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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Korean Institute of Electromagnetic Engineering and Science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
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Volume & Issues
Volume 11, Issue 8 - Dec 2000
Volume 11, Issue 7 - Oct 2000
Volume 11, Issue 6 - Sep 2000
Volume 11, Issue 5 - Aug 2000
Volume 11, Issue 4 - Jun 2000
Volume 11, Issue 3 - Apr 2000
Volume 11, Issue 2 - Feb 2000
Volume 11, Issue 1 - Jan 2000
Selecting the target year
Broad Band Microstrip Antenna with Saw Tooth Perturbations for Polarization Diversity
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 505~513
This study suggests new antenna design for polarization diversity. For dual polarization, two port feeding lines are printed on two separate layers and cross-shaped aperture is located on ground between the substrates. For reducing back radiation, a reflector is attached around
/4 behind feeding substrates. For wide bandwidth we use a perturbed patch with saw tooth shaped. This perturbation effect causes reduction of antenna size and also reduction of array size. With the antenna proposed here,
array dual polarization antenna for polarization diversity of PCS base station is built. One single element has as large as 10.3%, 11.3% bandwidths at each port, V.S.W.R less than 1.3 and the isolation is less than -40 dB, also array antenna has 13.2% 12.7% band bandwidth, V.S.W.R less than 1.3 the isolation below -36dB and the XPD of 10 dB.
A Study on A Dimensional Active Phased Array Antenna
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 514~522
In this thesis, a two-dimensional active phased array antenna without phase shifter is studied for two-dimensional beam scanning. A designed two-dimensional oscillator-type active array antenna, radiation elements and the oscillator circuits were combined with via-hole and coupled by slot on the opposite ground plane. The operating characteristics are analyzed and experimentally demonstrated , The two-dimensional
elements were designed for the proper coupling strengths and coupling phases by adjusting the width, length and offset position of slot-lines. The fabricated active phased array antenna shows the beam shift characteristics capable of scanning from
with respect to broadside in one dimension, from
in two dimension. The experimental results show that it is possible to use the oscillator-type active phased array antenna as a two-dimensional planar array antenna.
A Smart Antenna Test-bed Utilizing TMS320C30 in Smart Antenna System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 523~533
In this paper, we present the hardware implementation of a smart antenna test-bed for a real -time performance analysis of the beam-forming algorithm operating in a wide-band CDMA environments of the WLL(Wireless Local Loop) standard. The test-bed introduced in this paper includes an external PC and signal generating module as well as the beam-forming module in order to perform, analyze, and evaluate the performance of the proposed smart antenna system. In the beam-forming module, the optimal weight vector is provided by the modified CGM algorithm. The computed weight vector is transferred back to the external PC for the performance analysis based on the off-line processing. From our analysis obtained in the hardware of the test-bed, it is concluded that the proposed smart antenna system for the WLL system is appropriate for enhancing the communication quality and capacity tremendously at the cell-site of the CDMA environment.
A Comparative Study on the FBG Filter Design for Dense Wavelength Division Multiplexing Optical Fiber Transmission System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 534~543
In this paper, when the current optical communication system is used for the DWDM. The FBG filter for the DWDN is able to reduce the interferences between the adjacent channels. In this paper, therefore, we find the relection spectrums for the three types of induced index changes, that is, uniform, Gaussian apodized, and raised-cosine apodized. From the obtained result in this paper, we can see that uniform FBG does not fit, and that the smaller the maximum induced index change
is and the larger the value of parameter C in the raised-cosine apodized FBG and G in the Gaussian apodized FBG are the fitter they are on the narrow filter for DWDM.
A Study on the Fabrication of Microstrip Array Antenna for Koreasat Reception
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 544~552
In this paper, the microstrip antenna is studied to replace the parabolic antenna in the DBS reception. It is expected that the good picture quality DBS reception will be possible with this antenna irrespective of rain attenuation for the 99.9% time in a monthly average since the C/N ratio f 19dB is proved by the reception experiment of a Koreasat with fabricated antenna. From the results of this paper, it is shown that the electrical characteristics of the microstrip antenna can be improved to the level similar to that of the parabolic antenna. Hence, it is considered that the fabricated microstrip antenna can replace the parabolic antenna in DBS service coverage.
