High-Gain S-band Patch Antenna System for Earth-Observation CubeSat Satellites

A novel S-band circularly polarized patch antenna system suited for earth-observing CubeSats is presented. The antenna consists of four rectangular patches properly excited in order to have the maximum gain in the boresight direction and produce circular polarization. The antenna has a compact size, and its geometry and characteristics are compatible with any CubeSat standard structure. A 57-mm-wide square window allows to accommodate imaging system optics in its center leading to a very compact overall system. A prototype of the designed antenna system has been used to validate simulation results that showed a gain of 7.3 dBi. Experimental measurements confirm that the antenna achieves good impedance match at the desired frequency of 2450 MHz, a directivity of 8.3 dBi, and 60
^°
3-dB beamwidth, in good agreement with the simulation results.