Development of Dual-Band Couplers and Filters with Microwave C-Sections

This two-year project demonstrates new dual-band designs of microwave passive devices including hybrid couplers and bandpass filters with circuit miniaturization. In the first year (2009/08-2010/07), a newly hybrid transmission line section, composing of two microstrip sections and a microwave C-section in between, is proposed to realize a phase change of 90o at the first frequency, and 270o at the second passband. The circuit synthesis is based on the equivalence established by the transmission line theory, and transcendental equations are derived to determine its structure parameters. Hybrid couplers are designed to have a dual-band characteristic and a miniaturized area. Several IEEE journal publications and conference papers can be expected with this study. In the second year (2010/08-2011/07), based on the above microwave C-section, a novel resonator is proposed to contrive dual-band bandpass filters in a stacked configuration. Emphasis is placed on realization of high-order circuits having prescribed passbands at two designated frequencies. Bandwidth design graphs derived from the coupling characteristics of adjacent resonators for the dual-passband purpose are presented. Several circuits will be realized and several publications on the IEEE journals and conferences can be expected with this study.

Project ID:PB9902-1375
External Project ID:NSC98-2221-E182-067-MY2