Kwangwoon University

About: Kwangwoon University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Resonator. The organization has 4020 authors who have published 8217 publications receiving 104365 citations.

Dual-band design of single-stub impedance matching networks with application to dual-band stubbed T-junctions

Abstract: A new design method of single-stub impedance matching networks is presented for the dual-band application. The dual-band operating conditions are analyzed in detail and the design equations are derived in concise form for different locations and termination types of the stub line. The proposed impedance matching scheme is successfully applied to the design of a stubbed dual-band T-junction power divider. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1359–1362, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25201

A Compact Bandpass Wilkinson Power Divider With Ultra-Wide Band Harmonic Suppression

Abstract: A Wilkinson power divider (WPD) with bandpass property and an ultra-wide band harmonic suppression is proposed in this letter. The frequency-selecting coupling structure is embedded to the conventional quarter-wavelength transmission line, which can realize an ultra-wide harmonic suppression with three transmission zeros. Short-ended meander line stubs are shunted at the both output ports for dc block and provide an extra transmission zero for the passband. The proposed WPD operates with a −20 dB bandwidth from 1.74 to 3.71 GHz with an ultra-wide stopband to suppress the dc, $3f_{0}$ , $5f_{0}$ , and $7f_{0}$ harmonic components. The proposed WPD has a compact size of 14.65 mm $\times19.64$ mm ( $0.19\lambda _{g} \times 0.25\lambda _{g})$ .

Multifunctional and high-performance GeSe/PdSe2 heterostructure device with a fast photoresponse

Abstract: Two-dimensional (2D) material based heterostructures have gained tremendous attention because of their capability and multi-functionality in electronic devices. In this work, high gate-modulated rectification in a van der Waals (vdW) heterostructure composed of p-type germanium selenide (p-GeSe) and n-type palladium diselenide (n-PdSe2) with pure ohmic contacts is introduced and examined. A large rectification ratio is extracted, up to 5.5 × 105, arising from the clean interface of p-GeSe and n-PdSe2 and low Schottky barriers. Further, the photovoltaic characteristics are measured under incident light with a wavelength λ = 532 nm and different power intensities (20–100 nW). The obtained results showed a high photoresponsivity of 1 × 103 A W−1 with an EQE of 47%. Fast rise (2 μs) and decay times (4.5 μs) are estimated. Furthermore, the heterostructure of p-GeSe/n-PdSe2 showed extraordinary performance in CMOS binary inverter and rectifier behavior. Such devices based on the TMD heterostructure may improve energy harvesting along with multifunctional logic switches.