Piezoelectric actuated MEMS for use in microwave switching and filtering applications

Abstract

The paper reviews the developments made for designing and fabricating a piezoelectric driven actuator and its integration into coplanar wave guide (CPW) microwave structures. In the first part of this work the electromechanical properties of different lead–zirconate–titanate (PZT) thin films are investigated. A modified precursor route for chemical solution deposition (CSD) is introduced to minimize the thermal budget of the PZT by maintaining its superior piezoelectric properties. The second part deals with the fabrication of a piezoelectric driven actuator for use in RF switching applications. Advantages of bulk and surface micromachined devices are compared and a suitable actuator design is proposed. Based on these results, a piezoelectrically actuated shunt switch for use in CPW devices is developed and optimized, and the concept is confirmed by measurements. Finally, novel reconfigurable CPW band‐pass filters are presented, which demonstrate the usefulness of the developed shunt switches in microwave applications. Microwave switch Distribution of surface current density (background), image of copper contact (top) and micro switch schematic (bottom).

Enhanced electrical conductivity of Au–LaNiO3 nanocomposite thin films by chemical solution deposition

“…In the pseudo-cubic form, LNO has a parameter of 0.384 nm matching well with most perovskite ferroelectric lms that have been extensively studied for applications in microelectronics, micro-electromechanics, nonvolatile ferroelectric randomaccess memory devices, and energy harvesting devices. [3][4][5][6] The LNO thin lms are extensively used as electrodes for ferroelectric and multiferroic lms. However, the resistivity of the LNO thin lms prepared on SiO 2 /Si substrates is in a range of 750-2000 mU cm, which is much higher than that of metal Pt lms.…”

Hybrid organic–inorganic perovskites as microwave radiation switches

“…In highly integrated devices, which have to support multiple communication standards simultaneously, a reconfigurable filter can help reduce the total number of filters which would benefit the miniaturization of devices. Switching with smart materials is considered to be an efficient alternative to classical techniques for microwave switching, such as p-i-n diodes, 25,26 microelectromechanical systems, 27,28 field effect transistors, 29,30 etc. For example, successful switching has been shown by dielectric anisotropy control in liquid crystals.…”

Tunable microwave absorption of switchable complexes operating near room temperature

“…[11][12][13][14] Notably, switchable radar absorbing materials attract considerable attention. 15 Except for more classical approaches, which use electrically recongurable devices such as PIN diodes 16,17 or microelectromechanical systems 18,19 for microwave switching, a new direction that employs phase transition materials to control microwave frequency signal is being developed. 20 For example, the most studied phase transition material, which was used for microwave switching, is vanadium dioxide (VO 2 ).…”