N-Port Perfect splitting in rectangular waveguides enabled by evanescent coupling and its potential for analogue computing

Computing with electromagnetic waves has opened many opportunities for high-speed low-power devices with the ability to perform analogue operations. Recently, it has been proposed how networks of N-port perfect splitters (where the incident signal is divided equally in all directions, including the incident port) can be exploited to, for instance, mimic Kirchhoff law in photonic structures as well as the calculation of the solution of partial differential equations. Here, we propose and study a structure using interconnected rectangular waveguides with the ability to achieve perfect splitting via evanescent field coupling. It is shown how the structure can be implemented for other fundamental operations such as signal routing and linear comparators.