JPH0715272A - Surface acoustic wave device and information processor using the same - Google Patents

Abstract

PURPOSE:To provide a desired characteristic by unifying stress distribution formed by the cross part if electrode fingers by widening the arrangement intervals of paired electrode fingers at the electrode finger cross part along a direction where the the electrode fingers are extended. CONSTITUTION:An interdigital electrode 2 provided with a pair of electrode fingers 3a and 3b and a pair of common electrodes 2a and 2b is formed on a piezoelectric substrate 1. Concerning the electrode fingers 3a and 3b, the almost top of the faced electrode fingers 3b and 3a sides is constituted by providing inclined parts 6b and 6a, and the interval of the electrode fingers 3a and 3b is gradually widened toward the terminal part of an electrode finger cross part 4. In this case, an electric field to be generated at the electrode finger cross part 4 is almost uniform electric field intensity distribution inside the electrode finger cross part 4. Therefore, the distortion of the piezoelectric substrate 1 is made uniform as well, and the degradation of a frequency characteristic or a group delay characteristic caused by the disturbance of stress distribution can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving the performance of a surface acoustic wave device without increasing the number of manufacturing steps, and to an application device of the surface acoustic wave device.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, an electrode finger crossing portion 4 ("two bus bars 2a, 2
b and a portion surrounded by the pair of electrode fingers 3a and 3b in the direction in which the electrode fingers extend, the portion "where the two electrode fingers intersect" will be referred to as "below"). Was there. In FIG. 3, 101 is a comb-shaped electrode provided with electrode fingers, and 100 is an excitation source intensity distribution (for example, electric field intensity). Generally, in such an electrode finger crossing portion 4, the electric field intensity distribution between the crossing electrode fingers 4 is not uniform in the extending direction of the electrode fingers.

That is, the electric field strength becomes stronger toward the end of the electrode finger crossing portion due to the terminal effect of the electrode fingers, the sheet resistance, etc. Therefore, the electric field is excited by the piezoelectricity which is a characteristic of the substrate in accordance with the electric field. The distribution of the surface acoustic wave source, that is, the stress distribution, becomes non-uniform as shown in FIG. 3 in the direction in which the electrodes extend, and it is not possible to obtain desired characteristics, that is, a uniform stress distribution in the intersection. However, it is a cause of deterioration of the frequency characteristics of the amplitude and the group delay characteristics of the surface acoustic wave device.

Therefore, a conventional technique, for example, actual fairness 2-1
In Japanese Patent No. 5390, the tip corners of the electrode fingers are configured such that the radius of curvature R and the electrode finger width m have a relationship of R ≧ (m / 3), or the tip corners of the electrode fingers are concave. It has been proposed to perform processing such as notching on the. This technology
This has the advantage that the leakage electric field can be suppressed at the crossing ends of the electrode fingers of the interdigital transducer.

[0005]

However, in the above-mentioned prior art, with respect to the non-uniformity of the stress distribution, no consideration is given to measures against the non-uniformity, and the above-mentioned problem is solved. It is impossible to obtain a uniform stress distribution only by processing the electrode finger shape.

It is an object of the present invention to provide a surface acoustic wave device which takes measures against the above-mentioned non-uniformity of stress distribution, and in particular has desired frequency amplitude characteristics, group delay characteristics and the like required by a designer.

[0007]

In order to solve the above problems, the following means are considered. A substrate and at least one interdigital electrode provided on the substrate, two common electrodes (referred to as “bus bars”) having different electrical polarities forming the interdigital electrode, and a pair extending from each bus bar. Surface acoustic wave that excites a surface acoustic wave according to an electric field generated at an electrode finger crossing portion, which is an area where the pair of electrode fingers intersects in the direction in which the electrode fingers extend in the region including the electrode fingers. In the device, the 1 at the electrode finger intersection
The surface acoustic wave device has a location in which the pair of electrode fingers are arranged at intervals that extend along the direction in which the electrode fingers extend.

A surface acoustic wave device comprising a substrate and an input electrode and an output electrode provided on the substrate, wherein one of the input electrode and the output electrode has an electrical polarity provided by the electrode. Of two different busbars and a pair of electrode fingers extending from each busbar.
The arrangement interval of the pair of electrode fingers at the electrode finger intersection portion, which is a region where the pair of electrode fingers intersects in the direction in which the electrode fingers extend,
Having a part that extends along the direction in which the electrode fingers extend,
Further, it is also preferable that the lengths of the electrode finger intersections are not the same in all the electrode finger intersections, that is, weighting is performed.

