A.A. Volkov – Ph.D. (Eng.), Lecturer, 
Military Educational-Research Centre of Air Force «Air Force Academy n.a. professor N.E. Zhukovsky  and Y.A. Gagarin» (Voronezh) E-mail: volkov_aa@autorambler.ru

Formulation of the problem. When setting requirements for the parameters of high-power microwave generators, it becomes necessary to take into account the phenomenon of air breakdown in the antenna as a factor limiting the radiation efficiency. The energy of the electromagnetic field removed to the atmosphere should not exceed the energy of air breakdown in the antenna of the generator. Typical antennas of high-power microwave generators are superficial antennas – dielectric windows in instrument housings. To ensure this condition when choosing the parameters of the generator, it is necessary to know the pattern that relates the breakdown energy of air on the radiating surface of the antenna with the duration, repetition period and the number of emitted pulses. In the well-known literature such laws are not given.
Purpose. Determination and analysis of the dependence of the breakdown energy of air in the superficial antenna of a microwave generator on the parameters of the emitted pulse sequence.
Results. An expression is obtained for the energy of air breakdown in a superficial antenna, taking into account the duration, repetition period, and number of pulses. It is established that the breakdown energy has a minimum pulse duration. Estimated expressions of the pulse duration and breakdown energy at the minimum point are obtained. The upper limit of the range of pulse durations emitted without breakdown is determined. The dependences of the breakdown energy in the antenna of a high-power microwave generator on the pulse duration for different radiation modes are calculated. It is shown that the minimum breakdown energy is in the subnanosecond range. The minimum breakdown energy decreases with a decrease in the repetition period, while the pulse duration at the minimum point also decreases. With an increase in the pulse duration, the dependence of the breakdown energy on the repetition period and the number of pulses weakens.
Practical significance. The results can be used to justify the requirements for the radiation parameters of high-power electromagnetic field generators.

Volkov A.A. Air breakdown energy in a superficial antenna // Electromagnetic waves and electronic systems. 2020. V. 25. № 1–2. P. 96−101. DOI: 10.18127/j15604128-202001-2-11 (in Russian). 

1. Ajzenberg G.Z. Antenny ul'trakorotkih voln. M.: Gosudarstvennoe izdatel'stvo literatu-ry po voprosam svyazi i radio. 1957. 700 s. (in Russian).
2. Didenko A.N. SVCH-energetika: Teoriya i praktika. M.: Nauka. 2003. 446 s. (in Russian).
3. Mak-Donald A. Sverhvysokochastotnyj proboj v gazah. M.: Mir. 1969. 212 s. (in Russian).
4. Zarin A.S., Kuzovnikov A.A., SHibkov V.M. Svobodno lokalizovannyj SVCH-razryad v vozduhe. M.: Neft' i gaz. 1996. 204 s. (in Russian).
5. Gurevich A.V. Ionizirovannyj sloj v gaze (atmosfere). Uspekhi fizicheskih nauk. 1980. T. 132. № 4. S. 685–690 (in Russian).
6. Aleksandrov A.F., Bychkov V.L., Grachev L.P., Esakov I.I., Lomteva A.YU. Ionizaciya vozduha v okolokriticheskom elektricheskom pole. Zhurnal tekhnicheskoj fiziki. 2006. T. 76. № 3. S. 38–43 (in Russian).
7. Barashenkov V.S., Grachev L.P., Esakov I.I., Kostenko B.F., Hodataev V.K., Yur'ev M.Z. Proboj vozduha v narastayushchem SVCH-pole. Zhurnal tekhnicheskoj fiziki. 2000. T. 70. № 10. S. 34–39 (in Russian).
8. Shifrin Ya.S. Antenny. Har'kov: VIRTA. 1976. 408 s. (in Russian).
9. Volkov A.A. Ogranicheniya na minimal'nye razmery antenn dlya izlucheniya moshchnyh sverhvy-sokochastotnyh impul'snyh polej. Antenny. 2014. № 10. S. 54–59 (in Russian).