• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.223-228
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• 2018

In this paper the water sensor using a coaxial cavity resonator is designed and manufactured. The water sensor which can sense water drop linearly has been constructed with voltage controlled oscillator(VCO), coaxial cavity resonator, RF switch, RF detector, A/D converter, DAC and micro controller. The operating frequency range of the designed water sensor is from 2.5GHz to 3.2GHz and the input voltage and current source are 24[V/DC] and 1[A]. The designed sensor circuit includes VCO, RF switch, RF detector which varies the frequency characteristics of the devices in the high frequency of 3GHz. And so we should correct the error of the frequency characteristics of those devices in the sensor circuit. To do this, we make the reference path which switches the signals to the RF detector directly without sending it to the resonator. According to the result of simulation and measurement, we can see that there is 0-50MHz difference between simulated resonator frequency and manufactured resonator frequency.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.421-422
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• 2012

본 논문은 넓은 범위에서 변화하는 입력 전압과 출력 전류 조건에서 동작하는 공진형 직류-직류 컨버터의 디지털 제어기 해석 및 설계에 대해 기술한다. LLC 직렬 공진형 컨버터의 전력 변환단 동 특성을 기반으로 디지털 제어기를 해석 및 설계하고, DSP 기능을 내장한 16 비트 마이크로 컨트롤러를 이용하여 제어기를 구현한다. 개발된 디지털 제어기를 150W 공진형 컨버터 보드에 적용하여 설계 이론을 실험적으로 검증하고, 종래의 아날로그 제어기를 적용한 컨버터와의 장단점과 동 특성을 비교 검증한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1175-1180
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• 2014

In this paper, the open ring type DGS(Defected Ground Structure) resonator, applicable to MMIC(Monolithic Microwave Integrated Circuit), is proposed to improve phase noise characteristics of RF oscillator. This resonator is planar type, therefore, it easy to design miniaturrized., and takes relatively high Q value. Modeling the equivalent parameter of resonator is needed, when designing the RF oscillator with resonator. The mathematical method to solve the equivalent parameter of the resonator from the measured results of resonator is introduced in this paper. To verify the method, DGS resonator with 5.8 GHz center frequency is fabricated, for measuring characteristics and calculating the equivalent parameter. The result from this process is compared with the data of the ADS simulation, and as a result both were identical.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.3
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• pp.39-43
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• 2011

Effects of cavity material on the Q-factor measurement of microwave dielectric materials were studied by HFSS simulation and the measurements using metal cavity. $TE_{01\delta}$ mode resonant frequency was determined from the electric and magnetic field patterns and the loaded Q-factor was calculated from 3dB bandwidth of $S_{21}$ spectrum. When the cavity metal materials were Cu, SUS and Au cavity, the level of Q-factor was similar. However, Q-factor was significantly decreased when the cavity metal material was CuO. The Q-factor measurements of dielectric resonator by network analyzer using various metal cavity exhibits consistent behavior.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.463-470
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• 2015

In this paper, a new dual-band bandpass filter(BPF) that has resonators and feed lines with Stepped-Impedance Resonator(SIR) structures is proposed. Feed lines with SIR structure provide maximum magnetic field points which occur at the same locations of the input and output feed lines, so the insertion loss of BPF was reduced. Applying the SIR structure to the BPF for the first passband improves rejection characteristics between the first passband and the second passband. It reduces the coupling between the BPF for the first passband and the BPF for the second passband, so it makes the dual-band BPF more compact. The proposed design method provides independent changes of both the center frequency and the bandwidth for each resonator, and also improves filtering characteristics. The validity of the proposed design method is confirmed by comparisons between the designed parameters and the measured results satisfying WLAN specifications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1255-1260
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• 2009

Microstrip interdigital filter is designed with the width and length of a resonator, the gap distance between resonators and the location of a tap. When designing filters, it is a benefit to design with few design parameters comparing to many design parameters. In this paper we design and implement two microstrip interdigital filters operating in the UWB(Ultra Wide-Band) frequency band, one using a fixed width of a resonator and the other using a different width of resonators. The test results of the implemented filters show that the low-band high filter with a fixed width has the insertion loss of 1.49dB, -10dB band width of 720MHz, -35.7dBattenuation at 4.8GHzand below -13dB of S11. The filter with a different width of resonators has the insertion loss of 1.6dB, -10dBbandwidth of 1.63GHz and below-8dBof S11.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.20-22
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• 2003

본 논문에서는 Photonic Bandgap(PBG)를 공진 특성을 이용하여 마이크로파 발진기의 위상잡음을 줄이기 위한 기술을 제시한다. 마이크로스트립 라인으로 구현한 공진기는 낮은 Q(Quality factor)를 가진다. PBG를 적용했을 때 공진기의 Q값을 높여줌으로써 발진기의 위상잡음 특성이 향상됨을 보이고자 한다.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.4
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• pp.42-47
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• 1999

Based on characteristics of resonator in BPF, a resonant characteristic is obtained by using variation of characteristic impedance in rectangular waveguide. And we have designed and made a novel waveguide BPF with this phenomenon. This filter can be made with arbitrary lengths of rectangular waveguide resonators.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.1
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• pp.19-24
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• 2003

A very small size 2.4 GHz ISM band BPF(Band Pass Filter) is realized using LTCC Multi-layer technology. Proposed design method enables to achieve BPF size $2.0\times1.2\times0.8mm^3$. A $lambda/4$ resonator with shunt-to-ground loaded capacitor is used to shorten resonator length, achieving higher quality factor. Also this resonator enables BPF to improve out-of-band rejection. Coupling coefficients between coupled strip-line resonators and external quality factor (Qe) of a resonator are derived and applied to the filter design. The measured results show good agreement with simulated data.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.91-95
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• 2002

A very small size BPF is realized using LTCC Multilayer technology. A λ/4 resonator with shunt-to-ground loaded capacitor is used to shorten resonator length and achieve higher qualityfactor. Also this resonator enable BPF to improve out-of-band rejection. Coupling coefficients between coupled stripline resonators and external qualityfactor of a resonator are derived and apply to the filter design. The measured results show a good agreement with the simulation.