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.