A 300-330GHz Symmetrical Duplexer Based on Chebyshev Narrowband Bandpass Filter

This paper presents a waveguide duplexer based on symmetrical three-port junction. And the performances of the duplexer under different symmetrical conditions are simulated and analyzed. It is composed of two Chebyshev narrowband bandpass filters (BPF) and in the form of reactance coupling half-wavelength conversion. The proposed duplexer is fabricated through high-precision computer numerical control (CNC) milling technology with accuracy of ±3 μm. The feasibility of proposed duplexer can be verified. The measured results exhibit that in 300.1-309.8 GHz and 322.9-332.1 GHz, its insertion loss is within 1.9 dB and the return loss is less than -15 dB.