CN201918484U - Split resonators based on metaisotropic media - Google Patents

Abstract

The utility model aims to provide a split-type resonator based on metamaterial, which comprises resonance cavities, negative permeability media and feeder lines, wherein the two resonance cavities are connected together; through holes are formed on the upper covers of the resonance cavities; the feeder lines are mounted at the through holes; and the negative permeability media are placed into the resonance cavities. By adopting the split-type resonator based on metamaterial, the resonance frequency in the resonance cavities can be conveniently changed according to different practical requirements, so that the split-type resonator is flexible at a certain extent, and can be fabricated and processed simply and conveniently.

Description

Split resonators based on metaisotropic media

technical field

The utility model relates to a resonance mechanism.

Background technique

The concept of new artificial electromagnetic media can be traced back to the 1960s. In a paper published by the former Soviet scientist Veselago, a medium with negative permittivity and magnetic permeability was hypothesized, and it was pointed out that there are many strange electromagnetic phenomena in this medium. Anisotropic medium is a new type of artificial electromagnetic medium with periodic structure that appeared in the 1990s. It has negative permittivity and negative magnetic permeability at the same time, resulting in the electric field, magnetic field and wave of electromagnetic waves propagating in the medium. The vector no longer obeys the right-hand rule of the conventional medium, but follows the left-hand rule, so the medium is also called an anisotropic medium.

With the development of microwave technology, people pay more and more attention to small-sized microwave devices. Through the in-depth study of metaisotropic media, it is found that many microwave devices designed using metaisotropic media have good advantages, one of which is to use the anomalous electromagnetic properties of metaisotropic media to reduce the volume or occupied area of microwave devices. At present, various miniaturization based on anisotropic media have been continuously researched and designed, especially the ultra-small resonator researched and designed by Harbin Institute of Technology, which solved the theoretical size limit of resonator miniaturization and based on three-dimensional anisotropy. The problem that the miniaturized resonant cavity of the medium cannot be processed and manufactured under the existing technical level, but once the research and design are made, its structural size and the resonant frequency of the resonant cavity are fixed, it is not convenient to change according to different actual requirements in practical applications The resonant frequency of the resonant cavity lacks flexibility; the ultra-small resonant cavity is a rectangular resonant cavity, and the cavity of the resonant cavity is a hollow cuboid, which is relatively difficult in the process of manufacturing.

Contents of the invention

The purpose of the utility model is to provide a split-type resonator based on an anisotropic medium, which solves the problem of miniaturization of the resonant cavity and has the characteristics of flexibility in size and resonant frequency.

The purpose of this utility model is achieved in that:

The utility model is a split resonator based on anisotropic medium, which is characterized in that it includes a resonant cavity, a negative magnetic permeability medium and a feeder line, the resonant cavity includes two, the two resonant cavities are connected together, and the upper cover of the resonant cavity is set A through hole, the feeder is installed at the through hole, and the negative magnetic permeability medium is placed in the resonant cavity.

The split resonator based on the heterotropic medium of the present invention can also include:

1. The resonant cavity is a half cylinder, the two resonant cavities are equal in size, and the two resonant cavities are connected together through the rectangular surface of the half cylinder.

2. The ratio of the height of the negative magnetic permeability medium to the height of the air in the resonant cavity is equal to the ratio of the refractive index of the air to the refractive index of the negative magnetic permeability medium.

The utility model has the advantages that it is convenient to change the resonance frequency of the resonance cavity according to different actual requirements, has certain flexibility, and is simple and convenient to manufacture and process.

Description of drawings

Fig. 1 is the proportional schematic diagram of the structural size of the present utility model;

Figure 2 is a semi-cylindrical resonant cavity when the utility model does not contain an anisotropic medium;

Fig. 3 is the internal structure diagram of the split cylindrical resonator based on the heterotropic medium of the present invention;

Fig. 4 is the external block diagram of the utility model.

Detailed ways

The utility model is described in more detail below in conjunction with accompanying drawing example:

Combined with Figures 1 to 4, the utility model includes a resonant cavity, a negative magnetic permeability medium and a feeder line. The resonant cavity includes two, and the two resonant cavities are connected together. For the feeder, the medium with negative magnetic permeability is placed in the resonant cavity.

