Frequency Reconfigurable Antennas

This chapter focuses on frequency reconfigurable antennas (FRAs). It discusses various FRAs which are categorized based on how reconfiguration is achieved, and describes the mechanism of frequency reconfigurability. The operating frequency of reconfigurable antennas can be changed to handle several wireless services over a wide frequency spectrum. FRAs can be classified based on how they are made reconfigurable. Electrical, optical, and micro-electro-mechanical-system switches are used to obtain frequency reconfigurability. Frequency reconfigurability has been demonstrated by introducing change in the material used in the antenna fabrication. The chapter also discusses other methods of frequency reconfigurability such as by mechanical changes or material changes. It presents the use of FRAs in emerging applications, such as cubesats and software-defined radios. Frequency reconfigurable, along with polarization and pattern reconfigurable, antennas are the core of any communication system which undergoes changes. The technology will continue to evolve to newer methodologies to meet the demand of emerging technologies.