Aperture-Coupled Frequency and Patterns Reconfigurable Microstrip Stacked Array Antenna

This paper investigates a novel structure of a reconfigurable microstrip antenna integrated with the aperture coupling technique which can reduce spurious radiation pattern with stacked patch in order to enhance the gain and bandwidth performance. The antenna design implements a new concept of the frequency reconfigurability methods applying in an aperture-coupled technique. Four PIN diode switches named as Switch A were used to activate the selected aperture slots on the ground, thus resulting in two different operating frequencies either at 2.6 or 3.5 GHz. Meanwhile, an additional four PIN diode switches named Switch B, positioned at the four L-stub elements were used to turn ON the patterns capabilities while maintaining the frequencies. The beam angle of the antenna can be controlled with turning ON Switch C and Switch D alternately in order to activate selected numbers of stacked radiating patches, either the two upper patches or two lower patches. With six cases of the switches configuration, the antenna has the capability to change its patterns with its beam directed at +32°, +3°, or -1° at 2.6 GHz or at +28°, +23°, or -24° at 3.5 GHz.