Further, between the input electrode and the output electrode,
It is also preferable to provide a sound velocity correction thin film.

The electrode fingers are preferably split connect type electrode fingers.

[0011]

The characteristic of the electrode finger pair which has been formed with a constant interval by forming the interval between the pair of intersecting electrode fingers wider toward the end of the electrode finger intersection. That is, the nonuniformity of the electric field strength distribution shown in FIG. 3 can be improved to a substantially uniform electric field strength distribution in the extending direction of the electrode fingers at the electrode finger crossing portion.

This is because by widening the electrode finger spacing in the portion where the electric field strength is strong compared to the electrode finger spacing in the portion where the electric field strength is weak and weakening the electric field strength, in the direction in which the electrode fingers at the electrode finger crossing portion extend, It is realized by keeping the electric field strength constant.

Therefore, the stress distribution generated corresponding to the electric field distribution becomes substantially uniform in the electrode finger crossing portion, and the surface acoustic wave device having the frequency amplitude characteristic, the group delay characteristic and the like required by the designer is realized. It becomes possible to do.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment according to the present invention. Hereinafter, for simplification, one electrode finger intersection 4
Only this will be considered, and this will be illustrated, and illustration of other electrode finger intersections will be omitted.

In this embodiment, a comb-shaped electrode 2 having a pair of electrode fingers 3a and 3b and bus bars 2a and 2b is formed on a piezoelectric substrate 1. Reference numeral 4 indicates an electrode finger crossing portion, and 5 indicates a surface acoustic wave.

The structure will be specifically described as follows. As the piezoelectric substrate 1, for example, a 128 ° rotation Y-axis cut X-axis propagation lithium niobate single crystal is used, and an input interdigital transducer electrode 2 having a metal thin film such as Al deposited thereon is formed on the substrate 1. , The interdigital electrode 2 is composed of bus bars 2a and 2b having different polarities, and electrode fingers 3a and 3b extending from the bus bars 2a and 2b. It is configured to have an intersection.

The electric signal input to the interdigital transducer 2 is
It is converted into surface acoustic waves 5, propagates on the piezoelectric substrate 1, and is converted into an electric signal by the output interdigital transducer (not shown here).

Further, the electrode fingers 3a and 3b are formed with inclined portions 6b and 6a near the tips of the electrode fingers 3b and 3a facing each other.
The distance (d: d is not shown) between the electrodes is widened toward the end of the electrode finger crossing portion 4.

FIG. 2 is a diagram showing the effect of the present invention.

The electric field generated at the electrode finger crossing portion 4 as described above has a substantially uniform electric field strength distribution in the electrode finger crossing portion 4.

The reason for the uniformity will be described below.

Therefore, due to this electric field, the piezoelectric substrate 1
Since the strain excited by the piezoelectricity, which is a property of, that is, the stress distribution that is the excitation source of the surface acoustic wave 5 is also uniform in the electrode finger crossing portion 4, the frequency characteristic, the group due to the disturbance of the stress distribution, It is possible to suppress the deterioration of delay characteristics and the like, and it is possible to obtain the characteristics required by the designer.

As described above, FIG. 3 is a diagram showing a conventional electrode finger crossing and its electric field intensity distribution. The electrode finger crossing portion 4 formed by the conventional interdigital transducer 101 generates the excitation source intensity distribution 100.

In the example shown in FIG. 3, the excitation source intensity distribution 100
The strength at the end portion of the electrode finger crossing portion 4 is about “2.35 times” the strength at the central portion of the electrode finger crossing portion 4 in the electric field strength distribution 100.

According to "Science Technical Report US92-54 (1992-09)",
The relationship between the metallization ratio and the conversion ratio (also referred to as "transformer ratio", which is the conversion ratio of electric signal energy to surface acoustic wave energy) is shown in FIG.

Here, the "metallization ratio" means the ratio of the electrode finger width to the electrode finger array period, as shown in FIG.

In FIG. 4, the transform ratio is a value when the characteristic impedance of the surface acoustic wave when viewed from the input side is normalized to "1", and is a relative value depending on the metallization ratio. Because of the relationship, the transformation ratio may be "1" or more.

When the metallization ratio is about 1.0, the conversion ratio is about 1.2, and when the metallization ratio is about "0", the conversion ratio is about 0.5.
When the metallization ratio is about 1.0, the conversion ratio is
The metallization ratio is about 2.4 times (> 2.35) the conversion ratio when it is almost "0".

