Specific embodiment
Below by drawings and Examples, technical scheme is described in further detail.
As shown in Fig. 2 it is the two-dimensional piezoelectric photonic crystal radio frequency acoustic wave guide structural representation of the embodiment of the present invention.
Two-dimensional piezoelectric photonic crystal radio frequency acoustic wave guide includes two-dimensional metallic dot matrix 1 and piezoelectric substrate 2.Two-dimensional metallic dot matrix 1
With y directions lattice paprmeter be in the form of 1.5~4.5 times of x directions lattice paprmeter layout on piezoelectric substrate 2.Wherein, two-dimensional gold
Category dot matrix can be circular, square, oval or rectangle etc. using the metal materials such as aluminium, copper, tungsten or gold, its shape of cross section.
The band connection frequency f in the x directions of two-dimensional metallic dot matrix 1x,pWith stop-band frequency fx,sBy formula(1)With(2)It is calculated,
fX, p=Vp/a (1)
fx,s=Vs/a (2)
A for two-dimensional metallic dot matrix 1 x directions lattice paprmeter, VpAnd VsFor passband different in two-dimensional metallic dot matrix 1 and resistance
With corresponding acoustic wave mode speed, generally there are multiple values.
Likewise, the band connection frequency f in the y directions of two-dimensional metallic dot matrix 1y,pWith stop-band frequency fy,sBy formula(3)With(4)Meter
Obtain,
fy,p=Vp/b (3)
fy,s=Vs/b (4)
B is the y directions lattice paprmeter of two-dimensional metallic dot matrix 1.
If during equal with the y directions lattice paprmeter b i.e. two-dimensional symmetric metal lattice of x directions lattice paprmeter a, y directions
It is the corresponding stop-band frequency in x directions that stop-band frequency is corresponding, i.e. fy,s=Vs/b=Vs/a=fx,s, so x directions and y directions are simultaneously anti-
Acoustic surface wave energy is penetrated, acoustic waveguide function can not be realized.
In order to realize acoustic waveguide function, then need to change lattice paprmeter a and b, make the stop-band frequency correspondence x directions on y directions
On passband.Assume that a is constant, change b, then the stop-band frequency and band connection frequency in x directions is constant, and the stop-band frequency in y directions
Can change with band connection frequency.Adjustment b so that stop-band frequency f on y directions 'y,sPassband f on correspondence x directionsx,p, so fx,p=
f’y,s=Vs/b.Thus formula can be obtained(5), by formula(5)It can be seen that the y directions stop-band frequency and x of two-dimensional symmetric metal lattice
Direction band connection frequency ratio is equal to the lattice paprmeter ratio in y directions and x directions.
fy,s/fx,p=(Vs/a)/(Vs/b)=b/a (5)
Therefore according to the x directions band connection frequency and y directions stop-band frequency ratio adjustment two-dimensional metallic of two-dimensional symmetric metal lattice
The x directions of dot matrix 1 and y directions lattice paprmeter ratio can just realize that surface acoustic wave x directions in piezoelectric photonic crystal efficiently pass through,
And realize that Energy Efficient reflects in y directions, so as to realize acoustic waveguide function.
But, the x directions band connection frequency of the two-dimensional symmetric metal lattice 1 on the piezoelectric substrate 2 of different materials and y directions hinder
Band frequency is than difference, therefore the x directions lattice paprmeter after adjusting is also different from y directions lattice paprmeter ratio.
In the present embodiment, piezoelectric substrate 2 adopts lithium tantalate, lithium niobate, quartz, two-dimensional metallic dot matrix 1 to adopt metallic aluminium.Two
All in the λ scopes of 0.5% λ to 10%, λ is surface acoustic wave wavelength to dimension aluminium dot matrix thickness, within the range, two-dimensional lattice frequency response point
Cloth is held essentially constant.
Specifically, piezoelectric substrate 2 adopts 360During YX lithium tantalates, as shown in figure 3, it is 360YX lithium tantalates are piezoelectric substrate
Two-dimensional symmetric aluminium pixel frequency response diagram.It can be seen that the band connection frequency f that x directions ripple is little, relative amplitude is highx,pPoint
Cloth near 0.2, y directions stop-band frequency value fy,sIt is distributed near 0.3~0.36,0.41,0.65,0.75,0.85,0.9, because
This is 1.5~4.5 than b/a values scope than the lattice paprmeter after adjustment according to x directions band connection frequency and y directions stop-band frequency.