其中ε₀与μ₀分别为自由空间中的介电常数和磁导率，n₁＞0。在一定频段内介电常数ε₂＜0和磁导率μ₂＜0无损异向介质平面板，折射系数为

n₂在该频段内是一个实数。随着平面波在第一个介质板后，平面波进入异向介质板，最后在第二块介质板离开，功率流在第一块介质板的方向和第二块介质板的方向相同。在第一个介质板的功率流与相速方向是相同的，然而在第二块介质板两个矢量刚好相反。因此波矢k₂≡n₂k₀与波矢k₁≡n₁k₀方向完全相反，k₀代表自由空间的波矢，因此电磁波在通过这两层介质板后总的相位差为n₁k₀d₁-n₂k₀d₂。如果d₁与d₂的比值接近d₁/d₂＝n₂/n₁，则电磁波在通过这两层介质板前后总的相位差可变为零。虽然电磁波通过这两层介质板，但是可能不会产生相位差，这点足以在人们设计相关微波电路或特殊元器件时引起强烈的兴趣。除此之外，利用电磁波在负磁导率介质和负介电常数介质的交界面会发生隧道效应，使得分裂式谐振器的谐振频率不再依赖于谐振腔的尺寸。分裂式谐振器具有测量物料的水分及湿度的作用，其应用领域非常广泛。The basic properties of the anisotropic medium mentioned in the utility model are that the anisotropic medium without loss within a certain frequency range has a negative permittivity and a magnetic permeability at the same time, and the refractive index in the medium is also negative. Therefore, Veselago theoretically predicts that electromagnetic waves can propagate in this heterotropic medium. However, for such a monochromatic uniform plane wave in this anisotropic medium, the phase velocity and the direction of the Poynting vector wave generation are opposite to each other. Considering the dielectric constant ε ₁ >0 and the magnetic permeability μ ₁ >0 of ordinary lossless media, the refractive index is

Where ε ₀ and μ ₀ are the permittivity and permeability in free space, respectively, and n ₁ >0. In a certain frequency band, the dielectric constant ε ₂ <0 and the magnetic permeability μ ₂ <0 are lossless anisotropic dielectric plane plates, and the refractive index is

n ₂ is a real number in this frequency band. As the plane wave passes behind the first dielectric plate, the plane wave enters the anisotropic dielectric plate and finally exits at the second dielectric plate. The direction of power flow in the first dielectric plate is the same as the direction of the second dielectric plate. The power flow in the first dielectric plate is in the same direction as the phase velocity, while in the second dielectric plate the two vectors are just opposite. Therefore, the wave vector k ₂ ≡ _{n 2} k ₀ is completely opposite to the direction of the wave vector k ₁ ≡ _{n 1} k ₀ , and k ₀ represents the wave vector in free space, so the total phase difference of the electromagnetic wave after passing through these two dielectric plates is n ₁ k ₀ d ₁ -n ₂ k ₀ d ₂ . If the ratio of d ₁ to d ₂ is close to d ₁ /d ₂ =n ₂ /n ₁ , the total phase difference of the electromagnetic wave before and after passing through the two dielectric plates can become zero. Although electromagnetic waves pass through these two dielectric plates, there may not be a phase difference, which is enough to arouse strong interest when people design related microwave circuits or special components. In addition, the tunneling effect occurs at the interface between the negative magnetic permeability medium and the negative permittivity medium by using electromagnetic waves, so that the resonant frequency of the split resonator no longer depends on the size of the resonant cavity. The split resonator has the function of measuring the moisture and humidity of the material, and its application field is very wide.

Implementation mode 1:

A semicircular negative magnetic permeability medium occupying the lower side of the cavity is placed in the resonant cavity, wherein the negative magnetic permeability medium is filled with non-magnetic Teflon material with excellent anti-aging performance. The total thickness of the negative magnetic permeability medium is d ₁ , the thickness of the ordinary medium (air medium) filled above the negative magnetic permeability is d ₂ , and the ratio of d ₁ to d ₂ is close to d ₁ /d ₂ =n ₂ / n ₁ . Two semi-cylindrical resonant cavities are put together to form a resonator, and the through holes of the two semi-circular upper covers of the split resonator are respectively connected with input and output tuners, and the resonator tuner There is a loop feeder line inside the cylindrical resonant cavity to carry out the input and output of electromagnetic wave energy.

Claims (3)

1. A split resonator based on an anisotropic medium, characterized in that it includes a resonant cavity and a feeder, the resonant cavity includes two, the two resonant cavities are connected together, and the upper cover of the resonant cavity is provided with a through hole, and the feeder is installed on the through hole At the hole, the resonant cavity is filled with a negative magnetic permeability medium. 2. The split resonator based on anisotropic medium according to claim 1, characterized in that: the resonant cavity is a half cylinder, the two resonant cavities are equal in size, and the two resonant cavities pass through the half cylinder The rectangular faces are joined together. 3. The split resonator based on anisotropic medium according to claim 1 or 2, characterized in that: the ratio of the height of the negative magnetic permeability medium in the resonator cavity to the height of the air is equal to the ratio of the refractive index of the air to the The ratio of the refractive index of a negative permeability medium.

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