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 14, Issue 12 - Dec 2003
Volume 14, Issue 11 - Nov 2003
Volume 14, Issue 10 - Oct 2003
Volume 14, Issue 9 - Sep 2003
Volume 14, Issue 8 - Aug 2003
Volume 14, Issue 7 - Jul 2003
Volume 14, Issue 6 - Jun 2003
Volume 14, Issue 5 - May 2003
Volume 14, Issue 4 - Apr 2003
Volume 14, Issue 3 - Mar 2003
Volume 14, Issue 2 - Feb 2003
Volume 14, Issue 1 - Jan 2003
Selecting the target year
CPW Fed Ultra Wide Band Slot Antenna
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 663~668
In this paper, a CPW fed slot antenna with novel broadband feed structure is presented. To enhance the impedance bandwidth of the slot antenna we proposed the broadband feed structure of new bow-tie slot which is combined with four λ/2 rectangular radiation slot and inductively coupled. The measured 10 dB impedance bandwidth is about 60 %(5.2∼9.4 GHz) and the simulated antenna gain is about 6 dBi at 7.36 GHz.
Design of a TEM Horn Antenna for Impulse Response Measurement System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 669~676
In this paper, a novel design method for an ultra-wide band TEM horn antenna is proposed on the basis of parallel plate waveguide theory. A principle of TEM modes generation is analyzed and the characteristics of this antenna are experimentally investigated. The proposed TEM horn antenna has an exponentially tapered structure to increase matching bandwidth. Also, the designed TEM horn has shortened length but increased aperture so that the bandwidth for cutoff frequency is increased. The measured result show that the proposed TEM hem antenna has the frequency band of 75 MHz to 1200 MHz for VSWR less than 2.0 and the bandwidth of the TEM horn becomes more than twice comparing to that of a linearly tapered TEM hem. It is anticipated that the manufactured antenna is applicable to UWB systems for impulse response measurement.
Design and Performance Analysis of the SPW Method for PAPR Reduction in OFDM System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 677~684
This paper addresses the subblock phase weighting(SPW) method to reduce the PAPR in OFDM system. This method divides the input block of OFDM signal into many subblocks and lower the peak power by weighting the phase of each subblocks properly. SPW method can be realized by only one IFFT. PAPR reduction performance is novelly examined when the adjacent, interleaved and random subblock partitioning schemes are used in the SPW system. The random subblock partition scheme has the most effective. More subblocks can effectively reduce the PAPR, but there is a problem that the processing time of iteration is increased. We propose a new weighting factor combination of the complementary sequence characteristic with threshold technique. OFDM data can be recovered by the inserted side information of weighting factor in the feed forward type. Also, BER performance of this SPW system is analyzed when error happens in the side information.
Effects of the Phase Noise in the Frequency Synthesizer on the SFH/M-NCFSK System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 685~691
This paper newly analyzes the effect of the phase noise in the frequency synthesizer on the performance of SFH/M-NCFSK system by standard frequency deviation(equation omitted) when noncoherent FSK demodulation of the square-law detector is considered. We derive the SER in the SFH system and analyze the effect of phase noise on the SFH/M-NCFSK system performance according to the hopping frequency spacing (1/T
h/) and the variation of the standard frequency deviation (equation omitted). The required SNR is about 13.4 dB to meet Ps=10
-3/ when the standard frequency deviation is about 4.0 Hz and the hopping frequency spacing (1/T
h/) in the SFH/2-NCFSK system is 30. So, there is about 2.4 dB power penalty than the phase noise-free system. If the hopping frequency spacing 1/T
h/ is under 30, the error floor may happen and SER considerably grows up. We show that the analytic results closely match with the simulation results.
The IM Model of 3 Port RF Passive Component
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 692~698
This paper presents IM model which is produced in 3 port RF passive component. We calculated forward and reflect PIM of 3 port component by using the model. And they are reasonable agreement with measurement result like below. In the case of forward IM, calculated result is -122 dBc(at 43 dBm), which differ 2.5 dB with measurement result. And reflected IM, the average calculated result is -130 dBc(at 43 dBm), which differ 3 dB with measurement result. The results which are calculated and measured under various condition(IM source level, frequency sweep, contour length, etc.) show that forward method gets more fixed result than that of reflect. Consequently, PIM of 3 port component is predicted and analyzed for desensitizing by the proposed model.
