CN103150954B - Method for demonstrating shielding effect of photonic crystal - Google Patents

Abstract

The invention belongs to the technical field of radio communication and relates to a method for demonstrating a shielding effect of a photonic crystal. The method comprises the following steps of: longitudinally and transversely setting up and regularly arranging rectangular glass columns with higher refractive index according to the requirements of a woodpile structure to form a packed structure, and removing part of rectangular glass columns at the center of the packed structure to form a cavity convenient to place a mobile phone, wherein the rectangular glass columns around the cavity are regularly arranged; placing the mobile phone which is not switched off into the cavity, covering the rectangular glass columns at the upper part in an oppositely closing manner and measuring that the mobile phone does not receive an electromagnetic signal; and then after switching on the mobile phone into a call state, placing the mobile phone in the cavity and covering the rectangular glass columns at the upper part, so that the mobile phone signal is interrupted and the shielding effect is obvious. A packing method adopted by the invention is simple in process; demonstration cost is low; experiment stability is high; the method is simple and convenient to operate; the shielding effect is obvious; and a novel packed structure is realized for shielding the electromagnetic signal of the mobile phone.

Description

A kind of method of photonic crystal shield effectiveness demonstration

Technical field:

The invention belongs to telecommunication technology field, relate to a kind of with high index rectangle glass column three-D photon crystal demonstration technique that make, that can shield mobile phone signal, the particularly method of a kind of photonic crystal shield effectiveness demonstration.

Background technology:

In existing mechanics of communication, by mobile phone be placed on be sealed in metal box after due to shielding action, mobile phone cannot be received signal and send the sound, wireless reception is also had to identical situation; Mobile phone is placed in a rickle glass column or glass bead, and mobile phone still can receive that signal sounds; If glass column or glass bead is regularly arranged, likely, as metal, shield relevant electromagnetic signal, this just need to talk about from photonic crystal and forbidden band.Photonic crystal is a kind of new material occurring over nearly twenties years, it has the features such as periodic structure and transmission forbidden band, can provide and be different from former Electromagnetic Wave Propagation and control method, its appearance becomes the focus of domestic and international physics, chemistry, material and area researches such as communicating by letter.The architectural feature of photonic crystal is periodic arrangement and scattering unit: periodic arrangement can be summarized with Bravais lattice, as square and hexagon etc.; Scattering unit refers to geometry and the physical arrangement that forms photonic crystal cellular, and the factors such as size and shape of periodic arrangement and scattering unit can affect the bandgap structure of photonic crystal.

The typical structure of photonic crystal is to change in refractive index (specific inductive capacity in other words) cycle, this periodic variation requires the electromagnetic wavelength order of magnitude of transmission suitable, when relative index of refraction changes greatly, there will be and be similar to can be with and band gap in crystal, this material with photonic band gap and band gap is called as photonic crystal, the maximum feature of photonic crystal is to have forbidden photon band, the electromagnetic wave of some frequency can not be propagated in structure, at this moment material is the metal that the relative index of refraction of structure is larger, semiconductor, oxide and polymkeric substance etc., as glass passes through rare earth doped material (as Nd ₂o ₃), its refractive index can reach 2.2, even higher, meanwhile, by electromagnetic frequency photonic crystal, can be divided into microwave photon, infrared waves photon crystal, optical photon crystal etc., by its purposes photonic crystal, can be divided into photon crystal micro cavity, photon crystal wave-guide, photonic crystal light and photonic crystal antenna etc., mobile phone belongs to the microwave communication of centimetre-sized, so the forbidden band of the photon crystal structure adopting is also in centimetre-sized, the Spatial Dimension changing according to the refractive index cycle of photonic crystal, can be divided into 1-D photon crystal, 2 D photon crystal and three-D photon crystal.Only having three-D photon crystal is by the two media spatial-periodic structure that alternative arrangement forms in the dimension of three, space, in three dimensions all directions, all there is forbidden photon band, be that refractive index is all periodic arrangement at space three-dimensional, forbidden photon band will appear in all directions, can reach the object that shields mobile phone signal completely, shielding mobile phone signal adopts the three-dimensional photon crystal structure of Microwave Frequency Domain simple in structure, it is identical with the receive frequency of mobile phone that structure all has forbidden photon band in all directions, the signal of this frequency just can not arrive mobile phone, nonmetallic materials are passed through periodic arrangement, also can shield electromagnetic signals, thereby change people's traditional understanding, excite people to material new construction, new functional study interest, there is important theory and realistic meaning.

