Smart materials in wireless communication technology

Abstract

The wireless systems operating in the microwave region is required to be lightweight, compact and of low cost, which could be addressed by miniaturization and integration. Recently strong interest has focused on the development of frequency and phase agile microwave electronic devices such as tunable filters, voltage controlled oscillators, varactors, delay lines, and phase shifters. Ferroelectrics and certain type of dielectric thin films have been studied for these smart electronic devices because they can respond to an external stimulus and hence they can incorporate the control capabilities in devices. Electric field is the external control parameter for these materials and hence they are considered as the smart materials in wireless communication regime. The critical material parameters for these thin films are the tunability of the dielectric constant and the dielectric loss. This chapter describes the current understanding of the fundamental mechanisms of these properties and the research efforts on the development of tunable microwave devices. © 2012 by Nova Science Publishers, Inc. All rights reserved.