A diplexer for terahertz full-duplex communication systems

In this paper, a 220GHz discontinuous manifold coupled waveguide diplexer is proposed for future terahertz multichannel communication applications. The diplexer consists of two Chebyshev bandpass filters based on metal waveguide technology. Through the co-design of the low order electromagnetic distribution model and the full wave electromagnetic model, the optimization design with high computational efficiency and high design precision is realized. The multiplexer is manufactured using low-cost CNC milling technology, with an in-band insertion loss of 0.8dB per channel filter and an average common-port return loss of 15dB. The measured results are in good agreement with the simulation results, which verifies the correctness of the whole design process.