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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 20, Issue 12 - Dec 2009
Volume 20, Issue 11 - Nov 2009
Volume 20, Issue 10 - Oct 2009
Volume 20, Issue 9 - Sep 2009
Volume 20, Issue 8 - Aug 2009
Volume 20, Issue 7 - Jul 2009
Volume 20, Issue 6 - Jun 2009
Volume 20, Issue 5 - May 2009
Volume 20, Issue 4 - Apr 2009
Volume 20, Issue 3 - Mar 2009
Volume 20, Issue 2 - Feb 2009
Volume 20, Issue 1 - Jan 2009
Selecting the target year
Design of Two-Inductor Loaded Small Loop Antennas Using Genetic Algorithm
Cho, Gyu-Yeong ; Kim, Jae-Hee ; Park, Wee-Sang ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1021~1030
DOI : 10.5515/KJKIEES.2009.20.10.1021
We propose optimization method of two-inductor loaded small loop antennas using simple genetic algorithm. To optimize the loop antennas for the RFID and the mobile phone band, we changed positions and values of the two inductors in the loop antenna. Visual basic was used to make genetic algorithm and to calculate fitness values by controlling the commercial EM software. The bandwidth of the optimized RFID loop antenna is 10 MHz at the center frequency of 922 MHz and that of the mobile phone antenna are 84 MHz and 266 MHz at the center frequency of 948 MHz(GSM band) and 1.81 GHz(DCS band), respectively.
Macro-Micro Reconfigurable Antenna for Multi Mode & Multi Band(MMMB) Communication Systems
Yeom, In-Su ; Choi, Jung-Han ; Jung, Young-Bae ; Kim, Dong-Ho ; Jung, Chang-Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1031~1041
DOI : 10.5515/KJKIEES.2009.20.10.1031
A small microstrip monopole antenna for macro-micro frequency tuning over multiple bands is presented. The meander-shape antenna is fabricated on a conventional printed circuit board(FR-4,
). The antenna operates over WiBro(2.3~2.4 GHz) and WLAN a/b(2.4~2.5 GHz/5.15~5.35 GHz) service bands with an essentially constant antenna gain within each service band. Two diodes, a PIN diode and a varactor, are embedded into the antenna for frequency reconfiguration. The PIN diode is used for frequency switching(macro-tuning) between 2 GHz and 5 GHz bands while the varactor is used for frequency tuning(micro-tuning) within the service bands, 2.3~2.5 GHz and 5.15~5.35 GHz. Unwanted resonances between the two frequency bands(2 GHz and 5 GHz) are suppressed by filling up the gaps between the meander lines. The antenna gain is essentially constant and higher than 2 dBi within each service band. The measured performance of the proposed antenna system suggests the macro-micro frequency tuning techniques be useful in reconfigurable wireless communication systems.
Optimization of a Broadband Waveguide Magic-T for X-Band Monopulse Tracking Radars
Hwang, Keum-Cheol ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1042~1049
DOI : 10.5515/KJKIEES.2009.20.10.1042
Design and optimization of a broadband waveguide magic-T was performed for X-Band tracking radars. A multi-stepped conducting cylinder was used to enhance the bandwidth performance of the conventional waveguide magic-Ts. Particles swarm optimization in conjunction with genetic algorithm was employed to obtain the optimized geometrical parameters. The optimized design exhibits low reflection coefficient below -20 dB at all waveguide ports with frequency bandwidth of 12%. The transmission loss and difference are within 0.2 dB and 0.1 dB, respectively. Measured results are also shown to be in good agreement with the simulated results. Finally, the bandwidth performances for five and seven-stepped conducting cylinders are also investigated.
