RU164858U1 - DIRECTED DIRECTOR ANTENNA - Google Patents

Abstract

An omnidirectional director antenna consisting of one active vibrator in the form of a piece of conductor having a length of about a quarter of the wavelength of the electromagnetic wave, located perpendicular to a flat conductive surface and connected to the power line from the edge closest to the conductive surface, and a plurality of passive director vibrators in the form of wire segments having a length less than the length of the active vibrator located parallel to it and connected with one of its edges to a conductive surface, characterized in that the sibling director vibrators are arranged so that the projections of their midpoints on the conductive surface are located along circles whose center coincides with the center of the projection of the active vibrator onto this surface, at the same distance from the projections of their midpoints of the adjacent passive vibrators directors along the circular arc, while the lengths of the passive vibrators-directors belonging to one circle are equal, and with the increase in the radius of the circle on which the midpoints of the passive vibrators-directors are located, the length of the pass GOVERNMENTAL vibrators are not changed, and each circle has to at least three passive vibrators directors.

Description

The utility model is intended for use as part of radio engineering devices of television, broadcasting and radio communications in the decameter, meter, decimeter and centimeter wave ranges. A known antenna with a controlled radiation pattern [1], consisting of asymmetric vibrators with a length of about a quarter of the electromagnetic wavelength, mounted perpendicular to a flat conductive surface and connected to it through controlled p-i-n diodes. In such an antenna, the central vibrator is active and is driven by a coaxial cable. The remaining vibrators are passive and, when the diode is on, play the role of reflectors. Vibrators with the diode turned off are electrically transparent and have practically no effect on the resulting radiation pattern. Due to this, radiation directed in two planes is formed, and the main lobe is deviated from the conducting plane by a certain angle. With all the diodes turned on, it is theoretically possible to obtain radiation omnidirectional in the same plane. However, in another plane it will not be focused and the coefficient of directional action will be low, since passive vibrators in this case shield the radiation of the central vibrator.

The technical result of the utility model is to increase the directional coefficient of the antenna with omnidirectionality in one of the planes.

To achieve the technical result, an omnidirectional director antenna is proposed, consisting of one active asymmetric vibrator in the form of a conductor segment located perpendicular to a flat conductive surface, and a plurality of passive director vibrators in the form of conductor segments connected to a flat conductive surface having a length less than the length of the active asymmetric vibrators located parallel to it and connected by the near edge to the conductive surface. In this case, the passive vibrator directors are located so that their projections on the conductive surface are located along circles whose center coincides with the projection of the active vibrator on this conductive surface, at the same distance from the projections of neighboring passive vibrator directors on the conductive surface along the circular arc. An active asymmetric antenna vibrator is about a quarter of the length of an electromagnetic wave.

Radiation into the lower half-space of the conducting screen is limited by diffraction effects at its edges and will be the smaller, the larger the screen size. Due to this, the radiated power is concentrated in only one half of the space and the directivity of the antenna will be higher than that of the prototype. In addition, the presence of a solid screen eliminates the need for additional inductances, and the antenna is tuned by changing the length of the passive elements.

As the radius of the circles along which the passive vibrators are increasing, that is, as the passive vibrators move away from the active vibrator, the lengths of the passive vibrators do not change.

The utility model is illustrated by drawings, in which:

FIG. 1 - unbalanced omnidirectional director antenna

An asymmetric version of an omnidirectional director antenna contains passive director vibrators in the form of conductor sections 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26 and 27-28, located perpendicular to the flat conductive surface 1. The active vibrator 2-3 has a length of about a quarter of the length of the electromagnetic wave. One wire of the power line is connected to the edge 3 of the active vibrator, and the second to the conducting plane 1. Passive vibrator directors 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26 and 27-28 have a length shorter than the active vibrator, and with their proximal ends 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 , 26 and 28 are connected directly to the conductive surface 1.

The ends of the passive vibrator directors, indicated by points 6, 8,10, 12, 14, 16, 18, 20, 22, 24, 26 and 28 are located on circles whose centers coincide with each other and with point 4, which is the projection of the active vibrator 2-3 on a conductive surface. The distances between points 6 and 8, 8 and 10, 10 and 12, 12 and 6, located on the same circle, are equal. The distances between points 14 and 16, 16 and 18, 18 and 20, 20 and 22, 22 and 24, 24 and 26, 26 and 28, 28 and 14, located on the other circle, are also equal.

The lengths of the passive vibrator directors 5-6, 7-8, 9-10 and 11-12 are equal to each other. Also equal are the lengths of the passive vibrator directors 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26 and 27-28. The lengths of the passive vibrator directors 13-14, 15-16, 17-18, 19-20, 21-22, 23-24,25-26 and 27-28 are equal to the lengths of the passive vibrator directors 5-6, 7- 8, 9-10 and 11-12.

Omnidirectional director antenna works as follows.

