A. M. Bobreshov – Dr.Sc. (Phys.-Math.), Professor,

Voronezh State University (Voronezh)

G. K. Uskov – Dr.Sc. (Phys.-Math.), Associate Professor,

Voronezh State University (Voronezh)

E-mail: Uskov@phys.vsu.ru

D. P. Kondratyev – Student,

Voronezh State University (Voronezh)

E-mail: kondratyev777@gmail.com

S. E. Neskorodov – Post-graduate Student,

Voronezh State University (Voronezh)

Constructor,

PC «Concern «Sozvezdie» (Voronezh)

E-mail: neskorodov93@mail.ru

Increase of the bandwidth of radio systems requires the same from antenna technology as part of the radio path. In modern conditions, the band of resonant antennas is not enough, and the use of classical broadband antennas, such as horn, biconical one, discoconus one, in the range of meter waves is difficult due to their bulkiness. Despite the fact that the radio system band is only a few hundred MHz, the overlap factor can reach 4, 5. Under these conditions, even the use of line conditioning devices cannot solve the problem: the radiation in the direction of the main lobe decreases, and the side lobes rapidly grow – the diagram deteriorate. The aim of the article is to obtain a broadband omnidirectional asymmetric emitter with a constant direction of maximum radiation with an overlap ratio (ratio of the upper operating frequency to the lower frequency) equal to at least 5. A vibrator was used to preserve the small transverse size of the antenna. For line conditioning, capacitive loads located in the vibrator arm were used. The preservation of the radiation pattern at high frequencies is achieved by an external cylinder that serves to transfer the feed point. The outer cylinder has a slit at the base, which ensures proper performance at the bottom of the range.

The proposed antenna of vertical polarization of omnidirectional radiation has an acceptable matching (VSWR < 3,5) with the ratio of the upper frequency to the lower one 5:1 and a stable direction of the radiation maximum in the operating range. A method was proposed for estimating some parameters of the resulting antenna. To verify the parameters of the obtained antenna, numerical simulation was carried out, and also measurements of VSWR and radiation patterns of the fabricated prototype were carried out. The resulting emitter does not exceed the dipole antennas size, and it has gain comparable with a tuned vibrator; it has also high electrical strength and can be used for work with powerful VHF radio stations operating on decimeter and meter waves.

1. US Patent 9379441 B2. Very wide band tactical vehicular antenna system. A.M. Gary, M. John. May 21, 2013; Jun 28, 2016.
2. US Patent 8779996 B2. Low profile, broadband monopole antenna with heat dissipating ferrite/powder iron network and method for constructing the same. A.M. Gary, R.J. Henry. July 21, 2010; July 15, 2014.
3. SU 1626289 A1. Antenna. V.B. Akhmedov, N.M. Korchevsky, A.F. Zotov, Ya.M. Felman, E.A. Khadzhigolo. Claimed 04.04.1988. Publ. 07.07.1991. [In Russian]
4. Nadenenko S.I. Antennas. M.: Svazizdat. 1959. [In Russian]
5. Ovsyannikov V.V. Vibrator antennas with reactive loads. M.: Radio and communication. 1985. [In Russian]
6. Fikhtengolts G. Course of differential and integral calculus. In 3 t. T. I. M.: Fizmatlit. 2003. [In Russian]
7. Lebedev I.V. Technique and microwave devices. M.: High School. 1970. [In Russian]
8. Sivukhin D.V. General physics course. Electricity. T. III. M.: Science. 1977. [In Russian]
9. Gorbachev A.P., Yermakov E.A. Designing printed phased antenna arrays in the CAD system “CST Microwave Studio”. Novosibirsk: NSTU. 2008. [In Russian]
10. Bobreshov A.M., Kretov P.A., Sbitnev N.S., Uskov G.K. Experimental study of TEM-horn with non-uniform dielectric filling. Physics of wave processes and radio systems. 2016. Т. 19. № 3. P. 6–11. [In Russian]
11. Bobreshov A.M., Kretov P.A., Sbitnev N.S., Uskov G.K. Synthesis of an inhomogeneous dielectric medium to improve the characteristics of a horn. Radiotechnika. 2016. № 6. P. 159–162. [In Russian]
12. Gmurman V.Ye. Probability theory and mathematical statistics: Textbook for universities. M.: High School. 2003. [In Russian]
13. Specifications for CNI24 series VHF/UHF/L-band antenna. URL: https://www.harris.com/sites/default/files/antenna-cni24-series.pdf (date of the application 19.03.19).
14. VHF3088VM-PM series VHF dipole antenna, permanent mount. URL: https://www.comrod.com/wp-content/uploads/VHF3088VM-PMSeries.pdf (date of the application 19.03.19).
15. Additional equipment of the complex "Aqueduct" R-168E. OJSC "ElectroSIGNAL". 2008. URL: http://xn--80aajzhcnfck0a.xn--p1ai/Public Documents/0811279.pdf (date of the application 19.03.19). [In Russian]
16. Petrenko V.I., Rachkov V.E., Ivanov Yu.V. Systems and means of mobile radio communication. Manual. Stavropol: SVIS RV. 2010. [In Russian]
17. Measuring instruments for complex transmission and reflection coefficients OBZOR-304, OBZOR-304/1. Manual. Specifications. Chelyabinsk. 2017. [In Russian]
18. R&S®HL223 Log-periodic antenna. Rohde & Schwarz HF – VHF/UHF – SHF Antennas. Catalog 2017/2018.
19. Muravev Yu.K. Handbook for the calculation of wire antennas. Leningrad: VAS. 1978. [In Russian]
20. Fano R. Theoretical limitations of matching arbitrary impedances. M.: Sov. radio. 1965. [In Russian]