Polar Ceramics in RF-MEMS and Microwave Reconfigurable Electronics: A Brief Review on Recent Issues

Abstract

Properties and fabrication status of microdevices for microwaves based on polar ceramics are reviewed. We discuss bulk acoustic wave devices with AlN films, rf-MEMS capacitive switches with high permittivity materials, and tunable ferroelectrics. The relevant properties of ferroelectrics for microwave applications are summarized with emphasis on composites and thin films.

Fabrication of Perovskite‐Based High‐Value Integrated Capacitors by Chemical Solution Deposition

“…W ith the continuing trend of electronic device miniaturization, the need for low‐cost, high‐performance, and reliable passive components (capacitors, resistors, inductors) is a prominent issue. Because these passive components can occupy as much as 60% of the total area on many electronic devices, integration of passives onto the same platform or substrate as the chip package is a current focus 1 . Integration of passives aids size reduction efforts, and can also reduce cost and improve device performance by eliminating parasitic capacitance and inductance that results from connections between the chip package and external passive components 1,2 …”

“…Because these passive components can occupy as much as 60% of the total area on many electronic devices, integration of passives onto the same platform or substrate as the chip package is a current focus. 1 Integration of passives aids size reduction efforts, and can also reduce cost and improve device performance by eliminating parasitic capacitance and inductance that results from connections between the chip package and external passive components. 1,2 Applications for next-generation integrated capacitors include integrated circuit switching decoupling, frequency tuning, dc power storage, and pulse discharge.…”

“…1 Integration of passives aids size reduction efforts, and can also reduce cost and improve device performance by eliminating parasitic capacitance and inductance that results from connections between the chip package and external passive components. 1,2 Applications for next-generation integrated capacitors include integrated circuit switching decoupling, frequency tuning, dc power storage, and pulse discharge. [3][4][5] A common goal for each of these applications is higher capacitance density than is currently available in integrated capacitors.…”

Fabrication of (Ba,Sr)TiO3 high-value integrated capacitors by chemical solution deposition

“…[1] - [3] Integration of these passives aids in size reduction efforts and can also reduce cost and improve device performance.…”

New Tunable Microwave Ba0.6Sr0.4TiO3/MgO Phase Shifters Using Interdigital Capacitors and Slit-Inductors

“…As growing of systems, the tuned circuits such as tunable matching network, tunable filters, and phase shifters have also attracted much attention. 1,2) In particular, Ba 1Àx Sr x TiO 3 (BST) films have been widely studied as one of potential alternatives for tunable elements in microwave band due to its high nonlinear dependence of the dielectric constant on the electric field. 3,4) There have been some earlier promising results in coplanar waveguide (CPW) phase shifters with the use of BST films using interdigital capacitor (IDC) configurations on single crystal substrate such as MgO which can provide low insertion loss, good lattice match, and good mechanical support.…”