The Application of Reconfigurable Filtennas in Mobile Satellite Terminals

Reconfigurable antennas play an important role in wireless communication systems as the physical and electrical properties of their structures can be modified, allowing them to be used in different applications. In this paper two reconfigurable filtennas are presented to integrate mobile devices that communicate (uplink and downlink) with satellites in low-orbit constellations. A microstrip patch antenna in uplink mode (29 GHz), is surrounded by copper structure that, once connected via a PIN diode, takes the antenna to resonate in a lower frequency band (20 GHz). To deal with both bands, two filters were integrated into the radiating structure: edge-coupled and hairpin filters. The antennas were characterized and compared through simulation and measurements, in terms of impedance adaptation, radiation pattern and isolation between operating bands, validating their operability. Their small size and low cost allow these antennas to be integrated into mobile terminals that communicate with satellites or 5G systems.