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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
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Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
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Volume & Issues
Volume 23, Issue 12 - Dec 2012
Volume 23, Issue 11 - Nov 2012
Volume 23, Issue 10 - Oct 2012
Volume 23, Issue 9 - Sep 2012
Volume 23, Issue 8 - Aug 2012
Volume 23, Issue 7 - Jul 2012
Volume 23, Issue 6 - Jun 2012
Volume 23, Issue 5 - May 2012
Volume 23, Issue 4 - Apr 2012
Volume 23, Issue 3 - Mar 2012
Volume 23, Issue 2 - Feb 2012
Volume 23, Issue 1 - Jan 2012
Selecting the target year
Optimized Design of Wide-Band Subarray Using a Genetic Algorithm
Kim, Doo-Soo ; Lee, Dong-Koog ; Kim, Seon-Joo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 415~423
DOI : 10.5515/KJKIEES.2012.23.4.415
This paper specifies on optimized design of wide-band subarray using a Genetic Algorithm. First wide-band radiator was designed at triangle lattice of infinite array structure. It is the radiator of notch type that has a wide-band characteristic of ratio 2:1 between maximum and minimum frequency satisfying active reflection coefficient under -10 dB at boresight. And a Genetic Algorithm was applied to optimize subarray partition of antenna consisting of 1,100 array elements. It was confirmed that an optimized subarray antenna has a 4.5-5.5 dB more improved maximum SLL (Side-Lobe Level) than regular subarray antenna.
Analysis of Effect of Capacitor Position in Ground Radiation Antenna
Park, Bum-Ki ; Liu, Yang ; Choi, Hyeng-Chul ; Kim, Hyung-Hoon ; Kim, Hyeong-Dong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 424~430
DOI : 10.5515/KJKIEES.2012.23.4.424
A ground radiation antenna is designed using a capacitor connected between two ground points by a strip line. This paper analyzes the variations of radiation performance when changing the capacitor position. The surface current distribution of the ground antenna was investigated as the capacitor position is changed, in order to demonstrate the effects on the impedance bandwidth and antenna efficiency. Our antenna is for the Wi-Fi application. It is verified that the capacitor at the end of the strip line provides a wide impedance bandwidth(7.2 % at the 2.45 GHz frequency) and good antenna efficiency(measured as 66 % averaged over the overall Wi-Fi frequency band).
Design of Beam-Forming Array Antenna with a Reconfigurable Power Divider
Tae, Hyun-Sung ; Son, Wang-Ik ; Jang, Hyung-Seok ; Oh, Kyoung-Sub ; Yu, Jong-Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 431~440
DOI : 10.5515/KJKIEES.2012.23.4.431
In this paper, new beam-forming array antenna is proposed. The proposed beam-forming array antenna has control ability for beam-direction/width by employing low loss reconfigurable power divide and three-dimensional array structure. The reconfigurable power divider is key idea in the proposed antenna, because it has reconfigurable RF power distribution ability to each antenna. And, for research and verification of the proposed antenna, 3-dimensional beam-forming array antenna is implemented, and the experimental results show that the proposed antenna has various radiation modes from 1:1 to 1:N by adjusting RF power distribution.
Design of a Multiband MIMO Antenna for USB Dongle Application
Lee, Young-Ki ; Choi, Jea-Hoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 441~448
DOI : 10.5515/KJKIEES.2012.23.4.441
This paper proposes a multiband Multi-Input Multi-output(MIMO) antenna for universal serial bus(USB) dongle application. The proposed MIMO antenna consists of a modified meander strip line and inverted L stub. The two radiating elements of the MIMO antenna are symmetrically placed with respect to the center of the ground plane. The fabricated antenna satisfied a VSWR below 3 and an efficiency over 35 % in the LTE band 13, 17(704 MHz-787 MHz), DCS/PCS/WCDMA band(1.71 GHz-2.17 GHz), and LTE band 7(2.5 GHz-2.7 GHz). The envelope correlation coefficient(ECC) has below 0.45 in the LTE band 13, 17 and 0.1 in the DCS/PCS/WCDMA band and LTE band 7, respectively.
Design of a Waveguide 8×8 Butler Matrix for Ka-Band Broadband Multi-Port Amplifiers(MPAs)
Lee, Hong-Yeal ; Uhm, Man-Seok ; Yom, In-Bok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 449~456
DOI : 10.5515/KJKIEES.2012.23.4.449
Herein, we design a wideband
waveguide Butler matrix in order to use in a multi-port amplifiers(MPAs) at Ka-band. To achieve the broadband characteristic, we design a binomial 6-slot 3 dB directional coupler which is used to configure the
Butler matrix. The measured results of the fabricated
Butler matrix have low insertion loss of less than 0.3 dB, good return loss of over 26 dB and high isolation of over 35 dB within the design bandwidth of 3 GHz.
