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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
Low Phase Noise VCO Using Microstrip Square Open Loop Resonator and Tunable Negative Resistance
Choi, Jae-Won ; Lee, Chong-Min ; Seo, Chul-Hun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1143~1149
The microstrip square open loop resonator has been employed to reduce the phase noise in VCO. The microstrip square open loop resonator has the large coupling coefficient value, which makes a high Q value, and has reduced the phase noise of VCO. To increase the tuning range of VCO, varactor diode has been connected at the tunable negative resistance in VCO. The output power and harmonic characteristics of VCO has been obtained 4.83 dBm and -28.83 dBc, respectively. The phase noise of VCO has been
@ 100 kHz in the tuning range,
Design of Hair-Pin Band-Pass Filter Using New Equivalent Circuit of Tapped-Line
Yun, Tae-Soon ; Kwoun, Sung-Su ; Hong, Tae-Ui ; Lee, Jong-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1150~1155
In this paper, the equivalent circuit of tapped-line that is applied in the band-pass filter is suggested and the value of an equivalent circuit is mathematically defined. An equivalent circuit of tapped-line is composed by open stub and transmission line that has negative electrical length, and the position of tapped-line and the value of resonator's length can be obtained by the impedance of resonator and the inverter. The new design method using equivalent circuit leads to very good agreement compared with theoretical value. The hair-pin band-pass filter using equivalent circuit of tapped-line shows the insertion loss of 1.1 dB and the return loss of 20 dB at the center frequency of 2 GHz.
Design of 2nd-harmonic Quadrature Mixer for Ultra Wideband(UWB) Systems
Jung, Goo-Young ; Lim, Jong-Hyuk ; Choi, Byung-Hyun ; Yun, Tae-Yeoul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1156~1163
This paper presents an ultra wideband(UWB) direct conversion mixer for IEEE 802.15.3a applications with simulation and measurement results. Since the direct conversion mixing causes dc-offset and even-order distortion, the proposed mixer adopts an anti-parallel diode pairs(APDPs) to solve these problems. The proposed mixer consists of an in-phase wilkinson power divider over
, a wideband
power divider over
, and miniatured band pass filters(BPFs) for RF-LO isolations. The conversion loss is optimized with impedance matchings between APDPs and wideband components. The measured mixer shows the conversion loss of 13.5 dB, input third-order intercept-point(
) of 7 dBm, and 1-dB gam compression point(
) of -4 dBm. Quadrature(I/Q) outputs have the magnitude difference of about 1 dB and phase difference of
A Turbo Processing MIMO System with Non-Linear MMSE Detector for High-Speed Wireless Communications
Kang, Byeong-Gwon ; Cho, Dong-Kyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1164~1171
In this paper, a simple and nonlinear MMSE detector is derived from the conventional linear MMSE detector to improve the system performance in turbo processing MIMO system and a new turbo processing MIMO system with nonlinear MMSE detector and Gaussian approximation is proposed. In turbo coded turbo processing MIMO system, the proposed system of M=N=4 performs about 0.5 dB better than the conventional system and the proposed system of M=N=8 performs about 0.4 dB better than conventional system at 1 % FER. In addition, the average number of outer iterations of proposed system shows lower than that of conventional system. This is caused by the fact that the nonlinear MMSE detector of proposed system decides soft-outputs of coded bits based on the observation of received signals, so that it can reduce the uncertainty region in estimating the coded bits.
Verification of Surface Scattering Models and Inversion Algorithms with Measurements of Polarimetric Backscattering Coefficients of a Bare Soil Surface
Hong, Jin-Young ; Jung, Seung-Gun ; Oh, Yi-Sok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1172~1180
The backscattering coefficients of a bare soil surface were measured using an R-band polarimetric scatterometer, which were used to verify the validities of scattering models and inversion algorithms. The soil moisture contents and the surface roughness parameters (the RMS height and correlation length) were also measured from the soil surface. The backscattering coefficients were obtained from several scattering models with these surface parameters, and the computation results were compared with the measured backscattering coefficients. The soil moisture contents of the surface were retrieved from the measured backscattering coefficients, and compared with the measured surface parameters. This paper shows how well the scattering models agree with the measurements, and also shows the inversion results.
