Advanced 3.5 GHz Microstrip Array Antenna Technology for IoT Integration and Satellite Communications in Floating Photovoltaic Energy Systems

Floating photovoltaic (FPV) systems provide an effective approach to expanding renewable-energy generation without increasing pressure on land resources. However, remote FPV installations often face limitations in communication infrastructure, making continuous monitoring and supervisory control challenges. This study develops a 3.5 GHz 4 × 2 microstrip array antenna to support Internet of Things (IoT)-based monitoring and satellite-oriented communication for a 20 kWp FPV system at Rawa Pening, Indonesia. The antenna was designed on an FR-4 substrate and optimized using CST Studio Suite by refining the patch geometry, feed network, and element configuration. Simulation results showed resonance at 3.502 GHz, with a return loss of −36.70 dB, VSWR of 1.13, gain of 12.96 dBi, and directivity of 15.26 dBi. Prototype measurements confirmed operation at 3.5 GHz, achieving a return loss of −13.799 dB and a VSWR of 1.513, while radiation-pattern measurements demonstrated directional characteristics suitable for long-range wireless communication. The results indicate that the proposed antenna offers a compact and practical solution for transmitting FPV operational and environmental data in locations with limited terrestrial communication infrastructure. This design provides a promising foundation for reliable FPV telemetry, remote supervision, and future hybrid terrestrial–satellite communication systems.