V.F. Mikhailov

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

On the descent trajectory of the spacecraft, the onboard antennas are exposed to high-temperature aerodynamic heating. Due to the temperature change in the electrical parameters of the thermal protection material, a significant change in the antenna radiation characteristics is possible, which affects the loss of communication on the descent trajectory. The known mathematical models of onboard antennas, taking into account thermal protection, estimate the occurrence of reflection from the heated thermal protection. However, this does not take into account the effect of changing the properties of the thermal protection material on the field distribution in the antenna aperture due to a change in the reflection coefficient.

Target – to develop a mathematical description of the field distribution in the antenna aperture, taking into account the reflection coefficient from the heated thermal protection by applying the method of eigenfunctions.

As a result, relations were obtained that describe the occurrence of higher modes in the antenna aperture due to the reflection of the fundamental mode from the heated heat shield.

The results obtained make it possible to clarify the characteristics of the radiation of the onboard antenna under conditions of hightemperature aerodynamic heating, which provides an assessment of the presence of radio communication on the descent trajectory.

Mikhailov V.F. Radiation characteristics of the airborne antenna taking into account higher modes. Science Intensive Technologies. 2021. V. 22. № 8. P. 21−25. DOI: https://doi.org/10.18127/j19998465-202108-04 (in Russian)

1. Mikhailov V. Radiation of a Flat Waveguide Closed by Inhomogeneous Thermal Protection. V sb. Wave Electronicsandits Application in Information – and Telecommunication System (WECONF) Saint-Petersburg, Russia. 2019. P. 4–6. DOI: 10.1109/weconf.2019.8840596.
2. Mihajlov V.F. Radiotekhnicheskie harakteristiki bortovyh antenn s uchetom poverhnostnyh voln. V sbornike XXIV MNK Volnovaya elektronika i infokommunikacionnye sistemy. SPb. 2021.S. 147-149 (in Russian).
3. Mihajlov V.F., Pobedonoscev K.A., Bragin I.V. Prognozirovanie ekspluatacionnyh harakte-ristik antenn s teplozashchitoj. SPb. Sudostroenie. 1994. 300 s. (in Russian).
4. Zargano G.F., Zemlyakov V.V., Krivopustenko V.V. Elektrodinamicheskij analiz sobstvennyh voln v pryamougol'nom volnovode s dvumya vystupami. Radiotekhnika i elektronika. 2011. T. 56. № 3. S. 285–294 (in Russian).
5. Malyh M.D. Razrabotka metodov chislennogo analiza zakrytyh elektromagnitnyh volnovodov. Dissertaciya na soiskanie uchenoj stepeni doktora fiziko-matematicheskih nauk. M. 2018. 215 s. (in Russian).
6. Usov V.I. Reshenie odnogo integral'nogo uravneniya Fredgol'ma pervogo roda. Molodoj uchenyj. 2019. № 40 (278). S. 1–4 (in Russian).
7. Mkrtumyan E.L. Matrichnaya matematika. M.–Erevan. 2019. 145 s. (in Russian).
8. Mihajlov V.F. Harakteristiki izlucheniya kruglogo volnovoda cherez ploskuyu odnorodnuyu teplozashchitu. Elektromagnitnye volny i elektronnye sistemy. 2019. № 1. S. 12–19. DOI: 10.18127/j15604128-201901-02 (in Russian). 
9. Mikhailov V.F. Characteristics of Radiation of a round Waveguide through a Flat Homogeneous Heat Shield. Electromagnetic Propagation and Waveguides in Photonics and Microwave Engineering. London, United Kingdom, Intech Open. 2020. P. 167–179. DOI: 10.5772/intechopen.92036.