Advances in wireless technology have sparked interest in multiband reconfigurable antenna, an emerging technique that can shape the future of wireless technology. For various IoTs applications, it is desirable to have an efficient reconfigurable antenna in limited space. Configurability can be achieved by changing the physical parameters through electronic switches, optical switches, or metamaterials. This review paper comprehensively surveys recent cognitive radio antenna (CRA) advancements. The CRA is opportunistic spectrum accessibility (OSA) for "underutilized spectrum" feasible for utilizing resources and boosting licensed spectral occupancy. It significantly integrates two crucial concepts of spectrum sensing and communication. A thorough analysis of several interweave cognitive radio (CR) antennae is done. An explanation of filtering for hybrid CR approaches is also included, which offers a glimpse into the future. The ultra-wideband (UWB) / narrow band (NB) antenna's sensing and communication capabilities have been elaborated, which is best suited for CR.