Gas-tight, high-frequency permeable window arrangement in a coaxial line, particularly for traveling wave tubes

#1. Field of the Invention

#The present invention relates to a gas-tight, high-frequency permeable window arrangement between a coaxial line on the input side and a coaxial line on the output side, particularly for traveling wave tubes.

#2. Description of the Prior Art

#Other objects, features and advantages of the invention, its organization, construction and operation will be best understood from the following detailed description, taken in conjunction with the accompanying drawing, on which:

#FIG. 1 is a longitudinal sectional view of a window arrangement constructed in accordance with the present invention;

#FIG. 2 is a longitudinal sectional view of another window arrangement constructed in accordance with the present invention; and

#In the window arrangements illustrated on the drawing, an output coupled from the delay line of an amplifier (not illustrated) is supplied by way of a coaxial line 3, 4 to the input side of the window arrangement. The window arrangement comprises a hollow cylinder 1 comprising dielectric material whose one end face is soldered to the outer conductor 4 of the coaxial line 3, 4 at the input side. The other end face is soldered to a flange 5 which is soldered between the two inner conductors 3, 3' of the coaxial lines 3, 4, 3', 4', respectively, of the input and output sides. A metallic compensation element 2 is preferably provided between the two outer conductors 4, 4' of the coaxial lines 3, 4 and 3', 4' of the input and output sides, the compensation element 2 surrounding the inner conductor 3, 3' and the hollow cylinder 1 comprising dielectric material and, together with these elements, adapting the window arrangement to the coaxial connection lines over a broad frequency band without reflection (r<10% of, for example 2 GHz-8 GHz). Thereby, the compensation element can be of a stepped cylindrical shape as illustrated in FIGS. 1 and 3, or can be conical and comprise two parts 2, 2' as illustrated in FIG. 2.

#Since the electric field lines only partially proceed in the dielectric and predominantly in error in the exemplary embodiments illustrated on the drawing, the dielectric load of the ceramic hollow cylinder is low, so that broad-band window arrangements can also be constructed with Al.sub.2 O.sub.3 (.epsilon.=9).

#Although I have described my invention by reference to particular illustrative embodiments thereof, many changes and modifications thereof may become apparent to those skilled in the art without departing from the spirit and scope of the invention. I therefore intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of my contribution to the art.