435 MHz monopole antenna design for Turksat - 3USAT nano satellite

In this paper, a 435 MHz monopole antenna for Turksat-3USAT project is designed and manufactured by using HFSS design tool. Antenna should be winded up to be closed during launch. Beryllium-copper alloy is preferred as material due to high durability. Length of λ/4 monopole antenna is determined as 0.257*λ for 435 MHz (177.5mm) with regard to simulation results. Monopole´s structure is determined as rectangular because of easy deployment process and to overcome difficulties in manufacturing from alloy mould, therefore thickness and width are calculated as 0.25mm and 3 mm respectively depending upon simulation results. After manufacturing, antennas´ length and reflection coefficient value are measured as 180 mm and -29.6dB (S₁₁). -22,14 dB is the worst case value of reflection, depending upon swings of antenna in space. Gain factor is determined as 3.4 dBi in simulation. In addition to, it is aimed to observe effects on antenna caused by periodic and multidirectional moves of satellite in free space.