A Design and Fabrication of the X-Band Transmit/Receive Module for Active Phased Array SAR Antennas
Chong, Min-Kil ; Kim, Sang-Keun ; Na, Hyung-Gi ; Lee, Jong-Hwan ; Yi, Dong-Woo ; Baik, Seung-Hun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1050~1060
DOI : 10.5515/KJKIEES.2009.20.10.1050
In this paper, a X-Band T/R-module for SAR(Synthetic Aperture Radar) systems based on active phased array antennas is designed and fabricated. The T/R modules have a and width of more than 800 MHz centered at X-Band and support dual, switched polarizations. The output power of the module is 7 watts over a wide bandwidth. The noise figure is as low as 3.9 dB. Phase and amplitude are controlled by a 6-bit phase shifter and a 6-bit digital attenuator, respectively. Further the fabricated T/R module has est and calibration port with directional coupler and power divider. Highly integrated T/R module is achieved by using LTCC(Low Temperature Co-fired Ceramic) multiple layer substrate. RMS gain error is less than 0.8 dB max. in Rx mode, and RMS phase error is less than
max. in Rx/Tx phase under all operating frequency band, or the T/R module meet the required electrical performance m test. This structure an be applied to active phase array SAR Antennas.
Design of 4-Bit TDL(True-Time Delay Line) for Elimination of Beam-Squint in Wide Band Phased-Array Antenna
Kim, Sang-Keun ; Chong, Min-Kil ; Kim, Su-Bum ; Na, Hyung-Gi ; Kim, Se-Young ; Sung, Jin-Bong ; Baik, Seung-Hun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1061~1070
DOI : 10.5515/KJKIEES.2009.20.10.1061
In this paper, we have designed TDL(True-time Delay Line) for eliminating beam-squint occurring in active phased array antenna with large electrical size operated in wide bandwidth, and have tested its electrical performance. The proposed TDL device is composed of 4-bit microstrip delay line structure and MMIC amplifier for compensation of the delay-line loss. The measured results of gain and phase versus delay state satisfy the electrical requirements, also P1dB output power and noise figure meet the requirement. To verify the performance of fabricated TDL, we have simulated the beam patterns of wide-band active phased array antenna using the measured results and have certified the beam pattern compensation performance. As a result of simulated beam pattern compensation with respect to the 675.8 mm size antenna which is operated in X-band, 800 MHz bandwidth, we have reduced the beam squint error of
. So this TDL module is able to be applied to active phase array antenna system.
Embroidery 'ㅂ' Character Type UHF RFID Tag Antenna Design
Chung, You-Chung ; Kim, Yeon-Ho ; Lee, Kyoung-Hwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1071~1076
DOI : 10.5515/KJKIEES.2009.20.10.1071
A wearable embroidery 'ㅂ' character shape UHF RFID tag antenna has been designed using conductive electro-thread. After testing characteristics of various electro-threads, the embroidery tag, with a T-matching structure, has been designed on a cloth with 200D(denier) electro-thread which performs electrically better. The embroidery tag on a piece of fabric or clothes made with the flexible electro-thread is a wearable tag and possible to be recognized by an RFID system. The conductivity of different deniers of electro-threads has been measured. The measured conductivity has been used for simulation and fabrication to have accurate simulation results. To verify the characteristics of the tag antenna, the return loss and reading range of the fabricated embroidery electro-thread UHF RFID tag antenna have been tested. The reading range is approximately 1.52 m.
A Study on Optimizing the Clutter Rejection Capability for a High-Speed Scanning MTI-Pulse Radar
Kim, Jong-Geon ; Jang, Heon-Soon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1077~1083
DOI : 10.5515/KJKIEES.2009.20.10.1077
To reject the Doppler frequency spectrum dispersion of clutter caused by high-speed antenna rotation of MTI radar system due to terrain characteristics, signal processing parameters(MTI filter constant, M/N detector ration, K-factor and offset of CFAR) are adjusted for the optimal elimination of the ground clutter. For this investigation, logging equipment is designed and utilized for the collection of classified ground clutter data. Test case is devised through Matlab simulation for the classified analysis and optimization of clutter rejection. Then indoor radar test and outside test in accordance with terrain characteristics are repeatedly performed for the verification of the test. This whole process is through the evolutional development model and repeated for the optimization. Final result is that ground-clutter rejection capability is 5.6 times(7.5 dB) better than that of existing radar system.
