• Proceedings of the IEEK Conference
• /
• 2001.06a
• /
• pp.245-248
• /
• 2001

In this paper, we have investigated the design technique and fabricated the surface acoustic wave (SAW) filter for duplexer, which consists of Tx. and Rx. filter, and antenna terminal. For Tx. and Rx. bandpass filters we used the one-port SAW resonators with n-section ladder structure. The structure is composed of couples of series-arm resonators and parallel-arm resonators. RF filter using ladder structure was designed and fabricated on 36$^{\circ}$Y-X LiTaO$_3$ substrates. Designed filters, insertion loss is less than 1.5dB, the bandwidth is more than 25MHz, rejection band level is less than -30dB and center frequency is 820MHz.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.975-976
• /
• 2006

The passive type RFID (Radio Frequency Identification) System using Surface Acoustic Wave (SAW) tag at 900 MHz in the range of more than 1 m was fabricated. To improve interrogation range of the system propose a method to increase isolation between transmitter and receiver. This method using a direct conversion architecture achieves a leakage rejection of 10 dB increased compared with conventional system. Measured interrogation range is more than 1 m.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1992.05a
• /
• pp.73-76
• /
• 1992

In this study, piezoelectric ceramics of composition 0.08Pb(Mn$\sub$1/3/Sb$\sub$2/3/)O$_3$ were manufactured by the Hot-press method and structural, piezoelectrical properties and temperature stability were investigated with addition of 0, 02, 0.4, 0.6, 0.8, 1.0 [wt%] Cr$_2$O$_3$. Also the SAW delayline was fabricated and the propagation characteristics of SAW were considered with SAW theories.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.932-934
• /
• 2004

Due to the increasing variety and capacity of information and communication media, systems of microwave band communication have branched out extensively. Surface acoustic wave (SAW) devices fabricated FeSiB thin films on quartz substrate were deposited by RF magnetron sputter and by photolithographic processes. This device is with a center frequency 146MHz and the insertion loss as low as -43dB was obtained.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.4
• /
• pp.766-771
• /
• 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
• /
• v.16 no.3
• /
• pp.86-93
• /
• 1997

A Design & Simulation Tools of Surface Acoustic Wave(SAW) Filters for Mobile Communication Systems, which is based on Optimization of Impulse Samples with Object Function of Amplitude, Ripple and Group Delay Characteristics, is developed and is also evaluated by designning and simulating the SAW IF Filter for PCS. In Optimization Process, fast calculation algorithm of Object Function is proposed. With this Design Tools, Transversal SAW IF Filters can be easily designed under limited conditions of small chip size and package size. It may be also applicable to wide Band Pass Filters in future Communication Systems such as FPLMTS.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.248-249
• /
• 2000

파장분할다중 광통신시스템은 파장통과 대역폭이 좁으면서, 파장통과 대역을 넓게 가변시킬 수 있는 집적광학형 광여파기를 필요로 하고 있다. 지금까지 전기광학효과$^{(1)}$ , 스트레인광학효과$^{(2)}$ , 음향광학효과$^{(3)}$ 들을 이용하여 다양한 형태의 광여파기들이 연구되어져왔다. 특히 음향광학효과를 이용한 편광모드변환형 가변파장 광필터 (AOTF: Acousto-Optic Tunable Filter)는 150nm 이상의 넓은 파장가변 범위, 1nm이하의 좁은 파장대역폭, 수 $\mu\textrm{s}$ 정도의 비교적 빠른 스위칭 속도, 그리고 여러 파장 채널을 동시에 선택할 수 있는 특성들 때문에 많은 연구가 진행되어져 왔다. 본 논문에서는 음향파 장벽(acoustic barrier)를 이용하여 표면 음향파(SAW: Surface Acoustic Wave)의 RF 구동파워를 감소시킬 수 있는 구조의 AOTF를 제작하고, 측정 결과를 음향파 장벽을 이용하지 않은 AOTF의 측정 결과와 비교, 검토하였다. (중략)

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.1
• /
• pp.218-224
• /
• 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 Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.7
• /
• pp.288-292
• /
• 2003

AlM thin film has been deposited on A1$_2$O$_3$ substrate by reactive radio frequency(RF) magnetron sputtering method under various operating conditions such as working pressure, fraction of nitrogen partial pressure, and substrate temperature. Scanning Electron Microscope(SEM), X-ray Diffraction(XRD), and Atomic Force Microscope(AFM) have been measured to find out structural properties and preferred orientation of AlN thin films. SAW velocity of IDTs/AlN/Si structure was about 5038［㎧］ at the center frequency of 251.9［MHz］ and insertion loss was measured to be relatively low value of 35.6［dB］. SAW velocity of IDTs/AlN/A1$_2$O$_3$ structure was improved to be about 5960［㎧］ at the center frequency of 296.7［MHz］.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.8
• /
• pp.1767-1775
• /
• 2003

The SAW device is extensively used as a electro$.$mechanical band­pass filter in which a two­pairs of interdigital transducers are provided over the surface of the piezoelectric substrate. For the design requirement, the central frequency and the bandwidth of the passband, and the attenuation level of the stopband region are specified. The configuration is made so as to satisfy the specification given. The central frequency is mainly determined by the distance between the pair of the finger electrodes. The design is considered as an optimization problem with which the error norm, the distance between the desired characteristics and the calculated for a given model is to be minimized. The delta function model and the electrical equivalent circuit model are utilized to represent the SAW filter characteristics. Genetic algorithm is used for optimization in which apodization of the transducer fingers is chosen as a design variable.