Phononic Crystals: A New Device Paradigm for Integrated SAW Filters for Wireless Systems
The target of this research is to develop compact SAW filters using phononic crystals (PCs) for the state-of-the-art wireless systems in the GHz frequency regime. The PC structures developed in this research will be fabricated on semiconducting substrates to facilitate dense integration. To achieve this goal, we propose a combined theoretical and experimental effort in PCs including the following high-level research tasks: 1) The development of fast and efficient three-dimensional analysis tools to carefully investigate the fundamental properties of PC structures, 2) The development of a systematic method for dispersion engineering in PC waveguides and cavities and combining these devices to design and optimize SAW filters, 3) The development of an optimum procedure for fabricating PC structures for operation in GHz frequency range, 4) The development of accurate characterization tools for experimental measurement of PC SAW filters. Within the three year period of this research, we will optimize, fabricate, and demonstrate the fundamental building blocks for such filters, i.e., demonstrate PCs with phononic bandgap, optimal PC waveguides, and optimal PC cavities. We will also investigate the optimization of coupling between PC waveguides and cavities to form simple SAW filters.
Broader Impact: PC structures as defined in this proposal have the prospect of creating a revolution in on-chip filtering for wireless systems. In addition to traditional filtering, the technology could pave the way towards new types of filters such as a single-chip channelizer whereby different frequency bands are routed to different output filters within a very small device footprint. Once the fundamentals are understood, we have the prospect of creating adaptive filters for software-defined radio.
Two graduate and several undergraduate students as well as an outstanding high school students will be trained. Providing K-12 and minority students and high school teachers with the opportunity of learning some basics of wireless SAW devices as well as improvement of an existing graduate level course on "Acoustic Devices and Materials" involving teachers are other aspects of this proposal.
