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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal 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 12, Issue 4 - Dec 2012
Volume 12, Issue 3 - Sep 2012
Volume 12, Issue 2 - Jun 2012
Volume 12, Issue 1 - Mar 2012
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A Biomolecular Sensing Platform Using RF Active System
Kim, Sang-Gyu ; Lee, Hee-Jo ; Yook, Jong-Gwan ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 227~233
DOI : 10.5515/JKIEES.2012.12.4.227
This paper describes a novel and compact biosensing platform using an RF active system. The proposed sensing system is based on the oscillation frequency deviation due to the biomolecular binding mechanism on a resonator. The impedance variation of the resonator, which is caused by a specific biomolecular interaction results in a corresponding change in the oscillation frequency of the oscillator so that this change is used for the discrimination of the biomolecular binding, along with concentration variation. Also, a Surface Acoustic Wave (SAW) filter is utilized in order to enhance the biosensing performance of our system. Because the oscillator operates at the skirt frequency range of the SAW filter, a small amount of oscillation frequency deviation is transformed into a large variation in the output amplitude. Next, a power detector is used to detect the amplitude variation and convert it to DC voltage. It was also found that the frequency response of the biosensing system changes linearly with three streptavidin concentrations. Therefore, we expect that the proposed RF biosensing system can be applied to bio/medical applications capable of detecting a nano-sized biomolecular interaction.
A Compact Ka-Band Doppler Radar Sensor for Remote Human Vital Signal Detection
Han, Janghoon ; Kim, Jeong-Geun ; Hong, Songcheol ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 234~239
DOI : 10.5515/JKIEES.2012.12.4.234
This paper presents a compact K-band Doppler radar sensor for human vital signal detection that uses a radar configuration with only single coupler. The proposed radar front-end configuration can reduce the chip size and the additional RF power loss. The radar front-end IC is composed of a Lange coupler, VCO, and single balanced mixer. The oscillation frequency of the VCO is from 27.3 to 27.8 GHz. The phase noise of the VCO is -91.2 dBc/Hz at a 1 MHz offset frequency, and the output power is -4.8 dBm. The conversion gain of the mixer is about 11 dB. The chip size is
. The compact Ka-band Doppler radar system was developed in order to demonstrate remote human vital signal detection. The radar system consists of a Ka-band Doppler radar module with a
patch array antenna, baseband signal conditioning block, DAQ system, and signal processing program. The front-end module size is
. The proposed radar sensor can properly capture a human heartbeat and respiration rate at the distance of 50 cm.
Circuit Model Analysis for Traces that Cross a DGS
Jung, Kibum ; Lee, Jongkyung ; Chung, Yeon-Choon ; Choi, Jae-Hoon ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 240~246
DOI : 10.5515/JKIEES.2012.12.4.240
This paper presents a novel modeling technique for traces that cross a defected ground structure. A simple and accurate equivalent circuit model provides clear insight into the coupling mechanism between a microstrip line and a slot or split. The circuit models consist of a transformer as the coupling mechanism and LC resonators as the ground with a slot or split structure. Resistors, capacitors, and inductors are added to the model to increase accuracy and equivalence at high frequency. Simulated and measured S-parameters are presented for defected ground structures. The accuracy and validity of the proposed equivalent circuit model is verified by evaluation of the S-parameter characteristics of the defected ground structures and comparison with measured results.
Front-to-Back Ratio Improvement of a Microstrip Patch Antenna Loaded with Soft Surface Structure in a Partially Removed Ground Plane
Lee, Hong-Min ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 247~253
DOI : 10.5515/JKIEES.2012.12.4.247
This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna. The back radiation of the microstrip patch antenna is reduced by removing some metallic parts around the ground plane and placing a new soft-surface configuration, consisting of an array of stand-up split-ring resonators on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional microstrip patch antenna with a full ground plane of the same size, our proposed microstrip patch antenna experimentally achieves an improved F/B ratio of 9.6 dB.
Closely Spaced Two-Element Folded-Dipole-Driven Quasi-Yagi Array
Ta, Son Xuat ; Kang, Sang-Gu ; Park, Ikmo ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 254~259
DOI : 10.5515/JKIEES.2012.12.4.254
This paper presents a closely spaced two-element folded-dipole-driven quasi-Yagi array with low mutual coupling between adjacent elements. The antenna utilizes a T-junction power divider as the feeding network, with an input impedance of
. A microstrip-stub is added to the ground plane in the middle of the two elements to improve the mutual coupling characteristics. The folded dipole driver is connected to a
microstrip line via a broadband microstrip-to-coplanar stripline transition with a quarter radial stub. A mutual coupling of less than -22 dB is measured between two folded-dipole-driven quasi-Yagi antennas with a center-to-center spacing of 30 mm (
at 5.5 GHz). The proposed quasi-Yagi array yields a measured bandwidth of 4.75~6.43 GHz for the -10 dB reflection coefficient and a gain of 6.14~7.12 dBi within the bandwidth range.
