Design of reflectarray antennas to achieve an optimum near-field radiation for RFID applications via the implementation of SDM procedure

Abstract

This paper presents the design of reflectarray antennas to radiate an optimum near-field distribution by using the procedure of steepest decent method to synthesize the impressed phases of reflectarray elements. In particular, the closed-form formulations used in the electromagnetic modeling were developed for an efficient design. The design was further implemented to realize a reflectarray of microstrip patch elements, which is illuminated by the radiation of a feed antenna at the 2.4 GHz band in the radio frequency identification applications. Numerical investigations as well as experimental measurements over a prototype are presented to validate the feasibility of the developed models and the implemented antenna structure. Key Points Reflectarray antenna for near-field applications Efficient synthesis of contoured patterns Closed-form formulations for efficient computation