KR20030048759A - Noise blocking device of surface acoustic wave filter system - Google Patents

Noise blocking device of surface acoustic wave filter system Download PDF

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Publication number
KR20030048759A
KR20030048759A KR1020010078772A KR20010078772A KR20030048759A KR 20030048759 A KR20030048759 A KR 20030048759A KR 1020010078772 A KR1020010078772 A KR 1020010078772A KR 20010078772 A KR20010078772 A KR 20010078772A KR 20030048759 A KR20030048759 A KR 20030048759A
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South Korea
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saw filter
surface acoustic
acoustic wave
package
filter system
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KR1020010078772A
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Korean (ko)
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김주상
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엘지이노텍 주식회사
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Priority to KR1020010078772A priority Critical patent/KR20030048759A/en
Publication of KR20030048759A publication Critical patent/KR20030048759A/en

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    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46Filters
    • H03H9/64Filters using surface acoustic waves
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02Details
    • H03H9/125Driving means, e.g. electrodes, coils
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/25Constructional features of resonators using surface acoustic waves
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/30Time-delay networks

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

PURPOSE: An apparatus for preventing noise of a surface acoustic wave filter system is provided to minimize noise due to feedthrough by installing a shield portion between an input portion and an output portion of the surface acoustic wave filter system. CONSTITUTION: A surface acoustic wave filter system includes a package(10) and a shield portion(50). A circuit including a surface acoustic wave filter(40) is installed in inside of the package in order to protect and array the circuit. The shield portion shields particular signals which is directly transmitted from an input portion to an output portion instead of the surface acoustic wave filter. The shield portion is formed with a metal plate which is connected to an external earth portion. The shield portion is provided to a lid of the package.

Description

표면탄성파 필터 시스템의 잡음 방지 장치{ Noise blocking device of surface acoustic wave filter system}Noise blocking device of surface acoustic wave filter system

본 발명은 표면탄성파(Surface Acoustic Wave, 이하 SAW 라고 함)필터 시스템의 잡음 방지 장치에 관한 것으로서, 특히 SAW 필터 패키지 내부에서 외부로부터 입력된 신호가 SAW 필터를 통하지 않고 직접 SAW 필터의 입력측에서 출력측으로 방사되는 것을 방지함으로써, 잡음이 효과적으로 방지되어 SAW 필터의 성능을 향상시킬 수 있는 SAW 필터 패키지의 잡음 방지 장치에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a noise suppression apparatus for a surface acoustic wave (SAW) filter system. In particular, a signal input from the outside inside a SAW filter package is directly transmitted from the input side of the SAW filter to the output side without passing through the SAW filter. By preventing radiation, noise is effectively prevented so that the SAW filter package noise prevention device can improve the performance of the SAW filter.

일반적으로, 표면탄성파는 기판의 표면을 따라 전달되는 파동의 상태를 나타내는 것으로 깊이 방향으로 급격히 감쇄되는 특징을 가진다. SAW 필터는 이러한 특징을 주파수 선택기능 소자로 응용한 것이다.In general, surface acoustic waves represent a state of waves transmitted along the surface of the substrate and have a feature of rapidly attenuating in the depth direction. The SAW filter uses this feature as a frequency selective device.

즉, 상기 SAW 소자는 절연성이 큰 기판에 금속 전극을 형성해 압전을 걸면 일시적으로 기판 표면이 뒤틀리는데, 이 작용을 이용해 물리적인 파를 일으키게 된다. 상기 SAW 소자 표면을 전달하는 표면파가 전자파보다 느리기 때문에 일시적으로 전기 신호를 지연시키거나 특정 주파수 신호만을 통과시키는 필터로 이용된다.That is, the SAW device temporarily forms a metal electrode on a highly insulative substrate and applies a piezoelectric twist to the substrate surface. This action causes a physical wave. Since the surface wave transmitting the surface of the SAW element is slower than the electromagnetic wave, it is used as a filter that temporarily delays an electric signal or passes only a specific frequency signal.

