Stepped Non-Coplanar Transmission Lines Based on Decremental Waveguides

To solve the problem of changing the signal phase center in MIMO systems, this paper designs, fabricates, and characterizes millimeter-wave noncoplanar transmission lines based on decremental waveguides. The relatively smooth transition structure based on the stepped waveguide facilitates the smooth transition of the electric field. The square cut angle structure is applied at right angle coupling to carry millimeter wave transmission. The experimental results show that the relative bandwidth of the non-coplanar transmission line is 20.5% in the WR-10 band. The insertion loss of the transmission line is less than 0.6 dB in the frequency range of 91-110 GHz. This non-coplanar transmission line that changes the phase center of the signal can be used as an integrated device in MIMO systems.