Küp uydu anten sistemlerinin tasarım, benzetim ve üretimi

This study aims to design, simulate, and fabricate on-board and ground station antenna systems for CubeSats, i.e., the most affordable space missions. An on-board UHF turnstile antenna system is optimized in simulation evironment in accordance with different pattern requirements, by changing the orientation of the antenna arms. In order to feed the turnstile antenna arms by successive 90 degrees phase differences between them, a four-way quadrature splitter circuit is designed and fabricated. Antenna pattern measurement is conducted in anechoic chamber by connecting the monopole antenna arms to the fabricated power splitter circuit, while the arms are oriented in the optimized directions and placed on a generic 1U CubeSat platform. In addition to the fabricated UHF turnstile antenna, a novel dual-band V/UHF trapped turnstile antenna involving traps on the antenna arms is designed in simulation environment. On the other side, a circularly polarized VHF ground station Yagi antenna system is designed to achieve optimum gain and size, and it is also fabricated by using low-cost materials to be employed for amateur radios. In addition to the radiating metal structure, the VHF Yagi antenna system includes a Wilkinson power divider and impedance matching baluns fabricated by coaxial transmission lines. Besides the reflection coefficient measurements, the constructed ground station antenna system is used for the reception of a Slow Scan TV (SSTV) image broadcasted by International Space Station (ISS) to test its functionality. Finally, as another component of a sub-GHz CubeSat ground station, a circularly polarized UHF Yagi antenna system is designed, based on the experience gained from the VHF ground station antenna design and measurement.