Chin-Min Hsiung

DESIGN OF A HIGH BAND ISOLATION DIPLEXER FOR GPS AND WLAN SYSTEM USING MODIFIED STEPPED-IMPEDANCE RESONATORS

In this paper, we presented the design of a high performance diplexer for applications of global positioning system (GPS) at 1.575GHz and wireless local area network (WLAN) at 2.4GHz, simultaneously. Two bandpass fllters (BPFs) using the modifled stepped-impedance resonators (SIRs) operated at 1.575GHz and 2.4GHz are the main blocks for the proposed diplexer. By discussing and analyzing the admittance of the even and odd modes, the transmission zero of the modifled SIR can be found, and the

Preparation of a Counter Electrode with P-Type NiO and Its Applications in Dye-Sensitized Solar Cell

This study investigates the applicability of a counter electrode with a P-type semiconductor oxide (such as NiO) on a dye-sensitized solar cell (DSSC). The counter electrode is fabricated by depositing an NiO film on top of a Pt film, which has been deposited on a Fluorine-doped tin oxide (FTO) glass using an ion-sputtering coater (or E-beam evaporator), using a simple spin coating method. This study also examines the effect of the average thickness of TiO2 film deposited on a working electrode upon the power conversion efficiency of a DSSC. This study shows that the power conversion efficiency of a DSSC with a Pt(E)/NiO counter electrode (4.28%) substantially exceeds that of a conventional DSSC with a Pt(E) counter electrode (3.16%) on which a Pt film was deposited using an E-beam evaporator. This result is attributed to the fact that the NiO film coated on the Pt(E) counter electrode improves the electrocatalytic activity of the counter electrode.

A High Performance Bandpass Filter with a Wide and Deep Stopband by Using Square Stepped Impedance Resonators

In this paper, a microstrip bandpass filter with a wide and deep stopband by using the modified stepped-impedance resonator (SIR) was designed and implemented. The modified SIR is formed by properly folding the conventional SIR to be a square open-loop SIR. By analyzing the admittance of the even and odd mode, the transmission zero of the modified SIR can be easily found, thus having a wide and deep stopband simultaneously. Bandpass filter (BPF) can have high performances with a wide and deep stopband as well as good selectivity by using the proposed SIR, compared to the conventional SIR. A filter example centered at f 0 of 1.26 GHz has been implemented to verify the design concept. The results showed that the |S 21| was greater than 65 dB at the spurious response of 2f 0 and a wide stopband with a rejection level over 50 dB is extended from 1.5f 0 to 3.5f 0. Moreover, experimental results have a good agreement with the simulated results.

Design of a New Dual-Band Diplexer for GPS, WLAN and WiMAX Applications

Abstract In this paper, a dual-band diplexer is proposed. Two dualband bandpass filters (DB-BPFs) using coupled stepped-impedance resonators (SIRs) operated at 1.575/2.13 GHz and 3.15/5.2 GHz are main blocks combined with a branch matching circuit for the proposed dual-band diplexer. By analyzing the input impedance Zin of different loading structures, we can precisely predict the stopband positions of the loading structures to avoid the interference between the two sets of different channels. A high isolation of 40 dB between the two sets of channels is obtained. The simulated and measured results have a good agreement with the proposed design concept.