• 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.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.469-470
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• 2006

Surface Acoustic Wave(SAW) devices can be used to as wireless sensor elements, called SAW transponders, for measuring shysical quantities such as temperature that do not need any power supply and may be accessed wirelessly. SAW devices were fabricated on Y-Z $LiNbO_3$ piezoelectric substrate with a good temperature coefficient property. The signal response of SAW sensor on the temperature change were compared. To measure the change of SAW velocity. Temperature changed form $20^{\circ}C$ to $400^{\circ}C$ was linearly changed, the SAW sensor is application to the temperature sensor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.59-60
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• 2010

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.3
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• pp.206-211
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• 2011

In this paper, we report a high-precision wireless gap sensor based on a surface acoustic wave (SAW) device. The sensing element is a parallel-plate capacitor whose dimensions are $3{\times}3\;mm^2$, and is attached to the SAW device as an external load. The SAW device, equipped with an RF antenna, serves simultaneously as a signal conditioner and an RF transponder. The center frequency of the SAW device is 450 MHz. The wireless gap sensor prototype exhibits a resolution of 100 nm and a sensing range of $50{\mu}m$. The proposed sensor system can be used for remote, high-precision gap measurement in hard-to-reach environments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.594-599
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• 2011

A SAW strain sensor based on Shear Horizontal wave with an 92 MHz central frequency was developed. It consists of SAW sensor, PCB substrate and bonding material (Loctite 401). External force applied to PCB substrate bonded to a piezoelectric substrate induces strain at the substrate surface, which causes changes in the elastic constant and density of the substrate and hence the propagation velocity of the SAW. The change in the velocity of the SAW result in a frequency shift of the sensor and by measuring a frequency shift, we can extract the strain induced by the external force. The $41^{\circ}$ YX $LiNbO_3$ was used because it has a Leaky shear horizontal(SH) wave propagation mode and a high electromechanical coupling coefficient ($K^2$=17.2%). And to compare with Rayleigh wave mode, $128^{\circ}$ YX $LiNbO_3$ was used. And to make a stable and low insert loss, Split IDT structure was used. The obtained sensitivity and linearity of the SAW strain sensor in the case of Split IDT were measured to be 17.2 kHz / % and 0.99, respectively.

• 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.

• 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.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.144-148
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• 2003

Volatile components were detected from domestic and imported Angelica gigas Nakai without any pretreatment using GC based on Surface Acoustic Wave (SAW) sensor. This system produced a frequency proportional to the amount of column effluent deposited on the SAW sensor. Discrimination between domestic and imported Angelica gigas Nakai was achieved through recognition of visual pattern using $VaporPrint^{TM}$ derived from frequency and chromatogram of GC-SAW sensor.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.367-370
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• 1999

일반적 인 SAW 필터에서 발생하는 선형성의 한계 및 천이대역의 특성을 개선하기 위한 새로운 구조의 이중구조 사다리형 SAW 필터의 최적 설계 방법을 제시하고 그 가능성을 확인하였다. 이중구조 SAW 필터는 일반적인 사다리형 필터의 구조를 바탕으로 하되, 두 개의 서로 다른 필터가 각각 주어진 대역사양을 반반씩 만족시켜 전체의 필터특성이 구현될 수 있도록 하였다. 특히 고주파 대역에서 만족시키기 어려운 정재파비 및 뛰어난 천이대역 특성을 만족시킬 수 있는 장점을 가지며, 이를 위해 withdrawal 가중기법 및 기판상에 encp화된 마이크로 스티 립라인 인덕터를 이용하였다. 우선 이중 구조 필터구조를 결정한 후, microstrip 라인 인덕터의 위치 및 인덕턴스 변화에 따른 필터특성 변화를 살펴보았으며, 필터의 각종 형상변수의 변화에 따른 필터 특성변화를 조사하였다. 이상의 결과를 바탕으로 새로운 방법의 이중구조 SAW 필터의 설계방법을 제시하였으며 그 타당성을 검증하기 위해 1.8 GHz 대역의 RF 필터에 대한 설계 결과를 나타내었다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1515_1516
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• 2009

A 440MHz wireless and passive surface acoustic wave (SAW) based micro-sensor was developed for simultaneous measurement of temperature and humidity. The developed sensor is composed of a SAW reflective delay lines structured by an IDT (Inter-Digital Transducer), four reflectors and humidity sensitive film (polyimide). Polyimide was dry-ecthed by RIE (Reactive Ion Etching) to obtain high roughness, which gives the large reaction area resulting in high sensitivity. In wireless testing using a network analyzer, sharp reflection peaks with high S/N ratio, small signal attenuation, and few spurious peaks were observed in the time domain. High sensitivity towards the temperature and humidiy were also observed in the large concentration range. The obtained sensitivity was $16.8^{\circ}/^{\circ}C$ for temperature sensor and $15.8^{\circ}$/%RH for humidity sensor.