CN202737825U

CN202737825U - SR580T75 type low loss SAW resonator

Info

Publication number: CN202737825U
Application number: CN201220343355.7U
Authority: CN
Inventors: 赵成; 林波; 王敬元
Original assignee: TAIZHOU OUWEN ELECTRONIC TECHNOLOGY CO LTD
Current assignee: TAIZHOU OUWEN ELECTRONIC TECHNOLOGY CO LTD
Priority date: 2012-07-11
Filing date: 2012-07-11
Publication date: 2013-02-13
Anticipated expiration: 2022-07-11

Abstract

Provided is an SR580T75 type low loss SAW resonator, belonging to the surface acoustic wave field. The SR580T75 type low loss SAW resonator solves the problem that the insertion loss of the conventional SAW resonator is too large. The SAW resonator of the utility model comprises a piezoelectric wafer, an interdigital energy transducer arranged upon the piezoelectric wafer, and a first short circuit digit reflective array and a second short circuit digit reflective array which are arranged at two sides of the interdigital energy transducer, and the interdigital energy transducer is the GAM optimization weighing unit. The SAW resonator of the utility model has a metal structure of relatively small size, with the insertion loss being relatively low, the center resonant frequency ranging from 579MHZ to 580MHZ, and the resonance amplitude being 28dB.

Description

A kind of SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator

Technical field

The utility model relates to the SAW (Surface Acoustic Wave) device technical field, relates in particular to a kind of SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator.

Background technology

Do the time spent when the crystal with piezoelectric effect is subject to external carbuncle, can produce the electric field that is directly proportional with stress; Otherwise when crystal was subject to External Electrical Field, crystal also produced the elastic deformation that is directly proportional with external electric field simultaneously, and this elastic deformation inspires sound wave, and the sound wave that excites is propagated along plane of crystal and formed surface acoustic wave.Utilize the propagation of above-mentioned surface acoustic wave can realize that the signal of telecommunication arrives acoustical signal and acoustical signal to the conversion of the signal of telecommunication.

SAW (Surface Acoustic Wave) resonator refers to make interdigital transducer at piezoelectric chip, also is provided with reflective array in the interdigital transducer both sides simultaneously.This interdigital transducer can be finished sound-electric conversion, this reflective array forms distributed resonant cavity, on a certain frequency, when the length of this resonant cavity equals the integral multiple of half-wavelength, form acoustic resonance, thereby this acoustic resonance is converted to the function that electric resonance realizes SAW (Surface Acoustic Wave) resonator by interdigital transducer.

Existing SAW (Surface Acoustic Wave) resonator is because the imperfection of its interdigital transducer and reflective array design has larger insertion loss.And the centre frequency of existing SAW (Surface Acoustic Wave) resonator is generally 315MHZ, 433MHZ, and this frequency range reusability is high, and the channel jam is serious, when consisting of private radio systems, and anti-interference and poor stability.

The utility model content

The purpose of this utility model is to overcome deficiency of the prior art, provides that a kind of fail safe is good, the resonance amplitude of oscillation is large, the lower SAW (Surface Acoustic Wave) resonator of loss.

The technical scheme that its technical problem that solves the utility model adopts is to propose a kind of SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator, the first short circuit digital reflex battle array and the second short circuit digital reflex battle array that it comprises piezoelectric chip, is arranged at the interdigital transducer on the piezoelectric chip and is arranged at the interdigital transducer both sides; Described interdigital transducer is that GAM optimizes weighted units.Described GAM is a kind of method of weighting based on neural network theory.

Further, frequency is the resonator of 579MHZ to 580MHZ centered by the described resonator, and the insertion loss of described resonator is 1 to 1.5dB, and the resonance amplitude of oscillation is 28dB.

Further, described interdigital transducer comprises the first transducer electrode bar and the second transducer electrode bar that be arranged in parallel, is placed with many strip metals bar between described the first transducer electrode bar and the second transducer electrode bar; Every strip metal bar links to each other and does not link to each other with other transducer electrode bars with arbitrary transducer electrode bar in the first transducer electrode bar and the second transducer electrode bar; The transducer electrode bar that adjacent bonding jumper connects is different.

Further, described the first short circuit digital reflex battle array is identical with the second short circuit digital reflex battle array structure, include the first reflective array electrode strip and the second reflective array electrode strip that be arranged in parallel, equally spacedly between the first reflective array electrode strip and the second reflective array electrode strip be connected with many short circuit bonding jumpers, these many short circuit bonding jumpers all connect the first reflective array electrode strip and the second reflective array electrode strip.

Further, the length of described transducer bonding jumper is symmetric take the central metal bar as symmetry axis, and the length of bonding jumper is successively decreased gradually to both sides.Adopt the symmetric mode bonding jumper of arranging, guaranteed the efficient of the sound-electric conversion of SAW (Surface Acoustic Wave) resonator.

Further, the width of transducer bonding jumper is according to the difference of surface acoustic wave resonance frequency and difference, and the ratio of transducer bonding jumper and short circuit bonding jumper width is special ratios, to realize specific resonance frequency.

The utility model SAW (Surface Acoustic Wave) resonator by the design interdigital transducer structure and adopt the structural material of albronze matter so that the more conventional SAW (Surface Acoustic Wave) resonator of its centre frequency is high, the metal structure yardstick is less, the resonance amplitude of oscillation is large, insertion loss is lower.Simultaneously, the resonance band of the utility model SAW (Surface Acoustic Wave) resonator has been avoided the general frequency range that signal blocks up, and when being used for private radio systems, safe, antijamming capability is strong.