Summary of the invention:

The object of the invention is to overcome the shortcoming that prior art exists, the method of seeking to design the photonic crystal shield effectiveness demonstration of three layers of ordered structure that a kind of high index rectangle glass column forms, the photonic crystal of building demonstration packed structures has the function of shielding handset electromagnetic signal.

To achieve these goals, the present invention amasss the rectangle glass column of high index the requirement of (woodpiles) structure according to yard, build in length and breadth regularly arranged composition packed structures, central authorities in packed structures remove segment rectangle glass column formation cavity, be convenient to holding mobile telephone, cavity surrounding rectangle glass column is regularly arranged; Its concrete technology step is:

(1), parameter setting: adopt the refractive index of glass material of plane wave expansion method calculating and setting rectangle glass column used, size and the spread parameter of rectangle glass column; First the specific inductive capacity of electromagnetic wave and periodic distribution is launched into the stack of a series of plane waves, the more general Maxwell system of equations of substitution changed into an eigen[value, the eigenvalue that solves this eigen[value obtains the band gap Distribution Value of photon;

(2), the determining of rectangle glass column size and spacing: by given operation wavelength, medium refraction index, grating constant and structure forbidden band, the parameter of further adjusting and optimize structure, defines size and the spacing of rectangle glass column; The height and width of setting rectangle glass column are all a, mobile phone receive frequency is fMHz, wavelength is λ cm, by refractive index n=2.5 of rear-earth-doped rectangle glass column glass, by calculating the height and width a of rectangle glass column, be 0.492 λ, rectangle glass column mutual spacing is 2a, and the back gauge of both sides gets respectively 0 and 1.5a, makes the frequency of mobile phone be in the middle position in forbidden band;

(3), packed structures is built: choose the rectangle glass column of some same sizes, its height and width are a=0.492 λ, and length is greater than 20a, and rectangle glass column rule is piled up and four layers of circulation; Wherein, the 1st layer, laterally discharge, both sides are from side 1.5a, and middle every two adjacent rectangle glass columns are at a distance of the space of 2a; The 2nd layer, longitudinally discharge, both sides are from side 1.5a, and middle every two adjacent rectangle glass columns are at a distance of the space of 2a; The 3rd layer, laterally discharge, the side rectangle glass column that keeps to the side does not interspace, and all the other have the space of 2a; The 4th layer, longitudinally discharge, the side rectangle glass column that keeps to the side does not interspace, and all the other have the space of 2a; 5-8 layer repeats the circulation of 1-4 layer, and each four layers of circulation, and the multiple that total number of plies is 4, is built into the packed structures for photonic crystal demonstration;

(4) the bonding and cavity setting of packed structures: be divided into upper and lower part from the middle symmetry of packed structures, respectively by the bonding formation integrative-structure of seccotine for the lateral surface of upper and lower part, centre in lower part is removed na by the glass column of the superiors, n equals the arbitrary value in 1-6, form the cavity of 5a * na * a, in order to holding mobile telephone;

(5) experimental demonstration: the mobile phone of not cutting out puts into cavity, and opposite covers segment rectangle glass column, record mobile phone and can't accept electromagnetic signal; Again mobile phone is connected and after talking state, put into cavity, cover segment rectangle glass column, mobile phone signal interrupts, and shield effectiveness is obvious.

