Defected Ground Structure (DGS)-Based Koch Fractal Antenna for S and C-Band Applications

This paper presents a Koch fractal monopole antenna, which resonates at
$2\text{GHz}$
and
$3.44\text{GHz}$
with
${S_{11}}$
values of
$ - 20.42\text{dB}$
and
$ - 40.83\text{dB}$
respectively. The radiator is miniaturized by using the fractal technique, and wideband is achieved with the help of the Defected ground structure technique. To achieve impedance matching, a microstrip feedline is considered. FR4 substrate having a permittivity of 4.4 is considered for the design. Overall, the dimensions of the proposed design are restricted to
$58{\mathrm{\;mm\;}} \times {{\;}}38{{\;mm\;}} \times {{\;}}1.6{{\;mm}}$
. This radiator covers the frequency range from
$1.76\text{GHz}$
to
$4.29\text{GHz}$
with an impedance bandwidth of
$83.58{{\% }}$
. This monopole exhibits a VSWR of 1.02. In the operational frequency range, the proposed structure maintains a positive gain with a peak gain of 4.06 at 4.19 GHz. Hence, the proposed antenna can be a suitable candidate for
$\mathrm{S}$
and
$\mathrm{C}$
band applications.