D. A. Antropov – Ph.D. (Eng.), Associate Professor, Professor,
Academy of Military Sciences (Moscow)
O. Yu. Perfilov – Dr.Sc. (Eng.), Professor, Chief Research Scientist,
16th Central Scientific Research and Testing Institute of Ministry of Defense of the Russian Federation
V. E. Fidel’man – Honored Inventor of RF
At present, our country pays considerable attention to the development of hard-to-reach areas in order to extract minerals, develop new transport routes and develop infrastructure. The problems of ensuring electromagnetic compatibility of a variety of radioelectronic devices, effective use of limited radio-frequency resource, and a high degree of physical protection of the antenna-feeder devices (AFD) are becoming urgent.
The main goal of the article is to develop protected AFD structures – broadband plate doublet antennas (DA) placed at the border of the air-to-ground material media for radio relay communication facilities and complexes.
Known doublet antennas consist of the active part of the loop-vibrator (left and right sections symmetrically located relative to the conventional central axis of the antenna), the U-shaped passive part, made of plate metal wires and symmetrical RF power feeder. The disadvantages of such structures of DA are the uneven distribution of current along the sections of the active part of the loopvibrator and low matching of the input resistance of the loop-vibrator with the RF feeder in the operating frequency range. The noted disadvantages do not provide high values of antenna gain and traveling wave factor (TWF).
The new design of DA differs from the original one by the central section in its active part and changing the order of connection of the feeder cable to the side and central sections of the active part, which reduces unevenness of the current distribution along DA conductors in the operating frequency range, and improves matching with the feeding line. The increase (in average) in antenna gain by 25–30% and TWF by 15–20% has been experimentally proved. A patent of the Russian Federation has been obtained for the proposed solution.
It is often necessary to reduce DA geometric dimensions in order to deploy it. To eliminate this drawback in the following DA design, all partitions of its active part and passive long loop are placed in parallel planes, and the side sections of the passive antenna are located in the planes orthogonal thereto, the width of the passive long loop is chosen equal to or slightly greater than the width of the active part of the antenna. In addition, to improve the uniformity of the current flow in the DA and to increase its mechanical strength in the central section of the active part of the doublet antenna, a rectangular metal partition is added, placed in the orthogonal plane. This partition is equal in geometric dimensions to the side sections of the passive part of the antenna. In practice, as a passive long loop can be used a metal surface of the roof of the car body.
The added changes allow us to obtain technical results: reducing the geometric dimensions (width) of the new DA design to the width of the sites of its practical placement on various mobile and stationary communication facilities; reducing the unevenness of the current distribution along the DA conductors in the operating frequency range; improving matching with the feeder; increasing the antenna gain and TWF by an average of 10–15% compared to the known DA designs. A patent of the Russian Federation has been obtained for the proposed solution.
- Zayavka na patent № 2119901 Frantsiya. Priemnaya antenna. B. Keravenant. 1972.
- Zayavka na patent № 2311422 Frantsiya. Dublet-antenna, sognutaya iz plastin. G. Dubost, N. Khavot. Opubl. 05.01.1977.
- Patent RF № 2568328. Dublet-antenna. D.A. Antropov, I.B. Vasserman, V.N. Kira, O.Yu. Perfilov, V.E. Fidel'man. Opubl. 20.11.2015. Byul. № 32.
- Drabkin A.L., Zuzenko V.L. Antenno-fidernye ustrojstva. M.: Sov. radio. 1961.
- Patent RF № 2686856. Dublet-antenna. D.A. Antropov. Opubl. 06.05.2019. Byul. № 13.