A Highly Tunable Barium Strontium Titanate Thin Film MIM Varactor With Floating Metal

A ferroelectric metal insulator metal (MIM) varactor structure incorporating a floating metal and coplanar waveguide (CPW) has been introduced here. The work of the proposed varactor is based on the field-dependent material properties of (Ba, Sr) TiO
₃
(BST) thin film. A capacitance tunability of 44% has been achieved for the bias voltage of 0–10 V over a frequency range of 1–3 GHz. The proposed varactor structure yields a compact area, high capacitance density, and reduced mask process (two masks).