Recently there has been interest in the study of microstrip patch antennas
because of their compactness, lightweight, easy fabrication, low production cost, etc.
(Balanis, 1997). But one of the main limitations is their narrow bandwidth (Bhal
and Bhartia, 1981), and hence restricts their many useful applications in
microwave communication system. Several approaches have been reported in literature
to overcome this limitation such as incorporating slots (Steven et al., 2003), use of stacked patches (Zehforoosh et al., 2006), use of parasitic branches (Wang et al., 2008), use of impedance matching networks, etc. (Puaes and Van Decapelle, 2006).
Further, the dual band antennas are more attractive in microwave
communication system because a single antenna can be used for both transmitting and
receiving applications, particularly in Synthetic Aperture Radar (SAR) (Wei et al., 2004). Various techniques are available in literature to achieve dual band operation (Jui, 1999;
Shun-Yun and Kin-Lu, 2001; and Amelia et
al., 2005), but this study uses a simple concept to get dual band operation by increasing the thickness of
conventional square microstrip patch. Further, the upper resonating band of this antenna
is enhanced to a greater extent by loading slot on the conducting patch.
This enhancement does not affect much the magnitude of the lower operating band
and nature of radiation characteristics. This kind of study on square
microstrip antenna is rarely found in literature. |
