Astronomical Antenna for a Space Based Low Frequency Radio Telescope

The Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR) project is investigating an orbiting low frequency radio telescope. Due to strong ionospheric interference and Radio Frequency Interference (RFI) found at frequencies below 30 MHz, such an instrument is not feasible on Earth, hence the proposed solution of a swarm of autonomous nano-satellites sent to a remote location in space. On each satellite, the astronom- ical antenna consists of three orthogonal dipoles designed to work within the constraints of a nano-satellite. Due to mechanical constraints, the dipoles are not optimally integrated into the nano-satellites from an antenna point of view. Therefore, the e_ect of the _nite non uniform ground plane, the non symmetrical antenna deployment, and the non in_nitesimal dipole gap on the antenna properties need to be investigated. Unfortunately, the operational band of 0:3 MHz to 30 MHz and the dimensions of the astronomical antenna of just under 5:0 m prohibit tests within the controlled environment of an anechoic chamber; ergo, a scale model is required. This work describes the design, simulation and measurement of such a scale model.