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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 19, Issue 12 - Dec 2008
Volume 19, Issue 11 - Nov 2008
Volume 19, Issue 10 - Oct 2008
Volume 19, Issue 9 - Sep 2008
Volume 19, Issue 8 - Aug 2008
Volume 19, Issue 7 - Jul 2008
Volume 19, Issue 6 - Jun 2008
Volume 19, Issue 5 - May 2008
Volume 19, Issue 4 - Apr 2008
Volume 19, Issue 3 - Mar 2008
Volume 19, Issue 2 - Feb 2008
Volume 19, Issue 1 - Jan 2008
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Gate-Bias Control Technique for Envelope Tracking Doherty Power Amplifier
Moon, Jung-Hwan ; Kim, Jang-Heon ; Kim, Il-Du ; Kim, Jung-Joon ; Kim, Bum-Man ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 807~813
DOI : 10.5515/KJKIEES.2008.19.8.807
The gate-biases of the Doherty power amplifier are controlled to improve the linearity performance. The linearity improvement mechanism of the Doherty amplifier is the harmonic cancellation of the carrier and peaking amplifier at the output power combining point. However, it is difficult to cancel the harmonic power for the broader power range because the condition for cancelling is varied by power. For the linearity improvement, we have explored the linearity characteristic of the Doherty amplifier according to the input power and gate biases of the carrier and peaking amplifier. To extend the region of harmonic power cancellation, we have injected the proper gate bias to the carrier and peaking amplifier according to the input power levels. To validate the linearity improvement, the Doherty amplifier is designed using Eudyna 10-W PEP GaN HEMT EGN010MKs at 2.345 GHz and optimized to achieve a high linearity and efficiency at an average output power of 33 dBm, backed off about 10 dB from the
. In the experiments, the envelope tracking Doherty amplifier delivers a significantly improved adjacent channel leakage ratio performance of -37.4 dBc, which is an enhancement of about 2.8 dB, maintaining the high PAE of about 26 % for the WCDMA 1-FA signal at an average output power of 33 dBm. For the 802.16-2004 signal, the amplifier is also improved by about 2 dB, -35 dB.
Design of a Diode Detector Using Ultra-Wideband Transitions
Kim, In-Bok ; Kim, Young-Gon ; Kim, Tae-Gyu ; Kim, Kang-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 814~819
DOI : 10.5515/KJKIEES.2008.19.8.814
In this paper, a design of broadband detectors utilizing two ultra-wideband transitions is described for the first time, and the implementation method and measurement results of the detectors are provided. Two ultra-wideband transitions are used for input/output matching circuits for the diode detectors. Two detectors have been implemented using general Schottky diodes and zero-bias Schottky diodes. With general Schottky diodes, the fabricated detector provides less than 10 dB return loss from 11 GHz to 20 GHz, and the detector sensitivity is 30 mV/mW. The detector with zero-bias Schottky diodes shows significantly higher detection sensitivity(300 mV/mW).
A Method to Improve Isolation of MIMO Antenna System for Wireless Portable Devices Using Multiple Pairs of L-Slots
Lee, Hyun-Seok ; Yoon, Sang-Won ; Park, Hyun-Chang ; Park, Hyung-Moo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 820~825
DOI : 10.5515/KJKIEES.2008.19.8.820
A method to improve isolation characteristics of internal MIMO antenna systems for wireless portable devices operating in the
GHz band is presented. The proposed system incorporates multiple pairs of L-slots between the two antennas in the ground plane, which operate like a band-stop filter, suppressing mutual coupling between the antennas and resulting in improved isolation. A MIMO antenna system with 6 pairs of L-slots shows reflection loss of -26.4 dB and isolation of -37.5 dB.
