Ferrite Loaded Antennas for Aerospace Applications

The effects of ferrite loading on the characteristics of the rectangular cavity slot antenna, the equiangular spiral antenna, and the log conical spiral antenna are studied. The object is size and weight reduction and this is accomplished at the expense of bandwidth and/or efficiency. The characteristics of the rectangular cavity slot antenna are analyzed and compared with experimental data. The operating frequency may be shifted by magnetic bias. Loading the spiral and log conical antennas lowers the low frequency limit by a factor of two or three. Data are presented on the temperature sensitivity of ferrite materials for aerospace antennas.