Optimum design of planar quasi-Yagi antenna for wearable Internet of Things (IoT) applications

This paper presents the design of a novel dual-band quasi-Yagi antenna for on-body communications. The proposed antenna is designed on 0.05 mm thin microwave laminate and is designed to cover the 2.45 and 3.5 GHz spectrum to meet the needs of on-body Internet of Things networks. Microstrip to slot-line transition is used for the excitation of the feeder element. The conventional feeder of the quai-Yagi is replaced with F-shaped radiators to obtain a dual-band response. In addition, a pair of directors are used to enhance the antenna gain. The proposed quasi-Yagi antenna is optimized using the spider monkey algorithm. The chosen algorithm is used to synthesize the dimensions of the dual-band radiator and is preferred to obtain quick convergence, unlike the traditional optimization algorithms. The optimized planar quasi antenna offers 5% bandwidth in both operating bands with a measured gain of 5.7 and 5.8 dBi, respectively. The optimization time is also considerably reduced in comparison with traditional optimization algorithms. The simulated and optimized antenna is fabricated and tested.