GB992067A - Improvements in or relating to apparatus for passing electromagnetic waves - Google Patents

Abstract

992,067. Matching impedances. GENERAL ELECTRIC CO. Ltd., W. L. BIRCH, J. L. DIX, and G. T. THOMPSON. Nov. 8, 1962 [Nov. 8, 1961], No. 40084/61. Heading H1W. Apparatus forming a transition between a waveguide and a coaxial line comprises a section 7 of rectangular waveguide, a section 6 of coaxial line and a plurality of sections 8, 9, 10 of transmission line forming a broad band transformer between the sections 7 and 6, at least one of the sections 8, 9 being ridged waveguide and the next adjoining section 10 of the transformer being quasi-coaxial line having an inner conductor 15a and an outer conductor formed by a continuation of the wall of the ridged waveguide section 9, and an electrically conducting member 16 which projects from the outer conductor into the space between the inner and outer conductors on the side of the quasi-coaxial line remote from the ridges 8 and 9. The transformer can be a Tchebyscheff transformer. The transformer can include a further section 11 of coaxial line. The junction of the inner conductor 15a of the quasi-coaxial line 10 and the inner conductor 15b of the coaxial line 11 does not quite coincide with the end of the quasicoaxial line 10 in order to reduce the impedance discontinuity at the junction. The inner conductor 15a of the quasi-coaxial line 10 can be directly connected to the ridge 14 of the ridged waveguide 9 and the member 16 can extend into the adjacent section 9 of ridged waveguide. The parts of the apparatus can be of brass. The member 16 is positioned in manufacture of the apparatus in a direction perpendicular to the longitudinal axis of the apparatus so as to give the optimum standing wave ratio over the band of frequencies used. Dimensions are stated.