• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.29-35
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• 2018

In this paper, we proposed a high sensitivity sensor that can detect the concentration change of Nacl aqueous solutions by using a slot coupling capacitor resonator in sub-microwave band. The resonator applied to the sensor consists of a parallel plate capacitor connected to an inductive slot utilizing the ground plane of the microstrip line. Based on the measurement data of the dielectric characteristics according to the concentration change, the resonance frequency was determined in the UHF band where the concentration change is evident and the Nacl aqueous solution is inserted into the capacitor. Based on the simulation, the proposed resonator was designed and fabricated. The concentration level was varied from 0 to 400 mg/dl as 100 mg/dl step, and the transmission scattering coefficient ($S_{21}$) was successfully measured. Experimental results show that it is applicable to the concentration detection sensor in Nacl aqueous solution by obtaining minimum 1.8 dB($S_{21}$) at each step.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.279-285
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• 2017

In this paper, the resonator with a parallel plate capacitor is newly proposed around sub-microwave frequency band and applied to earlobe for non-invasive glucose monitoring the human biological tissue. The capacitor including the earlobe as dielectric material is connected to inductive slot in the ground plane of the microstrip line. Based on the simulation, one port resonator circuit is designed and fabricated as a prototype. Three step glucose concentration levels(0, 250, 500 mg/dL) was tested, and its reflection coefficients($S_{11}$) were measured. Owing to high Q resonator more than 100, resonant frequency shift of about 9 MHz per glucose level of 250 mg/dL has been successfully measured. This proves that the proposed sensor is applicable to a blood glucose sensor.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.63-66
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• 2007

본 논문에서는 주변에서 쉽게 구할 수 있는 재료를 이용해 만든 인덕터와 커패시터를 사용해 윌킨슨 전력 분배기를 설계/제작하였다. 일반적으로 전력 분배기는 $\lambda/4$ 전송선로를 이용하기 때문에 인덕터와 커패시터를 사용할 수 있도록 전송선로를 집중소자로 변환해야 한다. 전송선로를 집중소자로 변환하기 위해 한 개의 직렬 인덕터와 두 개의 병렬 커패시터로 등가화하였다. 인덕터는 솔레노이드 형태로 선의 굵기와 솔레노이드의 반지름, 감은수에 변화를 주며 제작하였고, 커패시터는 평행판 커패시터 형태로 넓이에 변화를 주어 제작하였다. 구현된 전력 분배기는 설계 주파수에서 각각의 출력 포트에 -3.30dB, -3.31dB로 전력이 균등분배 되는 특성을 보였고, 반사손실은 -42.36dB, 출력 포트 간의 격리도는 -31.54dB로 설계 조건을 만족하였다.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.63-70
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• 2023

In this work, a capacitive wireless power transfer (C-WPT) system is presented for wireless sensor system (WSS) applications in marine propulsion shafts. For a single Q factor on both sides of the coupling capacitor and reactive power removal from the circuit, a double-sided LCLC converter and transformers topology are designed to drive the rotary C-WPT system for WSS on the shaft. Parallel-connected parallel plate rotating capacitors with a capacitance of 170 pF are designed and implemented for the C-WPT system on a snow rotating shaft. In the experimental results, the C-WPT system achieved a transmission efficiency of 66.67% with 7.8 W output power at 3 mm distance and 1 MHz operating frequency. Therefore, it was proved that the fabricated C-WPT system can supply power to the WSS of the rotating shaft.

• Progress in Medical Physics
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• v.12 no.1
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• pp.51-58
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• 2001

Synchrotron radiation (SR) has several advantages over convetional x-rays, including its phase, collimation, and high flux. A synchrotron radiation beamline 5C1 at Pohang Light Source (PLS) was recently built for imaging applications. We have shown that a SR imaging system is useful in imaging microscopic structures. SR with broad-band energy spectrum were adjusted to an object by Si wafers and their energy were approximately ranging from 6 keV to 30 keV. SR were passed through an object and finally transformed into visible lights by CdWO$_4$ scintillator screen. The visible lights which were reflected at an angle of 90 degrees by gold plated mirror were detected by a CCD camera and the image data were acquired using image acquisition system. A high-resolution phantom, capacitor, adult tooth, child tooth, cancerous breast tissue, and mouse lumbar vertebra were imaged with SR imaging system. The Objects were rotated within the field of view of the CCD detector, and their projection image data were obtained at 250 steps over 180 degrees rotation. Image reconstructions were carried out in a PC by using IDLTM(Research systems, Inc., US) program. The spatial resolution of the images acquired by the SR imaging system was measured with a high-resolution chart manufactured for several micrometer resolution. The specimens were also imaged with conventional x-ray radiography system to compare the image quality of radiography obtained with the SR imaging system. The results showed more structural details and high contrast images with SR imaging system than conventional x-ray radiography system. The SR imaging system may have a potential for imaging in biological researches, material applications, and clinical radiography.