RU2757866C1 - Antenna array on a radial waveguide - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: invention relates to antenna equipment, in particular, to broadband annular antenna arrays, and can be used in various broadband radio engineering systems for radio location, satellite and mobile communication. The technical result is achieved by the fact that the antenna array on a radial waveguide comprises an emitting system formed by printed low-quality patches located equidistantly along concentric circumferences lying in a plane parallel to the plane of the radial waveguide, wherein the centres of the concentric circumferences are aligned with the geometric centre thereof; a matching system formed by coaxial pins located perpendicular to the plane of the emitting system, and a non-uniform dielectric filling the space between the emitting, matching systems, and the radial waveguide.

EFFECT: reduction in the level of side lobes of the directivity pattern, decrease in the voltage coefficient of the standing wave, simplification in the antenna array matching.

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Description

The invention relates to antenna technology, in particular to broadband ring antenna arrays, and can be used in various broadband radio systems, such as radar, satellite and mobile communications.

Known design of the antenna array on a radial waveguide with non-protruding emitters in the form of slots (US patent 5175561 A - prototype).

The circular concentric antenna array, taken as a prototype, uses slots cut in the upper part of the radial waveguide as emitters, and to reduce reflections in the radial waveguide, a metal sheet is used, located at an angle of 45 to the plane of the radial waveguide along its perimeter.

The disadvantages of the described design include:

- a matching step transition is required for each emitter;

- it is necessary to optimize the design of each radiating element to reduce the reflection from the side walls of the radial waveguide;

- the use of an absorber in a radial waveguide reduces the reliability of the antenna array;

- it is necessary to use a protective fairing;

- the complexity of the implementation of an antenna system with electronic scanning;

The technical result of the invention is to improve the technical characteristics of the antenna array, which consists in lowering the level of the side lobes of the antenna array radiation pattern, reducing the voltage standing wave ratio, simplifying the matching of the antenna array.

The technical result is achieved by the fact that the antenna array is made on a radial waveguide with a non-uniform dielectric filling, to ensure the required phase distribution. The emitting system is a low-quality patch in the form of a regular hexagon located equidistantly along concentric circles. Communication with the waveguide is carried out by coaxial probes immersed in a radial waveguide.

The essence of the invention is illustrated by the drawings, in which FIG. 1 shows a model of the inventive annular antenna array, FIG. 2 shows a low-Q patch and a coaxial probe; FIG. 3 illustrates a lumped element coaxial pin system for reflection compensation used in the present invention; FIG. 4 shows the voltage standing wave ratio at the input of the inventive antenna array without a system of matching coaxial pins, obtained as a result of numerical simulation; FIG. 5 shows the voltage standing wave ratio at the input of the inventive antenna array with a system of matching coaxial pins, obtained as a result of numerical simulation; FIG. 6 shows the directional diagrams of the design of the inventive antenna array without a system of matching coaxial pins, obtained as a result of numerical simulation; FIG. 7 shows the directional diagrams of the design of the inventive antenna array with a system of matching coaxial pins, obtained as a result of numerical simulation, FIG. 8 shows the layout of the inventive antenna array, FIG. 9 shows the directional diagram measured experimentally.

Antenna array on a radial waveguide 1 contains an input 4, a radiating system formed by low-quality patches 3, located equidistantly along concentric circles in a plane parallel to the plane of the radial waveguide 1. The centers of the concentric circles coincide with its geometric center. Coaxial probes 5 are used to connect waveguide 1 with low-quality patches 3. The matching system is formed by coaxial pins 6 located perpendicular to the plane of the radial waveguide 1. Inhomogeneous dielectric 2 fills the space between the emitting, matching systems and radial waveguide 1.

The proposed antenna array works as follows.

The high-frequency signal arriving at the input 4 excites the radial waveguide 1. The wave, propagating from the center of the radial waveguide to its edges, excites the coaxial probes 5 immersed in the radial waveguide 1 and providing the connection of the low-Q patches 3 with the radial waveguide 1. The use of an inhomogeneous dielectric 2 allows you to select the required phase distribution, and the amplitude distribution is set by choosing the immersion depth of coaxial probes 5 coming from low-quality patches 3.

The emitting system, which is formed by low-quality patches 3, located equidistantly along concentric circles lying in a plane parallel to the plane of the radial waveguide 1, while the centers of the concentric circles coincide with its geometric center, coaxial probes 5, providing the connection of low-quality patches 3 with the radial waveguide 1, a matching system formed by coaxial pins 6 located perpendicular to the plane of the radial waveguide 1 and an inhomogeneous dielectric 2 filling the space between the radiating, matching systems and the radial waveguide 1.

In a radial waveguide antenna array, there is a problem with sidewall reflections. This problem is especially relevant in small antenna arrays.

In the claimed technical solution, to reduce reflections from the walls of the radial waveguide 1, a system of coaxial pins 6 is used, loaded on lumped resistors (Fig. 2). The system of coaxial pins 6 is located along the perimeter of the radial waveguide 1 at a quarter wave distance from the side wall. Each coaxial pin 6 is driven by a 50 ohm lumped resistor. Thus, the system of coaxial pins 6 plays the role of a matched load at the edges of the radial waveguide 1. With a grating diameter of 325 mm, the system consists of 68 coaxial pins.

The use of the coaxial pin system 6 shown in FIG. 3, made it possible to improve the voltage standing wave ratio in a wide band and reduce the level of side lobes by an average of 3-5 dB, depending on the frequency. The voltage standing wave ratio at the antenna array input is shown in FIG. 4 and 5.

One of the main characteristics of a radial waveguide antenna array is its spatial directional pattern. The radiation patterns calculated in the course of the numerical experiment are shown in Fig. 6 and 7.

An example of practical implementation.

The applicant and the authors made a prototype of the antenna array (Fig. 8) and measured the radiation pattern (Fig. 9).

Tests of a full-size sample of the antenna array have fully confirmed the correctness of the design and technological solutions.

The use of the proposed technical solutions will improve the indicators of electrical parameters, in particular, the voltage standing wave ratio, the level of side lobes, simplify the design of the antenna array using a planar emitting system, improve the manufacturability, and also improve the weight and size indicators.

Claims (3)

1. Antenna array on a radial waveguide, characterized in that it contains a radiating system, which is formed by printed low-Q patches located equidistantly along concentric circles lying in a plane parallel to the plane of the radial waveguide, while the centers of the concentric circles coincide with its geometric center, the matching system formed by coaxial pins located perpendicular to the plane of the radiating system, and an inhomogeneous dielectric filling the space between the radiating, matching systems and the radial waveguide. 2. Antenna array on a radial waveguide according to claim 1, characterized in that the printed low-Q patches have the shape of a regular hexagon, and the connection of the low-Q patches with the waveguide is carried out by coaxial probes immersed in the radial waveguide. 3. Antenna array on a radial waveguide according to claim 1, characterized in that the matching system consists of coaxial pins located from the outer edge of the radial waveguide at a distance equal to a quarter of the wavelength of the radiated electromagnetic signal, and each is loaded on a matching resistor.

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