Experimental Investigation of Electromagnetic (EM) Bridge for Deployable Antenna Array at P, L and S Band

This paper presents the practical investigation and evaluation of a contactless low profile electromagnetic (EM) bridge, which is used to deploy direct radiating arrays placed on different panels. The RF connectivity is established using an EM bridge, which offers low loss, phase stability and low passive intermodulation, compared to the cable assembly. For the evaluation, an EM bridge integrated with microstrip lines on different panels is designed and developed at $P(450 \mathrm{MHz}), \mathrm{L}$ band $(1.5 \mathrm{GHz})$ and S -band $(\mathbf{2} .8 \mathrm{GHz})$. The RF characterization of the EM bridges with microstrip lines is carried at various folding angles of the panels. The measured results show $\leq 0.08$ dB insertion loss in $P, L$ and S bands. The measured RF performance has also been compared with that of the cable assembly. It is found that EM bridge has superior RF performance and low profile in comparison of coaxial assembly for RF connectivity of foldable antenna.