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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 14, Issue 12 - Dec 2003
Volume 14, Issue 11 - Nov 2003
Volume 14, Issue 10 - Oct 2003
Volume 14, Issue 9 - Sep 2003
Volume 14, Issue 8 - Aug 2003
Volume 14, Issue 7 - Jul 2003
Volume 14, Issue 6 - Jun 2003
Volume 14, Issue 5 - May 2003
Volume 14, Issue 4 - Apr 2003
Volume 14, Issue 3 - Mar 2003
Volume 14, Issue 2 - Feb 2003
Volume 14, Issue 1 - Jan 2003
Selecting the target year
A Study on a Wideband Helical Antenna for Mobile Handset using Parasitic Element Effect
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 899~903
In this paper, a wide band helical antenna for mobile handset using parasitic element effect has been investigated. To obtain the effect of parasitic element, we utilized the cylindrical conductor which is not feed. As thickness of cylindrical conductor is increasing, second and third resonance frequency become abruptly variable. In case of that 4.5mm diameter parasitic element cylindrical conductor is inserted, normal mode helical antenna obtained bandwidth of around 900 MHz on the limit of R. L., - 5 dB.
A Technique for Reducing the Size of Microwave Amplifiers using Spiral-Shaped Defected Ground Structure
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 904~911
A new method to reduce the size of microwave amplifiers spiral-shaped defected ground structure(Spiral-DGS) is proposed. A microstrip line having Spiral-DGS on the ground plane produces increased slow-wave factor and electrical length for the fixed physical length. In addition, it provides an excellent rejection characteristic for a finite frequency band like band rejection filters. The rejection band is used for rejecting harmonic components of amplifiers. The reduced microstrip line lengths in matching networks by Spiral-DGS are 39 % and 44 % of the original ones in input and output matching networks, respectively. It is shown that the measured S-parameters of the reduced amplifier agree well with those of the original amplifier. The measured second harmonic of the reduced amplifier is much less than that of the original amplifier by at least 10 dB. The same technique is applied to reject the third harmonic using the proper Spiral-DGS for the third harmonic frequency. The measured third harmonic is smaller than that of the original amplifier by 25 dB.
Design and Implementation of Dual Band Monopole Antenna with Slot for Cellular CDMA and IMT-2000 Repeater
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 912~918
In this paper, we designed and implemented the dual band monopole antenna for cellular CDMA(Code Division Multiple Access) and IMT-2000(International Mobile Telecommunication 2000) repeater. The antenna was designed by using 3D simulations program, HFSS(High Frequency Structure Simulator). Electrical characteristics were measured by using HP 8720C network analyzer and measured maximum S
11/ was -10.9 dB for all frequency bands of interests in Cellular CDMA and IMT-2000. Simulation results for antenna gain at 859 MHz and 2027.5 MHz were 2.38 dBi and 4.02 dBi respectively with omni directional radiation pattern. The size of implemented antenna is compact and the antenna can be produced in low cost enough for commercialization.
Planar Balun using Microstrip to CPW Coupled Structure
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 919~923
In this paper, a double-sided planar balun using Microstrip-to-CPW coupled structure is fabricated and measured. The measured amplitude and phase imbalance are, respectively, less than 0.2 dB and 2.1
in a wide frequency range from 2.44 GHz to 4.33 GHz. It is expected that the proposed balun can improved the performance of balanced mixer, amplifier and feeding network of antennas. Also, it can be used in many microwave multilayer structures due to its structural characteristics.
Design of Microstrip Duplexer with Attenuation Poles
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 924~930
In this paper, a novel miniaturized microstrip duplexer with attenuation pole is proposed. A three-pole microstrip CT(Cascade Trisection) two bandpass filters have each asymmetrically prescribed transmission zero are design and fabrication. This CT bandpass filter changes coupling structure, which not only shifts the location of attenuation poles but also improves skirt characteristics. The duplexer results of measurement with the cross coupling CT bandpass filters has been yielded better isolation and sharper skirt behavior than that with a conventional bandpass filter. The results of measurement are almost similar to those of simulation results.
Design of GSM BPF using Dissimilar LTCC Technology
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 931~935
A multilayer two-stage LC bandpass filter using low-temperature cofired-ceramic(LTCC) is proposed in this paper. The proposed bandpass filter is composed of two ceramic substrates with different dielectric constant instead of single ceramic material from top to bottom layer. Inductive elements are designed in a low permitivity ceramic layer to reduce parasitic effects and loss, while capacitive elements are designed in a high permitivity ceramic layer for size reduction. The proposed filter has 950 MHz center &equency, 118 MHz tractional bandwidth, and 3.5 dB insertion loss. And, the total size of this filter is 2.5
. The performance of filter is analyzed by changing coupling capacitance between each resonator.
Design and Fabrication of FSK Transmitter for Miniaturized Wireless Endoscope
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 936~943
The miniaturized wireless endoscope consists of CMOS Image sensor, FPGA, LED, Battery, DC to DC Converter, Antenna and Transmitter. FSK transmitter is designed and fabricated with 10 mm(diameter)
23 mm(thickness) dimension considering the maximum permission exposure(MPE), system size, power consumption, linearity and modulation method. Experimental results is - 3.67 dBm output power level, 20 MHz frequency deviation, and - 99 dBc/Hz(@100 kHz offset) phase noise at 1.2 GHz. From the in-vivo experiment, the designed FSK transmitter has a acceptable capability for wireless endoscope.