This means that by changing the metallization ratio, that is, by changing the distance d between the electrode fingers, it is possible to uniformly correct the disturbed distribution so that the stress distribution of the excitation source becomes uniform. Shows.

That is, the transformer ratio is reduced by widening the distance between the electrode fingers of the portion having a high electric field strength as compared with the distance between the electrode fingers of the portion having a low electric field strength, and the electrode fingers of the electrode finger crossing portion 4 are A uniform stress distribution is generated in the extending direction. Although only one electrode finger crossing portion 4 of the input interdigital transducer 2 is shown here, it goes without saying that the present invention can be similarly applied to the output interdigital transducer.

FIG. 5 shows a second embodiment according to the present invention.

On the piezoelectric substrate 1, electrode fingers 7a and 7b extending from the bus bars 2a and 2b are provided. 4 is
One electrode finger crossing portion is shown, and for convenience of explanation, only one electrode finger crossing portion actually exists.

Electrode fingers 7 extending from the bus bars 2a, 2b
The side shapes of a and 7b are curved, and the distance d between the electrode fingers 7a and 7b is widened toward the end of the electrode finger crossing portion 4.

At the electrode finger crossing portion 4 in this embodiment, the distance d between the electrode fingers 7a and 7b is continuously widened, so that a more uniform electric field intensity distribution can be obtained. When the distance d between the electrode fingers 7a and 7b is a catenary (hyperbolic cosine) shape as shown below,
It has been confirmed that a more uniform stress distribution can be obtained.
That is, the electrode finger 7 is made to satisfy the condition of the following expression 1.
The distance d between a and 7b may be set.

D = {cosh (a · x)} (cosh represents a hyperbolic cosine) (Equation 1) where a is a real number 0 <a <5, x = w / L, w: electrode finger crossing The distance from the center of the portion 4 in the direction in which the electrode fingers extend L: Half the length of the crossing length of the pair of electrode fingers in the direction in which the electrode fingers extend in the electrode finger crossing portion 4.

FIG. 6 shows a third embodiment according to the present invention.

An interdigital transducer 8 for input is provided on the piezoelectric substrate 1.

The other structure is the same as that of the first embodiment according to the present invention.

In the interdigital electrode 8, the electrode finger crossing length, which is the length of the crossing portion of the pair of electrode fingers of the plurality of electrode fingers provided in the electrode in the extending direction, is changed to change the electrode finger crossing length. Is weighted.

Increasing the degree of design freedom by weighting is a known technique. Therefore, also in the surface acoustic wave device according to the present invention, there is an effect that the degree of freedom in design is increased by weighting the electrode finger crossing length.

Each crossing portion is, for example, as represented by the electrode finger crossing portion 4, near the end portion of the electrode finger, the inclined portion 6 is formed.
It is configured to have a and 6b.

According to this embodiment, the stress distribution excited by the electrode finger crossing portion 4 having an arbitrary electrode finger crossing width can be made substantially uniform, and desired frequency amplitude characteristics, group delay characteristics, etc. can be obtained. The surface acoustic wave device can be designed to obtain.

FIG. 7 shows a fourth embodiment according to the present invention.

On the piezoelectric substrate 1, an input interdigital electrode 9, an output interdigital electrode 10, and a shield electrode 11 are provided.

Interdigital electrode 9 and interdigital electrode 1
In 0, all of the electrode finger intersections defined for the pair of electrode fingers of each electrode have the same intersection width.

The shield electrode 11 existing between the input interdigital electrode 9 and the output interdigital electrode 10 is
In order to correct the sound velocity of the surface acoustic wave 5, that is, in order to equalize the propagation length of the surface acoustic wave, the correction metal films 12a, 1
2b, 12c and 12d are provided.

In this embodiment, the correction metal film 12a,
12b, 12c and 12d are interdigital electrodes 9 and
It has the same film thickness as the interdigital transducer 10 and is present at all positions in the extending direction of the electrode fingers existing in the propagation path 13 of the surface acoustic wave 5 shown by the broken line portion with respect to the surface acoustic wave propagation direction. The width b satisfies the following condition (Equation 2).

