A DESIGN METHOD FOR MICROMECHANICAL FILTERS WITH QUARTER WAVELENGTH ELEMENTS

Length expander type and thickness expander type micro-mechanical filters are proposed in this paper as attractive elements for an on-chip structure forming. The design principles have been theoretically studied by using a distributed constant circuit design theory. As the result, it is clarified that the method of inserting additional step elements in the middle of the filter is valid for solving the actualization problem of a large impedance step and a filter with the fractional bandwidth of less than 3% is realizable in a VHF and UHF band.