In satellite communication applications, particularly in the Industrial, Scientific, and Medical (ISM) band, antennas play a crucial role in ensuring efficient signal transmission and reception. However, a major challenge is achieving optimal performance in parameters such as S11, bandwidth, axial ratio, gain and radiation pattern, especially given the physical space constraints in small satellite platforms like CubeSats. Additionally, designing antennas with circular polarization often requires complex parameter optimization to meet system requirements effectively. Therefore, an innovative design approach, such as the Helix Conical Antenna with a Quadrifilar configuration, is needed to address these challenges.
Each antenna is optimized by adjusting key design parameters, including the inter-turn spacing (S), radius variation (rc), and conductor length (C), to enhance performance in terms of S11, bandwidth, axial ratio, and radiation pattern. Monofilar (MCHA), Bifilar (BCHA), and Quadrifilar (QCHA) designs incorporate multiplication patterns that combine isotropic planar elements with helical elements, modeled as a combination of loop antennas and dipole antennas. To achieve an optimal Quadrifilar configuration in the ISM band, simulations and parametric studies were conducted based on a conventional Monofilar design.
This thesis also aimed to analyze the influence of design parameters on an antenna performance in terms of S11, VSWR, far-field (rE), axial ratio, and radiation pattern. This analysis was conducted to understand how each antenna configuration could meet satellite communication requirements. Simulation results indicated that MCHA achieved the lowest S11 value of -33.45 dB and the highest far-field (rE) value of 10.44 dB, making it highly efficient for applications requiring minimal power reflection and focused radiation. Meanwhile, BCHA exhibited a wider bandwidth of 120 MHz, a superior axial ratio of 9.62 dB, and a gain of 5.59 dBi, providing greater flexibility for communication applications that required stability across a broad frequency range. The QCHA, with three turns, achieved a gain of 4.7 dBi, a bandwidth of 20 MHz, and an S11 value of -21.27 dB, making it advantageous in providing a focused and complex radiation pattern, suitable for precise directional communication.