GB867014A - Improvements relating to t.r. devices - Google Patents

Abstract

867,014. Waveguide seals. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. March 18, 1959 [March 31, 1958], No. 10287/58. Class 40(8) [Also in Group XL(a)] A vitreous enclosure, not integral with the glass of the window, is provided adjacent a glass-sealed resonant slot forming a window in a T.R. device to prevent products produced by a discharge across the slot from interacting with metal in the vicinity of the slot and elsewhere within diffusing distance. In one arrangement, Fig. 1, the T.R. device comprises a section of wayeguide 1 terminated by flanges 2 and sealed by metal walls 3 each containing a resonant slot 4 sealed by a glass window 5. A block 10, preferably of fused silica, ground as shown in Fig. 3 to provide an enclosure 11 is held in position by projections 8 extending from the wide walls of the waveguide and forming an iris 6 with two transverse walls (not shown) extending inwardly from the narrow walls of the guide. A suggested filling consists of krypton at a pressure of 10 mm. and water-vapour at a pressure of 4À5 mm. of mercury. The block 10 is not sealed to the glass 5 so the filling is able to enter the enclosure 11. In a T.B. cell, Fig. 4, the block 10 is held in position by the inturned edges 21 of a tuning diaphragm 18 which is brazed to the walls of the waveguide section 14 or may alternatively be held in position by burrs provided on the inner surfaces of the waveguide walls. A tuning bar 19 has a screw-theaded bore 20 to enable the position of the diaphragm 18 to be adjusted by a screw-threaded rod introduced temporarily through the evacuation tubulation 17. Specification 866,200 is referred to.