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Modified Slot-Loaded Multi-Band Microstrip Patch Antenna
Jong-Gwan Yook,Han-Kyu Park,Man-Shik Cho,Il-Kwon Kim,Han-Back Cho 한국전자파학회JEES 2003 Journal of Electromagnetic Engineering and Science Vol.3 No.1
In this paper, a triple-band planar antenna is proposed for the application to miniaturized automobile safety devices operating at X band(10.5 GHz), K band(24.15 GHz), and Ka band(34.3 GHz). The frequency ratio between the resonant frequencies of this antenna can be adjusted from 1.99 to 2.23 for both X band and K band by varying its slit length. Parasitic elements are added on the modified slot loaded antenna to obtain the third resonance. From numerical as well as experimental results, it has been confirmed that this type of antenna is appropriate for planar multi-band antenna systems.
Analysis of EMI Problems in Plit Power Distribution Network
Jong-Gwan Yook,Han-Kyu Park,Hwang-Yoon Shim,Ji-Seong Kim 한국전자파학회JEES 2002 Journal of Electromagnetic Engineering and Science Vol.2 No.2
Signal integrity problems and their possible solutions are addressed in this paper for split power plane of high-speed digital systems. Stitching and decoupling capacitors are proved to be very effective for reducing signal noise, ground bounce as well as electromagnetic radiation from the split power plane. Simulations based on 3D-Finite Difference Time Domain(FDTD) method are utilized for the analysis of practical high frequency multi-layered PC main board.
Air-Gap Type TFBAR Ladder Filters for Wireless Applications
Myeong-Gweon Goo,Jong-Gwan Yook,Han-Kyu Park,Kun-Wook Kim 한국전자파학회JEES 2002 Journal of Electromagnetic Engineering and Science Vol.2 No.1
TFBAR filters for wireless applications are simulated and fabricated. A CAD model is used to analyze the air-gap type single resonator and MBVD model, is used for filter design. Aluminum nitride is used as the piezoelectric material with platinum electrodes. To verify the CAD model, simulated and measured results are compared for various top electrode thicknesses, and the agreement is within 0.5% for the parallel resonance frequency. Various types of the ladder type band pass filters are predicted and their responses are compared with measured frequency data.
Dual-Polarized Annular Ring Patch Antenna for 2.4 ㎓ Doppler Radar
Seong-Ho Kim,Jong-Gwan Yook,Sung-Ho Cho,Byung-Jun Jang 한국전자파학회JEES 2010 Journal of Electromagnetic Engineering and Science Vol.10 No.3
A 2.4 ㎓ dual-polarized antenna for a Doppler radar is studied. The proposed dual-polarized antenna using a stacked annular ring patch with two co-centric gap-coupled feed lines and a 90° hybrid exhibits fairly good performance of 22 dB isolation at a center frequency of 2.4 ㎓. Using a 90° hybrid, a right-handed circular polarization for the transmitter and a left-handed circular polarization for the receiver are implemented. The gain of the designed antenna is about 0 dBi over operating frequencies. The antenna size including a ground plane is only 40×40 ㎟.
Low-Loss Broadband Planar Balun with CPW-to-Slotline Transition for UHF Applications
Young-Pyo Hong,Jong-Gwan Yook 한국전자파학회JEES 2009 Journal of Electromagnetic Engineering and Science Vol.9 No.3
This paper presents a low-loss broadband balun that uses a coplanar waveguide-to-slotline field transformation. It operates over a very wide frequency range and is of compact size since it does not depend on a resonant structure. To analyse imbalance, the coplanar wavelength(CPW) input ground is connected to the CPW output ground through various capacitors to introduce common-mode impedances. As the common-mode impedance increased the imbalance became significantly higher at the higher-frequency band compared with the lower-frequency band. The bias-circuit approach is used to improve the operation bandwidth of the lower-frequency band. The measured results show a passband of 200 ㎒ to 2 ㎓, an insertion loss of less than 0.75 ㏈, and a size of 20×14 ㎜. The amplitude imbalance is approximately 0.3 ㏈ and the phase imbalance is less than 6° over the entire operational range.
A parallel-plate-mode suppressed meander slot antenna with plated-through-holes
Jung-Min Kim,Jong-Gwan Yook IEEE 2005 IEEE antennas and wireless propagation letters Vol.4 No.-
<P>A meander slot antenna with plated-through-holes to suppress the parallel-plate-mode is proposed. This antenna is fed by a stripline and the via-fences are located around the meandered slot line in order to prevent the leakage of the electromagnetic fields into the substrate. By using the meandered slot and the plated-through-holes around the slot, 56% size reduction is achieved compared to a conventional patch antenna, and an unidirectional radiation pattern having 4.66 dBi peak gain is achieved.</P>
5 GHz Bow-tie-shaped Meander Slot Antenna
Jae-Yeong Park,Jong-Gwan Yook,Han-Kyu Park,Sang-Hyuk Wi,Jung-Min Kim,Tae-Hoon Yoo 한국전자파학회JEES 2002 Journal of Electromagnetic Engineering and Science Vol.2 No.1
In this paper, we propose a bow-tie-shaped meander slot antenna fed by a microstrip line to achieve compact size as well as wideband characteristic. While conventional bow-tie slot antennas exhibit wide band characteristic, they have relatively large. On the other hand, the meander slot antennas are very small, but they reveal quite narrow bandwidth (typically less than 1%). To realize miniaturized antennas having large bandwidth, combination of the bow-tie slot and the meander slot geometries is proposed in the paper. Theoretical results show that the proposed antenna with uniform slot width is 65.5% smaller than that of the conventional bow-tie antenna in size, while the bandwidth is 3 times larger than that of the meander slot antenna. Moreover, the non-uniform slot width antenna shows 60% smaller in size and about 3.5 times wider in bandwidth than the previous antennas. Measured antenna performance reveals excellent agreement with the predicted values.