Ferroelectric Varactor on Diamond for Elevated Power Microwave Applications

摘要

A ferroelectric (FE) varactor with a film structure BaxSr1-xTiO3 (BSTO)/SiC on a diamond substrate, designed for the use under elevated microwave (MW) power, was produced by an ion-plasma deposition technique. Comparative testing of the BSTO varactors produced on Al2O3 and diamond/SiC substrates was performed at the frequency of 3 GHz and different levels of MW power (up to P ~ 10 var). A significant difference in thermal response under MW power of the varactors on Al2O3 and diamond was demonstrated: the overheating of FE film was observed as AT ~ (20-30) K on Al2O3 and ΔT ~ 2 K on diamond at maximum MW power.