A Dual-Band Circularly Polarized Shared-Aperture Antenna for 1U CubeSat Applications

This communication presents a design of a dual-band circularly polarized antenna with structure reuse for one cubic unit (1U) CubeSat applications. It is a challenging to design an antenna with the limited space of a CubeSat platform. To improve the space utilization, an antenna is designed inspired by the concept of structure reuse. A meshed-like-structure is designed, which works as the radiator of a microstrip antenna at UHF band. However, it works as a partial reflective sheet for a Fabry–Perot resonator cavity antenna at C-band. Therefore, a microstrip patch antenna and a Fabry–Perot resonator cavity antenna share only single aperture. A shaped ground is used to decrease the resonance at the lower band. Then, the aperture of the antenna is only
$0.3\lambda _{0} \,\times \, 0.3\lambda _{0}$
, which makes it easy to integrate with a 1U CubeSat. The measurement reveals that the antenna has a common bandwidth of (
$\vert \text{S}_{11}\vert < -10$
dB, AR < 3 dB) 1% and 1.4%, an isolation higher than 35 and 20 dB, a peak gain of 5.82 and 13.75 dBic at UHF and C-band, respectively. The frequency ratio of these two bands reaches 6.4. The above properties make the proposed antenna suitable for a CubeSat system.