Linearly polarized and circularly polarized phased array antenna for beam-steering at sub-6 GHz

This work demonstrates a dual-band phased array antenna that exhibits circular polarisation from 4 to 4.7 GHz and linear polarisation in the frequency range 2–3 GHz and 4.8–6.3 GHz, making it suitable for 5G communications. Four petal-shaped patches have been used as antenna elements in an antipodal configuration in two columns to form a subarray. The novelty lies in incorporating leaf-shaped components within an antipodal subarray architecture, where mutual coupling, phase distribution, and polarisation orthogonality are simultaneously optimised. The suggested structure can be seen as a distributed current-shaping radiator instead of a separate patch element, which sets it apart from traditional antipodal geometries and confirms that current transitions are smoother. Four subarrays have been used to constitute a phased array antenna to perform beam-steering from −44.5° to 44.5°. Beam-steering is performed by providing phase shifts to the corresponding elements in the subarray, with peak gain varying from 16 to 19 dBi.