Multi-mode parasitic patch arrays have multiple resonant frequencies, each with an associated high-gain radiation pattern. The authors present a novel analysis technique that combines existing well-established models to characterise the structures and reduce the design cycle time. Passive radio frequency (RF) identification tags will benefit from this technology to improve the inherently limited range, since they derive their power from the incident RF signal and modulate the backscatter. Additional applications of these structures include microelectromechanical systems-based adaptive arrays that have additional beam-steering capabilities at each frequency. Hardware has been fabricated and tested for both applications, with good correlation between simulated and measured results.