Omnidirectional antenna bypassed feeding using a Turnstile Junction

Biconical antennas are widely used in satellites to provide omnidirectional radiation pattern [1] necessary during transfer orbit and on-station communications. Historically, the design of the feeding network has been critical, since the receive antenna must be situated right above of the transmit one to avoid interference. Instead of the traditional use of cables to reduce mass, in this paper a novel feeding configuration, entirely waveguide based, is proposed, as a trade-off between mass and robustness. The use of the Turnstile Junction to solve the spatial disposition conflict also provides a solid and reliable design, essential in space applications. Considerations on the design of the radiating elements and manufacturing will be also presented. Both, simulated performances and final flight model measurements, will be also provided and discussed.