The periodic computing method of distribution of the photonic crystal medium dielectric constant microwave medium the present invention relates to are:

$\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)=\mathrm{\ϵ}(\stackrel{\→}{r}+\stackrel{\→}{R})---\left(1\right)$

Wherein, for lattice vector, it is photonic crystal basic vector.M ₁, m ₂, m ₃for arbitrary integer.The inverse of specific inductive capacity is also periodically, can will be expressed as the stack of a series of plane waves:

$\frac{1}{\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)}=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}\mathrm{\η}\left(\stackrel{\→}{G}\right)\exp (i\stackrel{\→}{G}\·\stackrel{\→}{r})---\left(2\right)$

Corresponding coefficient expands into:

$\mathrm{\η}\left(\stackrel{\→}{G}\right)=\frac{1}{V}\underset{W}{\∫}{\mathrm{\ϵ}}^{-1}\left(\stackrel{\→}{r}\right)\exp (i\stackrel{\→}{G}\·\stackrel{\→}{r})d^{3}r---\left(3\right)$

Wherein, V is the volume of photonic crystal Wigner-Sai Ci (Wigner-Seitz) structure cell, is write electromagnetic field as general type:

$\stackrel{\→}{E}\left(\stackrel{\→}{r}\right)=E_x\left(\stackrel{\→}{r}\right)\stackrel{\→}{i}+E_y\left(\stackrel{\→}{r}\right)\stackrel{\→}{j}+E_z\left(\stackrel{\→}{r}\right)\stackrel{\→}{k}---\left(4\right)$

$\stackrel{\→}{H}\left(\stackrel{\→}{r}\right)=H_x\left(\stackrel{\→}{r}\right)\stackrel{\→}{i}+H_y\left(\stackrel{\→}{r}\right)\stackrel{\→}{j}+H_z\left(\stackrel{\→}{r}\right)\stackrel{\→}{k}$

By Maxwell equation:

$\▿\×\stackrel{\→}{E}\left(\stackrel{\→}{r}\right)=-\mathrm{i\ω}{\mathrm{\μ}}_0\stackrel{\→}{H}\left(\stackrel{\→}{r}\right)$ （5）

$\▿=\stackrel{\→}{H}\left(\stackrel{\→}{r}\right)=\mathrm{i\ω}{\mathrm{\ϵ}}_0\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)\stackrel{\→}{E}\left(\stackrel{\→}{r}\right)$

Can obtain thus 6 scalar equations:

$\frac{\∂}{\∂y}{E}_z\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂z}{E}_y\left(\stackrel{\→}{r}\right)=-\mathrm{i\ω}{\mathrm{\μ}}_0{H}_x\left(\stackrel{\→}{r}\right)$

$\frac{\∂}{\∂x}{E}_z\left(\stackrel{\→}{r}\right)\frac{\∂}{\∂z}{E}_x\left(\stackrel{\→}{r}\right)=\mathrm{i\ω}{\mathrm{\μ}}_0{H}_y\left(\stackrel{\→}{r}\right)$

$\frac{\∂}{\∂x}{E}_y\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂y}{E}_x\left(\stackrel{\→}{r}\right)=\mathrm{i\ω}{\mathrm{\μ}}_0{H}_z\left(\stackrel{\→}{r}\right)$

$\frac{\∂}{\∂y}{H}_z\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂z}{H}_y\left(\stackrel{\→}{r}\right)=\mathrm{i\ω}{\mathrm{\ϵ}}_0\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)E_x\left(\stackrel{\→}{r}\right)$

$\frac{\∂}{\∂x}{H}_z\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂z}{H}_x\left(\stackrel{\→}{r}\right)=-\mathrm{i\ω}{\mathrm{\ϵ}}_0\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)E_y\left(\stackrel{\→}{r}\right)---\left(6\right)$

$\frac{\∂}{\∂x}{H}_y\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂y}{H}_x\left(\stackrel{\→}{r}\right)=\mathrm{i\ω}{\mathrm{\ϵ}}_0\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)E_z\left(\stackrel{\→}{r}\right)$

Equation is merged to the component with cancellation electromagnetic field in z direction:

$\frac{\∂}{\∂y}{E}_z\left(\stackrel{\→}{r}\right)=-\frac{i}{\mathrm{i\ω}{\mathrm{\ϵ}}_0}\left\{\frac{\∂}{\∂x}\frac{1}{\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)}\right[\frac{\∂}{\∂x}{H}_y\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂y}{H}_x\left(\stackrel{\→}{r}\right)\left]\right\}-\mathrm{i\ω}{\mathrm{\μ}}_0{H}_x\left(\stackrel{\→}{r}\right)$

