METHOD OF ENSURING CONTINUOUS COMMUNICATION BETWEEN UNSTABILIZED NANO-SATELLITES IN CONSTELLATIONS

Abstract

The article presents a concept for ensuring continuous inter-satellite communication for unstabilized pico- and nanosatellites operating without an attitude and orbit control system (ADCS). The proposed approach is intended for spacecraft undergoing chaotic rotation and orbital drift, where traditional pointing or orientation-dependent communication schemes become ineffective. The concept is based on a multi-faceted antenna configuration that uses circular polarization to achieve spatial and polarization stability in radio communication under unpredictable changes in orientation.

The physical basis for testing the proposed communication method is a configuration of six patch antennas integrated on all faces of a 1U cubesat. The antenna elements are activated sequentially using a switching algorithm based on a pilot signal from the main satellite. The research focuses on creating a system and evaluating the link sustainability, particularly at the edges of the antenna radiation pattern, to determine the possibility of maintaining reliable inter-satellite communication in the absence of an attitude and orbit control system. Numerical modeling was performed in the 5.8 GHz range, with results that can be scaled to higher frequencies.

Based on the results of numerical modeling, the optimal PTFE substrate ZYF300CA-P was determined, which provided a gain of 4.1–6.1 dBi, a reflection coefficient better than -25 dB, and an axial ratio less than 5.6 dB over a beamwidth of over 110°. Additional modeling, taking into account the impact of the integrated solar panels, confirmed their minimal effect on system parameters – the deviation did not exceed 0.5 dB.

The results of the radio channel transmission loss calculation show losses in the range of (104; 107.5) dBm for a distance of 1500 m, which corresponds to a degradation of no more than 4 dB at the edges of the diagram, indicating the stability of communication under conditions of rotation and orbital drift. Analysis of the envelope for four coplanar elements shows that switching the best face provides continuous coverage without systematic deep nulls: for most orientations, the radio channel loss does not exceed 2 dB, while only narrow angular sectors show degradation up to 3 dB. Using circular polarization, unlike linear and elliptical polarization, minimizes polarization mismatch losses under dynamic orientation conditions and ensures link stability. The obtained results confirm the practical feasibility and effectiveness of the proposed antenna architecture for creating reliable inter-satellite communication systems in small satellite constellations without the need for an attitude and orbit control system.