Now, in the propagation direction of the surface acoustic wave 5, the correction metal films 12a, 12b, 12 are surrounded by the center lines of the interdigital transducers 9 and 10.
The length of the metal film excluding c and 12d is c, and the maximum value of the length is cmax. Further, in the propagation direction of the surface acoustic wave 5, the correction metal film 12 is formed in a region connecting the outermost edges of each of the interdigital transducer 9 and the interdigital transducer 10.
The length of the metal film excluding a, 12b, 12c, and 12d is d, and the maximum value of the length is dmax.

At this time, the following expression 2 is established at all positions in the propagation direction 13 of the surface acoustic wave 5 in the extending direction of the electrode fingers shown by the broken line portion.

Cmax-c ≦ b ≦ dmax-d (Formula 2) In this embodiment, the interdigital transducer 9 and the interdigital transducer 10 are provided.
Since the surface acoustic wave 5 propagating between the electrodes has the same propagation length at any position in the extending direction of the electrode fingers and passes through the metal film surface and the piezoelectric substrate 1, any position in the extending direction of the electrode fingers. Also in, the speed of sound becomes equal. Therefore, it is possible to obtain better group delay characteristics and the like.

FIG. 8 shows a fifth embodiment according to the present invention.

The interdigital transducer 14 for input is provided on the piezoelectric substrate 1. Other configurations are similar to those of the first embodiment according to the present invention.

The so-called split-connect type electrode fingers 15a and 15b, each of which has two divided electrode fingers, are provided from each of the bus bars 14a and 14b of the interdigital transducer 14 having different polarities. Is growing,
The electrode finger crossing portion 4 is configured.

The electrode fingers on the side adjacent to the electrode finger crossing portion 4 of the split connect type electrode fingers 15a and 15b have inclined portions 16a and 16b, and the split connect type electrode fingers 15a and 15b. The distance between and becomes wider toward the end of the electrode finger crossing portion 4.

According to the present embodiment, in addition to the effect of the first embodiment according to the present invention, it is effective in suppressing unnecessary reflection in the electrode, and further, the degree of freedom in design is increased. This is the so-called split connect type electrode fingers 15a and 15b.
This is because you are using. The effect of the split connect type electrode fingers themselves is known.

FIG. 9 shows a sixth embodiment according to the present invention.

The configuration other than the split connect type electrode fingers 17a and 17b according to the present embodiment is the same as that of the fifth embodiment according to the present invention.

Each of the split-connect type electrode fingers 17a and 17b has a correction metal film portion 18a between the two electrode fingers.
And 18b. These correction metal film part 1
Due to 8a and 18b, in addition to the fifth embodiment of the present invention, the correction metal film 12 of the fourth embodiment of the present invention
The same effect as a, 12b, 12c, 12d can be obtained.

FIG. 10 shows a seventh embodiment according to the present invention.

The configuration other than the split connect type electrode fingers 19a and 19b of the present embodiment is the same as that of the sixth embodiment according to the present invention.

Each of the split-connect type electrode fingers 19a and 19b is provided with correction electrodes 20a and 20b between the tips of the two electrode fingers.

In this embodiment, the correction electrodes 20a and 20a are
b is split-connect type electrode fingers 19a and 19
Since it is provided at the tip of b,
The same effect as that of the embodiment can be obtained. Further, since the correction electrode is connected to the tip end portion of the electrode finger formed of a thin film, it is possible to reduce the decrease in yield due to disconnection of the electrode finger or the like. Furthermore, it is also preferable to combine the seventh embodiment of the present invention and the sixth embodiment of the present invention.

FIG. 11 shows an eighth embodiment according to the present invention.

Here, five electrode finger crossing portions 41, 42, 43, 44, 4 of the weighted interdigital transducer 40 for input are used.
5 is shown, and other electrode finger intersections are not shown.

From the bus bars 40a and 40b having the characteristics of different polarities, the split connect type electrode fingers 46a, 47a, which are described in the fifth embodiment of the present invention, can be used.
48a, 46b, 47b and 48b are extended, and FIG.
, The electrode finger intersections 41, 42, 43, 44,
It comprises 45.

In this configuration example, the electrode finger crossing portions 41, 4
Nos. 2, 43, 44, and 45 have their respective center positions of the intersections of the electrode fingers in the extending direction of the electrode fingers deviated in the extending direction of the electrode fingers.

When such a comb-shaped electrode is used,
The intensity distribution of the surface acoustic waves propagating from the electrode finger crossing portions 41, 42, 43, 44, 45 constituted by the electrodes of the weighted interdigital transducer 40 in the extending direction of the electrode fingers is made more uniform. It is possible (that is, the center position of the intersection of the electrode fingers, which is the oscillation source of the surface acoustic wave, is shifted to make the intensity distribution of the surface acoustic wave uniform), and more excellent characteristics can be obtained.

