GB605253A - Improvements in and relating to concentric-conductor transmission lines - Google Patents

Abstract

605,253. Electric resonators. SPERRY GYROSCOPE CO., Inc. Dec. 21, 1945, No. 34771. Convention date, Dec. 21, 1944. [Class 40 (viii)] The inner conductor of a concentric trans-, mission line is supported by an annular disc including an electrical conductor, continuous between the two boundaries of the annulus but covering only part of its area, and forming an oscillatory circuit which is resonant at a particular frequency in the normal operational frequency band of the line. The bead will then not produce undesirable reflections in the operation of the line. For example, the inner conductor 12 of a line 10 may be supported by thin metal discs 13 and 14 in which a slot has been cut so that they each form a resonant circuit. The length of the slot is roughly inversely proportional to the resonant frequency and for low'frequencies a spiral slot may be required. Alternatively, as shown in Fig. 5, the slot may end in holes 20, which may be countersunk, which give a lower resonant frequency to the slot. The construction of Fig. 9 is suitable for still lower frequencies and comprises two conducting rings 25 and 26 forming a capacity, spaced by dielectric rings 28 and 29 and connected by a spirally wound conducting wire 30. An impedance transformer may be formed with these discs as shown in Fig. 15. The discs are adjusted by screws 48 and 49 extending through slots in the line. Disc 44 is rotated and disc 45 is moved axially along the inner conductor.