VHF-UHF passive filter synthesis based on acoustic resonator structures.

摘要

This thesis presents a novel design method for approximating standard bandpass filter transfer functions using surface acoustic wave (SAW) technology. This method is based on standard circuit simulation and optimization tools to generate physical specifications for the fabrication of a SAW impedance element filter (IEF) network. The IEF topology is verified in the design of a narrowband bandpass filter composed of commercial quartz SAW resonators. The utility of the design method is further demonstrated for a wider bandwidth filter based on custom resonators fabricated on a lithium niobate substrate. An optimum fit was obtained between the standard filter target response and the corresponding SAW IEF response. Comparisons made between the two networks show that by exploiting the high Q characteristics of SAW devices in an IEF configuration, smaller footprints and tighter filter tolerances are obtained.