Design and Implementation of Four-way Power Division Network with High Isolation in 220 GHz Band

The next generation of terahertz receivers is developing rapidly in the direction of multi-pixel. This paper aims to develop a four-channel power divider network with high isolation for the local oscillator application requirements in 220 GHz multi-pixel receiver system. The performance verification of this actual module is verified based on the computer numerical control (CNC) technology. The main contents include: designing a 3 dB waveguide directional coupler unit, constructing a four-channel power division circuit plane structure based on the high isolation characteristic of 3 dB waveguide coupler, designing the power division network with vertical compact structure for the local oscillator in 2×2 array receiver through cascading waveguide elbows, and manufacturing this four-way power division network based on the CNC technology. The measurement results based on the vector network analyzer, exhibit that the power divided ratios in each channel is -7 dB ± 1 dB, the insertion loss in each channel is about 1 dB, the 3 dB fractional bandwidth is 20% from 175 GHz to 220 GHz, the isolation between channels is better than 20 dB, which are slightly poor than the simulations. The research results have verified that this four-way power division network can obtain the equal power distribution of each channel, high isolation performance and easy-to-be manufactured structures.