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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design and Fabrication of Microwave Microstrip Planar Wideband and Multiband Bandpass Filters on Al2O3 Substrates

Kung, Cheng-Yuan 10 August 2011 (has links)
As the microwave wireless communication systems growing rapidly, microstrip planar ceramic filters attract many attentions because of the advantages of small size, low cost, easy fabrication, higher performance and easy integration. In this thesis, several kinds of bandpass filters are designed for different operating purposes. First, two kinds of dual-mode bandpass filters are designed for 2.4 GHz wideband with the T-shaped I/O arranging in a straight way for easy integration. Second, the hook-coupling and insert-coupling structures are adopted for series connecting of the stepped-impedance resonator structures, and 2.4/5.2 GHz dual-band filtering properties could be achieved. Third, two open-loop rectangular ring resonators and U-shaped I/O are designed for 2.4/5.2 GHz dual-band bandpass filters with deep transmission zeros. The quarter wavelength stubs and groove structures are used for enhancing deep transmission zeros between two passband and ripples of the second passband, respectively. Fourth, the parallel positioned resonators with phase difference method are used to design the dual-band (1.23/2.4 GHz) and quad-band (1.23/2.4/3.5/5.2 GHz) bandpass filter with asymmetrical bandwidths and transmission zeros. In the thesis, high quality Al2O3 ceramic substrates are used to fabricate different kinds of bandpass filters for pattern minimization and low losses. The electromagnetic simulators, HFSS and IE3D, were used to adjust and optimize the associated parameters. The printing method was used to fabricate the proposed bandpass filters, which did not need using the FeCl3 to etch the Cu plate from the surface of Duroid or the FR4 substrates. The proposed filters are measured by Agilent-N5230A with the SMA connectors welding. Finally, the simulated and measured results of proposed bandpass filters are in good agreement.

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