Description of drawings

Fig. 1 is the structural representation of the utility model SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator;

Fig. 2 is the package outline drawing of the utility model SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator.

Embodiment

Below be specific embodiment of the utility model and by reference to the accompanying drawings, the technical solution of the utility model is further described, but the utility model be not limited to these embodiment.

Please refer to Fig. 1, Fig. 1 is the structural representation of the utility model SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator, among Fig. 1, SR580T75 type low-loss sound surface resonance device comprises piezoelectric chip 5, be arranged at the interdigital transducer 6 on the piezoelectric chip 5, be arranged at the first short circuit digital reflex battle array 3 and the second short circuit digital reflex battle array 4 of interdigital transducer 6 both sides.

Interdigital transducer 6 is optimized weighting through GAM in the utility model, so that the utility model SAW (Surface Acoustic Wave) resonator resonance amplitude of oscillation strengthens, insertion loss reduces.

Interdigital transducer comprises the first transducer electrode bar and the second transducer electrode bar that be arranged in parallel, is placed with many strip metals bar between the first transducer electrode bar and the second transducer electrode bar; Every strip metal bar links to each other and does not link to each other with other transducer electrode bars with arbitrary transducer electrode bar in the first transducer electrode bar and the second transducer electrode bar; The transducer electrode bar that adjacent bonding jumper connects is different.

The first short circuit digital reflex battle array 3 is identical with the second short circuit digital reflex battle array 4 structures, include the first reflective array electrode strip and the second reflective array electrode strip that be arranged in parallel, equally spacedly between the first reflective array electrode strip and the second reflective array electrode strip be connected with many short circuit bonding jumpers, these many short circuit bonding jumpers all connect the first reflective array electrode strip and the second reflective array electrode strip.

More preferably, described transducer bonding jumper length is symmetric take the central metal bar as symmetry axis, and the length of each bonding jumper is successively decreased gradually to both sides.

More preferably, the width of described transducer bonding jumper is set to 1/4th operation wavelengths, and the transducer bonding jumper is 1: 0.9926 with the ratio of short circuit bonding jumper width, to avoid the resonance frequencies such as existing 315MHz, 433MHz and to realize the larger resonance amplitude of oscillation and less resonance loss.

Please refer to Fig. 1, Fig. 2, the structural representation when it is the encapsulation of the utility model SR580T75 type low-loss SAW (Surface Acoustic Wave) resonator.During encapsulation, also be connected with respectively first signal pin 5 and secondary signal pin 6 for the signal input and output on the first transducer electrode bar and the second transducer electrode bar; Be connected with grounding pin 7 on arbitrary reflective array electrode strip of two short circuit digital reflex battle arrays.Sealing cap 8 covers piezoelectric chip 1.

In a preferred embodiment, piezoelectric chip 1 adopts quartz to make, and interdigital transducer 2 and the first short circuit digital reflex battle array 3 and the second short circuit digital reflex battle array 4 are made by albronze.The thickness of interdigital transducer 2 and the first short circuit digital reflex battle array 3 and the second short circuit digital reflex battle array 4 is 0.015 to 0.025 millimeter.

In the preferred embodiment, the electric parameters of SAW (Surface Acoustic Wave) resonator such as following table:

Specific embodiment described herein only is to the explanation for example of the utility model spirit.The utility model person of ordinary skill in the field can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present utility model or surmount the defined scope of appended claims.

Claims

1. A SR580T75 type low-loss surface acoustic wave resonator is characterized in that: it comprises a piezoelectric wafer, an interdigital transducer arranged on the piezoelectric wafer and the first short-circuit finger arranged on both sides of the interdigital transducer The reflection array and the second short circuit refer to the reflection array; the interdigital transducer is a GAM optimization weighting unit.

2. The surface acoustic wave resonator according to claim 1, characterized in that: the resonator is a resonator with a center frequency of 579MHZ to 580MHZ, the insertion loss of the resonator is 1 to 1.5dB, and the resonance swing is 28dB.

3. The surface acoustic wave resonator according to claim 1 or 2, wherein the interdigital transducer comprises a first transducer electrode strip and a second transducer electrode strip arranged in parallel, the A plurality of metal strips are arranged between the first transducer electrode strip and the second transducer electrode strip; each metal strip is connected to any one of the first transducer electrode strip and the second transducer electrode strip. It is connected to the electrode strips of the transducer and not connected to other transducer electrode strips; the transducer electrode strips connected to the adjacent metal strips are different.

4. The surface acoustic wave resonator according to claim 1 or 2, characterized in that: the first short-circuit finger reflection array and the second short-circuit finger reflection array have the same structure, and both include the first reflection array electrode strips arranged in parallel As well as the second reflective array electrode strips, the first reflective array electrode strips and the second reflective array electrode strips are equidistantly connected with multiple short-circuit metal strips, and the multiple short-circuit metal strips connect the first reflective array electrode strips and the second reflective array electrode strips. The two reflection array electrode strips are connected.

5 . The surface acoustic wave resonator according to claim 3 , wherein the lengths of the metal strips of the transducer are distributed symmetrically with the central metal strip as the axis of symmetry, and the lengths of the metal strips gradually decrease toward both sides. 5 .