Design and Experiment of a Miniaturized Waveguide Band-Pass Filter Using L-Type Inverter and Small Resonant Aperture
Choi, Jin-Young ; Kim, Byung-Mun ; Cho, Young-Ki ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 457~467
DOI : 10.5515/KJKIEES.2012.23.4.457
In this paper, a miniaturized band-pass filter structure, which comprises the irises of small resonant aperture and L-type irises inverter, is proposed. Ridged circular aperture iris is chosen as an elementary resonator. L-type iris which is placed between two adjacent elementary resonators is newly proposed as impedance inverter in order to reduce longitudinal length of the proposed filter. The fabricated minimized filter has 400 MHz bandwidth at the 10 GHz center frequency and the whole size is reduced to 70 % in length compared to conventional filter.
Low-Phase Noise Oscillator Using Substrate Integrated Waveguide and Complementary Split Ring Resonator
Park, Woo-Young ; Lim, Sung-Joon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 468~474
DOI : 10.5515/KJKIEES.2012.23.4.468
A low phase-noise microwave oscillator is presented by a substrate integrated waveguide(SIW) loading a complementary split ring resonator(CSRR) in this paper. The unloaded
-factor of the SIW cavity is increased by loading a complementary split ring resonator(CSRR) and its value exhibits 1960. It is theoretically and experimentally demonstrated that the proposed circuit generates 11.3 dBm of output power at 9.3 GHz and a phase-noise of -127.9 dBc/Hz at 1-MHz offset.
Design of Hybrid Supply Modulator for Reconfigurable Power Amplifiers
Son, Hyuk-Su ; Kim, Woo-Young ; Jang, Joo-Young ; Lee, Hae-Jin ; Oh, Inn-Yeal ; Park, Chul-Soon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 475~483
DOI : 10.5515/KJKIEES.2012.23.4.475
This paper presents new type of the hybrid supply modulator for the next reconfigurable transmitters. The efficiency of the hybrid supply modulator is one of the most important performance. For enhancement the efficiency, multi-switching structure in the hybrid supply modulator is employed. Additionally, input envelope signal sensing stage is employed for implementation multi-mode operation. To compare the performance of the proposed hybrid supply modulator, the conventional hybrid supply modulator is also designed. The measured efficiency of the proposed hybrid supply modulator is 85 %/84 %/79 % for EDGE/WCDMA/LTE signals which have 384 kHz/3.84 MHz/5 MHz bandwidth, respectively. The efficiency of the proposed hybrid supply modulator is higher than the conventional hybrid supply modulator. Therefore, this structure shows good candidate for the reconfigurable transmitters.
Linearity Enhancement of RF Power Amplifier Using Digital Pre-Distortion Based on Affine Projection Algorithm
Seong, Yeon-Jung ; Cho, Choon-Sik ; Lee, Jae-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 484~490
DOI : 10.5515/KJKIEES.2012.23.4.484
In this paper, we design a digitally pre-distorted RF power amplifier operating in 900 MHz band. The linearity of RF power amplifier is improved by employing the digital pre-distortion(DPD) based on affine projection(AP) algorithm, where the look-up table(LUT) method is used with non-linear indexing. The proposed DPD with AP algorithm is compared with that with normalized least mean square(NLMS) algorithm, applied to the RF power amplifier. A commercial power amplifier module is used for verification of the proposed algorithm which shows improvement of adjacent channel leakage ratio(ACLR) by about 21 dB.
Adaptive Channel Estimation and Decision Directed Noise Cancellation in the Frequency Domain Considering ICI of Digital on Channel Repeater in the T-DMB
Kim, Gi-Young ; Ryu, Sang-Burm ; Ryu, Heung-Gyoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 491~498
DOI : 10.5515/KJKIEES.2012.23.4.491
Recently, many papers have been proposed in order to improve the OFDM system performance in T-DMB DOCR (Digital On Channel Repeater), by using removing the feedback signal so that the transmitter power can be increased or by using the equalizer to remove ICI. Despite these efforts, however, signal quality at the receiving terminal has not been improved because of constellation smearing in T-DMB DOCR. In this paper, in order to suppress constellation smearing, we propose an effective equalizer algorithm that can improve system performance. We perform adaptive channel estimation and non-coherent decision directed noise cancellation method that can estimate the channel subsequently during data symbols period in the frequency domain. So we can obtain better quality of the signal at the receiving terminal. In order to secure QoS(Quality of Service) required in T-DMB handsets, we evaluate SNR and BER in T-DMB DOCR(Digital On Channel Repeater) and verified by simulation. In this simulation results, this system is satisfied the performance of BER=
at less than SNR=14 dB at the receiver after compensation of phase noise -18 dBc.
A Complexity Reduced PNFS Algorithm for the OFDM System with Frequency Offset and Phase Noise
Kim, Do-Hoon ; Ryu, Heung-Gyoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 499~506
DOI : 10.5515/KJKIEES.2012.23.4.499
In this paper, we analyze the effects of phase noise and frequency offset that cause performance degradation. Basically, we like to propose reduced PNFS(Phase Noise and Frequency offset Suppression) algorithm. The OFDM system is seriously affected by ICI component such as phase noise, frequency offset and Doppler effects. Especially, complicated processing algorithm with high complexity was required it in order to compensate those ICI components. So, we propose PNFS algorithm that can decrease complexity and compensate ICI components. We propose a method decreased complexity by approximation of parameters that affect slightly performance change and compare the quantity of conventional and revised PNFS algorithm. Also, simulation shows that BER performance of revised PNFS algorithm can be improved slightly.
