'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
Cataloged from PDF version of article.Dual-frequency operation of antennas has become a
necessity for many applications in recent wireless communication
systems, such as GPS, GSM services operating at two different frequency
bands, and services of PCS and IMT-2000 applications. Although
there are various techniques to achieve dual-band operation
from various types of microstrip antennas, there is no efficient
design tool that has been incorporated with a suitable optimization
algorithm. In this paper, the cavity-model based simulation
tool along with the genetic optimization algorithm is presented for
the design of dual-band microstrip antennas, using multiple slots
in the patch or multiple shorting strips between the patch and the
ground plane. Since this approach is based on the cavity model,
the multiport approach is efficiently employed to analyze the effects
of the slots and shorting strips on the input impedance. Then,
the optimization of the positions of slots and shorting strips is performed
via a genetic optimization algorithm, to achieve an acceptable
antenna operation over the desired frequency bands. The antennas
designed by this efficient design procedure were realized experimentally,
and the results are compared. In addition, these results
are also compared to the results obtained by the commercial
electromagnetic simulation tool, the FEM-based software HFSS by
ANSOFT