CN103117727A - High-impedance sound surface wave resonator - Google Patents
High-impedance sound surface wave resonator Download PDFInfo
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- CN103117727A CN103117727A CN2013100477726A CN201310047772A CN103117727A CN 103117727 A CN103117727 A CN 103117727A CN 2013100477726 A CN2013100477726 A CN 2013100477726A CN 201310047772 A CN201310047772 A CN 201310047772A CN 103117727 A CN103117727 A CN 103117727A
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Abstract
The invention discloses a high-impedance sound surface wave resonator which comprises two inter-digital transducers and two reflecting gratings, wherein the two inter-digital transducers are arranged side by side, and the two reflecting gratings are positioned on two sides of the inter-digital transducers. An input bus bar of the first inter-digital transducer is connected with an input port, an output bus bar of the first inter-digital transducer is electrically connected with an input bus bar of the second inter-digital transducer, an output bus bar of the second inter-digital transducer is connected with an output port, the input bus bar of the first inter-digital transducer and the output bus bar of the second inter-digital transducer are positioned at the same end, the output bus bar of the first inter-digital transducer and the input bus bar of the second inter-digital transducer are positioned at the same end, and the two reflecting gratings are positioned on the outer sides of the two inter-digital transducers. The impedance is improved by four times without increasing the size and under the condition of the same structural parameters, so that the resonator can be miniaturized.
Description
Technical field
The present invention relates to the improvement of SAW (Surface Acoustic Wave) resonator technology, be specifically related to a kind of SAW (Surface Acoustic Wave) resonator structure with high impedance, belong to the SAW (Surface Acoustic Wave) resonator technical field.
Background technology
In mobile communication equipment, Surface Acoustic Wave Filter is connected to become the band pass filter between antenna and low noise amplifier usually.In this case, because low noise amplifier often is operated in high-impedance state, in order to realize the coupling between low noise amplifier and filter, tend to build very complicated matching network between amplifier and filter, this must increase volume and the cost of whole module.In order to address this problem, need the Surface Acoustic Wave Filter output port is designed to high-impedance state, usually the way that adopts is to add the one-port resonator of a high resistant at the output port of former filter, its structure is seen Fig. 1, is made of the interdigital transducer of tape input busbar and output busbar and two reflecting gratings that are positioned at interdigital transducer both sides.But, because the one-port resonator of the high-impedance state of existing structure has larger volume, be difficult to satisfy the requirement of device miniaturization a few days ago.
Summary of the invention
For the prior art above shortcomings, the object of the present invention is to provide a kind of high impedance SAW (Surface Acoustic Wave) resonator, this resonator can in the situation that do not increase volume, significantly improve impedance.
To achieve these goals, the technical solution used in the present invention is such:
a kind of high impedance SAW (Surface Acoustic Wave) resonator, comprise tape input busbar and the interdigital transducer of output busbar and two reflecting gratings that are positioned at the interdigital transducer both sides, it is characterized in that: described interdigital transducer is for referring to that logarithm is complete and two of being arranged side by side, two interdigital transducers share two reflecting gratings, the input busbar of the first interdigital transducer is connected with input port, the output busbar of the first interdigital transducer is electrically connected to the input busbar of the second interdigital transducer, the output busbar of the second interdigital transducer is connected with output port, the input busbar of the first interdigital transducer and the output busbar of the second interdigital transducer are positioned at same end, the output busbar of the first interdigital transducer and the input busbar of the second interdigital transducer are positioned at same end, two reflecting gratings are positioned at the outside of two interdigital transducers, and namely the reflecting grating of any one interdigital transducer one side of two interdigital transducers all is positioned at that side away from another interdigital transducer.
The substrate material that this high impedance SAW (Surface Acoustic Wave) resonator adopts is the monocrystalline piezoelectric substrates such as lithium tantalate, lithium niobate, quartz.
Existing surface acoustic wave one-port resonator, it refers to that logarithm is
, interdigital overlap length is
, its impedance computation formula can be expressed as
（1）
Wherein
For the acoustic radiation electricity is led,
Be the acoustic radiation susceptance, its size is directly proportional to referring to logarithm and interdigital overlap length,
For single to interdigital capacitor,
High impedance SAW (Surface Acoustic Wave) resonator structure of the present invention, its structure can equivalence be the resonator series connection that two finger logarithms are N/2, single finger logarithm is
The impedance of resonator be:
Therefore, the impedance of high impedance SAW (Surface Acoustic Wave) resonator of the present invention is:
Therefore, this SAW (Surface Acoustic Wave) resonator is not in the situation that increase volume, in the situation that the same structure parameter improves 4 times with impedance, therefore be beneficial to the miniaturization that realizes device.
