Повышение электронного КПД ЛБВО Kuи К-диапазона

Increase of electronic efficiency of Kuand K-band TWTO

The method of synthesis of the quasi-optimal law of the TWT helix pitch change on the basis of the law of change of the phase difference of the grouped beam current and the wave is described. The dependence of the phase difference between the electromagnetic wave and the beam current along the longitudinal coordinate have the form of a constant for the input and middle sections of the TWT and have the form of a two-segment broken for the output section. The phase difference of the fields and currents at the ends of the broken line was taken to be equal to π radians and had varied at the middle point. The results of the application of this method for Ku and K-frequency bands are presented. It is shown that the dependence of the electronic efficiency on the value of the phase difference between the current and the electromagnetic wave in the middle of the output section is significantly different for Ku and K-frequency ranges. In the first case, the maximum takes place in the region of 0.8·π radian, in the second cast 1.1·π radian. In the transition region at frequencies of 17-18 GHz there are both maxima. Synthesized the variation of the helix pitch for the Ku-band has a traditional look with the isochronism. Synthesized the variation of the helix pitch for the K-band takes a bizarre form of "splashes" and provides a significant increase in electronic efficiency compared to traditional homogeneous and isochronous spirals.