GB731473A - Improvements in or relating to electromagnetic wave-guiding members and apparatus - Google Patents

Abstract

731,473. R.-F. power measurements. WESTERN ELECTRIC CO., Inc. Feb. 13, 1953 [March 1, 1952], No. 4097/53. Class 37. [Also in Group XL (b)] A standing-wave detector for measuring the degree of match between a wave-guide and a load in the millimetric range comprises a network of dielectric-strip guides of non-circular, e.g. oval or rectangular, cross-section (see Group XL (b)). Two such guides 26, 27, Fig. 2, may be held spaced from each other in a dielectric block 28 to form a directional coupler. A coupler 80, Fig. 7, of this kind is arranged to sample energy at different points on a dielectric strip guide 83, the block 84 being slidable upon the guide 83. A further coupler 90, similar to the coupler of Fig. 2, is arranged to have a 3 db. coupling factor so that energy in either of the arms 86, 87 is divided equally between the arms 88, 89. Under these circumstances a fraction of the energy proceeding from a source 81 is coupled into the arm 86 and a fraction of the energy reflected from a mismatched load 82 is coupled into the arm 87. Both these fractions are distributed equally between a matched load 91 and a detector 92. The detector will thus register a quantity proportional to the sum of the forward and reflected energies in the guide 83 and will give a series of maximum and minimum readings as the coupler 84 is moved along this guide. In order to calibrate the instrument the guide 83 is terminated by a completely reflecting termination and a suitable attenuator 94 incorporated in one of the arms 86, 87 to obtain zero readings for the minima. Specification 706,234, [Group XL (b)], is referred to.