Reduction of Coupling between Flush-Mounted Antennas

This paper discusses some numerical aspects of the coupling study between two flush-mounted antennas. It is shown that a bed of nails embedded between flush- mounted quad-ridge horns separated by 20 cm (4 lambda(6 GHz)) edge-to-edge greatly reduces coupling by about 17 dB at lower frequency end, where the electrical distance between antennas is the shortest. The considered antenna system operates from 6-19 GHz and has vertical bar S-11 vertical bar < -10 dB, and coupling < -60 dB. The numerical modelling is carried out using MoM and FEM solvers. The computed results are in good agreement with measurements.