Seong-Ook Park

Learn More
A full-wave spectral-domain method with an asymptotic extraction technique is formulated for multilayer microstrip lines. This formulation provides a simple closed-form representation of the asymptotic part of the impedance matrix by using Chebyshev polynomial basis functions with the square-root edge condition and the asymptotic behavior of the Green’s(More)
The effective dielectric constants of a symmetric coupled microstrip line operating in the dominant mode are solved by using a closed-form formula of the asymptotic part of the impedance matrix elements. Using this asymptotic closedform solution, the finite upper limit for numerical integration in the evaluation of the impedance matrix elements is(More)
This article presents an antenna with a magnetodielectric material and its MIMO application for LTE-band. The proposed antenna is a folded monopole type and occupies a compact volume of 7.5 18.5 3.4 mm. For reducing the size, obtaining the broad bandwidth, and enhancing the isolation performance, the magneto-dielectric material is applied as a supporter.(More)
A planar inverted-F antenna type tunable antenna with U-shaped slot is proposed. A varactor diode is integrated between the slot and bias feeding strip line for tuning the operating frequency. This antenna covers from 1.64 GHz to 2.05 GHz refer to the dc bias voltage from 0 V to 20 V The frequency tuning range is about 410 MHz bandwidth which covers several(More)
This article presents measurement methods used to determine the human exposure to electromagnetic fields radiated from operating base stations. In Korea, when evaluating the human exposure to electromagnetic fields from operating base stations, the measurement procedure is different between the following cases: in situ measurement and electromagnetic(More)
This article presents the measurement results of human exposure to CDMA800 and CDMA1800 signals at locations in Korea where the general public has expressed concern. Measurements were performed at 50 locations across the country to compare the electromagnetic field levels with the general public exposure compliance limits. At each site, the distances(More)
Mobile convergence is an emerging trend in the wireless communication industry. Modern multi-standard mobile phones are required to provide a variety of location independent services like voice, data, video, the Internet and multimedia content without compromising on their weight, volume and performance. Therefore, it is important to develop compact(More)
We propose and develop a heterodyne frequency modulated continuous wave (FMCW) radar system. The system operates at 14 GHz with a 500-MHz bandwidth in a 100-μs sweeping period, based on two wideband linear RF voltage-controlled oscillator (VCO) sweeping sources, which are controlled by a direct digital synthesizer (DDS) through a phase-locked scheme,(More)