Loss Reduction Technique in Ferroelectric Tunable Devices by Laser Microetching. Application to a CPW Stub Resonator in $X$ -Band

摘要

Ferroelectric materials are known to be lossy at microwaves. A local microetching technique based on laser ablation is implemented here to reduce the insertion loss of highly tunable devices fabricated on KTaNbO (KTN) ferroelectric thin films. The relevance of this approach is studied in -band by comparing numerically and experimentally the performance of a frequency-tunable coplanar waveguide stub resonator before and after KTN microetching. The experimental data demonstrate a large loss reduction (by a factor 3.3), while keeping a high-frequency tunability (47%) under a moderate biasing static electric field (80 kV/cm). This approach paves the way for the design of ferroelectric reconfigurable devices with attractive performance in -band and even beyond.