Description of drawings
Surface acoustic wave one-port resonator structural representation in Fig. 1-prior art.
Fig. 2-high impedance SAW (Surface Acoustic Wave) resonator structural representation of the present invention.
The filter construction schematic diagram of Fig. 3-employing high impedance SAW (Surface Acoustic Wave) resonator of the present invention.
The filter frequency figure of Fig. 4-employing high impedance SAW (Surface Acoustic Wave) resonator of the present invention.
Embodiment
The invention will be further described below in conjunction with accompanying drawing.
Referring to Fig. 2, can find out on scheming, high impedance SAW (Surface Acoustic Wave) resonator structure of the present invention comprises the first interdigital transducer 1, the second interdigital transducer 2 and two reflecting grating 3a, 3b, two interdigital transducers share two reflecting gratings.Two interdigital transducers refer to that logarithm is complete and are arranged side by side, and each interdigital transducer is with the input and output busbar.Two interdigital transducer annexations are: the input busbar of the first interdigital transducer is connected with input port 5, the output busbar of the first interdigital transducer is electrically connected to the input busbar of the second interdigital transducer, the output busbar of the second interdigital transducer is connected with output port 6, the input busbar of the first interdigital transducer and the output busbar of the second interdigital transducer are positioned at same end, and the output busbar of the first interdigital transducer and the input busbar of the second interdigital transducer are positioned at same end.Therefore two interdigital transducer essence are the cascaded structure that is arranged side by side, consist of the composite fork finger transducer after series connection, the input busbar of the first interdigital transducer is the input busbar of composite fork finger transducer, and the output busbar of the second interdigital transducer is the output busbar of composite fork finger transducer.Two reflecting gratings are positioned at the outside of two interdigital transducers that are arranged side by side, and namely the first interdigital transducer 1 other reflecting grating is positioned at the end away from the second interdigital transducer 2, and the second interdigital transducer 2 other reflecting gratings are positioned at the end away from the first interdigital transducer 1.Two interdigital transducers share the sound passage that two reflecting gratings consist of.
The substrate material that high impedance SAW (Surface Acoustic Wave) resonator structure of the present invention adopts is the monocrystalline piezoelectric substrates such as lithium tantalate, lithium niobate, quartz.
In one-port resonator structure shown in Figure 1, suppose that it refers to that logarithm is
, interdigital overlap length is
, its impedance computation formula can be expressed as
Wherein
For the acoustic radiation electricity is led,
Be the acoustic radiation susceptance, its size is directly proportional to referring to logarithm and interdigital overlap length,
For single to interdigital capacitor,
High impedance SAW (Surface Acoustic Wave) resonator structure of the present invention as shown in Figure 2, its structure can equivalence be two and refer to that logarithms are the resonator series connection of N/2, single finger logarithm is
The impedance of resonator be:
Therefore, the impedance of high impedance SAW (Surface Acoustic Wave) resonator of the present invention is:
Therefore, in the situation that the same structure parameter in the situation that do not increase volume, has adopted the resonator of structure of the present invention can significantly improve impedance, be beneficial to the miniaturization that realizes device.
For verifying that this structure is on the impact of filter electrical property, the present invention selects certain Surface Acoustic Wave Filter as research object, this Surface Acoustic Wave Filter structure as shown in Figure 3, this Surface Acoustic Wave Filter substrate material is 42 ° of lithium tantalates, input impedance is 50 Ω, and output impedance is 150 Ω, and the input and output impedance ratio is 1:3, be applied to mobile phone front end, strobe.In experiment with structure of the present invention and in the past structure compare on electrical property, can find out from frequency response figure shown in Figure 4, the filter that the present invention obtains is consistent at the electrical property that the same filter in the past of the electrical properties such as passband shapes, rectangular degree, Out-of-band rejection obtains.
Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although with reference to preferred embodiment, the present invention is had been described in detail, those of ordinary skill in the art is to be understood that, can modify or be equal to replacement technical scheme of the present invention, and not breaking away from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of claim scope of the present invention.