When the power at points 3 and 4 is connected to the active vibrator 2-3, a standing current wave forms in it, and the active vibrator starts emitting electromagnetic waves. Since the length of the active vibrator is close to a quarter of the length of the electromagnetic wave, then, given the flat conductive surface, the maximum radiation is oriented normal to the axis of the active vibrator.

The electromagnetic field of the active vibrator excites currents in the passive vibrator directors 5-6, 7-8, 9-10, 11-12. The lengths of the passive vibrator directors are less than the length of the active vibrator, so a standing current wave is also formed in them. As a result, the passive vibrator directors, taking into account the flat conductive surface 1, create secondary electromagnetic waves, the maximum radiation intensity of which falls on the direction perpendicular to the axis of the passive vibrator directors located on the same radius of the circles.

The length of the passive vibrator directors 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26, 27 -28 less than the length of the active vibrator 2-3. Due to this, the capacitive nature of the resistance of the passive vibrator directors is achieved, and therefore the current in the passive vibrator directors lags behind the phase in the current in the active vibrator.

The field of the omnidirectional director antenna in the far zone is a superposition of the primary and secondary electromagnetic fields created by the active vibrator 2-3 and the passive vibrator directors 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26, 27-28, respectively. In the plane perpendicular to the passive vibrators-directors, in the direction from the active vibrator 2-3 to any of the passive vibrators-directors, for example, 5-6 lying with 2-3 on the same radius, the phase shifts obtained by the fields as a result of passing distances from one vibrators to another, will be compensated by phase shifts arising due to the phase difference between the currents in the vibrators 2-3 and 5-6, etc. As a result, all fields in the direction of the radius of the circles will add up in phase. By virtue of symmetry, this situation will take place in the direction of any of the directors. However, in the angle sector between the directors, partial compensation of the fields is possible, leading to irregularity of the radiation pattern.

In a plane passing through an active vibrator, an omnidirectional director antenna works like a wave channel antenna. In the directions perpendicular to the vibrators 2-3 and 5-6, 2-3 and 7-8, 2-3 and 9-10, etc., the primary and secondary fields are added in phase, which leads to an increase in directivity in the considered plane compared to a single asymmetric vibrator.

Due to the principle of mirror image, the influence of a flat conductive surface 1 in an asymmetric version of an omnidirectional director antenna can be taken into account by replacing this flat conductive surface with a mirror image of active 2-3 and passive vibrator directors 5-6, 7-8, 9-10 located above it, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26, 27-28 vibrators. In this case, the asymmetric version of the omnidirectional director antenna will become equivalent to its symmetrical version.

The operability of the proposed omnidirectional antenna is confirmed by the results of computer simulation of this antenna in the application in the MMANA-GAL Pro 2.5.5.30 program:

- FIG. 2 - antenna pattern with 4 passive directors-vibrators (active vibrator 2-3 and passive directors-vibrators 5-6, 7-8, 9-10, 11-12) in a plane perpendicular to the vibrators (in the omnidirectional plane);

FIG. 3 is a radiation pattern of an antenna with 4 passive vibrators directors (active vibrator 2-3 and passive vibrators directors 5-6, 7-8, 9-10, 11-12) in a plane passing through the active vibrator; FIG. 4-antenna pattern with 12 passive vibrators-directors (active vibrator 2-3, passive vibrators-directors 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26, 27-28), located in two circles, in a plane perpendicular to the vibrators (in the omnidirectional plane);

FIG. 5 is a radiation pattern of an antenna with 12 passive vibrators-directors (active vibrator 2-3, passive vibrators-directors 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24, 25-26, 27-28), located in two circles, in a plane passing through the active vibrator.

According to computer simulation, the gain in directional coefficient from the use of 4 passive directors-vibrators in comparison with a single asymmetric vibrator is about 1.9 dB.

The proposed omnidirectional director antenna in the plane perpendicular to the vibrators, remains omnidirectional, and in the plane parallel to it, has an increased coefficient of directional action of the antenna compared to a single asymmetric vibrator.

LITERATURE

1. Fedun I.V. Vibrator antenna of vertical polarization ... / Patent UA 88309 C2 of 12.10.2009

Claims (1)

An omnidirectional director antenna consisting of one active vibrator in the form of a conductor segment having a length of about a quarter of the electromagnetic wavelength, located perpendicular to a flat conductive surface and connected to the power line from the edge closest to the conductive surface, and many passive director vibrators in the form of wire segments having a length less than the length of the active vibrator located parallel to it and connected with one of its edges to a conductive surface, characterized in that the sibling director vibrators are arranged so that the projections of their midpoints on the conductive surface are located along circles whose center coincides with the center of the projection of the active vibrator onto this surface, at the same distance from the projections of their midpoints of the adjacent passive vibrators directors along the circular arc, while the lengths of the passive vibrators-directors belonging to one circle are equal, and with the increase in the radius of the circle on which the midpoints of the passive vibrators-directors are located, the length of the pass GOVERNMENTAL vibrators are not changed, and each circle has to at least three passive vibrators directors.

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