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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 17, Issue 12 - Dec 2006
Volume 17, Issue 11 - Nov 2006
Volume 17, Issue 10 - Oct 2006
Volume 17, Issue 9 - Sep 2006
Volume 17, Issue 8 - Aug 2006
Volume 17, Issue 7 - Jul 2006
Volume 17, Issue 6 - Jun 2006
Volume 17, Issue 5 - May 2006
Volume 17, Issue 4 - Apr 2006
Volume 17, Issue 3 - Mar 2006
Volume 17, Issue 2 - Feb 2006
Volume 17, Issue 1 - Jan 2006
Selecting the target year
High Efficient Phase Shifters Using Defected Ground Structures
Han Sang-Min ; Kim Chul-Soo ; Ahn Dal ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 1~7
New phase shifters with higher phase shift values are presented using defected ground structures(DGSs). The varactor diodes are mounted on DGSs of termination loads to control the large phase variation of the DGS at resonance. Two types of phase shifters are implemented with a branch-line and a coupled line hybrid. The experimental results of the proposed phase shifters show
increases in maximum phase shills, respectively, compared with those of conventional ones.
A Comparison between EFIU and HEIU Schemes in ADI-FDTD Simulations
Ju Sae-Hoon ; Lee Kyung-Hoon ; Hwang In-Ho ; Kim Hyeong-Dong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 8~16
In this paper, updating schemes for the alternating-direction implicit finite-difference time-domain method(ADI-FDTD) are studied, which method has the potential to considerably reduce the number of time iterations especially in case where the fine spatial lattice relative to the wavelength is used to resolve fine geometrical features. In numerical simulations for microwave structure using ADI-FDTD, time marching scheme comprises of two sub-iterations. Two different updating equation sets for ADI-FDTD simulations are presented. In order to discuss the characteristics of those schemes especially in view of applying boundary conditions, we solved two complementary 2-D problems.
Research on Low Phase Noise Oscillator Using Microstrip Square Open Loop Resonator
Park Eun-Young ; Seo Chulhun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 17~23
This paper has presented a low phase noise oscillator using a square open loop with microstrip structure. A square open loop resonator has a large coupling coefficient value, which makes a high Q value, and has reduced phase noise. This oscillator has presented the oscillation frequency of 5.84 GHz, harmonics of -15.83 dBc and the phase noise of -111.17 dBc/Hz at the offset frequency of 100 kHz. In conclusion, the proposal structure has improved phase noise of 15 dB at the offset frequency of 100 kHz compared with the conventional structure of oscillator.
Design of a Conical Spiral Antenna for Satellite TT&C Applications
Ko Han-Woong ; Lee Junwen ; Yu Jae-Deok ; Kim Se-Yon ; Ahn Bierng-Chearl ; Park Dong-Hee ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 24~38
In this paper, we investigate the design and fabrication of a conical spiral antenna suitable for satellite TT&C applications. The shape of the spiral is optimized using a commercial electromagnetic software for good gain and axial ratio performances over
frequencies. A coaxial infinite balun feeding the spiral is designed using experimental methods. A method for precision fabrication of the spiral is presented. Measurements of the fabricated antenna show satisfactory performances over
such as a reflection coefficient less than -18 dB, a maximum gain greater than 4 dB, a gain greater than 0 dB over angles
from the antenna boresight, an axial ratio less than 5 dB over angles
from the antenna boresight, a front-back ratio greater than 15 dB.
Comparison of Moment Method/Monte-Carlo Simulation and PO for Bistatic Coherent Reflectivity of Sea Surfaces
Kim Sang-Keun ; Oh Yi-Sok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 39~44
This paper proposes a method of moments(MoM)/Monte-Carlo simulation and Physical Optics(PO) model to determine Bistatic Coherent Reflectivity of sea surfaces at various wind speeds. For the MoM simulation, a Gaussian random rough sea surface was generated based on the data of Tae-An ocean at various wind speeds and sea surface heights. The numerical results of the MoM/Monte Carlo simulations were used to verify the validity region of the PO model. It was found that the numerical result for a flat surface agrees quite well with the Fresnel reflection coefficient. The validity of the PO model on the rough sea surface is shown by using ray tracing method.
