GB608254A - Improvements relating to guides for radio-electric waves associated with elements for regulating the propagation of said waves - Google Patents

Abstract

608,254. Electric resonators. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. Dec. 31, 1945, No. 35330. Convention date, Nov. 14, 1944. [Class 40 (viii)] A resonant filter for a wave-guide is constituted by a conductive diaphragm disposed within the guide with its general plane perpendicular to the longitudinal axis and provided with a slot having at least two limbs, the slots being dimensioned so as to be in resonance with the frequency of the wave traversing the guide, one of the limbs being disposed perpendicularly to the electrical lines of force of the waves, and one or more limbs being disposed parallel to the lines of force. In Fig. 5, the slot is U-shaped, being the space between a transverse diaphragm 4 and an adjustable plate 3. The side limbs 2, 2<1> are inductive and the base 1 is capacitive. Thus, adjustment of plate 3 alters the capacitive limit and hence the resonant frequency. If no adjustment is required, a U-shaped slot in a diaphragm may be used. Alternatively, a slot arranged at an angle to the lines of electric field, Fig. 3, acts as if it had one limb parallel to the field and one limb at right angles. Thus, rotating the slot relative to the field varies the relative lengths of the virtual limbs and so varies the resonant frequency.