RU2654914C1 - Wireless antenna - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and can be used in radar and communication systems. Antenna with a set of emitters and excitation system, made in the form of a lattice structure with dimensions of elements greater than the wavelength. Emitters are located on the screen side of the dielectric plate and are made in the form of a set of metallization fragments (plates) in the form of polygons, and are arranged so that there are slits between their vertices, the distances between them being more than half the wavelength. Excitation system is executed on the rear side of the plate in the form of a set of conductors. One end of each of these conductors, opposite to the slits on the screen side of the plate, is superimposed on it and connected to the metallization of the neighboring polygon, and the others are connected to each other and form the antenna input/output.

EFFECT: technical result consists in size reduction, gain increase, transmitted power increase, in the possibility of signal transmission with vertical and horizontal polarization and with a large transmitted power and circular (elliptical) polarization.

1 cl, 8 dwg

Description

The invention relates to the field of electrical engineering and can be used as a broadband omnidirectional antenna with vertical, horizontal and circular (elliptical) polarization, where a loop antenna (Alford frames) and a clover leaf type antenna are known [C. Schelkunov, G. Friis, Antennas (theory and practice), ed. Soviet Radio, Moscow, 1955, p. 56, p. 500 [1]; H. Meinke, F. Gundlach, Radio Technical Reference, Gosenergoizdat, Moscow, 1960, p. 324, Biconical horns and disc-cone antennas R. Kuhn, Microwave antennas (microwave antennas), ed. Shipbuilding, Leningrad, 1967, p. 250, J. Slatter. Transmission of ultrashort radio waves. OGIZ, Moscow, Leningrad, 1946, p. 344.

Also known are broadband frequency-independent antennas, "EQUIANQULAR antennas" (equiangular antenna), whose electrical characteristics are theoretically independent of frequency. The design of such an antenna is determined only by setting angles, but includes concepts such as an infinitely large aperture size and infinitesimal distances between points of the excitation node. Typical examples of such structures are numerous helical, self-complementary, logarithmic and log-periodic antennas, as well as biconical horns with various types of spatial and surface structures. Ramsey V. Frequency-independent antennas, M., Mir, 1968, p. 3-23, 51-80, Collection of Ultrawideband Antennas, Moscow, Mir, 1964. Such designs cannot be realized as ideal frequency-independent antennas, since neither infinite dimensions of the antenna nor infinitely small dimensions of the excitation node can take place. The main disadvantage of the method of constructing frequency-independent antenna systems based on spiral, self-complementary, logarithmic and log-periodic structures is their cumbersomeness and lack of linear phase response, which does not allow them to be used in radar systems for collecting information, communication systems for transmitting and processing large information streams. Known antenna systems with increased bandwidth, the structure of which is a geometric progression of elements, where each subsequent / previous element is similar to the previous / next, differing only in the frequency expansion coefficient "f". Such elements are usually connected sequentially one after another, forming an antenna array with sequential excitation and longitudinal radiation (axial radiation array). The phase center of such an antenna in the process of signal emission (when the frequency changes) moves along the structure, which explains the violation of the linear phase response. The main and main disadvantage of such antennas is the bulkiness and nonlinearity of the phase response.

These antenna systems (AS) are effective devices that allow you to obtain acceptable technical parameters in a limited frequency band. But the lack of a developed theoretical basis for the construction of ultra-wideband antennas makes them expensive, the technical parameters obtained are not optimal, and the overall dimensions are large, often unacceptable for widespread use (use). When trying to create an antenna system with a bandwidth of several octaves, up to a decade there are significant technical difficulties with providing electrical parameters that provide a wide bandwidth and a high transmission rate of information flows.

Currently, the need for omnidirectional antennas with circular radiation patterns (LH), providing continuous coverage of the territory is very great, especially for television (television centers (towers, towers)) and cellular communication systems.

A technical solution is known, described in RF patent No. 2093936, priority dated September 5, 1995, where a wide-range circular antenna array is proposed that contains at least one flat dielectric base with metallized layers in which the excitation system and associated radiating opening are made, made from horn emitters placed at several levels and forming a closed second-order curve, the metallized layers of the antenna array in which the radiating aperture is made are located outside and They insulate the dielectric base with the excitation system and are interconnected.

This technical solution, as the closest to the declared technical essence and the achieved result, is taken as a prototype.

The disadvantages of this device are:

- relatively large dimensions, which leads to the need for additional measures to ensure mechanical strength and operability of the device,

- limited (low power) transmitted by an extended slot line,

- the difficulty of matching wave impedances relative to an extended slot line with a microstrip (strip) transmission line;

- limited bandwidth

- limited gain.

The aim of the invention is to develop an ultra-wide-band omnidirectional antenna with small dimensions, increased gain, large transmitted power, vertical and horizontal polarization, and with large transmitted power and circular (elliptical) polarization.

, а система возбуждения исполнена на тыльной стороне пластины в виде набора проводников, при этом один конец каждого из этих проводников, расположенных оппозитно щелям на экранной стороне пластины накладывается на нее и соединен с металлизацией соседнего многоугольника, а остальные соединены между собой и образуют вход антенны.This is achieved in that the omnidirectional antenna with a set of emitters and an excitation system is made in the form of a lattice structure with the dimensions of the radiating elements greater than the wavelength, characterized in that the emitters are located on the screen side of the dielectric plate, made in the form of a set of metallization fragments in the form of polygons and placed so that between their vertices there are slots, the distances between which are more than half the wavelength

and the excitation system is made on the back of the plate in the form of a set of conductors, with one end of each of these conductors located opposite the slots on the screen side of the plate superimposed on it and connected to the metallization of the adjacent polygon, and the rest are interconnected and form the antenna input.

