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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of electromagnetic engineering and science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
Editor in Chief :
Volume & Issues
Volume 5, Issue 4 - Dec 2005
Volume 5, Issue 3 - Sep 2005
Volume 5, Issue 2 - Jun 2005
Volume 5, Issue 1 - Mar 2005
Selecting the target year
Design of a Planar Cavity Resonator for 12.5 GHz Low Phase Noise SiGe HBT Oscillator
Lee Jae-Woo ; Kim Yong-Hoon ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 153~160
In this paper, the novel microwave oscillator incorporating a planar cavity resonator(PCR) is presented to reduce the phase noise of the oscillator in a planar environment. Compared to the conventional planar(
/4 open stub resonator), the phase noise is improved about 16 dBc/Hz @100 kHz. The design of the oscillator is based on a reflection type configuration using the low 1/f SiGe HBT transistor(LPT16ED). The output power is measured 2.76 dBm at 12.5 GHz. In this paper, the oscillator used to the PCR can be expected to provide a solution for low phase noise oscillator in microwave circuits.
Coating Effects on Electromagnetic Wave Absorbers Prepared with Mn-Zn Ferrites
Song Jae-Man ; Kim Dong-Il ; Che Seung-Hun ; Choi Yun-Seok ; Kim Ki-Man ; Rhyu Keel-Soo ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 161~165
We prepared Mn-Zn ferrite Electromagnetic(EM) wave absorbers. The Mn-Zn ferrite EM wave absorbers were coated with Sr ferrite powders and
powders. The coated Mn-Zn ferrite EM wave absorbers show improved absorption compared with non-coated Mn-Zn EM wave absorbers.
A New Complementary Quadriphase Jacket Sequence with Good Cross Correlation
Hou Jia ; Lee Kwang-Jae ; Lee Moon-Ho ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 166~171
In this paper, a set of new complementary quadriphase sequences based on Jacket matrix is proposed. It is with a good zero cross correlation zone and efficiently eliminates the inter-user interferences for CDMA systems. Unlike the conventional complementary sequence designs, the proposed sequences can be easily extended to large odd and even sizes by using a fast linear transform for multi-user communication systems. The computer simulation shows that the proposed sequences have better performance than conventional multi-user spreading CDMA systems using ZCZ sequence.
Development of Paint-type and Spray-type Electromagnetic Wave Absorbers
Song Jae-Man ; Kim Dong-Ii ; Choi Jeung-Hyun ; Jeung Jae-Hyun ; Kim Ki-Man ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 172~175
Sometimes, it is more convenient to use paint-type and spray-type EM wave absorbers than bulk-type or sheet-type. Thus, in this paper, we prepared paint-type and spry-type EM wave absorbers. The proportion of ferrites to paints, particle size of magnetic material, and kinds of paint should be considered to prepare a superior paint-type EM wave absorber. There is no big gap between spray-type and paint-type in EM wave absorption of EM wave absorbers prepared with same composition.
An Efficient Multipaction Analysis of an Output Multiplexer for Satellite Applications
Uhm Man Seok ; Lee Juseop ; Yom In-Bok ; Kim Jeong-Phill ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 176~182
In this paper, an efficient multipaction analysis method of a manifold multiplexer for satellite applications is presented. While FEM(Finite Element Method) is used for the multipaction analysis of the lowpass filter, the equivalent circuit model is used for the analysis of the channel filters and the manifold. Employing equivalent circuit model for multipaction analysis takes less time than using EM(Electromagnetic) field analysis method while keeping the accuracy of the multipaction analysis. This present analysis method is applied to the manifold multiplexer for Ka-band satellite transponders and the results show that the present method is as accurate as the conventional EM field analysis method.
A Simple Microwave Backscattering Model for Vegetation Canopies
Oh Yisok ; Hong Jin-Young ; Lee Sung-Hwa ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 183~188
A simple microwave backscattering model for vegetation canopies on earth surfaces is developed in this study. A natural earth surface is modeled as a two-layer structure comprising a vegetation layer and a ground layer. This scattering model includes various scattering mechanisms up to the first-order multiple scattering( double-bounce scattering). Radar backscatter from ground surface has been modeled by the polarimetric semi-empirical model (PSEM), while the backscatter from the vegetation layer modeled by the vector radiative transfer model. The vegetation layer is modeled by random distribution of mixed scattering particles, such as leaves, branches and trunks. The number of input parameters has been minimized to simplify the scattering model. The computation results are compared with the experimental measurements, which were obtained by ground-based scatterometers and NASA/JPL air-borne synthetic aperture radar(SAR) system. It was found that the scattering model agrees well with the experimental data, even though the model used only ten input parameters.
