1. Tunable Passive Devices Keith Tang Supervisor: Sorin Voinigescu

2. Motivation Recent development on ferroelectric thin films demonstrates high tunability with low loss at RF and microwave frequency  Barium Strontium Titanate (Ba x Sr 1-x TiO 3 ) thin film with over 13:1 tuning range has been achieved Integration of tunable devices with BST thin film on silicon substrate will be investigated

3. BST Tunability Tuning range affected by:  Thin film thickness  Composition  Annealing temperature  Strain  Growth conditions Typical DC characteristic of BST thin film

4. BST Sample Characterization Coplanar waveguide model with BST/SiO 2 /Si substrate is constructed Characterization by metal plate capacitor is not allowed due to high annealing temperature (>600°C) of the BST thin film

5. Simulation Result CPW matched from 57GHz to 69GHz as dielectric constant of BST layer increases from 50 to 150