An ultra-wideband three-way power divider based on spoof surface plasmon polaritons

In this paper, an ultra-wideband spoof surface plasmon polaritons' (SSPPs) power divider with simplest odds ratio (1:3) composed of hexagonal ring unit cells is proposed. The creation of electromagnetic waves with high confinement in a collision between periodically decorated metal and dielectric is a fundamental property of SSPPs. Flexibility, low loss, decreasing cross coupling, and ability for integration are other advantages of SSPP transmission lines. In order to realize the proposed 3-way power divider, first, a novel low loss and compact subwavelength hexagonal unit cell is presented. Next, a plasmonic waveguide is designed. To decrease the dielectric losses, the effect of different substrates on transmission coefficient is investigated too. In the best condition, we have a transmission line with an excellent operation in the frequency range of 3 to 11.8 GHz with a fractional bandwidth (FBW) of 119%. Then, an equal and in-phase 3-way power divider with good isolation between three output ports is designed in a wide frequency range of 2.5-8 GHz with an FBW of 105%. Finally, the proposed 3-way power divider is fabricated and tested in the laboratory. A good agreement between simulations and measurement results proves the functionality of design properly. The ultra wide-bandwidth, low loss, flexibility, and stable performance of this power divider prove its high capability compared with the state-of-the-art references. The proposed power divider can be utilized in developing an integrated plasmonic feeding network of antenna arrays in microwave and millimeter wave frequency bands. Published by AIP Publishing.