A Compact Circularly Polarized Antenna Using an Array of Folded-Shorted Patches

The development and optimization of a circularly polarized (CP) antenna using an array of four folded-shorted patch elements is investigated. The realized antenna is compact ( 0.2λ
₀
by 0.2λ
₀
), highly integrated, and offers good radiation performance at 400 MHz. A compact coupler-based feeding network for the four elements within the array, integrated into the antenna ground plane, provides a sequential 90° phase difference between the radiating folded-shorted patches. This very compact CP antenna design may be useful for microsatellite and other miniaturized phased array systems for communications.