$\frac{\∂}{\∂x}{E}_y\left(\stackrel{\→}{r}\right)=-\frac{i}{\mathrm{\ω}{\mathrm{\ϵ}}_0}\frac{\∂}{\∂y}\left\{\frac{1}{\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)}\right[\frac{\∂}{\∂x}{H}_y\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂y}{H}_x\left(\stackrel{\→}{r}\right)\left]\right\}+\mathrm{i\ω}{\mathrm{\μ}}_0{H}_z\left(\stackrel{\→}{r}\right)$

$\frac{\∂}{\∂z}{H}_x\left(\stackrel{\→}{r}\right)=\frac{i}{\mathrm{\ω}{\mathrm{\μ}}_0}\frac{\∂}{\∂x}[\frac{\∂}{\∂x}{E}_y\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂y}{E}_x\left(\stackrel{\→}{r}\right)]+{\mathrm{i\ω\ϵ}}_0\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)E_y\left(\stackrel{\→}{r}\right)---\left(7\right)$

$\frac{\∂}{\∂z}{H}_y\left(\stackrel{\→}{r}\right)=\frac{i}{{\mathrm{\ω\μ}}_0}\frac{\∂}{\∂y}[\frac{\∂}{\∂x}{E}_y\left(\stackrel{\→}{r}\right)-\frac{\∂}{\∂y}{E}_x\left(\stackrel{\→}{r}\right)]-\mathrm{i\ω}{\mathrm{\ϵ}}_0\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)E_x\left(\stackrel{\→}{r}\right)$

By four components of electromagnetic field, write as the form of plane wave stack:

$E_x\left(\stackrel{\→}{r}\right)=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}{E}_x\left(\stackrel{\→}{G}\right)\exp (i{\stackrel{\→}{k}}_G\·\stackrel{\→}{r}),$ $E_y\left(\stackrel{\→}{r}\right)=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}{E}_y\left(\stackrel{\→}{G}\right)\exp (i{\stackrel{\→}{k}}_G\·\stackrel{\→}{r})$ （8）

$H_x\left(\stackrel{\→}{r}\right)=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}{H}_x\left(\stackrel{\→}{G}\right)\exp (i{\stackrel{\→}{k}}_G\·\stackrel{\→}{r}),$ $H_y\left(\stackrel{\→}{r}\right)=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}{E}_y\left(\stackrel{\→}{G}\right)\exp (i{\stackrel{\→}{k}}_G\·\stackrel{\→}{r})$

Specific inductive capacity is also write as the form of plane wave stack:

$\mathrm{\ϵ}\left(\stackrel{\text{\→}}{r}\right)=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}\mathrm{\ϵ}\left(\stackrel{\→}{G}\right)\exp (i\stackrel{\→}{G}\·\stackrel{\→}{r}),$ $\frac{1}{\mathrm{\ϵ}\left(\stackrel{\→}{r}\right)}=\underset{\stackrel{\→}{G}}{\mathrm{\Σ}}{\mathrm{\ϵ}}^{-1}\left(\stackrel{\→}{G}\right)\exp (i\stackrel{\→}{G}\·\stackrel{\→}{r})---\left(9\right)$

By they difference substitution system of equations (7), just can obtain wave vector expression formula in the z-direction, because be three-dimensional structure, formula is comparatively complicated:

$I\left(\begin{array}{c}{E}_x\\ E_y\\ H_x\\ H_y\end{array}\right)=k_z\left(\begin{array}{c}{E}_x\\ E_y\\ H_x\\ H_y\end{array}\right),$ $I=\left(\begin{array}{cc}{I}_{11}& I_{12}\\ I_{21}& I_{22}\end{array}\right)---\left(10\right)$

Wherein:

$I_{11}=I_{22}=\left(\begin{array}{cc}-\left[G_z\right]& 0\\ 0& -\left[G_z\right]\end{array}\right)$

