Characterization and Performance Analysis of BST-Based Ferroelectric Varactors in the Millimeter-Wave Domain
Aurélian Crunteanu, Vincent Muzzupapa, Areski Ghalem, Laure Huitema, Damien Passerieux, Caroline Borderon, Raphaël Renoud, Hartmut Gundel
Abstract
We present the realization and analysis of the microwave performances of interdigited varactors integrating thin ferroelectric layers of barium and strontium titanate (BaxSr1−xTiO3). Devices based on ferroelectric films of different compositions (x = 0.8 and x = 0.5) have been characterized in the millimeter-wave domain, from 200 MHz to 110 GHz. By applying different bias voltages, the tunability of the capacitance can reach up to 40% for the Ba0.8Sr0.2TiO3 composition, under relatively low applied electric fields of about 167 kV/cm. These promising characteristics allow the integration of the varactor devices in tunable antennas for a large frequency domain, from the microwaves to the millimeter waves range.