End-fire Yagi Antenna with DGS for WBAN Applications

A planar yagi-uda antenna backed by defected ground structure (DGS) and operating at wireless body area network (WBAN) is reported in this work. The strips in the design apart from the primary feed acts as director and partial ground plane at the back behaves as a reflector. The overall arrangement is suitable to exhibit end-fire radiation pattern with gain in the main lobe and efficiency of 6.8 dB and 90% respectively in air. The net dimension of the antenna is 50mm x 50mm x 1.594mm. Furthermore, the performance of the proposed antenna in terms of return loss, radiation pattern and gain is analyzed in close proximity to human body using the five layer model. The effectiveness of the proposed design is demonstrated through close agreement between the measured and simulated return losses of DGS backed antenna in air.