Dina V. Vasil'eva, Viktor F. Mikhaylov

 Saint Petersburg State University of Aerospace Instrumentation (SUAI) (St. Petersburg, Russia) 

 dolli.dina@mail.ru,  vmikhailov@pochta.tvoe.tv

The object of research is the onboard antennas of the returned spacecraft. On the trajectory of descent to earth, spacecraft are exposed to high-temperature aerodynamic heating and plasma. To protect against external influences, the onboard antennas are covered by heat-resistant radiolucent thermal protection. Structurally, the on-board emitter and thermal protection form a single design called the antenna window (AW). During high-temperature heating, the electrical parameters of thermal protection significantly change and, as a result, the radio-technical characteristics of the AW, as a result, communication with the spacecraft on the descent trajectory is disrupted. The development of methods for providing continuous radio communication on the descent trajectory of a spacecraft is possible only when assessing changes in AW characteristics under the influence of high temperatures and plasma. There are known mathematical models of AW, obtained taking into account the effect of high-temperature heating and plasma on the antennas. The use of these models is significantly limited due to the lack of data on the temperature variation of the electrical parameters of thermal protection. Field tests are not possible. There remains the only way - the way of experimental research in laboratory conditions when reproducing high-temperature heating and plasma at AW. A developed set of equipment is considered for modeling aerodynamic heating and plasma on standard AWs and simultaneously measuring their characteristics. Structural diagrams of the DC arc plasma torch and microwave equipment for studying the radiation pattern, efficiency, conductivity of the aperture and noise temperature of the AW are given, and their operation principle is discussed. References to the works of the authors are given, in which the parameters of the equipment complex, accuracy characteristics, and research results are described in sufficient detail. Fragments of the research results are given in the article. The scope of the complex under discussion and the directions of further research are shown.

Vasil'eva D.V., Mikhaylov V.F. Modeling on-board antennas of aerodynamic heating and plasma exposure with simultaneous measurement of their radio technical characteristics. Achievements of modern radioelectronics. 2020. V. 74. № 11. P. 12–16. DOI: 10.18127/j20700784-202011-03. [in Russian]

1. Martin Dzh. Vkhod v atmosferu. M.: Mir. 1969. [in Russian]
2. Golden R., Hanawalt H., Ossman W. The predication and measurement of dielectric properties and RF transmission through ablating boron nitride antenna windows. AIAA 16 the thermophysics conference. June 1981. P. 46–53.
3. Bachynski M.P., Clouter R.F. Antenna Radiation Pattern in the Presence of a Plasma Sheath. Electromagnetic Aspects of Hyper-sonic Flight/ New York/ Spartan Books. 1964. P. 169–195.
4. Matsumoto M., Tsutsumi M., Kumagai N. Millimetre-wave radiation characteristics of a periodically plasma-induced semiconductor waveguide. Electronics Letters (1986). V. 22(13). P. 710–711.
5. Hubregt J.V. Antenna Theory and Applications. John Wiley & Sons. 2012.
6. Mihajlov V.F., Pobedonoscev K.A., Bragin I.V. Prognozirovanie jekspluatacionnyh harakteristik antenn s teplozashhitoj. SPb.: Sudostroenie. 1994. [in Russian]
7. Best S.R. Advance in the Design of Electrically Small Antennas. Short Course. IEEE AP Symposium. 2003. P. 18–27.
8. Mihajlov V.F. Harakteristiki izluchenija kruglogo volnovoda cherez ploskuju odno rodnuju teplozashhitu. Jelektromagnitnye volny i jelektronnye sistemy. 2019. № 1. S. 12–19. [in Russian]
9. Mihajlov V.F. Opredelenie KPD bortovyh antenn vozvrashhaemyh kosmicheskih apparatov. Uspehi sovremennoj radiojelektroniki. 2019. T. 73. № 11. S. 7–12. DOI: 10.18127/j20700784-201911-02. [in Russian]
10. Vasil'eva D.V., Mihajlov V.F. Pogreshnost' opredelenija radiojarkostnoj temperatury plazmy. Mezhdunar. forum «Metrologicheskoe obespechenie innovacionnyh tehnologij». SPb. GUAP. 2020. S. 142–144. [in Russian]