$I_{12}=\left(\begin{array}{cc}-\frac{1}{{\mathrm{\ω\ϵ}}_0}\left[k_x\right]{\mathrm{\ϵ}}_{G,G^{\′}}\left[k_y\right]& -\mathrm{\ω}{\mathrm{\μ}}_0{\mathrm{\δ}}_{G,G^{\′}}+\frac{1}{{\mathrm{\ω\ϵ}}_0}\left[k_x\right]{{\mathrm{\ϵ}}^{-1}}_{G,G^{\′}}\left[k_x\right]\\ {\mathrm{\ω\ϵ}}_0{\mathrm{\ϵ}}_{G,G^{\′}}& -\frac{1}{{\mathrm{\ω\ϵ}}_0}\left[k_y\right]{{{\mathrm{\ϵ}}^{-1}}_{G,G^{\′}}}^{}\left[k_x\right]\end{array}\right)---\left(11\right)$

$I_{21}=\left(\begin{array}{cc}-\frac{1}{{\mathrm{\ω\μ}}_0}\left[k_x\right]\left[k_y\right]& -\frac{1}{{\mathrm{\ω\μ}}_0}{\left[k_x\right]}^2+{\mathrm{\ω\ϵ}}_0{\mathrm{\ϵ}}_{G,G^{\′}}\\ \frac{1}{\mathrm{\ω}{\mathrm{\μ}}_0}{\left[k_y\right]}^2-{\mathrm{\ω\ϵ}}_0{\mathrm{\ϵ}}_{G,G^{\′}}& -\frac{1}{{\mathrm{\ω\ϵ}}_0}\left[k_y\right]{{\mathrm{\ϵ}}^{-1}}_{G,G^{\′}}\left[k_x\right]\end{array}\right).$

Compared with prior art, its build up process method is simple in the present invention, and demonstration cost is low, and experiment stability is high, easy and simple to handle, and shield effectiveness is obvious, is a kind of packed structures of Novel shielding handset electromagnetic signal.

Accompanying drawing explanation:

Fig. 1 is the packed structures agent structure principle schematic of photonic crystal shield effectiveness demonstration of the present invention.

Fig. 2 is the top packed structures principle schematic of the packed structures of photonic crystal shield effectiveness demonstration of the present invention.

Fig. 3 is the bottom packed structures principle schematic of the packed structures of photonic crystal shield effectiveness demonstration of the present invention.

Fig. 4 is the three-dimensional energy band diagram of photonic crystal shield effectiveness of the present invention, and horizontal ordinate is all directions, and ordinate is normalized frequency, normalization forbidden band frequency range from 0.4767 to 0.5075, and relative bandwidth is 6.3%.

Fig. 5 is the forbidden band enlarged drawing of photonic crystal shield effectiveness demonstration of the present invention.

Embodiment:

Below by embodiment, be also described further by reference to the accompanying drawings.

The present embodiment amasss the rectangle glass column of high index the requirement of (woodpiles) structure according to yard, build in length and breadth regularly arranged composition packed structures, central authorities in packed structures remove segment rectangle glass column formation cavity, be convenient to holding mobile telephone, cavity surrounding rectangle glass column is regularly arranged; Its concrete technology step is:

(1), parameter setting: adopt the refractive index of glass material of plane wave expansion method calculating and setting rectangle glass column used, size and the spread parameter of rectangle glass column; First the specific inductive capacity of electromagnetic wave and periodic distribution is launched into the stack of a series of plane waves, the more general Maxwell system of equations of substitution changed into an eigen[value, the eigenvalue that solves this eigen[value obtains the band gap Distribution Value of photon;

(3), the determining of rectangle glass column size and spacing: by given operation wavelength, medium refraction index, grating constant and structure forbidden band, the parameter of further adjusting and optimize structure, defines size and the spacing of rectangle glass column; The height and width of setting rectangle glass column are all a, mobile phone receive frequency is fMHz, wavelength is λ cm, by refractive index n=2.5 of rear-earth-doped rectangle glass column glass, by calculating the height and width a of rectangle glass column, be 0.492 λ, rectangle glass column mutual spacing is 2a, and the back gauge of both sides gets respectively 0 and 1.5a, makes the frequency of mobile phone be in the middle position in forbidden band;

