substrate, the adjacent copper patches are mutually orthogonal, and the copper plating holes are formed in the copper patches.

Further, each structure of the rectangular patch made of copper comprises a front piece and a back piece, and the size of each structure is 12.7 × 3 mm.

Furthermore, two through holes are drilled at the boundary of each cell in the array, the edges of the through holes are plated with copper, the radius of each through hole is 0.4mm, and the size of the copper metal base plate is 21 × 21 mm.

Further, the dielectric constant of the F4B dielectric plate was 2.65, and the loss tangent was 0.001.

Further, the resonant cell size is 21 × 21 × 8mm, and the thickness is 1/6 operating wavelength.

Further, the polarization switching mechanism is: when the linearly polarized wave polarized in any direction of 5.8GHz is normally incident to the front surface of the structure, the planar monopole antenna is coupled to generate resonance, the energy received by the front monopole antenna is coupled to the back monopole antenna through the copper-plated hole, and the orthogonal decomposition of the incident electric field and the synthesis of the transmission orthogonal electric field are carried out, so that the incident linearly polarized wave is realized

An angle of rotation wherein

The included angle between the polarization direction of the incident electric field and the x-axis of the orthogonal coordinate system is called the polarization azimuth angle.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: (1) the planar monopole artificial electromagnetic structure is adopted, and linear polarized waves polarized in any direction can be orthogonally decomposed, so that the polarization of the artificial electromagnetic structure is insensitive; (2) the structure is simple, the processing is easy, and the tuning of the working frequency of the unit is realized by adjusting the geometric parameters of the structure of the unit; (3) the mass is light, the integration of a wireless communication or radar system is convenient, the reflection loss is low, and the interference to a transmitting antenna is small; (4) the resonance unit can be periodically expanded, and has the advantages of flexible structure, low cost and easy mass production.

Drawings

FIG. 1 is a schematic diagram of an array structure;

FIG. 2(a) is a schematic front view of a cell structure; (b) a metal patch schematic;

FIG. 3 is a diagram illustrating a polarization conversion mechanism (a) an exploded view of an electric field vector of an incident linearly polarized wave; (b) a transmission line polarized wave electric field vector synthesis graph;

FIG. 4(a) co-polarized reflection coefficients at normal incidence for linearly polarized waves of different polarization azimuths; (b) polarization transmission coefficients at normal incidence of linearly polarized waves of different polarization azimuths.

The specific implementation mode is as follows:

the technical scheme of the invention is further explained in detail by combining the attached drawings:

as shown in FIG. 1, the polarization angle converter is composed of 20 × 20 artificial unit structures regularly arranged along the orthogonal direction, in FIGS. 2(a) and 2(b), in FIGS. 2(a) -2.2(b), structures of each unit in the array are illustrated, wherein structures 1 and 2 are copper rectangular metal patches, each structure comprises two front and back sheets, the size of each sheet is 12.7mm × 3mm, structure 3 is a copper plated hole with the radius of 0.4mm, structure 4 is a copper metal ground substrate with the size of 21mm × 21mm, and structure 5 is two F4B dielectric substrates, the block size of each 21mm × 21mm × 4mm, the relative dielectric constant of 2.65 and the loss tangent of 0.001.

FIG. 3(a) shows the polarization azimuth angle

Fig. 3(b) is a schematic diagram of the linear polarization electric field vector after polarization conversion. Fig. 3 illustrates the polarization switching mechanism in detail. Fig. 3 indicates the directions of the coordinate axes in a spherical coordinate system. E represents incident electromagnetic wave of 5.8GHz, the incident direction is-z-axis, and the direction of the incident direction forms any included angle with the x-axis

Ex represents the x-axis component of the wave incident wave, Ey represents the y-axis component of the wave incident wave, the wave incident wave is respectively received by the copper patch monopole parallel to the x-axis and the copper patch monopole parallel to the y-axis, and is transmitted and coupled to the copper patch with the back surface vertical to the x-axis and the copper patch monopole vertical to the y-axis through the copper-plated hole to radiate and transmitAfter wave synthesis, an angle different from the polarization direction of incident wave is formed

And (4) degree. Ex 'and Ey' represent the x-axis component and the y-axis component of the transmitted wave, respectively.

Fig. 4(a) shows the co-polarized reflection coefficient of the incident wave when the linearly polarized waves with different polarization azimuth angles are incident (S11). FIG. 4(a) is a simulation of array S11 when electromagnetic waves are incident in each direction with respect to the x-axis. Fig. 4(b) shows the polarization transmission coefficient of the incident wave when the linearly polarized wave having different polarization azimuth angles is normally incident (S12). FIG. 4(b) is a simulation of the polarization conversion efficiency of the array when electromagnetic waves are incident in all directions along the x-axis. Fig. 4(a) and 4(b) show the verification of the polarization conversion effect of the linearly polarized wave at normal incidence for any polarization orientation. As shown in FIGS. 4(a) and 4(b), incident waves of different polarization orientations are irradiated onto the sample, resulting in the co-polarized reflection coefficients (S11) and

the angular polarization transmission coefficients (S12) are completely the same, and the characteristics that the polarization converter sample designed by the invention has the conversion of any polarization angle of the linearly polarized wave are verified, and the polarization conversion efficiency reaches more than 93%.

Claims (6)

1. The utility model provides a linear polarization wave arbitrary polarization angle converter, includes plane artifical electromagnetic structure, its characterized in that: the resonant unit forms an array and comprises three parts, wherein the first part consists of four rectangular copper patches, the second part is two F4B dielectric substrates, and the third part is a copper metal ground substrate which is pressed between the two dielectric substrates; each unit structure in the array comprises a copper patch, a copper plated through hole, a copper metal ground substrate and an F4B dielectric substrate; the copper patches are attached to the outer surface of the medium substrate, the adjacent copper patches are mutually orthogonal, and the copper plating holes are formed in the copper patches.

2. The polarization angle converter of claim 1, wherein each structure comprises two pieces, front and back, of rectangular copper patches, and has a size of 12.7 × 3 mm.

3. The polarization angle transformer of claim 1, wherein two vias are drilled and copper plated on the edge of each cell boundary in the array, the vias have a radius of 0.4mm, and the copper metal base plate has a size of 21 × 21 mm.

4. The polarization angle transformer of claim 1, wherein the F4B dielectric plate has a dielectric constant of 2.65 and a loss tangent of 0.001.

5. The polarization angle converter of claim 1, wherein the resonant cell size is 21 × 21 × 8mm and the thickness is 1/6 operating wavelength.

6. The polarization angle converter of claim 1, wherein the polarization conversion mechanism is: when the linearly polarized wave polarized in any direction of 5.8GHz is normally incident to the front surface of the structure, the planar monopole antenna is coupled to generate resonance, the energy received by the front monopole antenna is coupled to the back monopole antenna through the copper-plated hole, and the orthogonal decomposition of the incident electric field and the synthesis of the transmission orthogonal electric field are carried out, so that the incident linearly polarized wave is realized

An angle of rotation wherein

The included angle between the polarization direction of the incident electric field and the x-axis of the orthogonal coordinate system is called the polarization azimuth angle.

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