이러한, SAW 필터는 인터 디지털 트랜스듀서(interdigital transducer, 이하 IDT라고 함)가 입력단 및 출력단에 각각 설치되어 있어 입력단에서 압전 물체에 전기적 신호가 인가되면 이를 기계적 신호로 변환하고, 다시 출력단에서 이를 전기적 신호로 변환 출력하게 됨으로써 특정 주파수 대역은 통과시키고 나머지 주파수 대역은 저지시키게 된다.In the SAW filter, an interdigital transducer (hereinafter referred to as IDT) is installed at an input terminal and an output terminal, respectively, and when an electrical signal is applied to the piezoelectric object at the input terminal, the SAW filter is converted into a mechanical signal, and then the electrical signal is output at the output terminal. By converting the output frequency into a specific frequency band, the remaining frequency band is blocked.

상기 SAW 필터는 반도체 디바이스 또는 기능을 보호하는 세라믹스 용기로, 유해한 환경으로부터 내부회로를 보호하고, 내부에서 발생된 열을 방열하여 외부에접속하는 수단을 제공하는 패키지(Package)형태로 형성되어 있다.The SAW filter is a ceramic container that protects a semiconductor device or a function. The SAW filter is formed in a package form that protects an internal circuit from a harmful environment and provides a means for dissipating heat generated therein and connecting it to the outside.

도1 은 종래의 기술에 의한 SAW 필터 시스템의 구조가 도시된 도면으로써, 패키지(Package)(10)내에 설치되어 원하는 주파수 대역의 신호를 통과시키는 SAW 필터(20)로 구성된다.FIG. 1 is a diagram illustrating a structure of a SAW filter system according to the related art, and includes a SAW filter 20 installed in a package 10 to pass a signal having a desired frequency band.

여기서, 상기 SAW 필터(20)는 외부로부터 입력되는 전기적 신호를 표면탄성파로 변환하는 입력 IDT (21)와, 상기 표면탄성파를 전기적 신호로 변환하는 출력 IDT(23)와, 상기 입력 및 출력 IDT(21, 23) 사이에 위치되어 잡음이 제거되도록 하는 그라운드부(22)로 이루어진다.Here, the SAW filter 20 includes an input IDT 21 for converting an electrical signal input from the outside into a surface acoustic wave, an output IDT 23 for converting the surface acoustic wave into an electrical signal, and the input and output IDT ( It is made up of a ground portion 22 positioned between 21 and 23 to remove noise.

상기와 같은 종래의 SAW 필터 시스템의 동작을 설명하면 다음과 같다.The operation of the conventional SAW filter system as described above is as follows.

먼저, 외부로부터 전기적 신호가 입력되면 상기 입력 IDT(21)에 의해 표면탄성파로 변환후, 원하는 주파수 대역의 신호가 통과되어 출력 IDT(23)를 통해 상기표면 탄성파가 전기적 신호로 변환되어 외부에 출력된다.First, when an electrical signal is input from the outside, the surface is converted into a surface acoustic wave by the input IDT 21, and then a signal of a desired frequency band passes, and the surface acoustic wave is converted into an electrical signal through the output IDT 23 and output to the outside. do.

도2 는 종래의 기술에 따른 SAW 필터 시스템에서 잡음으로 작용되는 피드스루(feedthrough)의 방사형태가 도시된 도면이다.FIG. 2 is a diagram illustrating the radial form of feedthrough acting as noise in a SAW filter system according to the prior art. FIG.

이때, 상기 입력 신호중의 일부가 도2 의 화살표와 같이 SAW 필터를 거치지 않고 출력측으로 직접 방사되는 피드스루(feedthrough)가 발생되게 된다.At this time, a portion of the input signal is generated through the feedthrough (radiation) is directly radiated to the output side without passing through the SAW filter as shown by the arrow of FIG.

