Helix travelling-wave tube with a maximum small signal gain at the operating voltage

摘要

A helix travelling-wave tube of the present invention includes a helix wave delay circuit having velocity tapers for improving a beam efficiency and reducing backward wave oscillation. The tube allows a small signal and a large signal synchronous voltage to coincide or be extremely close to each other and thereby allows its circuit to have a minimum length. The tube is therefore small size and light weight and involves a minimum of gain variation against voltage variation.