Novel Mobile Satellite Communication Antenna Design Based on Shaped-Reflector
Jung, Young-Bae ; Park, Seong-Ook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 826~831
DOI : 10.5515/KJKIEES.2008.19.8.826
This paper presents hybrid antenna(HA) design based on shaped reflector for mobile satellite communication. HA is composed of a shaped reflector and a feeder having
linear phased array, and reflector shaping method is applied for the performance optimization with minimum aperture size. And, in the feeder design, HA has another merit to minimize the manufacturing cost by optimizing the number of element. Proposed HA is designed at Ka-band and can electrically control a beam pattern within
in the basic angle of
in elevation. This antenna is designed to meet ITU-R S.465-5 for beam pattern including side-lobe level.
Maximum Electromagnetic Transmission through a Narrow Slit in Conducting Screen
Lee, Jong-Ig ; Cho, Young-Ki ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 832~836
DOI : 10.5515/KJKIEES.2008.19.8.832
In this study, the electromagnetic coupling problem through narrow slit in an infinite conducting screen is considered for the case that the TM polarized plane wave is incident upon the slit. This study aims at explaining the mechanism of the maximum power transmission via the resonated slit using the equivalent circuit. It is shown that the transmitted power through the slit for the case of resonance corresponds to the power normally incident upon the conducting plane of the effective width 1/pi wavelengths, irrespective of the slit width. Some similarities between the maximum power transmissions observed in both the proposed structure and narrow slit in thick conducting screen are described from the viewpoint of equivalent circuit. In addition, it is found that, when the slit is resonated, the transmitted power equal to the scattered power.
Dual-Band Power Divider Using CRLH-TL
Kim, Seung-Hwan ; Sohn, Kang-Ho ; Kim, Ell-Kou ; Kim, Young ; Lee, Young-Soon ; Yoon, Young-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 837~843
DOI : 10.5515/KJKIEES.2008.19.8.837
This paper proposes a power divider based on meta-material structure with dual-band operation. The meta-material structures of left-hand characteristic are constituted of series capacitors and shunt inductors, but they have parasitic series inductance and shunt capacitance effects. There is represented the composite right/ left-handed transmission line (CRLH-TL) model. When the power divider is implemented by using the CRLH-TL, the power divider can operate dual band. To verify the power divider with dual band, we are implemented to operate dual-band that is 0.88 GHz and 1.67 GHz. The characteristics of divider have the return loss less than each 21.0 dB and 15.8 dB and the insertion loss better than 3.83 dB and 3.64 dB at each frequency. Also, the output phase difference is
Design of a LTCC Front End Module with Power Detecting Function
Hwang, Mun-Su ; Koo, Jae-Jin ; Koo, Ja-Kyung ; Lim, Jong-Sik ; Ahn, Dal ; Yang, Gyu-Yeol ; Kim, Jun-Chul ; Kim, Dong-Su ; Park, Ung-Hee ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 844~853
DOI : 10.5515/KJKIEES.2008.19.8.844
This paper describes the design of a FEM(Front End Module) having power detection function for mobile handset application. The designed FEM consists of a MMIC(Monolithic Microwave Integrated Circuits) power amplifier chip, SAW Tx filter and duplexer, diode power detector and stripline matching circuit. An LTCC(Low Temperature Co-fired Ceramics) technology is adopted for miniaturized FEM. The frequency band is
MHz which is the uplink Tx band of the CDMA mobile system. The size of designed FEM is
, which is an ultra-small size even though the power detector circuit is included. All sub-components of FEM have been developed and measured in advance before being integrated into FEM. The measured output power and gain are 27 dBm and 27 dB, respectively. In addition, the measured ACPR characteristics are 46.59 dBc and 55.5 dBc at 885 kHz and 1.98 MHz offset, respectively.
