Broadband Antenna With a Small Bezel Area for Terminal Applications

This paper proposes a broadband antenna with a small bezel area, which can be integrated into the rear cover area of a mobile terminal. To enable broadband performance while maintaining close proximity to the ground plane, the proposed antenna is designed as a leaky wave antenna (LWA), it consists of a set of composites right/left-handed (CRLH) structures. A deformation method of interdigital capacitor based on the traditional CRLH unit cell is proposed in this paper, which can effectively reduce the undesired coupling between the antenna structure and the ground plane, increase the energy leakage rate of the LWA, and then improve overlap of LWA topology. The fast wave region of the proposed unit cell obtained by simulation ranges from 3.14 to 6.09 GHz, covers the entire C-band (N77/N78/N79) in the FR-1 range of 5G applications and WiFi 5. The measured realized gain of an LWA consisting of 16-unit cells is 4.25 dBi at 4 GHz with a radiation efficiency of 61%. The results show that the proposed design method can reduce the bezel area by half, which makes it possible for CRLH-TL LWA integration to be applied to mobile terminals.