• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.447-450
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• 2010

SAW Device 라는 Passive 소자는 ID Tag나 소형센서들을 대체할 수 있는 MEMS 기술의 초소형 Device 다. 이 SAW Device를 이용하면 독립된 공간이나 전원이 필요한 센서 제어 등을 대신할 수 있을 것이다. 이렇게 활용범위가 확대됨에 따라 다양한 SAW Device를 사용하기 위한 플랫폼이 요구된다. 하지만 현재 SAW Sensor는 많은 발전을 해왔지만 SAW Sensor를 활용할 수 있는 플랫폼의 발전은 미흡하기 때문에 본 논문에서는 이러한 SAW Device를 측정할 수 있는 SAW Reader를 FPGA를 이용하여 좀 더 간단하고 효율적인 Reader platform을 구현해 보고자 한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.1
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• pp.54-62
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• 2013

In this study, a wireless and non-power SAW (surface acoustic wave) temperature sensor was developed. The single inter-digital transducer (IDT) of SAW temperature sensor of which resonance frequency is 434 MHz was fabricated on $128^{\circ}$ rot-X $LiNbO_3$ piezoelectric substrate by semiconductor processing technology. To find optimal acoustic reflector for SAW temperature sensor, various kinds of acoustic reflectors were fabricated and their reflection characteristics were analyzed. The IDT type acoustic reflector showed better reflection characteristic than other reflectors. The wireless temperature sensing system consisting of SAW temperature sensor with dipole antenna and a microprocessor based control circuit with dipole antenna for transmitting signal to activate the SAW temperature sensor and receiving the signal from SAW temperature sensor was developed. The result with wireless SAW temperature sensing system showed that the frequency of SAW temperature sensor was linearly decreased with the increase of temperature in the range of 40 to $80^{\circ}C$ and the developed wireless SAW temperature sensing system showed the excellent performance with the coefficient of determination of 0.99.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1
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• pp.1-7
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• 2004

We developed SH-SAW sensors to detect protein molecules in liquid solutions applying a particular antibody thin film on the delay line of transverse SAW devices. The antibody investigated was human-immune-globulin G (HigG) to hold the antigens (anti-HigG) in the protein solution. We fabricated the sensor generating 100 MHz with the piezoelectric single crystal LiTaO₃. We measured the frequency change of the sensor by adding the anti-body concentration on SAM (self assembled monolayer) deposited on the Au layer. The sensor showed stable response to the mass loading effects of the anti-HigG molecules with the sensitivity up to 10.8 ng/ml/Hz at noise level 400 Hz below.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.319-322
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• 2004

본 연구에서는 DNA의 상보적인 결합을 이용하여 DNA 혼성화 반응을 감지할 수 있는 SH형 SAW 센서를 개발하였다. 측정에 사용된 DNA는 15개의 염기를 가진 올리고 뉴클레오티드를 사용하였으며 이에 대해 상보적 결합이 가능한 염기서열을 가진 것과 그렇지 않은 미스매치 형태의 DNA 올리고뉴클레오티드를 이용하여 DNA 혼성화 반응 특성을 측정하였다. SH형 SAW 센서는 압전 단결정 $LiTaO_{3}$를 사용하여 100 MHz 발진되는 형태로 제작하였으며, 센서의 지연선 위에 Ti/Au 층을 증착하여 SH기가 수식된 탐침 DNA의 고정화가 가능하게 하였다. 제작된 센서는 Au가 증착된 박막위에 탐침 DNA를 SAM 방법으로 고정화 시켰을 경우와 고정화된 탐침 DNA와 표적 DNA와의 혼성화 반응을 시키고 난 후의 센서의 주파수 변화를 각각 측정하였다. 개발된 DNA 혼성화 반응 측정용 SH형 SAW센서는 DNA 혼성화 특성에 기인한 질량하중 효과에 따른 안정적인 주파수 변화를 나타내었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.218-224
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• 2013

Generally, SAW device, which uses Time Domain Sampling, requires high speed A/D converter because SAW device using TDS needs high sampling speed as much as its high data speed. However, the high price of A/D converter discourages makers from using it. On the other hand, SAW device, which uses Frequency Domain Sampling, does not required high speed A/D converter because SAW device using FDS does not need high sampling speed. It is very efficient in price comparison to its performance because high processing speed of SAW device using FDS can be implemented using low price Embedded Systems. The purpose of the paper is to solve the issues above by designing and realizing SAW device(FDS) using SAW sensor for TDS.

