Microstrip patch based switched beam antenna at 2.45 GHz for wireless sensor network applications

The design and development of a switched beam antenna at 2.45 GHz industrial, scientific and medical band for wireless sensor network applications is presented in this paper. The antenna is capable of switching the beam pattern in directions such as in the boresight direction 0°, ±63° and as a bidirectional endfire radiator (±85°). The directive gain of the antenna is 3.9, 5.8 and 5.8 dBi in respect to those angles. The shift in the resonance frequency is found to be negligible irrespective of the direction of the switched beam. The realized gain of the proposed antenna in the steering direction is found to be better than a standard microstrip patch antenna on the same size of the substrate and ground plane. The antenna was designed and optimized through simulations using CST microwave studio and the prototype was experimentally tested using R&S ZVB8 network analyser.