ALMA MEMO #469

A Broadband Waveguide Thermal Isolator

J. L. Hesler , A. R. Kerr ¹ and N. Horner ¹
University of Virginia Dept. of ECE, Charlottesville, VA 22902
¹National Radio Astronomy Observatory, Charlottesville, VA 22903

2003-05-30

This paper describes a new, compact, waveguide thermal isolator. The isolator is based on a recently developed microwave bandgap joint, a periodic structure which suppresses microwave fields propagating between two parallel conducting surfaces. When such a structure is placed between a pair of waveguide flanges, the flanges can be separated by a few percent of a wavelength before the leakage and mismatch become significant. The thermal isolator is relatively immune to misalignment and cocking. Simulations and measurements on WR-10 thermal isolators indicate excellent performance over the entire waveguide band. The design is readily scalable to other waveguide bands.

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