A Design of Predistorter for Controlling the Amplitude of Low-Frequency IM Signals
Jang Mi-Ae ; Kim Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 45~51
In this paper, a new predistortion linearizer for controlling the amplitude of low frequency intermodulation distortion signals is proposed. The low frequency intermodulation distortion(IMD) components are generated by harmonic generator. A vector modulator, modulate fundamental signal with low frequency IMD signals, generates predistortion IMD signals and controls amplitude and phase of them with modulation factors. As a result, this predistorter is suppressed IMD signals of power amplifier effectively. The predistortion linearizer has been manufactured to operate in cellular base-station transmitting band(
). The experimental results show that IMD3 of power amplifier are improved more than 20 dB for CW two-tone signals. Also, it's improved the adjacent channel power ratio(ACPR) more than 10 dB for IS-95 CDMA IFA signals.
The Effect of Finite Flange of Open-Ended Coaxial Probe on the Converted Complex Permittivity of PCB Substrate
Jung Ji-Hyun ; Kim Young-Sik ; Kim Se-Yun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 52~59
To construct its complex permittivity from the reflection coefficient of a thin film such as PCB substrate measured by open-ended coaxial probe, an integral equation is formulated using modal analysis and equivalent source. The accuracy of the conversion model based on the integral equation is confirmed in both cases of converted complex permittivities calculated from numerically computed and actually measured reflection coefficients. And the maximum valid frequency of open-ended coaxial probe is limited by the size of its flange.
A Circular Microstrip Patch Antenna for Switchable Polarization Using PIN Diodes
Lee Kun-Joon ; Jang Tai-Un ; Kim Young-Sik ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 60~66
In this paper, a circular microstrip patch antenna for switchable polarization is presented. For the switchable polarization, pairs of tuning stubs and two PIN diodes are utilized. By independently setting the PIN diodes on or off, the antenna produces either linear polarization or circular polarization. From the results, the -10 dB impedance bandwidths of 57.0 MHz(
) and 50.0 MHz(
) when operated in the linear polarization, and the 3 dB axial ratio bandwidth of
with minimum of 0.2 and 0.9 dB in the circular polarization have been observed.
A Design of Analog Predistortion Linearizer Using Even Harmonic Signals
Hwang Moon-Soo ; Jeon Ki-Kyung ; Kim Ell-Kou ; Cho Suk-Hui ; Kim Young ; Kim Byung-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 67~73
This paper proposes a new predistortion linearizer with controlling intermodulation distortion(IMD) signals. This linearizer achieves independent control of third- and fifth-order intermodulation distortion products using amplitude modulation with even harmonic signals. A vector modulator that modulate fundamental signal with both second- and fourth-order harmonic components generated by harmonic generator circuits, generates the inverse characteristics third-and fifth-order intermodulation signals of power amplifier and controls amplitude and phase of them with each other modulation factors. As a results, this linearizer is suppressed IMD signals of power amplifier effectively. The test results show that the third IMD is cancelled more than 25 dB and the fifth order IMD is cancelled about 18 dB for CW two-tone signals. Also, it's improved the adjacent channel power ratio(ACPR) more than 7 dB for IS-95 CDMA signals.
Expansion of Test Frequency Band and Improvements of Field Uniformity in a Reverberation Chamber by Using Dual-Band Diffusers
Lim Wook-Chae ; Rhee Joong-Geun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 74~80
This paper presents the characteristics of electromagnetic field uniformity in a reverberation chamber that can be used alternatively for the analysis, test and evaluation of electromagnetic interference and immunity. The dual-band diffuser, which can be used at two different frequency bands in a reverberation chamber, is applied, and it is made of two different single-band Schroeder's Quadratic Residue Diffusers. The FDTD method is used to analyze the field characteristics. Compared with single-band diffuser, the dual-band diffuser shows the improvement in not only expansion of test frequency band but also in characteristics of the field uniformity, polarity, power efficiency, and tolerance. Therefore, the reverberation chamber with the dual-band diffuser is a better facility, for the analysis and measurement of electromagnetic interference and immunity, than the reverberation chamber with a single-band diffuser.
Measurement of Spectrum Quantification Using Spectrum Use Factor
Shin Yong-Seop ; Hong Ic-Pyo ; Kim Young-Soo ; Park Han-Kyu ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 1, 2006, Pages 81~88
In this paper, spectrum use factor as the ratio between used spectrum bandwidth by the existing system and total spectrum resources at specific locations was derived and calculated. Spectrum use factor was also presented as a function of antenna patterns and transmitter power of existing systems. Real spectrum use factor was calculated for fixed radio station as a validity of this paper. With the results of this paper, we can use the spectrum more efficiently because the white space of spectrum space is replaced by the quantificated spectrum space.