Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Journal of Korean Institute of Electromagnetic Engineering and Science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
Editor in Chief :
Volume & Issues
Volume 15, Issue 12 - Dec 2004
Volume 15, Issue 11 - Nov 2004
Volume 15, Issue 10 - Oct 2004
Volume 15, Issue 9 - Sep 2004
Volume 15, Issue 8 - Aug 2004
Volume 15, Issue 7 - Jul 2004
Volume 15, Issue 6 - Jun 2004
Volume 15, Issue 5 - May 2004
Volume 15, Issue 4 - Apr 2004
Volume 15, Issue 3 - Mar 2004
Volume 15, Issue 2 - Feb 2004
Volume 15, Issue 1 - Jan 2004
Selecting the target year
Development of an SIS(Superconductor-Insulator-Superconductor) Junction Mixer over 120∼180 GHz Band
Chung, Moon-Hee ; Lee, Changhoon ; Kim, Kwang-Dong ; Kim, Hyo-Ryoung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 737~743
A fixed-tuned SIS(Superconductor-Insulator-Superconductor) mixer across 120∼180 GHz band has been developed. This mixer employs an SIS chip fabricated by Nobeyama radio observatory which consists of a series array of 6 Nb/Al-Al
/Nb junctions in a microstrip line on a fused quartz substrate. The SIS chip is placed at the center of the half-height waveguide mixer mount to have a good incoming signal coupling over the whole frequency band. No mechanical tuner was used in the SIS mixer and the RF signal and local oscillator power are injected to the mixer via a cooled cross-guide coupler. In order to prevent the IF signal loss, the If output impedance of the SIS mixer was matched to the 50
input impedance of the IF chain. Measured double sideband noise temperatures of a receiver using the SIS mixer are 32∼131 K over 120∼180 GHz band. The developed SIS mixer is now in use for radio astronomical observations on the TRAO 14 m radio telescope.
New Challenges for Low Cost and High Speed RF ATE System
Song, Ki-Jae ; Lee, Ki-Soo ; Park, Jongsoo ; Lee, Jong-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 744~751
This paper presents the implementation of the low cost and high speed RF ATE(Automatic Test Equipment) system, which can be a reasonable solution for reducing the test cost of RF devices. This paper suggests high speed and precise measurement capabilities which are realized by the 16 independent RF ports with high speed switching time and high accuracy digitizer using the industry standard Versus module eXtensions for Instrument(VXI) General Purpose Interface Bus(GPIB) interfaces. Also, the system has the capabilities of quad-site test which can dramatically increase the device throughput. This paper concludes with the demonstration of the implemented ATE system through the setup of RF Power Amplifier Module(PAM), which is under the most competitive market situation.
DC and RF Characteristics of AlGaN/InGaN HEMTs Grown by Plasma-Assisted MBE
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 752~758
This paper reports on the DC and RF characteristics of AlGaN/InGaN/GaN high electron-mobility transistors (HEMTs) grown by molecular beau epitaxy(MBE) on sapphire substrates. The devices with a 0.5
m gate-length exhibited relatively flat transconductance(g
m/), which results from the enhanced carrier confinement of the InGaN channel. The maximum drain current was 880 mA/mm with a peak g
m/ of 156 mS/mm, an f
T/ of 17.3 GHz, and an f
MAX/ or 28.7 GHz. In addition to promising DC and RF results, pulsed I-V and current-switching measurements showed little dispersion in the unpassivated AlGaN/InGaN HEMTs. These results suggest that the addition of In to the GaN channel improves the electron transport characteristics as well as suppressing current collapse that is related to the surface trap states.
MIMO Channel Analysis Method using Ray-Tracing Propagation Model
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 759~764
This paper proposes a method that estimates MIMO channel characteristics analytically using a 3D ray tracing propagation model. We calculate the discrete spatial correlation between sub-channels by considering phase differences of paths, and using this, estimate the mean capacity upper bound of MIMO channel by Jensen's inequality. This analysis model is a deterministic model that do not approach stochastically through measurement nor approach statistically through Monte-Carlo simulations, so this model has high efficiency for time and cost. And based on the electromagnetic theory, this model may analyze quantitatively the parameters which can affect the channel capacity - antenna pattern, polarization mutual coupling, antenna structure and etc. This model may be used for the development of an optimal antenna structure for MIMO systems.
