A Ka-Band Angular Log-Periodic Meander-Line SWS Supported by Diamond Rods

The angular log-periodic meander-line traveling wave tube (TWT) is a kind of low voltage, small-sized, high power, low cost, on chip amplifiers, and considered as a key part of the advanced communication systems, the future biomedical applications and the next electronic counter measure (ECM) instruments
et al.
Here, an angular log-periodic meander-line TWT is presented in this article. The angular log-periodic meander-line slow wave structure (SWS) is supported by two diamond rods. The dispersion and the impedance characteristics are analyzed in detail. In order to reduce the reflection loss, a gradual ridged waveguide is connecting the input–output standard rectangular waveguide to the meander-line SWS. The particle in cell (PIC) simulations show that the output power of the TWT can reach 55 W at 34 GHz with the operation voltage of 1800 V and the beam current of 0.2 A. The SWS is manufactured by a laser machine with Molybdenum sheet. The assembled TWT is tested and the results show that the
${S}_{{11}}$
is less than −10 dB at 30–39 GHz. The
${S}_{{21}}$
mismatch between the simulated and the measurement is discussed at the end.