Paper Title
Circularly Polarized Stacked Patch Antenna for Pico-Satellite Communications

This paper presents the studies of a novel circularly polarized stacked patch antenna for inter pico-satellites communications in S-band. Limited size, low mass, circular polarization, high gain and wide bandwidth are the main challenges of the antenna design for CubeSats. A combination of gain and bandwidth enhancement techniques including sequential phase-rotation and stack configuration has been performed to fulfil the requirements for Cube Sat antennas. The proposed antenna consists of four corner truncated square patches, the radiating patches on the upper layer substrate, fed by a coaxial probe feed in the ground plane through a power driven patch including asequential phase feeding network with a combination of two L-shapedparasitic patches and a slot on the lower layer substrate. The feeding point is placed at (xo, yo) of the driven patch where a point to match 50 ohm impedance of transmission line. These two antenna layers are stacked-up to form a single stacked patch antenna. For each layer, FR-4 Epoxy, which has dielectric constant and loss tangent of 4.4 and 0.025 with thickness of 1.6mm, has been considered as substrate material. After the study of the proposed antenna model, a stack patches with patch arrays configuration accomplished the requirements. The antenna model has been simulated at the resonant frequency of 2.45GHz using Computer Science Technology CST studio suite student edition. In this configuration, the maximum gain of 8.6-9.1 dB within the entire frequency range (2.414-2.518GHz), attaining the gain value 8.2 dB at the target resonant frequency 2.45 GHz and -10 dB impedance bandwidth is104MHz has been achieved. Radiation pattern shows a beam width of 60°-76° in this frequency range. Good circular polarization and a 3dB axial ratio bandwidth of 84MHz within the frequency range (2.403-2.487GHz) are obtained in this antenna configuration. Keywords - Circular Polarization, Bandwidth, Axial Ratio, Stack Configuration, High Gain, Pico-Satellites