A Ku-Band Crossover Based on Rectangular Waveguide and Its S-Parameter Analysis

In integrated circuits, interference between different signal paths should be avoided, but it could happen when two paths are overlapped. This paper presents a 4-port crossover with high isolation between different RF paths and 0-dB coupling for signal transmission. The design is based on rectangular waveguides (RWGs) propagating the TE
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mode in Ku-band, and two parallel RWGs are placed on the same plane, sharing a common narrow wall. The S matrix of the crossover is calculated theoretically, and simulation is conducted for verification after the physical structure is designed. Simulation shows isolation between the adjacent ports in its configuration below -20 dB from 13.70 to 16.33 GHz, and the relevant insertion loss in each diagonal pair of ports is no more than 0.07 dB. Such RWG-based crossover is an enclosed structure, with no exposure to the outside environment, and it can be further minimized by reducing the height, suitable for integrated and planar circuits.