A Two Step Stair Shaped Dielectric Resonator Antenna with AMC for UWB Applications

This paper presents an ultra-wide band (UWB) antenna with two steps stair shaped dielectric resonator (SSDR) antenna. The two steps SSDR is placed precisely on the aperture to achieve an ultra-wide bandwidth of 136.2%. The first step of SSDR
$(\text{DR}_{1}$
and
$\text{DR}_{2})$
is fed directly by the microstrip line through aperture coupling technique whereas the second step
$(\text{DR}_{3})$
is a parasitic DR placed adjacent to DR1. The SSDR is radiating with
$\text{TE}{{}^{\mathrm{y}}}_{1\delta 1}$
-like mode at 5.32 GHz and
$\text{TE}{{}^{\mathrm{x}}}_{\delta 11}$
-like mode at 6.3 GHz. The parasitic DR is improving the impedance matching and increasing the bandwidth by 11.3% due to the dielectric loading effect. Further a dual band artificial magnetic conductor (AMC) is placed below the UWB antenna to improve the antenna radiation characteristics. The improvement in average gain and gain variation is 36.7 % and 13.5% respectively. The antenna radiation efficiency is 81.6% with AMC reflectors.