JPS648701A - Waveguide device - Google Patents

Abstract

PURPOSE:To reduce the loss of a waveguide by making an inner wall of the waveguide with a superconducting material, providing the waveguide having a thickness over the skin depth of a high frequency current acting onto the inner wall and a cooling device bringing the temperature of the inner wall to a temperature causing the superconduction effect or below. CONSTITUTION:A waveguide 4 is provided, which consists of a rectangular outer wall made of a metal with excellent heat transfer performance and a rectangular inner wall 2 at the inner circumferential face of the outer wall 1. The inner wall 2 is made of a superconducting material, the waveguide consists of a hollow part 3 and the thickness is nearly the skin depth at minimum to efficiently propagate a high frequency signal of a microwave or the like. Then the inner wall 2 on the innercircumference of the outer wall 1 is formed by providing the superconducting material on the inner face of the outer wall 1 by vapor deposition or the like. Moreover, the waveguide 4 is provided with a cooler 7 cooling the inner wall made of a superconductor. In the cooler 7, liquid nitrogen or the like is filled inside of an air-tight case 5 having thermal insulation and the waveguide 4 is covered with a coolant 6. Thus, the inner wall 2 is cooled to bring its electric resistance to nearly zero and the skin resistance with respect to high frequencies is made nearly zero.