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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 16, Issue 12 - Dec 2005
Volume 16, Issue 11 - Nov 2005
Volume 16, Issue 10 - Oct 2005
Volume 16, Issue 9 - Sep 2005
Volume 16, Issue 8 - Aug 2005
Volume 16, Issue 7 - Jul 2005
Volume 16, Issue 6 - Jun 2005
Volume 16, Issue 5 - May 2005
Volume 16, Issue 4 - Apr 2005
Volume 16, Issue 3 - Mar 2005
Volume 16, Issue 2 - Feb 2005
Volume 16, Issue 1 - Jan 2005
Selecting the target year
Research on PAE and Linearity of Doherty Amplifier Using Adaptive Bias and PBG Structure
Lee Wang-Yeol ; Seo Chul-Hun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 777~782
In this paper, adaptive bias circuit and PBG structure have been employed to suppress IMD(Inter-Modulation Distortion) and improve PAE(Power Added Efficiency) of the Doherty amplifier. Gate bias voltage has been controlled with the envelope of the input RF signal and PBG structure has been employed on the output port of Doherty amplifier. The proposed power amplifier using adaptive bias circuit and PBG has been improved the
by 7.5 dBc, and the average PAR by
A Dual Band Directional Coupler with Feedback Compensation Using Diplexer Structure
Kim Ki-Joong ; Park Ja-Young ; Jeong Young-Hak ; Bae Hyo-Gun ; Kim Nam-Heung ; Kim Hak-Sun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 783~789
In this paper, a novel design and implementation of a dual-band directional coupler based on RF IPD(Integrated Passive Device)-on-glass technology is proposed, which can be adopted in GSM/GPRS cellular phones for closed loop power control at the output of the power amplifier. The proposed coupler has a compensation capacitor to improve the directivity, and was designed using a new diplexing structure to minimize the cross-band isolation.
Design of UWB Antenna for the External Receiver of Capsule Endoscopy
Kim Hong-Seok ; Oh Min-Seok ; Cheon Chang-Yul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 790~796
In order to accomplish a wireless communication of capsule endoscopy, an environment study in the human body and receiving antenna design have been performed. The proposed antenna is the loop antenna designed to minimize the propagation loss in multi-loss layer such as the human body and utilize the magnetic field. Considering the propagation loss in the human body, the frequency range is from 400 MHz to 500 MHz. Acorrrding to the FCC regulations, the permittivity and conductivity for each human tissue were extracted. We set up an equivalent model and make an aqueous solution which is replaced with the human body. Due to movement of capsule in the human body which propagation loss is extremly severe, an array antenna is required. Irrespective of the location of transmission antenna transmitting a signal of 1 mW, we confirme what it is possible for the enough signal detection as the average signal level of array antenna is -60 dBm.
RFID Tag Antenna Mountable on High-Conductivity and High Permittivity an Materials at UHF Band
Kwon Hong-Il ; Lee Bom-Son ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 797~802
In this paper, we design a UHF band RFID tag antenna which is conjugate matched to an impedance of a chip and also mountable on conductive materials. The proposed tag antenna is very compact(
) with a modified PIFA shape. The proposed tag antenna has an advantage of easy matching to various chip input impedances. The performance of the antenna is evaluated by monitoring RCS in the reader direction. The RCS of the designed tag is
when the chip is shorted and is
when the chip impedance is a complex conjugate of the antenna impedance.
A Design for Mutual Coupling Suppression between Elements in Planar Array Antenna
Min Kyeong-Sik ; Kim Dong-Jin ; Park Chul-Keun ; Moon Young-Min ; Kim Young-Eil ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 803~809
This paper presents a novel method of mutual coupling suppression between antenna elements for performance improvement in planar array antenna system. Two miniature patch antenna elements satisfied IEEE 802.1 la(
) are used for this research, they are arrayed by half wave length interval. It is observed about -20 dB mutual coupling between each antenna element at center frequency. To suppress mutual coupling, the arrayed antennas with a reversed 'U' structure are observed below -30 dB mutual coupling at IEEE 802.1la band.
Input Power Determination of TEM Cell Due to SAR for Mobile Phone Wave Blood Exposure
Youn Ji-Hun ; Son Tae-Ho ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 810~814
Input power for TEM cell apparatus due to SAR(Specific Absorption Rate) for culture blood cell is determined by the transmission and reflection measurement of blood into the TEM cell. Blood cell with skin cell are reference culture cells for the study of EM wave effect. Exposure RF power from exposure apparatus to culture cell should not only exact for SAR value, but also should be based on the theoretical theory. In this paper, insertion loss of 50 g blood was measured to know exposure power per gram for culture blood cell, and input power of TEM cell due to SAR 0.8, 1.6, 3, 4 mW/g using the measured data are delivered. This study is for applying to EM wave exposure apparatus to culture cell.