Measurement of Rainfall Characteristics and Rain-Attenuation at 38 GHz in Worst Months Affected by El Nino Signal in 1998
Jang Won-Gyu ; Choi Jae-Hoon ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 189~192
The measurement of unique rainfall phenomenon and rain attenuation on 38 GHz terrestrial links at South Korea in 1998 is presented. It was one of the most severe rainfall years at the measured region due to increased EI Nino signal. The rainfall rate exceeded at
was 97.4 mm/h during a worst month and annual rate was 63.5 mm/h. Experimentally measured results have been compared with some models and found that the rain attenuation by system level was underestimated by the existing prediction models. As it was measured only three months, further study and measurement of rainfall and rain attenuation in this region are needed for stable millimeter-wave system operation at all times.
Study on the Effect of Metal-Wall Loading on the DC Power-Bus
Kahng Sungtek ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 193~196
The DC power-bus for the PCB is loaded with metal walls on its selected sides and is characterized electromagnetically. This is a novel concept of approach to mitigate the spurious resonance and finally signal integrity problems. In particular, the peak at DC, which is always in the way to secure parallel-plates' EMC, can be completely removed by the proposed method. Through the findings of this study, the effect of metal-loading of the power-bus will be presented along with the impression that the suggested technique can tackle the headaches of signal integrity, ground bounce, EMIs.
Analysis of Interference Impacts by UWB System to WiBro Systems
Yoon Young-Keun ; Jin Rong-Reon ; Kim Kyung-Seok ; Choi Ik-Guen ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 197~203
This paper evaluates the impacts for interference from UWB system, and determines the tolerable UWB power spectral density(PSD) to the new deploying system, which is called a portable internet service in Korea. It also proposes the interference analysis scheme that can evaluate the characteristics of the performance degradation for portable internet service according to the emission power of UWB systems at the specified frequency bands. The proposed scheme includes a multi-rate and data service environments to deal with interference to portable internet service. It is obtained from simulation results that the transmission PSD of UWB systems should be rigidly restricted by less approximately 10
20 dB than FCC provisional limit for coexistence between UWB and portable internet service already allocated at 2.3 GHz frequency bands in Korea.
A Novel Phase Noise Reduction In Oscillator Using PBG(Photonic Band Gap) Structure and Feedforward Circuit
Seo, Chul-Hun ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 204~207
In this paper, PBG structure and feedforward circuit has been used to suppress the phase noise of the oscillator. Microstrip line resonator have low Q, but we can obtain high LO power by feedforward circuit and improve the resonator Q by the PBG, simultaneously. The proposed oscillator which uses PBG and feedforward circuit shows 0
20 dB phase noise reduction compared to the conventional oscillator. We have obtained -115.8 dBc of phase noise at 100 kHz offset from 2.4 GHz center.
Harmonic Suppression and Broadening Bandwidth of Band Pass Filter Using Aperture and Photonic Band Gap Structure
Seo, Chul-Hun ;
Journal of electromagnetic engineering and science, volume 5, issue 4, 2005, Pages 208~212
In this paper, we introduced a band-pass filter employed the PBG structure and the aperture on the ground together. The harmonics of band pass filter have been suppressed by employing the PBG structure and the bandwidth of it has been broadened by using the aperture on the ground. The designed PBG cells have three different sizes. The largest cells, the middle cells, and the smallest cells have suppressed the multiple of second harmonics, the multiple of third harmonics, and the multiple of fifth harmonics, respectively. The center frequency has been 2.18 GHz. The bandwidth has been increased from 230 MHz up to 310 MHz(80 MHz, about
) by the aperture and the ripple characteristics in passband have been improved and the harmonic frequencies have been suppressed about 30 dB by the PBG.