또한, 상기 피드스루(feedthrough)는 정상적인 신호의 전달이 아니라, 입력 신호가 바로 출력에 영향을 주는 원하지 않는 신호이기 때문에 SAW 필터가 적용된 시스템에 잡음으로 작용되어 시스템의 성능이 저하될 수 있는 문제점이 있다.In addition, since the feedthrough is not a normal signal transmission but an unwanted signal that directly affects the output, the feedthrough acts as a noise to the system to which the SAW filter is applied, thereby reducing the performance of the system. have.

본 발명은 상기한 종래 기술의 문제점을 해결하기 위하여 안출된 것으로서, 그 목적은 SAW 필터 패키지 내에서 외부로부터 입력된 신호가 SAW 필터를 따라 전달될 경우 SAW 필터를 거치지 않고 직접 입력측에서 출력측으로 방사되어 피드스루(feedthrough)가 발생되는 것을 방지하기 위해 SAW 필터의 입출력측 사이에 차단부를 형성하여 피드스루(feedthrough)가 잡음으로 작용되는 것을 최소화하는 동시에 SAW 필터의 성능 저하를 방지하는 SAW 필터 패키지의 잡음 방지 장치를 제공하는데 있다.The present invention has been made to solve the above-mentioned problems of the prior art, the object of which is that when the signal input from the outside in the SAW filter package is transmitted along the SAW filter is radiated from the direct input side to the output side without passing through the SAW filter Noise in the SAW filter package prevents performance degradation of the SAW filter while minimizing the feedthrough from noise by forming a block between the input and output sides of the SAW filter to prevent feedthrough. It is to provide a prevention device.

도1 은 종래의 기술에 따른 SAW 필터 시스템의 구조가 도시된 도면,1 is a view showing the structure of a SAW filter system according to the prior art;

도2 는 종래의 기술에 따른 SAW 필터 시스템에서 잡음으로 작용되는 피드스루(feedthrough)의 방사형태가 도시된 도면,FIG. 2 is a diagram showing the radial form of feedthrough acting as noise in a SAW filter system according to the prior art; FIG.

도3 은 본 발명에 따른 SAW 필터 시스템의 구조가 도시된 도면,3 is a view showing the structure of a SAW filter system according to the present invention;

도4 는 본 발명에 따른 SAW 필터 시스템에서 차단부에 의해 차단된 피드스루(feedthrough)의 방사형태가 도시된 도면이다.4 is a diagram illustrating the radial form of the feedthrough blocked by the blocking unit in the SAW filter system according to the present invention.

<도면의 주요 부분에 관한 부호의 설명><Explanation of symbols on main parts of the drawings>

30: 패키지40: SAW 필터30: Package 40: SAW Filter

41: 입력 IDT42: 그라운드부41: input IDT42: ground portion

43: 출력 IDT50: 차단부43: output IDT50: cutout

상기한 과제를 해결하기 위한 본 발명에 의한 SAW 필터 시스템의 잡음 방지 장치의 특징에 따르면, SAW 필터를 포함한 회로가 설치되어 그를 보호, 배치 및 접속 시키는 패키지와, 상기 SAW 필터를 통해 전달되는 특정신호중 상기 SAW 필터를 통과함 없이 바로 입력측에서 출력측으로 방사되는 신호를 차단시키는 차단부를 포함하여 구성된다.According to a feature of the noise protection device of the SAW filter system according to the present invention for solving the above problems, a package that includes a circuit including a SAW filter is installed, protects, arranges and connects it, and the specific signal transmitted through the SAW filter It comprises a blocker for blocking the signal radiated directly from the input side to the output side without passing through the SAW filter.

