Compact antenna for microsatellite using folded shorted patches and an integrated feeding network

This article focuses on the design and operation of a circularly polarized (CP) antenna unit for space applications using a four element array of folded-shorted patches. The metallic antenna structure is low-profile, ultra-compact (0.2λ
₀
by 0.2λ
₀
), and offers good CP performance at 400 MHz. Specifically, the four probe fed patch elements are placed in a sequential rotation configuration, while a miniaturized hybrid coupler based feeding network provides a 90° phase difference between the radiating elements. The feeding circuit is integrated on the underside of the antenna ground plane and a back plate housing encloses the printed circuit board. Measurements and simulations are in good agreement and the compact antenna unit may be useful for space communication systems using microsatellites and miniaturized phased arrays for security, surveillance, and other beam steering and direction finding applications.