Highly Efficient High Power Hybrid EER Transmitter for IEEE 802.16e Mobile WiMAX Application
Kim, Il-Du ; Moon, Jung-Hwan ; Kim, Jang-Heon ; Kim, Jung-Joon ; Kim, Bum-Man ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 854~861
DOI : 10.5515/KJKIEES.2008.19.8.854
We have described a high power hybrid envelope elimination and restoration(H-EER) transmitter for IEEE 802.16e Mobile World Interoperability for Microwave Access(WiMAX) using an efficiency optimized power amplifier(PA). The PA has been designed to have maximum PAE at the important power generation
, region using Nitronex 100-W PEP GaN HEMT. For the high power application, H-EER transmitter should be considered the regenerative oscillation problem due to the PA's bias fluctuation effect and bias modulator stability issue. Therefore, the bias modulator for H-EER transmitter has been designed to suppress the regenerative oscillation. For the interlock experiment, the bias modulator has been built with the efficiency of 72% and peak output voltage of 30 V for the envelope signal with a PAPR of 8.5 dB. The H-EER transmitter for WiMAX application has been achieved a high PAE characteristic, 38.8 % at an output power of 41.25 dBm. By using digital predistortion(DPD) technique, the Relative Constellation Error (RCE) has been satisfied the specification of -34.5 dB. This is the first work at 2.655 GHz high power H-EER transmitter for WiMAX application.
Compact and Wideband Coupled-Line 3-dB Ring Hybrids
Ahn, Hee-Ran ; Kim, Jung-Joon ; Kim, Bum-Man ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 862~877
DOI : 10.5515/KJKIEES.2008.19.8.862
In this paper, two types of wideband 3-dB ring hybrids are compared and discussed to show the ring hybrid with a set of coupled-line sections better. However, the better one still has a realization problem that perfect matching can be achieved only with -3 dB coupling power. To solve the problem, a set of coupled-line sections with two shorts is synthesized using one- and two-port equivalent circuits and design equations are derived to have perfect matching, regardless of the coupling power. Based on the design equations, a modified
of transmission-line equivalent circuit is newly suggested. It consists of coupled-line sections with two shorts and two open stubs and can be used to reduce a transmission-line section, especially when its electrical length is greater than
. Therefore, the
transmission-line section of a conventional ring hybrid can be reduced to less than
. To verify the modified
of transmission- line equivalent circuit, two kinds of simulations are carried out; one is fixing the electrical length of the coupled-line sections and the other fixing its coupling coefficient. The simulation results show that the bandwidths of resulting small transmission lines are strongly dependent on the coupling power. Using modified and conventional
of transmission-line equivalent circuits, a small ring hybrid is built and named a compact wideband coupled-line ring hybrid, due to the fact that a set of coupled-line sections is included. One of compact ring hybrids is compared with a conventional ring hybrid and the compared results demonstrate that the bandwidth of a proposed compact ring hybrid is much wider, in spite of being more than three times smaller in size. To test the compact ring hybrids, a microstrip compact ring hybrid, whose total transmission-line length is
, is fabricated and measured. The measured power divisions(
) are -2.78 dB, -3.34 dB, -2.8 dB and -3.2 dB, respectively at a design center frequency of 2 GHz, matching and isolation less than -20 dB in more than 20 % fractional bandwidth.
The Design of Balun-BPF with Double Ring-Resonators
Kang, Seong-Jun ; Hwang, Hee-Yong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 878~883
DOI : 10.5515/KJKIEES.2008.19.8.878
In this paper, we propose a double rings structure to improve the balanced-port characteristics of Balun-Bandpass Filter(Balun-BPF). The conventional Balun-BPF has limitations on output symmetry and skirt steepness. We introduce a double rings structure and the suitable coupling point between the two ring resonators to solve these problems. The fabricated double rings Balun-BPF shows excellent characteristics as a Balun-BPF without the conventional limitations.
A New Band-Pass Filter with Symmetrical Attenuation Characteristics
Bae, Ju-Seok ; Lim, Jong-Sik ; Kim, Kwi-Soo ; Ahn, Dal ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 884~890
DOI : 10.5515/KJKIEES.2008.19.8.884
In this paper, Characteristics responded to frequency of a band-pass filter with admittance inverters(J-inverters) is considered. As a result, it is confirmed that attenuation characteristics of upper and lower frequency is asymmetric. And a modified circuit and design formulas are proposed to improve the asymmetric attenuation characteristics. By confirming the simulated and measured results that are got from designed and made a experiment on the band-pass filter with the proposed circuit and formulas for design, we confirm that the asymmetric attenuation characteristics of the band-pass filter are improved without any optimization or iterative design procedures and additional calculation efforts.
