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 38 GHz. 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 8 GHz 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.
4. Efthimion, P., P. R. Smith, and S. P. Schlesinger, "Broad spectral electromagnetic radiation calorimeter: Centimeters to microns," Rev. Sci. Instrum., Vol. 47, No. 9, 1059-1062, 1976. doi:10.1063/1.1134817
5. Warton, C. B., L. M. Earley, and W. P. Ballard, "Calorimetric measurements of single-pulse high-power microwaves in oversized waveguides," Rev. Sci. Instrum., Vol. 57, No. 5, 855-858, 1986. doi:10.1063/1.1138824
6. Earley, L. M., W. P. Ballard, and L. D. Roose, "Rectangular waveguide calorimeter for single intense microwave pulses," Rev. Sci. Instrum., Vol. 57, No. 9, 2359-2361, 1986. doi:10.1063/1.1138678
7. Earley, L. M., et al., "Comprehensive approach for diagnosing intense single-pulse microwave sources," Rev. Sci. Instrum., Vol. 57, No. 9, 2283-2293, 1986. doi:10.1063/1.1138699
8. Zaitsev, N. I., et al., "A calorimeter for measuring the energy of a high-power electromagnetic pulse," Instrum. Exp. Tech., Vol. 35, No. 2, 283-284, 1992.
9. Belousov, V. I., et al., "Calorimeter for measuring the total energy of high-power pulse millimeter-range devices," Instrum. Exp. Tech., Vol. 39, No. 3, 402-405, 1996.
10. Belousov, V. I., et al., "A dry overmoded-waveguide calorimeter for measurement of high-power microwave pulse energy," Instrum. Exp. Tech., Vol. 35, No. 3, 482-487, 1992.
11. Bykov, N. M., et al., "Diagnosis of high-power nanosecond pulses of microwave-radiation," Instrum. Exp. Tech., Vol. 30, No. 6(2), 1393-1397, 1987.
12. Klimov, A. I., et al., "A calorimeter for high power microwave pulse measurement," Proceedings of 15th International Symposium on High Current Electronics, 422-424, Tomsk, Russia, 2008.
13. Lisichkin, A. L. and E. V. Nesterov, "Waveguide calorimeter for pulsed microwave radiation in the centimeter wavelength range," Instrum. Exp. Tech., Vol. 41, No. 3, 362-364, 1998.
14. Kiselev, V. A., et al., "A calorimeter with a capacitive probe for measuring microwave energy," Instrum. Exp. Tech., Vol. 48, No. 2, 230-233, 2005. doi:10.1007/s10786-005-0041-y
15. Lisichkin, A. L., E. V. Nesterov, and V. A. Stroganov, "Calorimeter for pulsed microwave radiation," Instrum. Exp. Tech., Vol. 39, No. 1, 70-72, 1996.
16. Shkvarunets, A. G., "A broadband microwave calorimeter of large cross section," Instrum. Exp. Tech., Vol. 39, No. 4, 535-538, 1996.
