GB620583A

GB620583A - Improvements in or relating to ultra high frequency electrical transmission systems

Info

Publication number: GB620583A
Application number: GB34712/45A
Authority: GB
Original assignee: Philco Radio and Television Corp
Current assignee: Philco Radio and Television Corp
Priority date: 1944-08-15
Filing date: 1945-12-21
Publication date: 1949-03-28
Also published as: US2473274A

Abstract

620,583. Power meters. PHILCO RADIO & TELEVISION CORPORATION. Dec. 21, 1945, No. 34712. Convention date, Aug. 15, 1944. [Class 37] [Also in Group XL (c)] Fig. 1 shows a directive coupling between rectangular wave-guides 11, 12 superposed at right angles on their broad faces. Slots 21, 22 cut in the contiguous faces of the guides intersect at a point 15 where the longitudinal and transverse currents are equal. These currents are phase displaced by 90 degrees, the sense of the displacement corresponding to the direction of propagation along the guide. Thus, energy propagated along guide 11 will produce at 15 a circularly polarized wave which is radiated through slots 21, 22 into guide 12 where it produces a unidirectional wave which is propagated along guide 12 in a direction which depends on the direction of propagation in guide 11. Thus, if guide 11 is feeding a load and there is some reflected energy, the reflected energy will produce a wave in one direction in guide 12, and the direct energy will produce a wave in the opposite direction. With a good absorbing wattmeter at one end of guide 12 and an absorbing termination at the other end, the direct or the reflected energy may be measured, since the unit comprising the crossed guides may be connected in either sense in guide 11. Fig. 2 shows a unidirectional coupling for coaxial lines. A coaxial line 32, 33 has a closed branch stub 36, 37 on which is a machined flat surface 44 in which are cut slots 45, 46 at a position where the longitudinal and transverse currents are equal and phase displaced by 90 degrees. Thus, if a similar unit is superposed at right angles so that the pairs of intersecting slots are in contact, a wave is generated in the second coaxial line having a direction of propagation dependent on that in the coaxial line 32, 33. The apparatus may be used for measuring the power in one direction in a coaxial line. Specification 592,224 is referred to.