A Study on Biomaterial Detection Using Single-Walled Carbon Nanotube Based on Interdigital Capacitors
Lee, Hee-Jo ; Lee, Hyun-Seok ; Yoo, Kyung-Hwa ; Yook, Jong-Gwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 891~898
DOI : 10.5515/KJKIEES.2008.19.8.891
In this paper, we have studied on the possibilities of the biomaterial detection using single-walled carbon nanotube (SWNT) based on interdigital capacitors. For the four different configurations, such as interdigital capacitor, SWNT in the
gap interdigital capacitor, biotinlated SWNT, and biotin and sreptavidin immobilization cases, the resonant frequency has been measured as 10.02 GHz, 11.02 GHz, 10.82 GHz, and 10.22 GHz, respectively. Assuming that the resonant frequency reflects the capacitance changes due to binding of two-different permittivity biomaterials, we have suggested an equivalent circuit model based on measured results, confirming the capacitance changes. For biotinlated SWNT and biotin-streptavidin immobilization cases, the capacitances are
. In this work, we experimentally demonstrated that the specific biomaterial binding causes the capacitance change and therefore this gives rise to resonant frequency. In conclusion, we confirmed the sufficient possibility as CNT biosensor because an analyte biomaterial(streptavidin) binding arouses a considerable resonant frequency change.
A Dual-Sprial Line Loaded Monopole Antenna having a Vertical Groundplane for Quadband Applications
Kim, Byoung-Chul ; Nguyen, Truong Khang ; Choo, Ho-Sung ; Park, Ik-Mo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 899~905
DOI : 10.5515/KJKIEES.2008.19.8.899
In this paper, we propose a dual-spiral line loaded monopole antenna having a vertical ground plane for quadband applications. The antenna occupies a volume of
ground plane. The measured impedance bandwidths of the antenna based on
are approximately of 11.7 % and 24.8 % in the first and second frequency band, respectively. The operating frequency can simultaneously cover Cellular(
), and IMT-2000(
) bands. The maximum gains of the antenna are -0.99 dBi, 4.07 dBi, 2.72 dBi, and 4.33 dBi at the center frequencies of the Cellular, PCS, UMTS, and IMT-2000 bands, respectively. Good radiation patterns are experimentally obtained.
3 Dimensional Mobile Phone Internal Antenna Using the Helix Element
Hong, Min-Gi ; Son, Tae-Ho ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 906~912
DOI : 10.5515/KJKIEES.2008.19.8.906
We designed and implemented a 3-dimensional structure internal antenna which has volume less than 1.5 cc for mobile phone to improve efficiency and gain. Multiple bending for the resonance of small internal antenna derives reduction of gain due to cancellation of antenna current. In this study, the current cancelation was reduced by the minimization of antenna bending. And the helix element was applied for the purpose both compensation of short antenna length and action of radiation element. For the verification of this study, a 1.5 cc volume 3D antenna which was fabricated by the press method applied to the dual band mobile phone. Measurement showed that efficiencies and gains under the slide down and up were 27.73 %, 0.29 dBi for the GSM band and 46.84 %, 2.27 dBi for the USPCS band, and had good performance under the small antenna volume. H-plane radiation pattern showed omnidirectional for the both band.