이하, 본 발명의 바람직한 실시예를 첨부된 도면을 참조하여 상세히 설명한다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

도3 는 본 발명에 따른 SAW 필터 시스템이 잡음 방지 장치의 구조가 도시된 도면이고, 도4 는 본 발명에 따른 SAW 필터 시스템의 잡음 방지 장치에서 차단부에의해 잡음으로 적용될 수 있는 피드스루(feedthrough)가 차단된 방사 형태가 도시된 도면이다.3 is a diagram illustrating a structure of a noise suppression apparatus of the SAW filter system according to the present invention, and FIG. 4 is a feedthrough that may be applied as noise by a blocking unit in the noise suppression apparatus of the SAW filter system according to the present invention. Is a diagram showing a radiation form with blocked).

본 발명에 의한 SAW 필터 시스템이 잡음 방지 장치는 SAW 필터(40)를 포함한 내부회로를 배치, 접속 및 보호하기 위한 직육면체의 패키지(30)와, 상기 패키지(40) 내부에 설치되어 원하는 주파수 대역의 신호를 통과시킬 수 있도록 입력 IDT(41), 그라운드부(42) 및 출력 IDT(43)로 이루어진 SAW 필터(40)와, 상기 SAW 필터(40)를 거치지 않고 직접 방사되는 신호를 방지하기 위해 상기 패키지(30)의 중앙부에 위치된 차단부(50)를 포함하여 구성된다.SAW filter system according to the present invention, the noise prevention device is a rectangular parallelepiped package 30 for arranging, connecting and protecting the internal circuit including the SAW filter 40, and installed inside the package 40 of the desired frequency band SAW filter 40 composed of an input IDT 41, a ground portion 42, and an output IDT 43 so as to pass a signal, and to prevent a signal radiated directly without passing through the SAW filter 40. It is configured to include a blocking unit 50 located in the central portion of the package 30.

여기서, 상기 차단부(50)는 접지와 연결되는 금속판으로 이루어지며, 상기 SAW 필터(40)를 통해 신호가 전달되는 것에 영향을 미치지 않도록 상기 SAW 필터(40)와 소정의 간격을 두고 형성된다.Here, the blocking unit 50 is made of a metal plate connected to the ground, and is formed at a predetermined interval from the SAW filter 40 so as not to affect the signal transmission through the SAW filter 40.

또한, 상기 차단부(50)는 상기 패키지(30)의 리드(Lid)에 제공된다.In addition, the blocking unit 50 is provided to a lid Lid of the package 30.

상기와 같이 구성된 본 발명에 따른 SAW 필터 시스템의 잡음 방지 장치의 동작을 살펴보면 다음과 같다.Looking at the operation of the noise protection device of the SAW filter system according to the present invention configured as described above are as follows.

먼저, 외부의 전기적 신호가 상기 패키지(30)를 통해 상기 입력 IDT(41)에 입력되면 상기 전기적 신호는 표면탄성파로 변환되고 상기 그라운드부(42)에서 잡음이 제거된다.First, when an external electrical signal is input to the input IDT 41 through the package 30, the electrical signal is converted into a surface acoustic wave and noise is removed from the ground part 42.

상기 그라운드부(42)에서 잡음이 제거된 상기 표면탄성파는 상기 출력 IDT(43)를 통해 전기적 신호로 변환되어 외부로 출력되게 된다.The surface acoustic wave from which the noise is removed from the ground part 42 is converted into an electrical signal through the output IDT 43 and output to the outside.

이때, 상기 입력 신호가 상기 패키지(30)의 중앙부에 형성되어 있는 금속판의 차단부(50)가 상기 패키지(30)내에서 상기 입력 및 출력 IDT(41, 43)사이의 에어 커플링(air coupling)에 의해 상기 SAW 필터(60)를 거치지 않고 상기 패키지(30)를 빈 공간을 통해 바로 출력측으로 방사되는 신호가 도4 의 화살표와 같이 차단 되는 동시에 그 차단된 신호는 상기 차단부(50)와 연결되어 있는 접지로 전달되게 되므로 피드스루(feedthrough)가 거의 발생되지 않거나 최소화되게 된다.At this time, the shielding part 50 of the metal plate in which the input signal is formed at the center of the package 30 is air-coupled between the input and output IDTs 41 and 43 in the package 30. The signal emitted to the output side through the empty space directly through the empty space is cut off as shown by the arrow of FIG. 4 without passing through the SAW filter 60, and the blocked signal is blocked by the blocking unit 50. Since it is transferred to the connected ground, feedthrough rarely occurs or is minimized.