Typical applications of the above-described embodiments of the surface acoustic wave device include, for example, filters and resonators. Hereinafter, an application example to the filter will be described.

FIG. 12 is a system block diagram according to a ninth embodiment in which the surface acoustic wave device according to the present invention is used as an intermediate frequency filter of a television receiver.

This system comprises an antenna 22, a tuner block 23, a surface acoustic wave device 21 according to the present invention, and a detection block 24. Further, the detection block 24 includes a video output terminal 25 and an audio output terminal 26.

The antenna 22 is means for receiving an electromagnetic wave or the like which is a reception signal, and can be realized by, for example, a parabolic antenna. The tuner block 23 and the detection block 24 are, for example, a CPU, a RAM, a ROM, and various CMs.
It can be realized by an electronic device such as an OS.

The signal received by the antenna 22 is converted into a so-called intermediate frequency signal in the tuner block 23.

The surface acoustic wave device 21 according to the present invention extracts a signal for one channel (performs so-called filtering processing) from the obtained intermediate frequency signal according to its frequency characteristic, and the extracted signal is , To the detection block 24 in the next stage.

After the detection processing in the detection block 24,
Video information and audio information are output to each of the video signal output terminal 25 and the audio output terminal 26.

As a matter of course, the surface acoustic wave device 21 uses various devices disclosed in the embodiments of the present invention to improve the out-of-band suppression degree, and prevents unwanted signals from being mixed from adjacent channels. , Good image signal and audio information are obtained.

FIG. 13 shows the present invention in accordance with CATV (Community
HDTV (High Definitio) by Antenna Television
n Television) MUSE signal (a signal used in HDTV, which is a kind of image compression signal), an IF (Intermediate Frequency) filter (IF: Intermediate Frequency) of the demodulation unit thereof is transmitted. It is a system block diagram of the 10th Example used as.

This system comprises a cable terminal, a first mixer 27, a second mixer 28, a surface acoustic wave device 29 according to the present invention, a detection circuit 30, and a MUSE decoder 31.

The surface acoustic wave device 29 uses the technique disclosed in the embodiment according to the present invention, improves the group delay flatness, and obtains a good image signal.

Further, the detection circuit 30 and the MUSE decoder 31 are, for example, CPU, RAM, ROM, various CMOs.
It can be realized by an electronic device such as S.

By the way, CA for coaxial cables, optical fibers, etc.
MU which is AM-modulated by propagating through a transmission means in a TV
The SE signal is converted into an intermediate frequency signal having a lower frequency through the first mixer 27 and the second mixer 28 via the cable terminal.

In this system configuration example, two mixers are provided, but it is sufficient to use the number of mixers required to reach the frequency of the intermediate frequency to be finally obtained.
It goes without saying that the number is not limited to two.

The surface acoustic wave device 29 filters the output signal of the second mixer according to its frequency characteristic. The signal subjected to the filtering process is input to the detection circuit 30, is subjected to the detection process, and is sent to the MUSE decoder 31 in the next stage. MUSE decorator 31
Has a function of decompressing transmitted image compression data and performing a series of processes for generating image information.

Although not particularly described, the present invention is
Interdigital electrode for unidirectional electrode, double mode resonator,
It goes without saying that it can be applied to any surface acoustic wave device such as a chirp surface acoustic wave filter, a matched filter, a dispersion delay line, and the like.

FIG. 14 is a frequency characteristic showing the effect of the present invention.

33a and 33b are the amplitude characteristic and the group delay characteristic of the surface acoustic wave device 29 according to the present invention used in the tenth embodiment, respectively. Conventional amplitude characteristic 32a
It can be seen that the out-of-band suppression degree is improved as compared with. Further, it can be seen that the in-band flatness of the group delay characteristic is also improved as compared with the conventional group delay characteristic 32b.

[0086]

According to the present invention, the stress distribution formed by the intersections of the electrode fingers of the interdigital electrode becomes substantially uniform, and desired characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment according to the present invention.

FIG. 2 is a diagram showing an effect of the present invention.

FIG. 3 is a diagram showing a configuration of a conventional electrode finger crossing and its electric field intensity distribution.

FIG. 4 is a diagram showing a relationship between a metallization ratio and a conversion ratio.

FIG. 5 is a diagram showing a second embodiment according to the present invention.