Performance Analysis of MFSK-MDPSK/DS-CDMa System Employing Diversity Techniquies and Error Coding Technique in Nakagami Fading Environment
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 553~564
In this thesis, mobile communication channel with multi-path fading which is major factor of performance degradation of DS-CDMA system has been considered. An MRC diversity and error correcting coding technique have been used to improve performance of MFSK-MDPSK/DS-CDMA system. The MFSK-MDPSK/DS-CDMA system performance has been obtained quantitatively by the numerical analysis. the modulations under consideration are noncoherent M-ary frequency shift keying(MFSK) and an MFSK based joint frequency phase modulation utilizing MFSK/DS-CDMA and MDPSK-DS-CDMA systems the MFSK-MDPSK/DS-CDMA system obtain a better performance . Also, the error performance of MFSK-MDPSK/DS-CDMA system in Nakagami fading environments is improved by increasing the number of diversity branch and coding gain.
A New Method of Estimating the Buried Location and Extracting Approximate image of Underground Structures using Ground Penetrating Radar
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 565~574
A new ground penetrating radar imaging method for the estimation of buried artificial structures location and their approximate shapes in dispersive lossy ground is investigated. Fundamental idea is based on estimating delayed time and amplitude retrieval coefficients from scattered signals by buried scatterers. Using absolute value integration of each scanning site not only improve the accuracy of measured scattered signal, but also offers convenient ways to extract the image of buried structures. Multi-term Debye model was employed to describe a dispersive and lossy ground medium. We used the finite difference time domain method to discretize the wave equation in continuous form into the machine suitable form. This imaging method uses a new wave path tracing technique in time domain, which is helpful to identify the exact position of buried structures against the ground surface fluctuations.
A New Active Phase Shifter using Vetor Sum Method
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 575~581
In this paper, a new active phase shifter is proposed using a vector sum method, and a unique digital phase control method of the circuit is suggested. The proposed scheme was designed and implemented using a Wilkinson power combiner/divider, a branch line 3 dB quadrature hybrid coupler and variable gain amplifiers (VGAs) using gate FETs(DGFETs). Furthermore, it was also shown that the proposed scheme is more efficient and works properly with the digital phase control method.
FDTD Modeling of the Korean Human Head using MRI Images
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 582~591
In this paper, the Finite-Difference Time-Domain(FDTD) modeling method of the Korean human head is introduced to calculate electromagnetic energy absorption for the human head by mobile phones. After MRI scanning data is obtained, 2 dimensional(2D) segmentation is done from the 2D MRI image data by the semi-automatic method. Then, 3D dense segmentation data with
is constructed from the 2D segmentation data. Using the 3D segmentation data, coarse FDTD models of human head that is tilted arbitrarily to model the condition of tilted usage of mobile phone.
New Perfectly Matched Layer for Absorbing Evanescent Modes in FDTD
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 592~598
The existin Berenger's PML(Perfectly Matched Layer) cannot absorb evanescent modes effectively generated in waveguides or periodic array structures. Although some absorbing boundary conditons(ABC) were introduced to absorp the evanescent modes, they did not show sufficient performance or could not be applied easily because of their much difference from Berengers PML. In this paper, NPML(New PML) is introduced to absorb the evanescent modes by splitting the conductivity and permittivity profile of the Berengers PML. The proposed NPML is certified as an ABC having enough performance for evanescent and propagating modes by analyzing the global error and the reflectivity of a waveguide.
Ku-Band Sub-Harmonically Pumped Single Balanced Resistive Mixers with a Low Pass Filter Using Photonic Band Gap
Kim, Jae-Hyuk ; Park, Hyun-Joo ; Lee, Jong-Chul ; Kim, Nam-Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 599~609
In this paper, sub-harmonically pumped single balanced resistive mixers are presented . Frequency bandwidth is selected for a Ku-band, which is 11.75-12.25GHz for RF, 5.375∼5.625 GHz for LO, and 1 GHz for IF signals. A rat-race hybrid is designed for the accomplishment of single balanced type. A low pass filter (LPF) with photonic band gap(PBG) structure is used for good conversion loss and unwanted harmonics suppression. Two types of mixers are suggested, which are one with no gate bias for no DC power consumption and the other with the IF amplifier for conversion gain. When a LO signal with the power of 6 dBm at 5.5 GHz is injected, a conversion loss of 12.17dB and a conversion gain of 7.83 dB are obtained for each mixer. For the both mixers , LO to RF isolation of 20 dB and LO to IF isolation of 60dB are obtained. With the RF power of -30dBm to -3dBm, the mixer shows linear characteristics region of IF. this mixer can be applied for Ku-band and other microwave communication systems.
