An Improved Rectangular Waveguide Thermal Isolator for Radio Astronomy Applications

We present the design of a thermal isolator, based on a simple gap in a standard rectangular waveguide with external circular profile. The proposed solution allows to achieve high return loss and low insertion loss by a suitable selection of the of the external radius of the waveguide circular profile, which determines the waveguide wall thickness. High robustness to misalignment is obtained, improving the performance of a recently published work in the same topic.