| 摘要 |
1,068,646. Crossed-field travelling wave tubes. SFD LABORATORIES Inc. March 9, 1965 [March 9, 1964], No. 10009/65. Heading H1D. An interdigital slow-wave circuit, e.g. for a crossed-field travelling wave tube, comprises a series of iterative sections 4 each of which includes a shunt impedance having a capacitative branch C, Fig. 7, shunted by an inductive stub transmission line L 2 to improve the interaction impedance of the circuit, the transmission line including first and -second conductors 3 of predetermined length positioned between the capacitative branch and a third short-circuiting conductor 5 connecting the ends of the first and second conductors which are remote from the capacitative branch, wherein the resonant frequency of the shunt impedances define the low cut-off frequency of an operating pass-band of the circuit, and the shunt impedances develop a succession of voltages along the @ for cumulative interaction with an electron stream directed along a path adjacent to the slow-wave circuit. The slow-wave circuit comprises interdigitated teeth 4 projecting from spines A, B, conductive stubs 3 being continuous with and projecting from the mid-point of each tooth, the free end of each stub being connected to a conductive wall 5, which also acts as a heat sink. The teeth of the combs may be bifurcated as described in Specification 1,063,922. Input or output coupling is by waveguide coupled to the slow-wave structure by a length of strip transmission line, one tooth of the slow-wave structure being mitred to turn the direction of propagation of the wave on the slow-wave structure to the direction on the strip transmission line. A dumbell-shaped iris couples the waveguide to the strip transmission line. |
