Broadside FD Antenna Topologies for Nanosat Intersatellite Link

This paper presents and compares four different antenna topologies dedicated to Full-Duplex (FD) applications. The proposed architectures are able to operate simultaneously for transmitting TX and receiving RX radiating elements along broadside direction, contrarily to most of state of the art FD RF front-ends that also rely on destructive wave's concept to get Self-Interference Cancellation (SIC). The four prototypes make use of three SIC stages and the common first level is obtained using orthogonal linear polarization between TX and RX. Step-by-step improvements are introduced from one to another topology in order to increase the SIC level and to reduce both side lobe levels and antenna size. Simulated and experimental results are provided, compared and discussed at the center frequency of 2.4 GHz as a proof of concept. The isolation obtained between TX and RX paths is higher than 80 dB in simulation and 60 dB in measurement. These results pave the way to an implementation of a high gain Full-Duplex Ka-band antenna for Nanosat Intersatellite Link.