Claims (2)
1. high impedance SAW (Surface Acoustic Wave) resonator, comprise tape input busbar and the interdigital transducer of output busbar and two reflecting gratings that are positioned at the interdigital transducer both sides, it is characterized in that: described interdigital transducer is for referring to that logarithm is complete and two of being arranged side by side, two interdigital transducers share two reflecting gratings, the input busbar of the first interdigital transducer (1) is connected with input port (5), the output busbar of the first interdigital transducer is electrically connected to the input busbar of the second interdigital transducer, the output busbar of the second interdigital transducer (2) is connected with output port (6), the input busbar of the first interdigital transducer and the output busbar of the second interdigital transducer are positioned at same end, the output busbar of the first interdigital transducer and the input busbar of the second interdigital transducer are positioned at same end, two reflecting gratings are positioned at the outside of two interdigital transducers.
2. high impedance SAW (Surface Acoustic Wave) resonator according to claim 1, it is characterized in that: the substrate material that this high impedance SAW (Surface Acoustic Wave) resonator adopts is lithium tantalate, lithium niobate or single crystal quartz piezoelectric substrate.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013100477726A CN103117727A (en) | 2013-02-06 | 2013-02-06 | High-impedance sound surface wave resonator |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2013100477726A CN103117727A (en) | 2013-02-06 | 2013-02-06 | High-impedance sound surface wave resonator |
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| CN103117727A true CN103117727A (en) | 2013-05-22 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107819449A (en) * | 2017-12-04 | 2018-03-20 | 中电科技集团重庆声光电有限公司 | Ultra-wideband surface acoustic wave resonator and filter |
| CN108933579A (en) * | 2018-06-22 | 2018-12-04 | 中国科学院声学研究所 | A kind of surface acoustic wave one-port resonator |
| CN115955212A (en) * | 2023-03-14 | 2023-04-11 | 阿尔伯达(苏州)科技有限公司 | SAW filter with enlarged bandwidth |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03295308A (en) * | 1990-04-12 | 1991-12-26 | Kokusai Electric Co Ltd | Surface acoustic wave resonator |
| JPH11340774A (en) * | 1998-05-26 | 1999-12-10 | Murata Mfg Co Ltd | Surface acoustic wave filter |
| CN1319950A (en) * | 2000-03-10 | 2001-10-31 | 株式会社村田制作所 | Acoustic surface wave device |
| CN203027216U (en) * | 2013-02-06 | 2013-06-26 | 中国电子科技集团公司第二十六研究所 | High-impedance surface acoustic wave resonator structure |
-
2013
- 2013-02-06 CN CN2013100477726A patent/CN103117727A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03295308A (en) * | 1990-04-12 | 1991-12-26 | Kokusai Electric Co Ltd | Surface acoustic wave resonator |
| JPH11340774A (en) * | 1998-05-26 | 1999-12-10 | Murata Mfg Co Ltd | Surface acoustic wave filter |
| CN1319950A (en) * | 2000-03-10 | 2001-10-31 | 株式会社村田制作所 | Acoustic surface wave device |
| CN203027216U (en) * | 2013-02-06 | 2013-06-26 | 中国电子科技集团公司第二十六研究所 | High-impedance surface acoustic wave resonator structure |
Non-Patent Citations (1)
| Title |
|---|
| 范子坤等: "GHz频带声表面波谐振器的研究", 《电子学报》, vol. 33, no. 5, 25 May 2005 (2005-05-25), pages 908 - 911 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107819449A (en) * | 2017-12-04 | 2018-03-20 | 中电科技集团重庆声光电有限公司 | Ultra-wideband surface acoustic wave resonator and filter |
| CN107819449B (en) * | 2017-12-04 | 2021-05-04 | 中国电子科技集团公司第二十六研究所 | Ultra-wideband surface acoustic wave resonator and filter |
| CN108933579A (en) * | 2018-06-22 | 2018-12-04 | 中国科学院声学研究所 | A kind of surface acoustic wave one-port resonator |
| CN115955212A (en) * | 2023-03-14 | 2023-04-11 | 阿尔伯达(苏州)科技有限公司 | SAW filter with enlarged bandwidth |
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Application publication date: 20130522 |