Microstrip Slot Array Antenna Design by Using Tansmission Line Model
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 610~618
A T-shaped microstripline -fed printed slot antenna is anlayzed by using the transmission line model(TLM) in this paper. Microstrip-slotline junction is modeled by employing a transformer and the transformer turn ratio is derived empirically. The method is extended to the case of
array antennas. Return loss results obtained by using the transmission line model. The maximum measured results and demonstrated the usefulness of the transmission line model. The maximum bandwidths of a single antenna,
array antennas are 28.5%, 47.8%, and 50.9%, respectively, for the VSWR
. The gain of
array antenna is 7.97dBi and the beamwidth is about
A Study on the Characteristics of the Corrugated Feed-Horn Antenna Using FDTD Method
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 619~626
The electromagnetic fields of the corrugated annular feed-horn antenna have been analyzed exactly by using the finite-difference time-domain (FDTD) technique. The radiation pattern and return loss characteristics of the antenna were obtained as a function of the impedance of feeding coaxial line at 11.8GHz. The return loss was determined to be less than -25dB at 30
. It was confirmed that the phase error is less compared to that of the antenna without corrugation, but the directivity of the radiation pattern needs to be improved.
Study on Rocket-Borne Antenna
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 627~633
In this paper, new printed-type inverted F antenna is designed and fabricated to gain the ideal radiation pattern of a rocket-borne antenna which is expected to show the omni-directional pattern characteristic in rear direction. The radiation pattern of this antenna is measured in condition that the antenna is mounted on the side of the fin which is located on the tail of a rocket or a missile. Measurement result shows that the improved symmetrical radiation pattern is obtained with respect to the radiation pattern of the existing inverted F antenna. Besides parasite element which can be operated as reflector is attached in front of the antenna with the distance between the antenna and the parasite element
/8. The result shows that the ratio of the front to the rear radiation level is improved by 8 dB.
Design and Fabrication of Switchable VCO for DECT Handset
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 634~641
A switchable VCO for DECT handset is designed and fabricated. In dual mode radios, a single VCO is desired to operate at two different frequencies to meet the requirement of two mode(Tx, Rx). The three design types of switchable VCO are switched resonator VCO, switched mode VCO and dual band VCO. In this paper, we use the switched resonator VCO type using pin diode switch to change the total amount of capacitance in the tank circuit. At the bias condition of 3 V and 13mA, the output power and phase noise are better than6.5dBm and -104dBc/Hz at 25khz offset from the carrier, respectively , across the operating frequency range. From these results, the fabricated switched VCO is applicable to the DECT handset.
Design of the Coaxially Fed Circularly Polarized Rectangular Microstrip Antenna Using the Genetic Algorithm
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 642~648
We introduce a new application of the genetic algorithm for design of the coaxial fed circularly polarized rectangular microstrip antenna. The GA shows excellent results for the design of the microstrip antenna which have a very complex objective function including the input impedance, the effective loss tangent and the axial ratio. The objective function is derived from the cavity model, and the size and the feeding point are optimized by the genetic algorithm. The experimental results show good agreement with the simulated results.
Approximation of the Characteristics Impedance of a Lossy Coaxial Line with a Thick Outer Conductor
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 649~656
In this paper, a closed exact from and its approximation of the characteristic impedance of a lossy coaxial line with a thick outer conductor are proposed. It is also shown for 3.5mm reference air line that the proposed approximation is accurate over the entire operating frequency range of the line.
Performance Evaluation of Reverse Link for Speech and Data Traffic ini CDMA-Based IMT-2000 System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 657~665
In this study, the bit error rate(BER) performance for the speech and data traffic is evaluated by results of the reverse link simulation of CDMA-based IMT-2000. Simulations in the reverse link are achieved for indoor, pedestrian, and vehicular environments, which are provided by ITU-R . Also, in the these simulations, the fast power control of 1.6kHz rate is applied. The amplitude and phase of the fading signal are estimated by using the 5-tap FIR filter, and the soft-decision Viterbi and Reed-Solomon (RS) decoding are applied. Simulation results provide the optimum ratio of pilot power to traffic power, the BER performance according to the number of fingers, and performance comparison between convolutional code and concatenated code at
BER in 5 MHz system.
The Analysis of Nonlinear Circuits Using a Hybrid Haar Wavelet MRTD/FDTD Technique
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 11, issue 4, 2000, Pages 667~673
This paper presents the modeling method of nonlinear circuits with lumped elements by using a hybrid Haar -wavelet MRTD/FDTD techniques. To analyze nonlinear circuits with lumped elements, the Haar-wavelet MRTD scheme is applied to the entire structure of interest and the conventional FDTD scheme is locally used to describe the characteristics of the lumped elements. To validate the scheme, microstrip structure with lumped elements and a single diode mixer are simulated.