(3), packed structures is built: choose the rectangle glass column of some same sizes, its height and width are a=0.492 λ, and length is greater than 20a, and rectangle glass column rule is piled up and four layers of circulation; Wherein, the 1st layer, laterally discharge, both sides are from side 1.5a, and middle every two adjacent rectangle glass columns are at a distance of the space of 2a; The 2nd layer, longitudinally discharge, both sides are from side 1.5a, and middle every two adjacent rectangle glass columns are at a distance of the space of 2a; The 3rd layer, laterally discharge, the side rectangle glass column that keeps to the side does not interspace, and all the other have the space of 2a; The 4th layer, longitudinally discharge, the side rectangle glass column that keeps to the side does not interspace, and all the other have the space of 2a; 5-8 layer repeats the circulation of 1-4 layer, and each four layers of circulation, and the multiple that total number of plies is 4, is built into the packed structures for photonic crystal demonstration;

(4) the bonding and cavity setting of packed structures: be divided into upper and lower part from the middle symmetry of packed structures, respectively by the bonding formation integrative-structure of seccotine for the lateral surface of upper and lower part, centre in lower part is removed na by the glass column of the superiors, n equals the arbitrary value in 1-6, form the cavity of 5a * na * a, in order to holding mobile telephone;

(5) experimental demonstration: the mobile phone of not cutting out puts into cavity, and opposite covers segment rectangle glass column, record mobile phone and can't accept electromagnetic signal; Again mobile phone is connected and after talking state, put into cavity, cover segment rectangle glass column, mobile phone signal interrupts, and shield effectiveness is obvious.

Embodiment 1:

It is example that the present embodiment be take mobile phone receive frequency f=900MHz, and its wavelength is 33cm, and the refractive index of selecting rear-earth-doped glass is 2.5, and longitudinally glass column length is a, and laterally glass column length is b, and glass column height is c; Laterally glass column d and longitudinally glass column e; The length and width height of glass column is f, and the spacing of the glass column that keeps to the side is g, and the spacing of intermediate glass post is h; The floor height of first half layer is j, and the floor height of the latter half is k, and the length of intercepting glass column is m, and by calculating, the value that glass column is wide and high is 0.492 λ cm=16.24cm; First make the rectangle glass column of some same sizes, wide and height be all 16.24cm, and long is 3.08m, the 1st layer: laterally, both sides are from side 24.36cm, the middle space of 32.48cm apart; The 2nd layer: longitudinally, both sides are from side 24.36cm, middle at a distance of the space of 32.48cm; The 3rd layer: laterally, the side glass column that keeps to the side does not interspace, and all the other have the space of 32.48cm; The 4th layer, longitudinally, the side glass column that keeps to the side does not interspace, and all the other have the space of 32.48cm; 5-16 layer repeats circulation above, the rectangle glass column of 1-8 layer and 9-16 layer is used respectively double strength glass glue bond, from 8 and 9 layers, structure is divided into upper and lower part like this, and the glass column in the latter half central authorities of structure removes 32.48cm(n=2), form a cavity that size is 81.2cm*32.48cm*16.24cm, be used for holding mobile telephone; The mobile phone of not cutting out puts into cavity, cover the first half, mobile phone just can't accept electromagnetic signal; Equally, mobile phone is connected and put into structure, cover the first half, mobile phone signal interrupts, and the mobile phone signal conductively-closed in microcavity is described.

Embodiment 2:

