Switchable meander-strip enabled frequency and pattern reconfigurable monopole antenna based on AlGaAs PIN diode

Abstract Dynamic electromagnetic environment demands real-time, multidimensional awareness, which drives the development of reconfigurable intelligent antennas. In this paper, a compact frequency and pattern reconfigurable monopole antenna is proposed. The antenna is composed of a serpentine-shaped reflecting patch and a defected ground structure (DGS) fabricated on an FR4 substrate. By controlling five PIN diodes, the effective radiator length will be changed, which can tune the frequency bands operated at 2.9 GHz and 3.2 GHz. Simultaneously, by altering the asymmetric surface current distribution, the radiation pattern can be switched among three distinct modes: +100° directional, −100° directional, and omnidirectional. The operation bands of the antenna range from 2.70 GHz to 3.13 GHz in the first mode and 2.87 GHz to 3.53 GHz in the second mode. The bandwidths of the antenna are 14.8% and 20.6%, respectively. This design offers significant potential for adaptive wireless systems requiring simultaneous optimization of operating frequency and spatial coverage in dynamic environments. Experimental results confirm the antenna’s successful realization of both frequency agility and radiation pattern diversity.