A comparison of the properties of helical type antennas when fed as a twin arm balanced pair

This paper describes the properties of twin arm wire helical antennas with a balanced feed. Included types are the cylindrical helical, the prolate spherical, the true spherical, the oblate spherical and the twin parallel spiral antenna. Examples for operation at 2.45 GHz for on-body antenna for a body area network are considered. Optimisation of cores with high permittivities was carried out using a genetic algorithm and CST Microwave Studio. A process for generating single and multilayer cores for the test samples of the preferred structure using an adaptation of available 3D plastic printing technology has been developed. A comparative analysis for use in Body Area Networks has been included.