Determination of Surface Currents on Circular Microstrip Antennas
Godaymi, Wa'il A. ; Mohammed, Abdul-Kareem Abd Ali ; Ahmed, Zeki A. ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 260~270
DOI : 10.5515/JKIEES.2012.12.4.260
This work aims to present a theoretical analysis of the electric and magnetic surface current densities of a circular microstrip antenna (CMSA) as a body of revolution. The rigorous analysis of these problems begins with the application of the equivalence principle, which introduces an unknown electric current density on the conducting surface and both unknown equivalent electric and magnetic surface current densities on the dielectric surface. These current densities satisfy the integral equations (IEs) obtained by canceling the tangential components of the electric field on the conducting surface and enforcing the continuity of the tangential components of the fields across the dielectric surface. The formulation of the radiation problems is based on the combined field integral equation. This formulation is coupled with the method of moments (MoMs) as a numerical solution for this equation. The numerical results of the electric and magnetic surface current densities on the outside boundary of a CMSA excited by
modes are presented. The radiation pattern is calculated numerically in the two principle planes for a CMSA and gives a good results compared with measured results published by other research workers.
Effect of Extremely Low Frequency Magnetic Fields on Gene Expression in Human Mammary Epithelial MCF10A Cells
Hong, Mi-Na ; Lee, Hyung-Chul ; Kim, Bong Cho ; Lee, Yun-Sil ; Gimm, Yoon-Myung ; Myung, Sung-Ho ; Lee, Jae-Seon ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 271~279
DOI : 10.5515/JKIEES.2012.12.4.271
The effects of extremely low frequency magnetic fields (ELF-MFs) on physiological processes at the cellular level remain unclear despite a number of studies. To investigate the effects of ELF-MFs on gene expression, we exposed human mammary epithelial MCF10A cells to fields of 1 mT magnetic flux density at 60 Hz for 4 and 16 h and measured the transcriptional responses of 24,000 genes using Illumina microarrays. In three independent experiments, we found no statistically significant alteration of expression levels for any of the genes assayed using a cutoff value of 1.2-fold. To confirm this result, we selected six genes with trends suggesting possible expression level changes, although these trends were not statistically significant, and investigated their expression levels further using a semiquantitative reverse-transcription polymerase chain reaction. In three independent experiments, we did not find any alterations in the expression levels of these genes. From these results, we conclude that ELF-MFs do not affect gene expression profiles under our exposure conditions.
Control of Phase and Phase Slope with Reinvestigation of 1D CRLH Transmission Lines
Jeon, Dongho ; Lee, Bomson ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 280~286
DOI : 10.5515/JKIEES.2012.12.4.280
The conventionally classified waves are reclassified in this paper, including the waves associated with metamaterial (MTM) transmission lines. Various types of guided waves in periodic structures are analyzed for 1D Composite Right/Left Handed (CRLH) transmission lines (TL). In addition, dispersion diagrams for 1D CRLH, RH, and LH TLs are presented in terms of radiation conditions. We have refined the design equations of the conventional 1D CRLH TL and proposed a condition to realize the desired phase shift and its slope per unit cell. This condition has been applied to the conventional Wilkinson power divider and realized into MTM added
hybrid coupler. Based on the 10 dB return loss and the
phase shift, the bandwidths of the MTM added
hybrid coupler are 82.25% and 103.5% against the conventional 23% and 52.5%, respectively.
Alternate Time-Switched Space-Frequency Block Coding Technique for OFDM Systems
Jung, Hyeok Koo ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 287~289
DOI : 10.5515/JKIEES.2012.12.4.287
This paper proposes an alternate time-switched space-frequency block coding transmission technique for orthogonal frequency division modulation systems. There are two antennas in the transmitter but it still has only a baseband and RF and a switch that alternates between the antennas at every symbol timing. Alternating transmit symbols result in zeros that make maximal ratio receive combining possible in the receiver. Simulation results show that it provides better performance than the traditional algorithm at the expense of one additional antenna.
Determination of Multisine Coefficients for Power Amplifier Testing
Park, Youngcheol ; Yoon, Hoijin ;
Journal of electromagnetic engineering and science, volume 12, issue 4, 2012, Pages 290~292
DOI : 10.5515/JKIEES.2012.12.4.290
This paper proposes a setup for a best multisine design method that uses a time-domain optimization. The method is based on minimization of the time-domain error, so its resulting multisine has a very accurate ACLR estimation. This is because its probability distribution and sample-to-sample correlation are close to those of the original signal, which are crucial for the testing of nonlinear power amplifiers. In addition, a hyperbolic-tangent function is introduced to control the ripple of tone magnitudes within signal bandwidth. For the verification, multisines were generated and compared for many aspects such as normalized error, in-band ripple, and ACLR estimation. Test results with different numbers of tones provide supporting evidence that the suggested multisine design has better ripple suppression, by up to 7 dB, and better accuracy, by up to 0.2 dB, when compared to the conventional method. The accuracy of the ACLR was improved by about 5 dB when the number of tones was 4. The suggested method improves the ACLR estimation performance of multisine testing due to its closer resemblance to the target modulation signal.