When piezoelectric substrate 2 adopts Y-Z lithium niobates, as shown in figure 4, it is the two-dimensional symmetric that Y-Z lithium niobates are piezoelectric substrate
Aluminium pixel frequency response diagram.It can be seen that the band connection frequency f that x directions ripple is little, relative amplitude is highx,pIt is distributed in 0.22 attached
Closely, stop-band frequency value f in y directionsy,sIt is distributed near 0.41~0.48,0.58, therefore according to x directions band connection frequency and y directions
Stop-band frequency is 1.9~2.6 than b/a values scope than the lattice paprmeter after adjustment.
Piezoelectric substrate 2 adopts 1280During YX lithium niobates, as shown in figure 5, it is 1280YX lithium niobates are the two dimension of piezoelectric substrate
Symmetrical aluminium pixel frequency response diagram.It can thus be seen that the band connection frequency f that x directions ripple is little, relative amplitude is highx,pIt is distributed in
Near 0.22, stop-band frequency value f in y directionsy,sIt is distributed near 0.38~0.45,0.5,0.55,0.71,0.84,0.9, therefore
It is 1.7~4.1 than b/a values scope than the lattice paprmeter after adjustment according to x directions band connection frequency and y directions stop-band frequency.
When piezoelectric substrate 2 adopts ST-X quartzy, as shown in fig. 6, it is the two-dimensional symmetric aluminium that ST-X quartz is piezoelectric substrate
Pixel frequency response diagram.It can thus be seen that the high band connection frequency f of the little relative amplitude of x directions ripplex,pIt is distributed near 0.2, y
Stop-band frequency value f in directiony,sIt is distributed near 0.31,0.39,0.5,0.55, therefore according to x directions band connection frequency and y directions
Stop-band frequency is 1.6~2.6 than b/a values scope than the lattice paprmeter after adjustment.
Ratio, the y directions lattice of the two-dimensional metallic dot matrix 1 that can be summarized as on piezoelectric substrate 2 are adjusted by above lattice paprmeter
Constant is 1.5~4.5 times of x directions lattice paprmeter.
By the lattice paprmeter ratio for changing the two-dimensional metallic dot matrix x directions on piezoelectric substrate and y directions so that x directions lead to
Band correspondence y directions stopband, makes surface acoustic wave efficiently pass through in x directions in the two-dimensional piezoelectric phonon crystal, and realizes energy in y directions
Amount effectively reflection, finally makes energy propagate in the x direction, so as to realize radio frequency acoustic waveguide function.
As shown in fig. 7, it is 1280YX lithium niobates modulate aluminium pixel frequency response diagram for the two-dimentional sound wave of piezoelectric substrate.This
The piezoelectric substrate of the two-dimensional piezoelectric photonic crystal radio frequency acoustic wave guide in embodiment adopts 1280YX lithium niobates, metal lattice adopts aluminium
Material, x directions lattice period is 10 microns, and the y directions point real cycle is that x directions are brilliant for 18.6 microns, i.e. y directions lattice paprmeter
1.86 times of lattice constant, cylindrical metal aluminium dot matrix radius is 7 microns.As seen from Figure 7, frequency 0.21~0.25 is for x side
To for band connection frequency, for y directions are stop-band frequency, therefore surface acoustic wave frequency is at 0.21~0.25, the two-dimensional piezoelectric sound
Sub- crystal can realize surface acoustic wave Energy Efficient reflection in y-direction, in the x direction efficient propagation.
The substrate of the two-dimensional piezoelectric photonic crystal radio frequency acoustic wave guide that the present invention is provided adopts piezoelectric, by piezoelectricity base
The regulation in two-dimensional metallic dot matrix x directions and y directions lattice paprmeter ratio on piece, makes the surface acoustic wave of radio band in phonon crystal
Realize propagating on x directions, realize that energy reflects in y-direction, so as to realize radio band acoustic waveguide function.
Above-described specific embodiment, has been carried out further to the purpose of the present invention, technical scheme and beneficial effect
Describe in detail, should be understood that the specific embodiment that the foregoing is only the present invention, be not intended to limit the present invention
Protection domain, all any modification, equivalent substitution and improvements within the spirit and principles in the present invention, done etc. all should include
Within protection scope of the present invention.