MULTIBAND CIRCULAR ANTENNA SYSTEM BASED ON HALF-WAVE VIBRATORS WITH BALANCING AND MATCHING DEVICES Russian patent published in 2021 - IPC H01Q21/24 H01Q9/28 

FIELD: radio engineering.

SUBSTANCE: invention relates to the field of radio engineering and can be applied in signal transmission/reception systems using several transmitters/receivers (signal transmission/reception channels) operating in different frequency ranges (spaced bands), including in cellular, trunking communication systems, in as part of base and dispatch stations, for building repeaters (repeaters) of medium and short range, as well as in systems for other purposes. The substance of the invention is a multi-band antenna system based on half-wave split vibrators (dipoles) with balancing and matching devices, providing a circular radiation pattern in the azimuthal plane for each transceiver (channel) in the corresponding frequency range with linear wave polarization. The multi-band antenna system consists of N half-wave vibrators (dipoles, the total electrical length of the arms of which, determined taking into account the shortening factor of the half-wave vibrator, corresponds to half the wavelength). A balancing and matching device is placed between the arms of each of the vibrators, which ensures the pairing of the symmetrical vibrator with the unbalanced feed line from the coaxial cable by inverting the signal phase and matching the input impedance of the half-wave vibrator with the characteristic impedance of the feed line. Half-wave vibrators are placed one above the other on a support - a pipe made of dielectric material, inside which coaxial cables (feeders) run, connecting each vibrator with a corresponding transmitter/receiver (transmission/reception channel) of a radio signal. The balancing and matching device of each half-wave vibrator is a modified U-elbow, consisting of two pieces of coaxial cable λ_n/4 and 3/4λ_n length, coiled in the form of spirals and sequentially located on the support pipe of the antenna system between the vibrator arms (λ_n is the wavelength, determined taking into account the shortening in the cable and corresponding to the n-th frequency range, n=1,…,N; N is the number of frequency ranges).

EFFECT: minimization of losses due to balancing and matching of the input impedances of the vibrators and the characteristic impedances of the feeders connected to them. In addition, with the vertical arrangement of the antenna system, a circular directional pattern in the azimuthal plane is provided for each of the vibrators with linear vertical polarization of the wave, and when the inclination of the antenna system is changed, horizontal or oblique polarization of the wave can be provided. The small diameter of the antenna system structure, placed in a radio-transparent housing (a pipe made of dielectric material), provides its effective protection against the effects of external unfavorable factors: climatic and mechanical influences.

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