It is example that the present embodiment be take mobile phone receive frequency f=1800MHz, and its wavelength is 16.5cm, and the refractive index by rear-earth-doped glass is 2.5, and longitudinally glass column length is a, and laterally glass column length is b, and glass column height is c; Laterally glass column d and longitudinally glass column e; The length and width height of glass column is f, and the spacing of the glass column that keeps to the side is g, and the spacing of intermediate glass post is h; The floor height of first half layer is j, and the floor height of the latter half is k, and the length of intercepting glass column is m, and by calculating, the value that glass column is wide and high is 0.492 λ cm=8.12cm; First make the rectangle glass column of some same sizes, wide and height is all 8.12cm, and long is 1.54m; The 1st layer: laterally discharge, both sides are from side 12.18cm, middle at a distance of the space of 16.24cm; The 2nd layer: longitudinally discharge, both sides are from side 12.18cm, middle at a distance of the space of 16.24cm; The 3rd layer: laterally discharge again, the side glass column that keeps to the side does not interspace, and all the other have the space of 16.24cm; The 4th layer, more longitudinally discharge, the side glass column that keeps to the side does not interspace, and all the other have the space of 16.24cm; 5-16 layer repeats circulation above, the rectangle glass column of 1-8 layer and 9-16 layer is used respectively to double strength glass glue bond, between 8 and 9 layers, structure is divided into upper and lower part, and the glass column in the latter half central authorities of structure removes 32.48cm(n=4), form a cavity that size is 40.6cm*32.48cm*8.12cm, be used for holding mobile telephone; The mobile phone of not cutting out puts into cavity, cover the first half, mobile phone just can't accept electromagnetic signal; Equally, mobile phone is connected, put into cavity, cover the first half, mobile phone signal interrupts, and the mobile phone signal conductively-closed in microcavity is described.

Claims (1)

1. the method for photonic crystal shield effectiveness demonstration, it is characterized in that the rectangle glass column of high index according to the requirement of long-pending (woodpiles) structure of yard, build in length and breadth regularly arranged composition packed structures, central authorities in packed structures remove segment rectangle glass column formation cavity, be convenient to holding mobile telephone, cavity surrounding rectangle glass column is regularly arranged; Its concrete technology step is:

(1), parameter setting: adopt the refractive index of glass material of plane wave expansion method calculating and setting rectangle glass column used, size and the spread parameter of rectangle glass column; First the specific inductive capacity of electromagnetic wave and periodic distribution is launched into the stack of a series of plane waves, the more general Maxwell system of equations of substitution changed into an eigen[value, the eigenvalue that solves this eigen[value obtains the band gap Distribution Value of photon;

(2), the determining of rectangle glass column size and spacing: by given operation wavelength, medium refraction index, grating constant and structure forbidden band, the parameter of further adjusting and optimize structure, defines size and the spacing of rectangle glass column; The height and width of setting rectangle glass column are all a, mobile phone receive frequency is fMHz, wavelength is λ cm, by refractive index n=2.5 of rear-earth-doped rectangle glass column glass, by calculating the height and width a of rectangle glass column, be 0.492 λ, rectangle glass column mutual spacing is 2a, and the back gauge of both sides gets respectively 0 and 1.5a, makes the frequency of mobile phone be in the middle position in forbidden band;

(3), packed structures is built: choose the rectangle glass column of some same sizes, its height and width are a=0.492 λ, and length is greater than 20a, and rectangle glass column rule is piled up and four layers of circulation; Wherein, the 1st layer, laterally discharge, both sides are from side 1.5a, and middle every two adjacent rectangle glass columns are at a distance of the space of 2a; The 2nd layer, longitudinally discharge, both sides are from side 1.5a, and middle every two adjacent rectangle glass columns are at a distance of the space of 2a; The 3rd layer, laterally discharge, the side rectangle glass column that keeps to the side does not interspace, and all the other have the space of 2a; The 4th layer, longitudinally discharge, the side rectangle glass column that keeps to the side does not interspace, and all the other have the space of 2a; 5-8 layer repeats the circulation of 1-4 layer, and each four layers of circulation, and the multiple that total number of plies is 4, is built into the packed structures for photonic crystal demonstration;

(4) the bonding and cavity setting of packed structures: be divided into upper and lower part from the middle symmetry of packed structures, respectively by the bonding formation integrative-structure of seccotine for the lateral surface of upper and lower part, centre in lower part is removed na by the glass column of the superiors, n equals the arbitrary value in 1-6, form the cavity of 5a * na * a, in order to holding mobile telephone;

(5) experimental demonstration: the mobile phone of not cutting out puts into cavity, and opposite covers segment rectangle glass column, record mobile phone and can't accept electromagnetic signal; Again mobile phone is connected and after talking state, put into cavity, cover segment rectangle glass column, mobile phone signal interrupts, and shield effectiveness is obvious.