Numerical Simulation of Wideband Calorimeter for High Power Microwave.

Autor: Kurkan, Ivan K., Klimov, Alexey I., Priputnev, Pavel V., Rostov, Vladislav V.
Předmět:
Zdroj: Progress in Electromagnetics Research M; 2020, Issue 92, p79-88, 10p
Abstrakt: The novel design of an ultra-wideband calorimeter for energy measurement of high power microwave pulses of nanosecond duration is proposed in this paper. The main idea is the use of a circular waveguide with losses in the wall and metal cone insertion at the axis to increase attenuation constant in the waveguide. The efficiency of the concept was proved with the numeric simulation and optimization of the calorimeter design with ANSYS HFSS software for frequencies from 8 to 38GHz. The operating modes are supposed to be symmetric TM0n ones. Ethanol was chosen as an absorbing medium. It is parted from the vacuum volume by a plastic tube. The frequency dependencies of ethanol's relative permittivity and loss tangent were taken into account in the simulation model. The reflection coefficient for TM01 mode is below -20 dB at the lowest frequency of 8GHz and well below the level of -25 dB from 10 to 38 GHz. The reflection coefficients for higher order modes remain below -30 dB until the operating frequency is close to the cut-off frequency for a particular mode. The maximum accepted power level is of hundreds of megawatts for pulses of a nanoseconds duration. The effect of waveguide modes mixture at the input of the calorimeter on the maximum accepted power level was considered. This level may differ by 4 times between specific modes mixtures. Therefore, the transition from a particular microwave source to the calorimeter input should be carefully optimized. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index