GB649916A - Improvements in and relating to high frequency oscillators - Google Patents

Abstract

649,916. Valve generating circuits. GENERAL ELECTRIC CO., Ltd., and HEATHCOTE, V. A. Feb. 13, 1948, No. 4320. [Class 40 (vi)] [Also in Group XL (a)] In a high-frequency oscillator of the kind incorporating an electron discharge device having two coupled coaxial line circuits, one circuit connected between the anode and control grid, and the other connected between the control grid and cathode of the device, the feed-back path between the grid-anode and grid-cathode circuits includes a cavity resonator having a resonance frequency equal to the frequency at which oscillations are generated. As shown, a valve 10 is arranged with its anodegrid circuit 11 and its grid-cathode circuit 12 in the form of coaxial lines, the inner conductor 13 carrying conductors for the cathode heater, and the outer conductor 14 of the grid-cathode circuit being brought close to the inner conductor at 15 to form a byepass condenser. A feed-back path in the form of a coaxial line 25 containing a resonator 18 is provided between a tapping point 16 on the inner conductor of the anode-grid circuit and a point 17 on the inner conductor of the grid-cathode circuit. The resonator, Fig. 2 (not shown) comprises an outer conductor of cylindrical shape closed at both ends, an inner conductor of cylindrical shape being disposed coaxially within the outer conductor, connected to the outer conductor at one end and spaced from it at the other end. The resonant frequency of the resonator may be adjustable as by adjusting the length of the inner conductor.