Twisting Effects on X-Shaped Millimeter-Wave Plastic Waveguides

This paper presents a theoretical and experimental study of the effects of a twist on the hybrid HE11V and HE11H mode propagations of X-shaped plastic waveguides. Plastic waveguides, providing a light-weight and low-cost alternative to optical fibers and copper lines for high data rate transmissions, are of high interest, particularly for applications in data centers and emerging autonomous cars. While the bending effects on plastic waveguides have been reported in the literature, to the best of the authors’ knowledge, twisting effects were not addressed. The X-shaped plastic waveguide optimizing the sensitivity and loss trade-off compared to solid and hollowed circular plastic waveguides is considered in this study. First, the effects of a twist are analyzed in theory and simulation with an experimental validation. Then, the case of a twisted bent waveguide is investigated. The study concludes that for the X-shape topology, the polarization direction remains invariant (i.e., it does not rotate) in the two considered cases despite the twist.