Characterization of a Structure Consisting of Magnetostatic Responsive Microscopic Particles and Its Applications In Antennas

Abstract

Wireless communication systems often require that a single antenna work at different frequencies. Thus the recon gurable antennas are useful in frequency agile environments to receive a signal over multiple bands. Research on antenna recon gurability using mechanical systems and radio frequency (RF) switches have been implemented in the past years. One problem for these voltage- controlled switches is that they require direct current (DC) bias control lines for operation. The incorporation of DC biasing circuitry also limits designers to explore the recon gurable capacity of many antennas. The DC bias control lines can possibly degrade the antenna performance. Moreover, because of the additional control signals, many existing multiband systems cannot use recon gurable antennas. In this research, magnetostatic responsive particles are used in micro-sized cavities to manufacture novel magnetic switches that are activated in a magnetic eld. Furthermore, the characterization, modeling in simulation software, and lumped element model extraction of these micro electromechanical systems (MEMS) based on magnetic switches is presented. A re ned method of quantifying the micro sized magnetic particles in a cavity and the response of the proposed micro level magnetic switches in the RF eld is also explained in detail. Then, a microstrip patch antenna loaded with Electromagnetic Band Gaps (EBGs) that cannot be recon gured using existing RF switching devices was recon gured using the proposed magnetic switches and is presented in this research for the rst time. A comparison between PIN diodes and the proposed magnetic switches on a microstrip patch is also included in this research to show the efficiency of the proposed structure. Overall, the proposed magnetic switches showed good results when used in antenna systems to achieve recon gurability and do not effect the radiation characteristics of the recon gured antenna.