RU2257650C1 - H-plane omnidirectional antenna assembly - Google Patents

Abstract

FIELD: antenna engineering.

SUBSTANCE: proposed high-directive-gain antenna assembly that can be used in television and in general-purpose corporative, departmental, and radiophone communication systems and incorporates provision for obtaining H-plane omnidirectional directivity pattern while maintaining narrow E-plane directivity pattern has metal reflector of (2 - 4)λ, where λ is wavelength, and excitation source in the form of electric dipole; reflector is made in the form of set of conductors disposed around dipole, in parallel to the latter, and possesses partially directive system property.

EFFECT: improved design of antenna assembly.

1 cl, 4 dwg

Description

The proposed device relates to the field of antenna technology and can be used, for example, in television and corporate, departmental and radiotelephone public communications.

In such systems, the use of antenna devices with a circular radiation pattern in the horizontal plane is often required at base stations (BS). To increase the energy of radio links, BS antennas must have a sufficiently high coefficient of directional action (KND). To increase the directivity of such antennas, various methods are used, in particular, it can be arrays of vertically arranged vibrators.

Known devices of this type:

- Omni-directional antenna devices with high gain VOA 35-08 with a gain of 8 dB, VOA 35-11 with a gain of 11 dB (RFS catalog);

- A rod OMNI antenna with a circular pattern for base and subscriber stations manufactured by OJSC TsKB-Svyaz with a low gain of 10 dB, Lviv.

Closest to the technical nature of the proposed device is the "Antenna device with an increased directivity in the E-plane", according to the patent of the Russian Federation No. 2216831, taken as a prototype.

Figure 1 presents the drawing of the antenna prototype, where indicated:

1 - source of excitation - an electric vibrator;

2 - reflector.

An antenna device with an increased directivity in the E-plane is a cylindrical metal surface 2 with a height of (2 ÷ 4) λ (λ is the wavelength) with a width (0.3 ÷ 0.7) λ cut along the generatrix, inside which there is an excitation source - an electric vibrator 1 .

This antenna has a narrow (~ 20 °) beam pattern in the E-plane and a sector (60-120 °) beam pattern in the H-plane.

The disadvantage of the prototype device is the inability to provide a circular pattern in the N-plane.

To eliminate this drawback, an antenna device containing a metal reflector with a height of (2 ÷ 4) λ, where λ is the wavelength and the excitation source is an electric vibrator, according to the invention, the reflector is made in the form of a system of conductors located around the vibrator parallel to it, and has property of a partially guiding system.

The proposed antenna device provides a narrowing of the beam in the E-plane and increasing the directivity gain to 8-10 dB or more. Almost the distance from the vibrator to the conductors in order to reduce the antiphase emf induced in them should be taken more than 0.25λ, the length of the conductors is up to 4λ, depending on the required low voltage. Conductors can be thin, wide enough or have a variable cross-section. They can be located both uniformly around the perimeter and at the same distance from the source of excitation (to obtain a circular beam or a beam with circular symmetry), and uneven (to obtain any preferred directions in the beam). In this case, the reflector has the property of a partially guiding system.

Figure 2 presents a drawing of the proposed antenna device (General case: conductors of different widths, at different distances from the vibrator), where it is indicated:

1 - source of excitation - an electric vibrator;

2 - reflector.

DN in the general case has unevenness in the N. plane

Figure 3 shows, from the whole set of possible options for reflectors, two particular cases giving DNs with circular symmetry:

- figa - thin conductors are evenly spaced at the same distance from the vibrator. The DN has circular symmetry, and with a sufficient number of conductors it is close to circular;

- figb - wide conductors at an equal distance from the vibrator. Qualitatively, the DN has the same character as that of the variant of figa.

The technical result of the proposed antenna device is:

- providing radiation in all directions in the H-plane with an ND having a shape either close to circular, or different from circular, but having circular symmetry, or having some preferred directions, i.e. having an uneven circular pattern;

- a significant narrowing of the MD in the E-plane (10 ° or less) with an LPC of up to 8-10 dB or more.

A distinctive feature of the proposed antenna device from the prototype antenna is the possibility of obtaining a circular or slightly directional pattern in the H-plane and a narrow pattern in the E-plane with a simple power supply system and without the use of gratings of radiating systems.

Claims (1)

An omnidirectional antenna device in the H-plane, containing a metal reflector with a height of (2-4) λ, where λ is the wavelength, and the excitation source is an electric vibrator, characterized in that the reflector is made in the form of a system of conductors arranged parallel to it around the vibrator and providing omnidirectional radiation in the H-plane.

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