FIG. 6 is a diagram showing a third embodiment according to the present invention.

FIG. 7 is a diagram showing a fourth embodiment according to the present invention.

FIG. 8 is a diagram showing a fifth embodiment according to the present invention.

FIG. 9 is a diagram showing a sixth embodiment according to the present invention.

FIG. 10 is a diagram showing a seventh embodiment according to the present invention.

FIG. 11 is a diagram showing an eighth embodiment according to the present invention.

FIG. 12 is an example of a system block diagram of a ninth embodiment according to the present invention.

FIG. 13 is an example of a system block diagram of a tenth embodiment according to the present invention.

FIG. 14 is a diagram showing an example of frequency characteristics representing the effect of the present invention.

[Explanation of symbols]

1 ... Piezoelectric substrate, 2, 8, 9, 10, 40 ... Interdigital electrodes, 2a, 2b, 14a, 14b, 40a, 40b ... Bus bar, 3a, 3b, 7a, 7b, 15a, 15b, 1
7a, 17b, 19a, 19b ... Electrode fingers 4, 41, 4
2, 43, 44, 45, 46a, 46b, 47a, 47
b, 48a, 48b ... Electrode finger crossing portion, 5 ... Surface acoustic wave,
6a, 6b ... Inclined portion, 11 ... Shield electrode, 12a,
b, c, d, 18a, 18b, 20a, 20b ... Correction metal film, 13 ... Propagation path, 21, 29 ... Surface acoustic wave filter, 22 ... Antenna, 23 ... Tuner block, 24 ...
Detection block, 25 ... Video signal output terminal, 26 ... Audio output terminal, 27 ... First mixer, 28 ... Second mixer, 30 ...
Detection circuit, 31 ... MUSE decoder, 100 ... Excitation source intensity distribution, 101 ... Conventional interdigital transducer

Claims (7)

[Claims] 1. A substrate, at least one interdigital electrode provided on the substrate, and two common electrodes (referred to as "bus bars") having different electric polarities and each constituting the interdigital electrode and each of the electrodes. In a region including a pair of electrode fingers extending from the bus bar, a surface acoustic wave is generated according to an electric field generated at an electrode finger crossing portion which is a region where the pair of electrode fingers intersect in the electrode finger extending direction. In the surface acoustic wave device to excite, the arrangement interval of the pair of electrode fingers at the electrode finger crossing portion has a portion extending along the extending direction of the electrode fingers. 2. A surface acoustic wave device comprising a substrate and an input electrode and an output electrode provided on the substrate, wherein either the input electrode or the output electrode has an electrical polarity provided by the electrode. Of the two electrode bars different from each other and a pair of electrode fingers extending from each bus bar, the pair of electrodes at an electrode finger crossing portion which is a region where the pair of electrode fingers intersect in the direction in which the electrode fingers extend. The elastic surface is characterized in that the arrangement intervals of the fingers have portions that extend along the direction in which the electrode fingers extend, and that the lengths of the electrode finger intersections are not the same at all electrode finger intersections. Wave device. 3. A surface acoustic wave device comprising a substrate and an input electrode and an output electrode provided on the substrate, wherein either the input electrode or the output electrode has an electrical polarity provided by the electrode. Of the two electrode bars different from each other and a pair of electrode fingers extending from each bus bar, the pair of electrodes at an electrode finger crossing portion which is a region where the pair of electrode fingers intersect in the direction in which the electrode fingers extend. A surface acoustic wave device, characterized in that an arrangement interval of fingers is widened along a direction in which electrode fingers extend, and a sound velocity correcting thin film is provided between the input electrode and the output electrode. 4. The surface acoustic wave device according to claim 1, wherein the electrode fingers are split connect type electrode fingers. 5. The surface acoustic wave device according to claim 4, wherein the split connect type electrode finger further includes a sound velocity correcting thin film on a part thereof. 6. The surface acoustic wave device according to claim 2, wherein the positions of the central points of the electrode finger intersections in the electrode finger extending direction are displaced in the electrode finger extending direction. 7. A surface acoustic wave device according to any one of claims 1, 2, 3, 4, 5, and 6, wherein an intermediate frequency signal is generated based on a receiving means and a signal output from the receiving means. Intermediate frequency generating means for generating, filter means for filtering the signal output from the intermediate frequency generating means, and detection output for detecting and outputting information including audio and video signals based on the signal output from the filter means An information processing apparatus, which is used as the filter means in an information processing apparatus configured to include a means.