The Double Balance Mixer Design with the Characteristics of Low Intermodulation Distortion, and Wide Dynamic Range with Low LO-power using InGaP/GaAs HBT Process
S. H. Lee ; S. S. Choi ; J. Y. Lee ; J. C. Lee ; B. Lee ; J. H. Kim ; N. Y. Kim ; Y. H. Lee ; S. H. Jeon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 944~949
In this paper, the double balance mixer(DBM) for Ku-band LNB using InGaP/GaAs HBT process is suggested for the characteristics of low DC power consumption, low noise figure, low intermodulation distortion and wide dynamic range. The 5 dB conversion gain, 14 dB NF, bandwidth 17.9 GHz and 50.34 dBc IMD are obtained under RF input power of -23 dBm, with bias condition as 3 V and 16 mA. The linearity of InGaP/GaAs HBT, the broad band input matching scheme and the optimization of bias point result in the low IMD, the broad bandwidth and the low power consumption characteristics.
Reduction Characteristics of Electromagnetic Fields in Cavity by Lossy Dielectric Materials
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 950~954
This paper presents the delivered power and reflection coefficient in metallic shielding enclosure excited by the interior source, which are evaluated with the method of moments, and describes a method for reducing the radiation of electromagnetic fields in the cavity by putting lossy dielectric material in one inside wall. In this paper we introduce carbon polystyrene-foam as lossy dielectric material and observe it's effects of reduction when the thickness and permittivity of lossy dielectric material are changed. The results show that the reduction of the electromagnetic radiation can be achieved by controlling the amount of carbon in lossy dielectric material. The theoretical analysis is verified by the measured delivered power.
Complex Permittivity Measurement using a Coaxial Slotted Line of Reference Liquids at Mobile Communication Frequencies
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 955~960
In this paper, complex permittivities of reference liquids were measured by a sample holder of terminated slotted coaxial line with a movable probe at mobile communications frequencies. The validity of the liquid measurement system was checked by experimental tests with the reference liquids proposed in IEEE Std 1528-200X.
Bandwidth Enhancement of a Meander Slot Antenna with Harmonic Suppression
Hwang, Kwang-Sun ; Kim, Hyung-Rak ; Chang, Ki-Hoon ; Ha, Jung-Uk ; Yoon, Young-Joong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 961~966
Bowtie shaped meander slot antenna with harmonic suppression is designed and demonstrated experimentally. A substrate with height of 0.508 mm and relative permittivity of 2.5 is used, and the fundamental resonant frequency is 5.536 GHz. With thin conductor line in the antenna, harmonic suppression characteristic is obtained, and return losses at the 2nd and 3rd harmonic frequencies are -0.56 dB and -1.9 dB, respectively. Also, bowtie shape is applied to the antenna design for bandwidth enhancement, and the resulting bandwidth is 3.7 %, which is about three times wider than the reported meander slot antenna with harmonic suppression
A Design of Predistortion Linearizer using 2nd Low Frequency Intermodulation Signal Injection
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 967~973
This paper presents a new predistortion method which injects the 2nd low-frequency intermodulation signal of RF signals into the input bias line of the amplifier. New 2nd intermodulation signal extraction circuit is also proposed. We have shown that this method can suppress the 3rd IM apparently and sometimes do the 5th IM, through mathematical analysis, then confirmed it with simulation and verified it on the desk test. When the input signal CDMA IS-95 lFA is applied, measured ACPR improvements are 25 dBc, 22.5 dBc, and 6 dBc at 0.885 MHz, l.25 MHz and 2.25 MHz offset respectively. Also, when applying the CDMA IS-95 3FA, the measured ACPR improvement is 20 dBc at 0.885 MHz offset.
Design and Implementation of Down-Converter for WCDMA Digital Optic Repeater
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 974~978
The down-converter of the WCDMA Digital Optic Repeater is developed. Based on the system specifications, the structure of the down-converter is accomplished and its block diagram is drawn. The down-converter is implemented according to these block diagrams. Subsequently a low pass filter, an automatic level controlled attenuator, a frequency synthesizer and other components for the down-converter are designed and implemented, and a main board to integrate these modules is also manufactured. To reduce the noise floor of system and suppress the RF spurious noise, a PCB layout is performed carefully. For each module consisting of the down-converter and the entire system, the performance tests are accomplished to check the performance about the specifications.
Reactive- Loaded Interstitial Antenna
Ahn, Hee-Ran ; Myung, Noh-Hoon ; Kim, Bumman ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 9, 2003, Pages 979~984
A reactive-loaded interstitial antenna(RLIA) is proposed for 2.45 GHz. It basically consists of a coaxial cable and a reactive load(RL). The RL is tipped at the end of the antenna and contributes to almost perfect matching and desirable heating area. For the almost perfect matching, a matching technique based on transmission line theory is suggested and the RLIA immersed in muscle phantom is designed, fabricated, measured and compared. The measured return loss of the RLIA is - 28.377 dB, which may be considered the best among those reported. Due to the excellent matching performance, the RLIA can also be applied for the treatment of deep-seated tumor or cancer with only one RLIA.