Ultra-Wideband Tapered Slot Antennas for Millimeter-Wave Systems
Woo, Dong-Sik ; Kim, Young-Gon ; Cho, Young-Ki ; Kim, Kang-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 913~919
DOI : 10.5515/KJKIEES.2008.19.8.913
A new design and its experimental results of a microstrip-fed ultra-wideband tapered slot antenna(TSA) for millimeter-wave systems are presented. By utilizing the ultra-wideband microstrip-to-CPS transition(balun), ultra-wideband characteristics of the inherent TSA are retrieved. Also, the design procedure of the TSA is simplified by performing simple impedance matching between balun and antenna. The proposed TSA is shaped by using the Fermi-Dirac tapering function and corrugated at the outer edge. The implemented antenna demonstrates ultra-wideband performance for frequency ranges from 23 to over 58 GHz with the relatively high and flat antenna gain of 12 to 14 dBi and low sidelobe levels. In addition, a 4-element linear antenna array for phased-array systems and mm-wave sensor applications is also presented.
Small Epsilon Negative ZOR Antenna with Improved Bandwidth
Ko, Seung-Tae ; Park, Byung-Chul ; Park, Jae-Hyun ; Lee, Jeong-Hae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 920~926
DOI : 10.5515/KJKIEES.2008.19.8.920
In this paper, small epsilon negative(ENG) zeroth-order resonance(ZOR) antenna with improved bandwidth is presented. To reduce the size of ENG ZOR antenna without narrowing bandwidth, large shunt inductance is introduced by adding patterns on patch and meandered via. The effective permittivity of meandered via is less dependent of frequency than that of straight via in same size. Thus, ENG ZOR antenna with meandered via has broader bandwidth. As a result, the bandwidth of ENG ZOR antenna with meandered via is 1.38 times as broad as that of spiral ENG ZOR antenna with straight via. On the other hand, the area of ENG ZOR antenna is reduced by 64 % compared with that of conventional mushroom ZOR antenna.
A Hadamard Matrix Feed Network for a Dual-Beam Forming Array Antenna
Kim, Jae-Hee ; Jo, Gyu-Young ; Park, Wee-Sang ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 927~932
DOI : 10.5515/KJKIEES.2008.19.8.927
We propose a novel
Hadamard matrix feed network for a
array antenna to form a dual beam. If each element of the array is excited following the elements in a row of the Hadamard matrix, a two-lobed antenna beam can be obtained. The angle between the two lobes can be controlled. The Hadamard matrix feed network consists of four
hybrids, a crossover and four
phase shifters. The array, including the Hadamard matrix feed network, was fabricated on a microstip structure. The measured beam directions of the two lobes are
depending on the choice of the input port of the feed network.
Composite EBG Power Plane Using Magnetic Materials for SSN Suppression in High-Speed Digital Circuits
Eom, Dong-Sik ; Kim, Dong-Yeop ; Byun, Jin-Do ; Lee, Hai-Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 933~939
DOI : 10.5515/KJKIEES.2008.19.8.933
In this paper, a new composite electromagnetic bandgap(EBG) structure using magnetic materials is proposed for simultaneous switching noise(SSN) suppression in the high-speed digital circuits. The proposed EBG structure has periodic unit cells of square-patches connected by spiral-shaped bridges. The magnetic materials are located on the unit cells of spiral-shaped EBG. The real part of the permeability shifts bandgap to the lower frequency region due to the increased effective inductance. The imaginary part of the permeability has magnetic loss that decreases parasitic LC resonance peaks from between the unit cells. As a result, the proposed structure has the lower cut-off frequency compared with conventional EBG structure and -30 dB SSN suppression bandwidth from 175 MHz to 7.7 GHz. The proposed structure is expected to improve the power integrity and reduce the size of the EBG power plane.
A Design and Fabrication of the Brick Transmit/Receive Module for K Band
Lee, Ki-Won ; Moon, Ju-Young ; Yun, Sang-Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 8, 2008, Pages 940~945
DOI : 10.5515/KJKIEES.2008.19.8.940
In this paper, we have designed the Brick Transmit/Receive Module for K-band which can be applied to active phase array radar system. The proposed structure of T/R Module for K band is brick type for MCM(Multi Chip Module) form and the satisfaction of tile type T/R Module can apply to structure of cavity and main characteristic. The fabricated brick type T/R Module confirmed the main characteristic for electrical goal performance in test and this structure can be applied to active phase array radar.