Design of Rectangular Patch Two-Element Array with and without Delay Line for Beam Steering

This paper presents the design of two, two-element microstrip antennas array with and without delay lines for beam steering applications. These two antennas have been designed and fabricated on substrate epsiv
_r
=4.4 and epsiv
_r
=2.1 with thickness 1.6 mm and 1.574 mm respectively with center frequency of 2.4 GHz. It has been observed that, the antenna without delay line provides the bandwidth 1.891% on epsiv
_r
= 2.1 and 2.772% on epsiv
_r
= 4.4 substrate. The antennas have also been fabricated and tested. It has been observed that with delay line, the antenna resonant frequency has been shifted to the lower side on both the substrates, with bandwidth 1.877% for Teflon and 2.351% for Glass Epoxy. This shows the bandwidth shrinkage of 0.014% and 0.421% with delay line for Teflon & Glass Epoxy respectively. Also, it shows that the input impedance changes as the beam steers, by using the delay line.