Capacitively Loaded Loop Antenna Fed with Metamaterial Balun
Jung, Youn-Kwon ; Lee, Bom-Son ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1084~1090
DOI : 10.5515/KJKIEES.2009.20.10.1084
This paper presents a balun consisting of a T-junction, a Right/Left Handed Transmission line(RLH-TL), and a conventional Right Handed(RH) line. It is assumed that the RLH-TL consists of N unit-cells. We provide closed-form solutions and design a very compact wideband(80 %) balun using CPW lines based on the obtained solutions. Then, we propose a capacitively loaded loop antenna designed for a uniform current distribution. The antenna resistance of the proposed antenna at resonance is about 204 ohms. The length of the unit cell is about
). The magnetic field generated from the proposed antenna is stronger than that of the conventional one by as much as 20 dB. We used a coplanar strip line(CPS) to combine the loop antenna and balun. The proposed antenna may be used as a near field UHF RFID reader antenna.
Analysis of Resonant MTM-TL Using Transmission Line Theory and Its Applications
Jang, Seong-Nam ; Lee, Bom-Son ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1091~1096
DOI : 10.5515/KJKIEES.2009.20.10.1091
Some closed-form expressions for circuit parameters are derived based on the equivalent circuits for the resonant MTM-TL(open and short). The lumped series resistance and shunt conductance, which explain radiation effects of a unit cell may be found by |
|(simulated or measured) with open and short terminations, respectively. The EM-simulated results, circuit-simulated results(obtained using extracted circuit parameters) and measurement results are shown to be in good agreement.
Design of Cross Monopole Antennas with Branch Element
Kim, Byung-Hoon ; Choi, Hak-Keun ; Park, Jae-Hyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1097~1106
DOI : 10.5515/KJKIEES.2009.20.10.1097
In this paper, the cross monopole antenna with branch element is presented and its radiation characteristics are investigated. To confirm the broadband characteristics of the proposed antenna, the experimental antenna is designed, fabricated, and its radiation characteristics are measured in PCS, WCDMA, WiBro and S-DMB band(1.750~2.655 GHz). It is shown that the designed antenna has the non-directional pattern in the horizontal plane, the directional pattern in the vertical plane, VSWR less than 1.5 and gain over 1.9 dBi in 1.72~2.82 GHz. From these results, the presented antenna is conformed as a broadband antenna which can be used for PCS, WCDMA, WiBro and S-DMB band.
Design of K-Band Frequency Divider Using 130 nm CMOS Process
Nam, Sang-Kyu ; Park, Deuk-Hee ; Kim, Seong-Kyun ; Kim, Byung-Sung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1107~1113
DOI : 10.5515/KJKIEES.2009.20.10.1107
In this paper, the design and implementation of K-Band frequency dividers using 130 nm CMOS process are presented. A Miller frequency divider is presented, which realizes a division range from 20 to 25 GHz with 7.2 mW power consumption from 1.2 V supply. The layout size of the core circuit is about
. In addition, a CML frequency divider which divides the output signal of the Miller frequency divider is also presented, which realizes a division range from 8.5 to 13 GHz with 5.7 mW power consumption. The layout size of the CML core is about
. Cascading the Miller and CML frequency dividers, we confirmed the divide-by-4 operation for the input signal from 20 to 25 GHz.
Design of Electro-Thread Embroidery UHF RFID Tag Antennas with Character Shapes
Choi, Jae-Han ; Chung, You-Chung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 20, issue 10, 2009, Pages 1114~1120
DOI : 10.5515/KJKIEES.2009.20.10.1114
The conductivity of various electro-threads is analyzed, and the washable electro-thread embroidery UHF RFID tag antennas using the character shape without T-matching structure are designed by adding a T-matching structure. The RFID tag antenna using the electro-thread is easy to be embedded on a cloth as a wearable antenna because it is flexible and different from general copper inlay shape and tape type tag. The embroidery tag antennas are designed with the English alphabet 'F' and the Korea alphabet 'ㄹ' character. Those are easy to be applied to general clothes. The parameters of antennas are optimized and fabricated. The characteristics and the reading range patterns of the tag antennas are measured. The reading ranges of wet tags(tap water, sea water and soapy water) are tested and compared.