Design and Development of Miniaturised Orbital Angular Momentum Antenna Using Uniform Circular Array for Higher Order Mode Generation

In order to produce higher order modes in orbital angular momentum (OAM), with fewer antenna elements, this article suggests a designing of the modified Uniform Circular Array (UCA) antenna. Antenna element number <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{N} \geq 2\left \Vert l_{\text {max }}\right \Vert$</tex> limit maximum number of OAM modes (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$l_{\max }$</tex>) might be produced utilizing traditional N-element UCA. The proposed design at frequency 2.52 GHz uses four/two ports to produce modes having higher order OAM by a square patch element connecting two square patch antenna components of a traditional four element UCA. Compared to the traditional 8-element UCA, the modified UCA is smaller and requires simpler power division phase networks to produce comparable <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$l_{\text {max. }}$</tex> An attempt is also made to reduce the number of feed ports to two in the same circuit to generate OAM mode <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$+1 \&amp;$</tex> +2.