결국, SAW 필터(40)를 거치지 않고 바로 입력측에서 출력측으로 방사되는 신호 차단함으로써, 피드스루(feedthrough)가 시스템의 잡음으로 작용되는 것을 최소화하는 동시에 시스템의 성능 저하를 방지할 수 있게 되는 것이다.As a result, by blocking the signal radiated directly from the input side to the output side without passing through the SAW filter 40, it is possible to minimize the performance of the system while minimizing the feedthrough acting as the noise of the system.

상기와 같이 구성되는 본 발명의 SAW 필터 시스템의 잡음 방지 장치는 SAW 필터 패키지내에서 신호가 입력되면 SAW 필터를 거치지않고 바로 출력측으로 방사되는 피드스루(feedthrough)를 방지하기 위해 입력측과 출력측사이에 차단부를 형성함으로써, 피드스루(feedthrough)가 시스템의 잡음으로 작용되는 것이 최소화되는 동시에 시스템의 성능저하를 방지할 수 있는 효과가 있다.The noise preventing device of the SAW filter system of the present invention configured as described above is cut off between the input side and the output side to prevent feedthrough radiated directly to the output side without passing through the SAW filter when a signal is input in the SAW filter package. By forming a portion, it is possible to minimize feedthrough from acting as noise of the system and to prevent performance degradation of the system.

Claims (3)

표면탄성파(Surface Acoustic Wave, 이하 SAW 라고 함) 필터를 포함한 회로가 설치되어 그를 보호, 배치 및 접속 시키는 패키지와;A package in which a circuit including a surface acoustic wave (SAW) filter is installed to protect, arrange, and connect the circuit; 상기 SAW 필터를 통해 전달되는 특정신호중 상기 SAW 필터를 통과함 없이 바로 입력측에서 출력측으로 방사되는 신호를 차단시키는 차단부를 포함하여 구성된 것을 특징으로 하는 SAW 필터 시스템의 잡음 방지 장치.And a blocking unit for blocking a signal radiated directly from an input side to an output side without passing the SAW filter among specific signals transmitted through the SAW filter. 제1 항에 있어서,According to claim 1, 상기 차단부는 외부의 접지와 연결되는 금속판으로 이루어지는 것을 특징으로 하는 SAW 필터 시스템의 잡음 방지 장치.The blocking unit is a noise prevention device of the SAW filter system, characterized in that made of a metal plate connected to the external ground. 제1 항 또는 제2 항에 있어서,The method according to claim 1 or 2, 상기 차단부는 상기 패키지의 리드(Lid)에 제공되는 것을 특징으로 하는 SAW 필터 시스템의 잡음 방지 장치.The cut-off unit is provided in the lead (Lid) of the package, characterized in that the noise protection device of the SAW filter system.
KR1020010078772A 2001-12-13 2001-12-13 Noise blocking device of surface acoustic wave filter system KR20030048759A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114094978A (en) * 2022-01-19 2022-02-25 深圳新声半导体有限公司 Decoupling packaging structure of surface acoustic wave filter bank

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114094978A (en) * 2022-01-19 2022-02-25 深圳新声半导体有限公司 Decoupling packaging structure of surface acoustic wave filter bank
CN114094978B (en) * 2022-01-19 2022-04-15 深圳新声半导体有限公司 Decoupling packaging structure of surface acoustic wave filter bank

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