Small Signal Response Characteristics of Microwave Reflectometry
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 699~704
The characteristics of microwave reflectometry as a non-invasive device to examine the density distribution of inhomogeneous media using the technology of FM radar is presented. The microwave reflectometry system requires an optimized system hardware and the understanding of system response from the density distribution in order to provide the system solution to describe the object under test quantitatively. Among the applications, the use of microwave reflectomeoy in the area of applied plasma physics has been newly proposed and the number of usage is found to be increasing gradually. The microwave reflectometry systems that depend on the nature of the object under test are described. The experimental method to characterize the system is explained and the experimental results on the wavenumber dependence and the sensitivity on density perturbation are presented as well as the comparison to the results from the one dimensional numerical simulations.
Scalable AlGaN/GaN HEMTGs Model Including Thermal Effect
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 705~711
In this Paper, 2
AlCaN/GaN HEMT's(on sapphire substrate) large signal model including thermal effect was extracted. An equation based empirical model was employed to make large signal model for convergence and high speed. Pulsed I-V measurement was performed to extract thermal resistance and capacitance. Power amplifiers with 9 mm and 15 mm AlCaN/GaN HEMTS were designed using scaled modeling results of 2
device respectively. From comparisons between measured and simulated data, the model considering of thermal effects gave better agreement than without one. It demonstrates that thermal modeling must be performed for power amplifier that uses large size transistors.
An Experimental Study on Shaping Flat-Topped Element Patterns of a Multi-layered Disk Array Structure Excited by Cross-Dipole Elements
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 712~720
In this paper, a multi-layered metallic disk array structure(MDAS) excited by cross-dipole elements was proposed for efficiently shaping of flat-topped element patterns(FTEP) with circular polarization. The MDAS excited by cross-dipole elements has advantages to decrease in volume and weight of an overall array antenna and so, it is appropriate for the FTEP applications of a ralativlely low frequency band. In order to verify the effectness of this structure, the MDAS breadboard operated at X-band(7.9 ∼ 8.4 GHz) was fabricated, and its design parameters were experimentally optimized on the basis of the previous design experience. The experimental results were shown that the MDAS could shape good FTEPs of
beam width at least within a 6.1 % frequency band.
A Single-Layer Waveguide Slot Array Antenna using Diaphragms for 38 GHz Frequency Band
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 721~726
This paper present a waveguide slot 16
16 assay antenna with diaphragms for 38 GHz frequency band. Diaphragms are used to control the impedance and to minimize the return loss of the structure. A 20 dB Chebyshev array of 16 waveguide slots has been designed by optimizing the positions and sizes of the diaphragms. A serial feeding system with
- and T-junction power dividers has also designed to get a 20 dB Chebyshev power distribution. A 16
16 slot array was designed for a Fixed Wireless Access System at 38 GHz frequency band, manufactured using a computer controlled milling technique, and measured for the return -19 dB and the frequency band of 740 MHz.
A Low Impedance and Short Guided-Wavelength Microstripline Employing a Periodically Perforated Ground Metal and Its Application to Miniaturized Ratrace MMIC
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 727~733
In order to realize miniaturized and low-impedance MMIC passive component, a novel microstripline structure employing periodically perforated ground metal was proposed. The novel microstripline structure showed much lower impedance, and shorter guided-wavelength than conventional one. Using the novel microstripline with periodically perforated ground metal, a miniaturized 15
ratrace was fabricated. The line width of the ratrace was 20
, and the size of it was 0.375 mm
, which is 9.3 % of conventional one. The ratrace exhibited good RF performances from 20 to 30 GHz.
Design and Fabrication of Broadband Phase Shifter Based on Vector Modulator
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 734~740
In this paper, A Vector Modulator based a wideband analog phase shifter is realized with four P-I-N diode attenuators, an asymmetric coupled line coupler, a symmetric coupled line coupler, and a power combiner. Simple configuration to have advantages in cost, size, power, and the number of passive circuits is presented. The phase variation due to phase and amplitude error of a P-I-N diode attenuator is derived and used to optimize the overall circuit. The phase shifter shows a total phase shift of 360
, a 8.2
maximum phase error, and a 16
2.5 dB insertion loss over the wide frequency range of 1 GHz to 3 GHz.
