TPoD stands for Thin-Film Piezoelectric-on-Diamond. This project focuses on design and fabrication of high frequency filters with low insertion loss and large bandwidth. The filters are fabricated on a stack of aluminum nitride (AlN) on ultrananocrystalline diamond. Why Ultrananocrystalline?! Because in order to get a high quality piezoelctric film with high piezoelectric coefficient, the grains of the film should be aligned in certain directions. This would require a very smooth surface.

In the monolithic filters of this work two different lateral-extensional modes of a single resonant structure are coupled together to make a second order filter.5th order filter

3D structure of a 5th order TPoD filter

frequency response of tpod filter

Frequency response of a TPoD monolithic filter at

900MHz, showing a very low insertion loss