Electric Field Tunable Multi-Ferroic Filters for C-band RF Applications

Tunable bandpass filters are more and more widely used in modern RF communication systems with the ever increasing availability of bandwidth. The demand has been growing for tunable bandpass filters with improved performance on insertion loss, tunable range, bandwidth, linearity, size, weight, and power efficiency. Semiconductor varactors are typically used for achieving tunability in RF circuits, but they are limited by their large loss and linearity above UHF. Tunable bandpass filters based on magnetic field tunable yttrium iron garnet (YIG) and on tunable RF MEMS devices are also good candidates, but they are limited by their relatively slow tuning speed. Electric field tunable multiferroic devices provide a unique alternative technology for electric field tunable filters, which are achieved through a strain mediated magnetoelectric coupling in magnetic/ferroelectric multiferroic heterostructures, leading to fast tuning, compact, lightweight and power efficient tunable filters that can be integrated in a hybrid manner with other circuits. In this project, we propose to demonstrate new improved tunable bandpass filters that meet the specifications of this SBIR Topic, based on our recent demonstrations of electric field tunable multiferroic heterostructures and electric tunable bandpass filters. The tunable bandpass filters will be demonstrated on the basis of a ferrite/PZN-PT (lead zinc niobate-lead titanate) heterostructure. These electric field tunable multiferroic bandpass filters will work in C-Band (5-7 GHz) with the following characteristics: a tuning range>33% (5-7 GHz), fractional 3-dB bandwidth<10%, low insertion loss<3 dB, IIP3>40 dBm, P1dB:>20 dBm, and fast tuning speed<10 s. At the same time, a clear feasible plan and successful path to the Phase II targets will be laid out. These compact electric field tunable multiferroic bandpass filters with combined large tunability, low insertion loss, high linearity and large power handling capability will provide great opportunities for future radars, electronic warfare and communication systems.