Development of Semi-Conformal Antennas for Telemetry and GPS Applications on Experimental Rocket

The telemetry and Global Positioning System (GPS) systems are crucial for experimental rocket communication systems. Such systems need antennas to receive data and send it to the ground station. This paper deals with the development of semi-conformal antennas implementable on an experimental rocket. The proposed semi-conformal antennas are intended to work at the frequencies of 0.91 GHz and 2.45 GHz for radio telemetry, and 1.575 GHz for GPS L1. The antennas are designed on a 0.254 mm thick Rogers/Duroid 5880 dielectric substrate with the relative permittivity of 2.2 and the dimensions of
$\mathbf{228.6}\ \mathbf{mm} \times \mathbf{304.8}\ \mathbf{mm}$
. The characterization results show the reflection coefficients of -14.93 dB, -19.1 dB, and -23.93 dB are achieved with the -10 dB bandwidth of 2.9 MHz, 2 MHz, and 10.4 MHz at three desirable frequencies, respectively, while the isolation is less than -40 dB. Right-Hand Circular Polarization (RHCP) GPS antenna is also obtained well indicated by the axial ratio value lower than 3 dB at the frequency of 1.575 GHz. The proposed antennas have nearly omnidirectional patterns with low gain achievement.