GB968904A - Crossed-field amplifier tubes - Google Patents

Abstract

968,904. Magnetron amplifiers. S-F-D. LABORATORIES Inc. Jan. 10, 1962 [Jan. 23, 1961], No. 960/62. Heading H1D. In order to stop the continued operation of a high-frequency crossed-field amplifier tube having a non-re-entrant slow wave circuit and a re-entrant space charge space after it has been turned off, due to self-sustained secondary emission at the surface of a cold secondary emissive cathode, a control potential pulse is applied to the cathode end hats 27, Fig. 1, to distort the carbode-anode potential distribution. The control pulse may be negative or positive. In Fig. 1 the anode structure comprises cavity resonators 16 communicating through apertures 19 with a serpentine non- re-entrant wave circuit 18. In the cathode structure of Fig. 3 control wires 37 extend between the end hats 35 and are positioned beyond the periphery of the cathode 34 or, as shown, within grooves in the periphery of the cathode. In another arrangement the control wires extend circumferentially. In Fig. 7 control electrode discs 51 intervene with cathode discs 52. The separate cathode and/or control sections may be operated at different potentials or different cathode-anode spacings may be used for the different cathode sections, e.g. to secure broad-banding of the tube operation. The control discs 51 need not extend beyond the surface of the cathode discs 52 or the control discs may be serrated by radial slots or by the provision of spaced-apart projecting hairpins or wires in order to avoid shorting out of the R.F. fields.