Frequency Reconfigurable Aperture-Coupled Microstrip Array Antenna Using Periodic Defected Ground Structures

In this paper, a design of 2 x 2 frequency reconfigurable microstrip array antenna using Defected Ground Structures (DGS) with aperture-coupled feed line for outdoor mobile applications. Two periodical dumbbell geometries with different dimensions etched on the ground plane. Each dimension of DGS structures etched on the ground plane resonant at two different frequency bands, (7.28-7.73 GHz) and (8.55-9.12 GHz), respectively. The reconfigurability of the antenna is based on the transition modes of switch on the feed line. When the switch is in "OFF" mode, the antenna resonant is at 7.5 GHz and covers 7.28-7.73 GHz frequency band while the antenna resonant is at 8.85 GHz in "ON" mode and covers 8.55-9.13 GHz frequency band. Switching modes for the preliminary prototype are presented in open and short condition of the feed line. The reconfigurable array antenna simulated using Computer Simulation Technology (CST). Results between simulation and measurement provide good agreement of the designed antenna. This new approach offers simple design and small volume of reconfigurable microstrip array antenna for future outdoor mobile applications.