http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
MOSFET 동기정류회로의 특성 고찰 : S.M.P.S.에서 In S.M.P.S.
박성교,박종백 조선대학교 동력자원연구소 1996 動力資源硏究所誌 Vol.18 No.1
To improve the rectification efficiency, designed S.M.P.S. were fabricated by replacing diodes with power MOSFETs. The characteristics between these S.M.P.S. and existing diode-type S.M.P.S. at a load of 2.5[A]and 5[A] were compared. The results represent that independent synchronous gate-driven half bridge MOSFET rectifier obtaines a little increased total rectification efficiency, that is, increased 4.84% at a load of 2.5[A] and 1.55% at a load of 5[A] and self synchronous gate-driven flyback MOSFET retifier obstaines a little incerased total rectification efficiency, that is, increased 2.49% at a load of 2.5[A] and 3.47% at a load of 5[A], than diode-type S.M.P.S..
박성교,박종백 조선대학교 생산기술연구소 1995 生産技術硏究 Vol.17 No.1
In this study, a L-Band Low Noise Amplifier(LNA) which can be used in mobile communication and satellite communication is designed and fabricated on the teflon substrate (ε_(r) : 2.15, h : 1.6 ㎜) with microstrip line. Using GaAs MESFET(KGF1254), LNA is designed with power gain of +10 dB at a center frequency of 1.5 GHz with ± 75 MHz bandwidth. The experimental results show that power gain is + 12 dB at a center frequency of 1.540 GHz with ± 25 MHz bandwidth and center frequency shifts by +2.7%. These measured data is in good agreement with the designed data.
박성교,박종백 조선대학교 에너지.자원신기술연구소 1998 에너지·자원신기술연구소 논문지 Vol.20 No.2
In this paper we fabricated QMSAs for 850㎒ band on the teflon substrate with ε_(r)=2.6, H=1.6㎜(±0.08) (CGP-500). The resonant frequency and the return loss were measured by cutting the gap L_(3) between radiation patch and ground plate, with a 5㎜ cutting length, step by step. As a result, we found that the measured return loss data were good when the gap L_(3) was shorter, especially under 10㎜, unlike the other papers reported.
기판의 유전율 및 전기적 두께가 X-벤드용 마이크로스트립 패치 안테나의 특성에 미치는 영향에 관한 연구
박성교,김준현,박종배 대한전자공학회 1996 전자공학회논문지-A Vol.33 No.3
In this study forty-five X-bnd rectangular microstrip patch antennas fed by microstrip line using ${\lambda}$/4 transformer were fabricated on teflon substrates with low high permittivities and varous thickness (substrate thickness : 0.6 ~ 2.4 mm, permittivities : 2.15 ~ 10.0), and effects of permittivity and electrical thickness on antenna characteristics were studied with measured return loss (1/S$_{11}$) and resonant frequencies. When substrate electrical thickness was greater than 0.060 ${\lambda}_{0}$return loss was very good and genrally more than 20 dB, but resonance characteristics was somewhat unstable. The more than 0.088 ${\lambda}_{0}$ the thickness was, the more unstable it was. As a result, in the rest range except 12, 13 GHz we had very good mesured return loss iwth greater than 20 dB, and in the range 7 to 9 GHz resonant frequencies were within $\pm$2 % error, on ${\epsilon}_{r}$=5.0, height = 2.4 mm substrate.
박성교,강철준,박종백 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.1
Radiofrequency thermal ablation (RTA) as one of the microwave hyperthermia is becoming the treatment of choice for small but inoperable tumors of the liver. In this paper, we deigned semi-rigid coaxial cable antenna with a ring slot for RTA applicator. To optimize the maximum output of radiation at 2450㎒, we simulated the antenna using 2D Electromagnetic Simulation Tools HFSS program and analyzed the return loss and the electric field Etot at the near-field region between the simulation results and measurement results. As a result, we obtained the return loss of -29.786㏈ at 2450㎒ when the antenna was placed between two blocks of a pig's liver, and the measurement results agreed with the simulation results well. Therefore, this semi-rigid coaxial cable antenna with a ring slot can be used very usefully as the applicator for RTA.
朴成敎,朴鍾伯 조선대학교 생산기술연구소 1996 生産技術硏究 Vol.18 No.1
In this study 45 X-band rectangular microstrip patch antennas over 7-15 GHz fed by microstrip line using λ/4 transformer were fabricated on teflon substrates with low · high permittivities and various thickness (substrate thickness : 0.6 ~ 2.4 mm, permittivities: 2.15 ~ 10.0 ), and effects of permittivity and electrical thickness on antenna characteristics were studied with measured return loss(1/S₁₁) and resonant frequencies. When substrate electrical thickness was greater than 0.060 λo return loss was very good and generally more than 20 dB, but resonance characteristics was somewhat unstable. The more than 0.088 λo the thickness was, the more unstable it was. As a result, in the rest range except 12, 13 GHz we had very good measured return loss with greater than 20 dB, and in the range 7 to 9 GHz resonant frequencies were within ±2 % error, on εr=5.0, height=2.4 mm substrate.
박옥동,박성교,박종백 조선대학교 에너지.자원신기술연구소 2000 에너지·자원신기술연구소 논문지 Vol.22 No.1
In this study, we designed and fabricated Voltage Controlled Transistor DRO (VCTDRO) using Varactor Diode with oscillation frequency of 3.2 GHz. A Dielectric Resonator Oscillator (DRO) which can obtain the high quality factor Q, minimized size, high temperature stability and high output power was used. This fabricated VCTDRO has 4 MHz of tuning band, -3.394 dBm of output power and -98 dBc/Hz of phase noise at 10 KHz offset frequency, at 3.2 GHz.
Micro Wave 대역의 Microstrip Antenna 기판에 관한 연구
朴鍾伯,朴成敎 조선대학교 생산기술연구소 1992 生産技術硏究 Vol.14 No.2
Most of the work on microstrip antenna theory and design has assumed electrically thin, low_ε_(r) substrates. With increasing interest in micro wave systems, electrically thicker substrates with high permittivity are being used. For such cases many of the analysis techniques that work well for thin substrates fail to accurately predict either the resonant frequency or input impedance, or both. The purpose of this study is to provide a set of measured data for rectangular micros trip antennas on low and high permittivity substrates of various thicknesses, and to compare this results with some of the popular theoretical models. In this way, the range of validity of the models can begin to be ascertained, and a database of experimental data made a vailable for the testing of future models.
朴種伯,朴成敎 조선대학교 생산기술연구소 1991 生産技術硏究 Vol.13 No.1
In this paper the diffraction effect is investigated in a systematic way using the shape function on the transducer shape and observation point. The frequency dependent attenuation is estimated by eliminating the errors caused by the diffraction effect. The results indicate that the proposed method improves the accuracy of the estimated value. The group delay function for a pulse-echo signal is also derived from the phase of the Fourier transform of the signal. The mean value of group delay function corresponds to the slope of the linear phase component in the phase function. Therefore the dispersion effect contained in the pulse-echo signal is eliminated by measuring the group delay function. The estimated value by the proposed method is more accurtae than that by the conventional method, resulting in error that is about 0.46% smaller.