Relation between Radar Backscattering Coefficients and Surface Profile Length for Bare Soil Surfaces Using Theoretical Predictions and Measurement Data
Oh, Yi-Sok ; Hong, Jin-Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1181~1188
The radar backscattering coefficients of soil surfaces with various roughness conditions are computed at first in this paper. The roughness parameters for various surface-profile lengths are also obtained. Then, the relationship between the radar backscattering coefficients and the profile length is studied. It was shown that the effect of the profile length is negligible on the backscattering coefficient, even though the roughness parameters vary a lot with the length of the surface profile.
Reduction of Radiated Emission from Signal Traces Using Modified and Small-Sized Ground Patterns
Park, Pil-Sung ; Lee, Jae-Wook ; Lee, Taek-Kyung ; Cho, Choon-Sik ; Kim, Jae-Heung ; Choi, Hyung-Do ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1189~1198
We analyze the radiated emission and mutual coupling problem from a single microstrip transmission line and double signal traces with various ground patterns. In this paper, it is shown that the reduction of the radiated emission from the signal traces can be accomplished by using the novel and compact patterns on the ground planes in a specific frequency band. The accuracy and validation of radiation mechanism from the transmission line on a novel ground plane are evaluated and explained by using a commercially available software and experiment, respectively.
A Wideband Bow-Tie Monopole Antenna with Improved Band Rejection Characteristics
Moon, Soo-Deok ; Choi, Kyoung ; Hwang, Hee-Yong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1199~1205
This paper proposes a wideband monopole antenna with improved band rejection characteristics by inserting two band notch slots with half wavelength in radiator. The designed antenna is composed of bow-tie patch fed electromagnetically with parasitic ground patch of a semicircular shape. We obtained band rejection filter-like characteristics by controlling coupling amounts between two horizontal resonance slots. Using this technique, we achieved the broad rejection bandwidth and improved skirt characteristics compared with only one notch slot. The measured bandwidth is from 2.7 GHz to 6.9 GHz for VSWR below 2.0 except the limited band of
. This antenna shows a similar radiation pattern of the ideal monopole and the radiation gain reduction is more than
on the x-z plane at rejection frequency.
Design of Balun-BPF Using Dual-mode Ring Resonator
Jung, Eul-Young ; Hwang, Hee-Yong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1206~1211
In this paper, a Balun-BPF with the balun and BPF characteristics is proposed by using dual-mode ring resonator of
. We obtained the property of balun with the phase imbalance by symmetrically placing each output of ring resonator. The dual mode has been made by impedance difference between input and output lines. The fabricated Balun-BPF shows bandwidth of 40 MHz and insertion loss of 2.4 dB at a center frequency of 2.45 GHz. It shows the phase imbalance of
degree and the magnitude imbalance of within 1 dB. The measured frequency responses agree well with simulated ones.
Development of Microcellular Radio Propagation Prediction Model in the 8 GHz Bands
Song, Ki-Hong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1212~1223
Microwave(M/W) bands, though having great demand in wireless services, have been used mostly for long distance communications. As a result, the studies on their mobile radio models have been made less than on VHF/UHF. However, as the mobile communication services with M/W bands have been increasing, the development of a more accurate prediction model of the mobile radio environments has been demanded. The development of a reliable radio prediction model in the mobile radio environments requires the measurement and analysis of the characteristics of the radio waves according to reflection, diffraction and scattering of radio signals in various mobile radio environments. The proposed 8 GHz band radio prediction models have 2 different categories: (1) LOS model and (2) non-LOS model. The LOS model predicts signal strength using the analytic result with measured pathless exponents for the waves direct and reflected by ground and buildings, and the non-LOS model suggests a prediction model of received power by calculating the signal variations after diffraction.