Analysis of Resonant Characteristics for a Metallic Shielding Enclosure with a PCB Source
Cho, Byung-Doo ; Kim, Ki-Chai ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 507~514
DOI : 10.5515/KJKIEES.2012.23.4.507
This paper proposed the analysis method of the cavity resonance characteristics for a metallic enclosure with a PCB trace source. In order to calculation the electromagnetic fields inside the cavity, coupled integral equations for a current distribution on the PCB trace and an aperture electric field distribution on the boundary of the PCB dielectric are derived and solved by applying Galerkin's method of moments. The result show that the resonant characteristics of the metallic enclosure are fairly good agreement with the simulation(HFSS) and the measured results. The resonant frequencies of the metallic enclosure with the PCB trace are changed by the PCB trace location inside of the cavity. In order to check the validity of the theoretical analysis, the calculated return losses are compared with the measured results.
Resonance Characteristics and Radiation Characteristics of a Spherical Patch on a Dielectric Sphere
Jeong, Yi-Ru ; Hong, Ic-Pyo ; Lee, Myung-Gun ; Chun, Hueng-Jae ; Yook, Jong-Gwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 515~523
DOI : 10.5515/KJKIEES.2012.23.4.515
In this paper, the resonance characteristics and radiation characteristics of a spherical patch on a dielectric sphere are analyzed. Resonance characteristics can be obtained from the resonant frequency and the quality factor. Radiation characteristics can be also analyzed from the E-field in the far region. In order to calculate these parameters, spectral domain analysis method is applied. Algebraic equation can be obtained in spectral domain through Vector Legendre transform pair and Galerkin's method. So, efficient calculation is possible numerically. It is investigated that radius, curvature of a spherical patch, and dielectric constant of a dielectric sphere have an effect on characteristics of a spherical patch.
MOM-Based Born Iterative Method for Medical Microwave Imaging
Son, Jae-Gi ; Kim, Bo-Ra ; Lee, Taek-Kyung ; Son, Seong-Ho ; Jeon, Soon-Ik ; Lee, Jae-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 524~532
DOI : 10.5515/KJKIEES.2012.23.4.524
In this paper, we used MOM-based BIM(Born Iterative Method) algorithm to implement the inverse scattering for the detection of cancer. We adopted two-dimensional breast structure, integral equations and two-dimensional Green's function is solved with MoM(Method of Moment) to analyzing electromagnetic scattering phenomena. In addition, verifying the calculation of developed inverse scattering algorithm and analyzing medical applicability and limitations of the algorithm.
Design of Wind Turbines for Reducing Interference to Radar Signals
Park, Kang-Kook ; Chin, Hui-Cheol ; Kim, Kyung-Tae ; Kim, Hyo-Tae ; Kim, Jin-Bong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 533~540
DOI : 10.5515/KJKIEES.2012.23.4.533
The use of wind energy is gaining importance because of its many advantages. Nations worldwide are promoting the installation of wind farms to produce electricity in an attempt to tackle climate change and increasing oil costs. But, wind turbines can generate undesired signals which disturb the performance of military radar systems. Because the current generation of on and off-shore three bladed wind turbines have radar signatures consistent with their very large physical size. So this study considers the options available for the reduction of wind turbine radar signature and presents solutions for each of the main external turbine components. The radar signature reduction approaches are based on existing technologies developed for aerospaces stealth applications. However, the realization of these for the purposes of reduction wind turbine radar signatures is a novel development, particularly in the solutions proposed. This paper is presented techniques which reduce radar signatures of wind turbine. We know that radar signatures of wind turbine reduce by using these techniques.
Improved Method of Moments Using Hybrid Technique of Galerkin's and Interpolation Methods for Numerical Analysis of Electromagnetic Waves
Hwang, Ji-Hwan ; Kwon, Soon-Gu ; Oh, Yi-Sok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 4, 2012, Pages 541~550
DOI : 10.5515/KJKIEES.2012.23.4.541
An improved method of moments using a hybrid Galerkin-interpolation technique for numerical analysis of electromagnetic wave scattering in the 3-dimensional space is presented in this paper. Basically, the EFIE(electric field integral equation) and RWG(Rao-Wilton-Glisson) basis function are used to compute a property of electromagnetic wave scattering. We propose a hybrid technique combining the existing Galerkin's method with the interpolation method to improve the efficiency of the numerical computation. Then, an index of relative distance of each cells was defined to distinguish the relatively far elements, which interpolation method can be applied. To verify the performance of the proposed technique, the analytical Mie-series solution was used to compute the theoretical RCS of a conducting sphere for the purpose of comparison. We also applied this hybrid technique to various scatterers such as trihedral/omni-directional corner-reflectors to analyze the radar backscattering properties.