Cross Phase Modulation Effects on 120 Gbps WDM Transmission Systems with Mid-Span Spectral Inversion for Compensation of Distorted Optical Pulse
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 741~749
In this paper, we investigated the degree of compensation for WDM channel signal distortion due to chromatic dispersion, self phase modulation(SPM) and cross phase modulation(XPM). The considered system is 120 Gbps (3
40 Gbps) intensity modulation direct detection(IM/DD) WDM transmission system with path-averaged intensity approximation(PAIA) mid-span spectral inversion(MSSI) as compensation method. This system have highly nonlinear dispersion shifted fiber(HNL-DSF) as nonlinear medium in optical phase conjugator(OPC). We use 1 dB eye opening peralty(EOP) in order to evaluate the characteristics of compensation for distorted WDM channels. We confirmed that improvement of transmission distance and performance is achieved by MSSI method to distorted long-haul IM/DD WDM channels due to chromatic dispersion, SPM and XPM. And in the aspect of compensation for distorted pulse due to XPM, the MSSI method is effective to IM/DD WDM transmission system with high fiber dispersion coefficient.
A Design of the New Three-Line Balun
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 750~755
This paper proposes a new three-line balun. The equivalent circuit of the proposed three-line balun is presented, and impedance matrix［Z］of the equivalent circuit is derived from the relationship between the current and voltage at each port. The design equation for a given set of balun impedance at input and output ports is presented using［S］parameters, which is transferred fom impedance matrix,［Z］. To demonstrate the feasibility and validity of design equation, multi-layer ceramic(MLC) chip balun operated in the 2.4 GHz ISM band frequency is designed and fabricated by the use of the low temperature co-fired ceramic(LTCC) technology. By employing both the proposed new three-line balun equivalent circuit and multi-layer configuration provided by LTCC technology, the 2012 size MLC balun is realized. Measured results of the multi-layer LTCC three-line balun match well with the full-wave electromagnetic simulation results, and measured in band-phase and amplitude balances over a wide bandwidth are excellent. This proposed balun is very easily applicable to multi-layer structure using LTCC as shown in the paper, and also can be realized with microstrip lines on PCB. This distinctive performance is very favorable for wireless communication systems such as wireless LAN(Local Area Network) and Bluetooth applications.
Manufacture of Composite Electromagnetic Absorber using Natural Lacquer Binder
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 756~761
The microwave absorption properties of silicone, chloride polyethylene(CPE), and natural lacquer which is newly suggested in this study as a binder for composite microwave absorber were investigated to develop a superior microwave absorber. MnZn ferrite composite microwave absorbers mixed with them were prepared and their absorption property was investigated. A MnZn ferrite microwave absorber mixed with natural lacquer showed an excellent microwave absorption property in expanded frequency band.
A Study on the Effects of Gain Flatness of Feedforward Power Amplifier for IMT-2000 Band
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 762~768
This paper reports the effects of gain flatness for linearity improvement of feedforward power amplifier fur IMT-2000 band. To investigate the operational characteristics for gain flatness of each amplifier, WCDMA 4FA input signal was used and measured 10 W output power. Especially, linearity improvement for variation of gain flatness of each amplifier was investigated that have an effect on linearity improvement such as delay line, phase, and amplitude imbalances. Variation of gain flatness of main amplifier is 40 MHz and of error amplifier is 40 MHz and 80 MHz bandwidth, respectively. Measured results, gain flatness of main amplifier is less than 1.5 dB and of error amplifier is less than 0.5 dB for more than 20 dB improvement at 5 MHz offset. In addition to that results, the characteristics of feedforward amplifier are drastically varied by gain flatness of error amplifier and it is shown that gain flatness of error amplifier is more important factor for linearity improvement.
An Analysis and Design of Wideband Microstrip Rotman Lens by Contour Integral and Segmentation Method
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 7, 2003, Pages 769~776
This paper presents analysis and design of microstrip Rotman lens operating over wide band and wide steering angle by the contour integral method along with the segmentation method. All mutual coupling, internal reflections between ports and the discontinuity at every junction are taken into account. Equally spaced ports are designed and realized, which make suppress output ripple through the array ports. Impedance matching and mutual coupling between ports are analyzed and optimized using 12 input and 12 output exponential tapers. The measured results of fabricated lens show
1.8 dB insertion loss deviation over 6∼18 GHz wide frequency range and beam steering accuracy less than 1
angle and agrees well with the analysis results.