Doherty Amplifier Using Load Modulation and Phase Compensation DGS Micro-Strip Line
Choi Heung-Jae ; Lim Jong-Sik ; Jeong Yong-Chae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 815~824
In this paper, we proposed a new DGS(Defected Ground Structure) Doherty amplifier for IMT-2000 band. Originally, active load-pull analysis of a Doherty amplifier assumes ideal harmonic termination condition. However, there have been no papers considering this ideal harmonic termination condition. We obtained excellent improvements of efficiency, gain, maximum output power as well as superior size reduction of a Doherly amplifier by satisfying the overlooked assumption of ideal harmonic termination through the adaptation of DGS at the output transmission line of carrier and peaking amplifier that is essential for Doherty operation. The amount of both the 2nd and the 3rd harmonic rejection of the proposed DGS Doherty amplifier over the conventional one are 44.92 dB and over 23.77 dB, respectively. The acquired improvement in Pl dB, gain, drain efficiency, and ACPR to WCDMA 1FA signal were 0.42 dB, 0.33 dB,
and 5.4 dBc, respectively. Moreover, electrical length of
is reduced at each of the DGS carrier amplifier path and DGS peaking amplifier path, therefore the whole amplifier circuit size is considerably reduced.
A Design of Ultra Wide-Band Feedforward Amplifier Using Equal Group-Delayed Signal Canceller
Jeong Yong-Chae ; Ahn Dal ; Kim Hong-Gi ; Kim Chul-Dong ; Chang Ik-Soo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 825~834
In this paper, a new signal canceller that input signals are equally group-delayed and cancelled each other is proposed and feedforward linearizing power amplifier that adopt the proposed signal cancellers is fabricated. Although the conventional signal canceller can't matches the phase and the group delay time of input signals simultaneously, the proposed signal canceller matches those simultaneously. Simultaneous matching of the phase and the group delay time can makes wideband signal cancellation. The main signal cancellation loop of the fabricated feedforward amplifier with the proposed signal cancellers cancel input signal more than 26.3 dB and the intermodulation distortion signal cancellation loop cancel more than 15.2 dB for 200 MHz bandwidth. And the proposed feedforward power amplifier improves C/I ratio by 20.8 dB with two tones at 2,115 MHz, 2,165 MHz, respectively.
A Size-Reduced CPW Balun with the Wilkinson Divider Structure Using a Crossing Structure
Lim Jong-Sik ; Yang Hoe-Sung ; Kim Dong-Joo ; Jeong Yong-Chae ; Ahn Dal ; Kim Kwang-Soo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 835~841
In this paper, a novel sized-reduced CPW(Coplanar Waveguide) balun is proposed. It has a crossing structure between signal line and ground planes of CPW transmission line for the
phase inversion. The
CPW transmission line is reduced to
in physical length while the electrical length is preserved to
phase inverting structure, while the previous balun by Lim et at. has a long
transmission section to from the Wilkinson divider structure having out of phase between output ports. In addition, the measured data which show the crossing structure has the wanted
phase change is presented in this work.
Development of Electromagnetic Wave Absorbers far Mobile Phone Using Sendust
Choi Jung-Hyun ; Kim Dong-Il ; Song Jae-Man ; Jung Jae-Hyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 842~847
In this paper, we fabricated sheet-type EM wave absorbers for mobile phones by using sendusts and tested EM wave absorption of it. The band-width of EM wave absorbers coated with
were larger than non-coated EM wave absorbers. Particle size decreased with increasing milling time, which made the result of increasing of EM wave absorption. The fabricated EM wave absorbers show a reflection coefficient 17.4 dB at 946 MHz for a 4 mm sample and 5 dB at 1.8 GHz for a 1 mm sample.
Empirical Study on the Prediction of Rain Attenuation in EHF(44 GHz) Band
Park Yong-Ho ; Lee Joo-Hwan ; Pack Jeong-Ki ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 8, 2005, Pages 848~854
The attenuation due to rain has been recognized as one of the major causes of unavailability of radio communication systems operating above about 10 GHz. To design radio links for telecommunications and to evaluate attenuation due to rainfall, it is important to have a good prediction model for rain attenuation such as a model for drop-size distribution of rainfall(DSD), a theoretical model for specific rain attenuation, and an empirical model fur effective path length through rain. In this paper, the extended generalized gamma distribution for drop-size distribution, based on the measurements in Chnugnam National University, is proposed as a new DSD model, and predicted specific attenuation characteristics using proposed DSD model and rain attenuation values in the 44 GHz satellite path using ITU-R effective path length model, are analysed. The predicted attenuation levels are also compared. It is found that an accurate prediction method for DSD is very important to reduce the prediction error in the local satellite path.