Linearly Polarized High-Purity Gaussian Beam Shaping and Coupling for 330 GHz/500 MHz DNP-NMR Application

Terahertz waves generated by vacuum electron devices have been successfully applied in dynamic nuclear polarization enhanced magnetic resonance (DNP-NMR) technology to significantly enhance the sensitivity of high-field NMR. To reduce field interference, high-power terahertz wave source and NMR spectrometer need be separated a few meters apart. Corrugated horns directional couplers are key components for shaping high linearly polarized Gaussian beam accurately coupling electromagnetic power transmission system. In this paper, corrugated TE11-HE11 mode converter three-port coupler realized its inner cylindrical wire array proposed 330 GHz/500 MHz DNP-NMR The output presents characteristic highly linear polarization, which is 98.8% at GHz subsequent low loss transmission. designed can produce approximately ?33 dB on port 3 frequency range between 300–360 stably, used measure line real-time. direction installed replaced easily waveguide