performance 5.8 GHz coupledpatch array antenna designed for efficient, reliable circularpolarized links Why this design matters gain while avoiding excessive sidelobes: gain is intentionally moderated below the theoretical maximum for a larger array to prevent sidelobes and preserve a good axial ratio. This tradeoff yields cleaner radiation patterns and more predictable link behavior. Improved radiation efficiency on FR4: although FR4 is lossy at 5.8 GHz, this design uses coupled patches to minimize feed network complexity and associated losses, delivering better overall efficiency than typical FR4 patch arrays. Stable axial ratio on and off axis: the antenna maintains an exceptionally good axial ratio not only directly perpendicular to the patch but also offcenter, improving polarization match and link consistency across practical pointing angles. Key benefits for users Better link reliability: stable circular polarization and controlled sidelobes reduce multipath sensitivity and polarization mismatch, helping maintain signal quality in realworld conditions. Lower system loss: a simplified feed network via coupled patches reduces insertion loss compared to complex feeding networks, making the most of available transmitter power. Practical gain: delivers meaningful gain improvements without the penalties of extreme array designs, balancing range and pattern cleanliness. Core attributes Function: circularpolarized array antenna for 5.8 GHz radio systems Frequency: optimized for the 5.8 GHz band Material: FR4 substrate with design measures to mitigate FR4 losses at 5.8 GHz Architecture: coupledpatch array with simplified feed network Performance highlights: yet moderated gain, good radiation efficiency for FR4 constructions, and axial ratio on and off axis Typical applications Longrange wireless video downlink for aerial platforms where stable circular polarization and predictable sidelobes improve reception Pointtopoint data links and telemetry systems operating in the 5.8 GHz band that require efficient, compact antennas with good polarization stability Wireless testing and prototype radio systems where a simple feed network and consistent performance across angles are important What makes it stand out Design tradeoffs focused on realworld performance rather than peak theoretical numbers Practical implementation that addresses known FR4 limitations at 5.8 GHz by reducing feed losses Consistent polarization quality across angles, improving link margin and reducing alignment sensitivity Technical summary Frequency band: 5.8 GHz Substrate: FR4 Radiating elements: coupled patches in an array configuration Feed: simplified feed network enabled by coupledpatch coupling Key performance: moderated gain, improved radiation efficiency for FR4, exceptional axial ratio on and off axis This antenna is suited for integration into 5.8 GHz communication systems where improved efficiency, stable circular polarization, and controlled radiation patterns are required.