A planar omnidirectional microstrip antenna for 2.4 and 5.8 GHz telemetry in drone ground control stations

The increasing use of UAVs (Unmanned Aerial Vehicles) for mapping, surveillance, environmental monitoring, and logistics has heightened the demand for reliable telemetry links between the aircraft and the Ground Control Station (GCS). Telemetry systems require antennas that are compact, low-cost, and capable of dual-band operation at 2.4 GHz and 5.8 GHz, which are widely used for control and data transmission. Microstrip antennas are suitable because of their light weight, compact size, and ease of integration, but their narrow bandwidth and limited gain reduce effectiveness in long-range UAV missions. This study presents a planar omnidirectional microstrip antenna designed for UAV GCS applications. The design adopts a coaxial collinear configuration with a 180° offset and integrates forked-open-ended stubs, U-slots, and Y-slots to enhance dual bandwidth and improve impedance matching. Fabricated on a low-cost FR- 4 substrate, the antenna was optimized through simulations and verified experimentally. The results show operating ranges of 2.258–2.571 GHz and 3.978–5.887 GHz, with bandwidths of 313 MHz and 1.909 MHz, return losses of 20.08 dB and 14.48 dB, and peak gains of 3.24 dBi and 7.09 dBi, respectively. Compared to typical dual-band microstrip antennas that often suffer from narrow bandwidth, moderate gain, or dependence on costly substrates, the proposed design achieves wider bandwidth and higher gain using simple slot modifications on low-cost FR-4. This balance of high performance and affordability highlights the novelty of the work, offering a practical and manufacturable solution for UAV telemetry applications.