Compact Folded-Shorted Patch Antenna Array with PCB Implementation for Modern Small Satellites

A compact circularly polarized (CP) antenna array is presented. The array utilizes folded-shorted patches (FSPs) and printed circuit board (PCB) technology for antenna miniaturization. Both techniques enable a size decrease of the quarter-wavelength shorted-patch by a factor of 1/N, where N is number of the layers above the ground plane while maintaining a quarter-wavelength resonant length. This results in a reduction of the antenna length by half or more. The feature of CP is achieved by a compact and planar feeding circuit defined by a network of meandered 90 and 180-degree hybrid couplers which can provide quadrature feeding of the FSP elements and can be integrated onto the backside of the antenna ground plane which is only 9 cm × 9 cm. To fine tune the resonant frequency of the FSP antenna, we select different relative permittivity values for the substrate. Agreement in terms of the simulations and measurements is observed for the compact antenna (size of 0.129λ × 0.129λ × 0.014λ) with realized gain, radiation beam patterns and axial ratio values reported at UHF frequencies (430 MHz).