Ferroelectric film mm-wave tripler for elevated power applications

The possibility of radical increasing the output mm-wave power of the tripler (20 GHz/60 GHz) due to use of planar ferroelectric varactor is considered. A theoretical analysis of a planar ferroelectric varactor potentiality for frequency triplers is presented. The analytic expression for the tripler conversion efficiency is derived and proved by computer simulation of the output tripler parameters using experimental data on Ba_0.3Sr_0.7TiO₃ film nonlinearity. Thermal conditions and nonlinear behavior of the FE varactor being under the exposure to high input microwave power is analyzed. It is demonstrated that the output power of ~ 26dBm (corresponding to maximal conversion efficiency of 17%) can be obtained for 20 GHz/60 GHz tripler based on the planar ferroelectric varactor (Ba_xSr_1-xTiO₃ film on the diamond substrate).