17. Lisichkin, A. L., et al., "A liquid pulsed microwave radiation calorimeter," Instrum. Exp. Tech., Vol. 50, No. 1, 82-85, 2007. doi:10.1134/S0020441207010101
18. Klimov, A. I., et al., "Measurement of parameters of X-band high-power microwave super radiative pulses," IEEE Trans. Plasma Sci., Vol. 36, No. 3, 661-664, 2008. doi:10.1109/TPS.2008.917300
19. Vykhodtsev, P. V., et al., "Liquid calorimeters for measuring the energy of high-power microwave pulses," Instrum. Exp. Tech., Vol. 58, No. 4, 510-514, 2015. doi:10.1134/S0020441215030264
21. Ye, H., et al., "Research on calorimeter for high-power microwave measurements," Rev. Sci. Instrum., Vol. 86, No. 12, 124706, 2015. doi:10.1063/1.4938160
22. Klimov, A. I. and V. Yu. Kozhevnikov, "Numerical optimization of aperture absorbing loads of liquid calorimeters for high-power microwave pulses," Rus. Phys. Journ., Vol. 60, No. 8, 1319-1324, 2017. doi:10.1007/s11182-017-1215-3
23. Dagys, M., et al., "The resistive sensor: A device for high-power microwave pulsed measurements," IEEE Antennas and Propagation Magazine, Vol. 43, No. 5, 64-79, 2001. doi:10.1109/74.979368
24. Ballard, W. P. and L. M. Earley, "Microwave detecting diode rise-time measurements," Rev. Sci. Instrum., Vol. 56, No. 7, 1470-1472, 1985. doi:10.1063/1.1138136
25. Lobaev, M. A., et al., "Effect of inhomogeneous microwave field on the threshold of multipactor discharge on a dielectric," Tech. Phys. Lett., Vol. 35, No. 12, 1074-1077, 2009. doi:10.1134/S1063785009120025
26. Chang, C., et al., "The effect of grooved surface on dielectric multipactor," J. Appl. Phys., Vol. 105, No. 12, 123305, 2009. doi:10.1063/1.3153947
27. Klimov, A. I. and E. M. Totmeninov, "Diffraction effects in measurements of characteristics of high-power microwave pulses with wide aperture liquid calorimeters," Rus. Phys. Journ., Vol. 60, No. 6, 964-971, 2017. doi:10.1007/s11182-017-1165-9
28. Tarakanov, V. P., et al., "Time-dependent numerical simulation of diffraction and absorption effects in diagnostics of short high-power microwave pulses using wide-aperture liquid calorimeters," EPJ Web Conf., Vol. 149, 04046, 2017. doi:10.1051/epjconf/201714904046
29. ANSYS HFSS 3D Electromagnetic Field Simulator for RF and Wireless Design [online] available at https://www.ansys.com/products/electronics/ansys-hfss,.
30. Schamiloglu, E., et al., "High-power microwave-induced TM/sub01/plasma ring," IEEE Transactions on Plasma Science, Vol. 24, No. 1, 6-7, 1996. doi:10.1109/27.491664
31. Ivanov, O. A., M. A. Lobaev, V. A. Isaev, and A. L. Vikharev, "Experimental study of a multipactor discharge on a dielectrics surface in a high-Q microwave cavity," Plasma Phys. Reports, Vol. 36, No. 4, 336-344, 2010. doi:10.1134/S1063780X10040033
32. Lobaev, M. A., et al., "Effect of inhomogeneous microwave field on the threshold of multipactor discharge on a dielectric," Tech. Phys. Lett., Vol. 35, No. 12, 1074-1077, 2009. doi:10.1134/S1063785009120025
33. Krupka, J., "Measurements of the complex permittivity of low loss polymers at frequency range from 5 GHz to 50 GHz," IEEE Microw. Wireless Compon. Lett., Vol. 26, No. 6, 464-466, 2016. doi:10.1109/LMWC.2016.2562640
34. Bao, J., M. L. Swicord, and C. C. Davis, "Microwave dielectric characterization of binary mixtures of water, methanol, and ethanol," J. Chem. Phys., Vol. 104, No. 12, 4441-4450, 1996. doi:10.1063/1.471197
35. Barthel, J. K. Bachhuber, R. Buchner, and H. Hetzenauer, "Dielectric spectra of some common solvents in the microwave region. Water and lower alcohols," Chem. Phys. Lett., Vol. 165, No. 4, 369-373, 1990. doi:10.1016/0009-2614(90)87204-5
36. Sato, T. and R. Buchner, "Dielectric relaxation processes in ethanol/water mixtures," J. Phys. Chem. A, Vol. 108, No. 23, 5007-5015, 2004. doi:10.1021/jp035255o
37., "Agilent basics of measuring the dielectric properties of materials. Application note," Agilent Technologies, 2013.
38. Cole, K. S. and R. H. Cole, "Dispersion and absorption in dielectrics. I. Alternating current characteristics," J. Chem. Phys., Vol. 9, 341-352, 1941. doi:10.1063/1.1750906