Preceding Scheme for Dual Spatial Multiplexing Systems with Limited Feedback
Lee, Myoung-Won ; Mun, Cheol ; Yook, Jong-Gwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1224~1230
In this paper, for spatial multiplexing with limited feedback, a precoding scheme is proposed based on the joint use of minimal instantaneous feedback and long-term feedback of a small number of bits, wherein the long-term feedback is used to convey a selected preceding matrix within a precodercodebook consisting of a number of unitary matrices, and the active column vectors of the selected unitary matrix are conveyed to the transmitter using instantaneous feedback. Focusing on the case of dual multi-input multi-output(MIMO) systems, precoder codebook design for maximizing the average throughput of a spatial multiplexing system with a zero-forcing(ZF) receiver is proposed. It is shown that the proposed scheme provides a considerable throughput enhancement over multi-mode antenna selection and multi-mode basis selection only with the additional long-yterm feedback of a small number of bits. For example, the throughput increases by 11.5 % than antenna selection and 5.1% than basis selection, respectively, when SNR=20 dB.
Analysis of ELF Magnetic Field Reduction Ratio on Passive Loop Using Scale Down Model of Transmission Line
Cho, Yeun-Gyu ; Myung, Sung-Ho ; Lee, Jae-Bok ; Chang, Sug-Hun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1231~1239
In this research magnetic field reduction effect of each passive loop was analyzed by using the scale down models of transmission lines. This paper examined magnetic field reduction effect of the passive loop that will be applied to actual facility through the experiment, which is about double vertical transmission line and horizontal transmission line. Consequently, by confirming the fact that magnetic field reduction effect can be obtained to 50 % by passive loop without reactive compensation, we insured technology about application of passive loop. And the case of 3 turns of loop showed two times reduction effect than that of 1 turns of loop in reducing magnetic field. Vertical passive loop is more efficient than horizontal passive loop in the aspect of reducing magnetic field on double vertical transmission lines. What is more, vertical passive loop showed good effect of reducing magnetic field in a far distance as well as in a short distance.
Near-Isotropic Tag Antenna in UHF band Using Inductively Coupled Feeding
Ahn, Jun-Oh ; Jang, Hyung-Min ; Moon, Hyo-Sang ; Lee, Bom-Son ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1240~1248
This paper presents an UHF band(911 MHz) RFID tag antenna which has near-isotropic radiation pattern and easy conjugate impedance matching characteristics to any commercial chips of usual practice through the application of an inductively-coupled feeding. The proposed antenna of compact size
has, at normal incidence, the maximum RCS of
and the 3 dB RCS bandwidth of 9 MHz(1 %) in case of short chip load. It has the maximum and minimum RCS' of
depending on the incident angles. The difference of about 4.5 dB is relatively small compared with that (about 70 dB) of a pure dipole antenna. The designed antenna has been fabricated and its RCS' have been measured varying the angles of incidence. The measured RCS' have been found to have good agreement with the simulated ones.
Analysis of Performance for Entropy-Based ISAR Autofocus Technique
Bae, Jun-Woo ; Kim, Kyung-Tae ; Lee, Jin-Ho ; Im, Jeong-Heom ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 17, issue 12, 2006, Pages 1249~1258
Two-dimensional(2-D) radar images, namely, ISAR images from a maneuvering target include unwanted phase errors due to the target's motion. These phase errors make ISAR images to be blurred. The ISAR autofocus technique is required in order to remove these unwanted phase errors. Unless those unwanted phase errors produced by the target's motion are removed prior to target identification, we cannot expect a reliable target identification performance. In this paper, we use the entropy-based ISAR autofocus technique which consists of two steps: range alignment and phase adjustment. We analyze a relationship between the number of sampling point and a image quality in a range alignment algorithm and also analyze a technique for reducing computation time of the SSA(Stage-by-Stage Approachng) algorithm in a phase adjustment.