GB591026A - Improvements in ultra-high-frequency circuits - Google Patents

Abstract

591,026. Electric resonators highfrequency discharge apparatus. GOODALL, M. C., and WRIGHT, C. S. April 21, 1945, No. 10098. [Classes 39 (i) and 40 (iii)] A coaxial resonator 1, 2, is tuned by moving a capacitive disc 9 towards or away from the end of the half-wave inner conductor 2, which is supported on a heat-conducting copper pillar 3. The disc 9 is of the same diameter as the conductor 2. Movement is effected bv turning a, screw-threaded 8, which is enclosed in a quarter-wave sleeve 14 -to give the effect of good contact between the shaft 8 and end plate 7. An approximately linear law of tuning is obtained when the diameters of the shaft 8 and central support 3, which may be of metal, are a quarter of those of the inner conductor 2 and tuning-disc 9. The inner diameter of the outer conductor 1 is twice as great, and is ¢# times the maximum working wavelength. When the resonator forms part of an oscillationgenerator of the velocity-modulated reflector type, the end wall 4 is provided with spring fingers 20 for making contact with an electrode 19 of a valve 18 of the disc-seal type, corresponding fingers 16 being provided on the inner conductor for another electrode 17. For connection to an external circuit a loop or probe coupling 23 is inserted close to the central pillar 3, on the side of it opposite' to the tuning-disc 9. This oscillation-generator may be ganged with a crystal mixer comprising a resonator similarly constructed but without the valve 18, a set screw for presetting the tuning being arranged instead of the valve in the end wall 4, while a crystal takes the place of the coupling 23, Fig. 1 (not shown).