Design of TTC antenna for mini-satellite application

The required performance of TTC (Tracking, Telemetry and Command) antennas for mini-satellite applications are briefly discussed and a new type of three-layered patch antenna is designed to meet the requirements. The antenna is constituted of two stacked annular ring radiators, the lower one of which is printed on a substrate with ε_r = 4.5 and directly fed by a coaxial probe, and the upper one is printed on a substrate with ε_r = 2. Rectangular slots are inserted into both patches to excite two orthogonal resonant modes to generate circular polarization. Between these two layers, there is an air layer of 10 mm height. The proposed antenna is simulated with CST. The impedance bandwidth is about 29.9%, the 3 dB axial ratio band width is 11%. Such performances ensure the proposed antenna for mini-satellite TTC application. The number and the position of such antennas mounted on a mini-satellite are optimized. Fairly good omni-directional coverage is achieved when 4 antennas are onboard the mini-satellite model.