• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.255-260
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• 2016

In this paper, a full-wave rectifier (FWR) with a simple vibration detector suitable for use with vibrational energy harvesting systems is presented. Conventional active FWRs where active diodes are used to reduce the diode voltage drop and increase the system efficiency are usually powered from the output. Output-powered FWRs exhibit relatively high efficiencies because the comparators used in active diodes are powered from the stable output voltage. Nevertheless, a major drawback is that these FWRs consume power from the output storage capacitor even when the system is not harvesting any energy. To overcome the problem, a technique using a simple vibration detector consisting of a peak detector and a level converter is proposed. The vibration detector detects whether vibrational energy exists or not in the input terminal and disables the comparators when there is no vibrational energy. The proposed FWR with the vibration detector is designed using a $0.35-{\mu}m$ CMOS process. Simulation results have verified the effectiveness of the proposed scheme. By using the proposed vibration detector, a decrease in leakage current by approximately 67,000 times can be achieved after the vibration disappears.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.429-432
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• 2017

In this paper, a full - wave rectifying harvesting circuit with a high-performance comparator is designed. Designed circuits are divided into Negative Voltage Converter and Active Diode stages. The comparator included in the active diode stage is implemented as a 3-stage type and divided into pre-amplification, decision circuit, and output buffer stages. The main purpose of this comparator is to reduce the propagation delay and improve the voltage and power efficiency of the harvesting circuit. The proposed circuit is designed with magna $0.35{\mu}m$ CMOS process and its operation is verified by simulation. The chip area of the designed energy harvesting circuit is $900{\mu}m{\times}712{\mu}m$.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.322-327
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• 2010

Spaceborne sparse array radar for ground moving targets indication (GMTI) has outstanding advantage over full array radar for constructing ultra-large aperture. Rapid development of millimeter wave (MMW) technology make it possible for realizing MMW GMTI radar, which is much more sensitive to slow moving ground target. The paper presented the system model of a multi-carrier frequency sparse array MMW radar as well as preliminary simulation results, which showed future application of the system is very promising.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.4
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• pp.535-541
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• 2003

This paper describes numerical analysis of the impulse turbine with fixed guide vanes, a high performance hi-directional air turbine having simple structure for wane energy conversion. A 3-dimensional incompressible viscous flow numerical analysis based on the full Reynolds-averaged Wavier-Stokes equations was made to investigate the internal flow behavior Numerical results ate compared with experimental data. As a result, a suitable choice for the one of design factors has been clarified.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.256-259
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• 2011

In this article, new microstrip slow-wave bandpass filters using open loop resonator loaded with inter-digital capacitive fingers is proposed. The filter features not only compact in size, but also exhibits spurious stop-band rejection. Filters of this type with elliptic function and Chebyshev response are demonstrated. There is good agreement between experimental and full-wave electromagnetic (EM) simulation results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.316-323
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• 2013

This paper deals with the near-field to far-field calculation for far-field characteristics of antenna and electromagnetic compatibility(EMC) testing. Since the conventional EMC testing process is inefficient such as measurements of the wide band signals and mega structures, Stratton-Chu formula is used to predict the far-field emission by simple and direct process. The usefulness of Stratton-Chu formula is verified by comparing to the analytic solution of the uniform distribution aperture in free-space. In order to inspect the far-fields and to get the near-field values, full-wave simulation solver is utilized. Through the full-wave simulation about the patch antenna, calculated far-field results from Stratton-Chu formula are proven. The predicted magnitudes of the far-field are in error by less than 6 %.

• Bulletin of the Korean Space Science Society
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• 2003.05b
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• pp.45-45
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• 2003

No Abstract, See Full Text

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.514-514
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• 2000

In this article, the realization of a precision full-wave rectifier circuit for analog signal processing, which operates throughout in the current domain, is presented. The circuit makes use of a MOS class B/AB configuration, and provides a wide dynamic range and wide-band capability. The rectifier has a simple circuit configuration and is suitable for implementing in CMOS integrated circuit form as versatile building block. The characteristic of the circuit exhibits a low distortion en the output signal at low level input signal. PSPICE simulation results demonstrating the characteristic of the proposed circuit are included.

• Journal of Communications and Networks
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• v.13 no.6
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• pp.625-632
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• 2011

This paper presents an overview of recent advances in radio frequency and microwave filter topologies for satellite communication systems. Many types of filters have been developed during the last years in order to satisfy the demands of modern applications in both terrestrial systems and onboard spacecrafts, leading to a great variety of aspects such as transfer functions, resonator implementations or coupling structures. This paper revisits some of the last advances in this area, including the modeling and full-wave simulation. Some recent designs using dual-mode cavities along with other novel implementations in ridge waveguide will be shown.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.130-131
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• 2007

This study investigates the performances of the signaling techniques including differential signals for the power-distribution network(PDN)s with and without the slit, using a rigorous evaluation method, validated by the FDTD simulation up to 5 GHz.