An Approximate Formulation for Scattering by Very Thin Dielectric Scatters
Koh, Il-Suek ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 765~774
In this paper, a novel approximate solution for scattering by a very thin planar homogeneous dielectric scatterer with an arbitrary shape is formulated. This solution is based on a volumetric integral equation and is expressed in terms of Fourier transform. It is shown that the obtained solution is reduced to an exact solution for an infinite dielectric slab. For 2D, or 3D scatterers, the formulation is verified numerically. Especially fur edge-on TM polarized wave incidence a closed-form solution of backscattering from a thin dielectric half-plane is formulated, which is very accurate for wide range of normalized surface impedance except very low impedances(│η│〈0.5).
Hybrid of SA and CG Methods for Designing the Ka-Band Group-Delay Equalized Filter
Kahng, Sungtek ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 775~780
This paper describes the realization of the Ka-band group-delay equalized filter desisted with the help of a new hybrid method of Simulated Annealing(SA) and Conjugate Gradient(CG), to be employed by the multi-channel Input Multiplexer for a satellite use, each channel of which comprises a channel filter and a group-delay equalizer. The SA and CG find circuit parameters of an 8th order elliptic function filter and a 2-pole equalizer, respectively. Measurement results demonstrate that the performances of the designed component meet the specifications, and validate the design methods.
The Design and Implementation of a Multi-Band Planar Antenna for Cellular/PCS/IMT-2000 Base Station
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 781~787
In this paper, a novel dual and wide band aperture stacked patch antenna for Cellular/PCS/IMT-2000 base station is presented. It consists of single microstrip patch having notches along the radiating patch, two dielectric substrates and a form material. To achieve wide band characteristic, we utilize the coupling effect between the notched patch and the resonant aperture in the ground plane and by properly cutting notches on the patch, an aperture stacked patch antenna could be designed to yield dual frequency operation. By the proper choice of resonant aperture size and height of a foam material, dual and wide band characteristic could be realized the measured impedance bandwidth(1:1.5 VSWR) of designed antenna at lower band(860 MHz) reaches 77 MHz and covers the Cellular CDMA band(824∼894 MHz). The measured impedance bandwidth(1:1.5 VSMR) of the designed antenna at upper band(1,960 MHz) is about 550 MHz and covers both the PCS band(1,750∼l,870 MHz) and the for-2000 band(1,920∼2,170 MHz). Good broadside radiation with high gain(5.65∼7.4 dBi) characteristics have also been observed.
Research Dual Band Power Amplifier using PBG Structure
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 788~793
This paper proposes new configuration for the dual power amplifier that operates at 5.8 GHz for the wireless LAN and 1.8 GHz for the PCS. It dose not select the input signal but amplify the dual band signals simultaneously. Broadband diplexer is used at the input to separate the dual band signals. Output power of each amplifier is 1 W. The PBG is employed to improve the performance of power amplifier. Generally, the PBG is employed at the end of output matching network. But in this paper, the PBG is employed in the load pull output matching circuit of amplifer to maximize the output power.
A Uniform Formulation for Scattering by Very Thin Dielectric Strips for TM Wave Incidence
Koh, Il-Suek ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 794~800
In this paper a new approximate formulation for bistatic scattering by a thin dielectric strip for TM wave incidence is obtained. This formulation is uniform which is valid for any incident angles, observation points, and any properties of the skip such as dielectric constants, width, and thickness. The accuracy of the proposed solution is examined by comparisons with a method of moments(MoM) for various situations.
Design and Near-Field Analysis of X-Band Linear/Circular Polarizer
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 15, issue 8, 2004, Pages 801~808
In this paper, we proposed the grating parallel plate waveguide structure for converting a linearly polarized wave to a circularly polarized wave. For the design of the polarizer, the moment method and Floquet's theorem are applied under two assumptions that the incident wave is a plane wave and the structure is infinitely periodic. In order for the more precise design, we performed the near-field analysis for the finite polarizer structure using MATLAB. By comparing with the measured results obtained by the near-field arrangement, we verified the correctness of our near-field analysis. By taking the ideal assumptions considered in the initial design procedure into account, newly designed modified dimensions for the polarizer was suggested which give improved performance.