Improvements in rejector circuits for electrical apparatus having high or ultra-high frequencies

摘要

488,081. Impedance networks ; valve generating and amplifying circuits. POULSEN, V., and GRETHER, D. P. L. Nov. 11, 1937, No. 31057. Convention date, Nov. 12, 1936. [Classes 40 (iii) and 40 (v)] In a high or ultrahigh frequency electrical apparatus, rejector circuits are included in all or a plurality of the leads to the apparatus, by making the leads of selfinductive wires which are housed in a metal tube which is itself one of the leads, one only of the leads being bridged by a condenser. The close coupling of the inductances makes the impedance of all the leads high at the frequency to which the tuned rejector circuit is tuned. The leads may be arranged inside a long flat metal tube which is shaped into a coil as shown in Figs. 2 or 3 or the various conductors may form a concentric cable as indicated by the cross-section in Fig. 4. the tubes being of round, oval or square crosssection as desired. The use of the circuits in the leads to short wave oscillators is described, the rejector circuits being in a single group with one tuned circuit or in two groups with a tuned circuit in each group. The tuning condensers may be mounted on the same shaft as the oscillator tuning condenser. Specification 476,906 is referred to.