• Journal of Sensor Science and Technology
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• v.5 no.3
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• pp.41-48
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• 1996

We developed SAW gas sensor for monitoring SOx gas with high sensitivity. It was fabricated as a microsensor for detecting SOx gas by depositing sensing material on SAW device. As a detecting layer material, CdS was selected. Deposition of CdS in the form of thin films was carried out by the ultrasonic spray pyrolysis method using ultrasonic spray nozzle. Thin films with the uniform and large surface area for sensors were deposited. The stable pyrolysis environment provided by uniform and fine droplets formed by spray nozzle made it possible to obtain thin films with excellent quality. The minimum grain size of the CdS thin films was about 50 nm when deposited at $300^{\circ}C$. SAW gas sensors showed reasonable sensitivity and reproducibility. Further studies are required to investigate the interference of other gases to SOx gas detection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.1030-1037
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• 2009

SAW Sensor is greatly developed today and Reader Platform which uses SAW Sensor for temperature or pressure is required to use TDS method for low power and high speed processing. For to use this Platform, high speed timer is required to measure a short interval between reference signal and reflectior's signal. This paper proposes that platform receive SAW Sensor's signals and transform digital signal through comparator. Next the transformed signal is measured by Timer Platform and the measured interval is displayed with time. This paper proposes method of measurment of time with nano sec unit.

• Electrical & Electronic Materials
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• v.8 no.1
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• pp.48-55
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• 1995

A surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing various phospholipids and fatty acids onto the surface of the SAW device. The characteristics of a SAW device operating at 310 MHz deposited with silicon monoxide were analyzed. Menthone, amylacetate, acetoin, and other organic gases show different affinities to the coated lipids. An explanation is given for different odorant affinities based on the monolayer properties of phospholipids. The identification of odorants depending on the tkpe of lipid used for coating is discussed in terms of the similarity of their normalized resonant frequency shift patterns. Using a number of different lipid-coated SAW devices, odorants can be identified by a computerized pattern recognition algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.766-771
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• 2008

As the practical range of SAW Device extended into various fields including physical sensor, chemical sensor and ID Tag, the platform for various SAW Devices is required more than ever. While SAW ID or Sensors advanced remarkably, the development of platform which applies to SAW Sensor left much to be desired. Therefore this paper represents the SAW platform in order to use SAW ID such as ID Tag or Sensors more conveniently. The SAW platform consists of a RF module which can recognize SAW ID and a main module which has a hish performance processor in order to process the response signal of SAW ID. The main module which has a high performance processor is designed by GUI environmental type to ensure that users are able to use the platform more easily. In this paper, the SAW platform, which is based on ARM9 core processor, used Windows Embedded CE 6.0 OS which brings friendly interface to users. Also the developers can make less effort to design various applications with sensors.

• The Journal of the Acoustical Society of Korea
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• v.24 no.3
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• pp.160-165
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• 2005

We have developed SH (shear horizontal) surface acoustic wave (SAW) sensors for detection of the immobilization and hybridization of DNA (deoxyribonucleic acid) on the gold coated delay line of transverse SAW devices. The experiments of DNA immobilization and hybridization were performed with 15-mer oligonucleotides (probe and complementary target DNA). The sensor consists of twin SAW delay line oscillators operating at 100 MHz fabricated on $36^{\circ}$ rotated Y-cut $LiTaO_3$ piezoelectric single crystals. The relative change in the frequency of the two oscillators was monitored to detect the hybridization between target DNA and immobilized probe DNA in pH 7.4 PBS (phosphate buffered saline) solution. The measurement results showed a good response of the sensor to the mass loading effects of the DNA immobilization and hybridization with the sensitivity up to $1.55{\cal}ng/{\cal}ml/Hz$.