The presented drawings explain the essence of the design and the principle of operation of the proposed device

In FIG. 1 shows three projections of an omnidirectional antenna, A is a top view, B is a straight view (full face), C is a side view (profile). Due to the circular symmetry of the antenna projection, the full face and profile coincide. In FIG. 2, 2a shows a radiating system executed on the screen side, and in FIG. 3, 3a — an excitation system executed on the back (current-carrying) side of the dielectric plate when structures with orthogonal and triangular (hexagonal) arrangement of elements are used as radiation sources. In FIG. 4 is a spatial radiation pattern (BH) of the antenna, and FIG. 5, 6 of its section in the main planes (azimuth, elevation).

щелями каждая, (источник магнитного излучения), так и многомодовый излучатель (L) с линейными размерами больше длины волны и возбуждаемый так же, как минимум двумя

щелями, расстояние между которыми больше половины длины волны, (источник электрического излучения),

The radiating antenna system is made on the screen side of the dielectric plate (Fig. 2, 2a) and (after partial removal of metallization) is a set of metallized fragments (plates) in the form of polygons (1), between the corners of which there are slots (4), while The radiation sources act as frames with current (7), which are formed by the metallized edges of polygons (1) and have a perimeter length greater than the wavelength and are excited by at least two

each with gaps, (a source of magnetic radiation), and a multimode emitter (L) with linear dimensions greater than the wavelength and excited in the same way by at least two

slots, the distance between which is more than half the wavelength, (source of electrical radiation),

On the back (current-carrying) side of the dielectric plate, an excitation system (Fig. 3, 3a) is made in the form of a set of current-carrying conductors (2, 3), with one end of each of these conductors (3) located opposite the slots (4) on the screen side plates, superimposed on them and electrically connected to the metallization of the adjacent polygon by means of a pin (jumper) (8) at the point (5), and the remaining conductors are electrically combined with each other and form the input / output of the antenna, connected to the connector (6).

In FIG. 1, 2, 2a, 3, 3a are designated:

1 - a set of fragments (plates) of metallization of a dielectric in the form of polygons of any configuration, which form a flat radiating structure, orthogonal, triangular, hexagonal and any other,

2, 3 - a set of current-carrying conductors on the back of the dielectric plate, (microstrip lines) forming an excitation system,

4 - a set of slots on the screen side of the dielectric plate, point sources (emitters), which are characterized by zero spatial extent, and are diverging,

5 - the end of the current-carrying conductor (3) located opposite the slots (4),

6 - input / output of the antenna (connector), the current-carrying core (conductor) of which is electrically connected to the excitation system on the back side, and the casing with metallization on the screen side of the plate,

щелями,7 - source of magnetic radiation - a frame with a current formed by the edges of metal plates of polygons and excited by at least two

slots

8 - a metal pin, through which the end of the current-carrying conductor (3) is electrically connected to the metallization of polygons, on the screen side of the plate,

9 - dielectric,

L - source of electrical radiation, (multimode emitter, the size of which is greater than the wavelength

L1 - the distance between the slots of the multimode emitter is more than half the wavelength

Since the gaps are formed by the vertices of the polygons and are diverging, their spatial extent is practically zero. It is known that such structures are characterized by a greater transmitted power than extended slot lines, in addition, with a similar slot design, the coordination of the wave impedances of the microstrip line with the slot is greatly simplified.

The following components of this field are usually distinguished from the physical concepts of the radiation process and the total energy of the antenna field:

- the energy of the traveling spatial wave, which is formed in the near zone of the antenna, which is the main (predominant) at large distances from the antenna;

- reactive energy equal to the difference between the magnetic and electric energies stored in the volume of the near zone of the antenna (the imaginary part of the stream of the Poynting vector);

- the bound energy involved in the mutual exchange between the electric and magnetic energies of the near field and the far-field radiation energy generating power.

One of the possible ways to solve the problem of creating small-sized ultra-wideband speakers is the symbiosis of electric and magnetic point sources (7, L), which are built into each other and combined by a common input / output (6). In this case, the opposite reactive energies of the near zone can partially or completely compensate each other, and the input impedance of the speaker (impedance) becomes almost active. In addition, this involves the conversion of a significant part of the power flow of reactive energy of the near field of the antenna into coupled energy, which helps to increase the intensity of the power flow of radiated energy.

The advantage and simplicity of this method is that, choosing the design of the emitters, their relative position, orientation, field structure and its polarization (in order to ensure spatial localization of electric and magnetic energies in the immediate vicinity of the antenna (near zone)), it is possible increase the flux density of the bound energy, through which the flow of radiated power is formed. In addition, since the near-field reactive energy supply decreases, the input impedance of the integrated antenna tends to be active. This means that its dependence on frequency is weakened, and this contributes both to the expansion of the passband and to the increase of the antenna efficiency.

Especially promising is the symbiosis of point magnetic and electrical sources (7, L), in which higher propagating modes are excited (exist), since such structures allow creating a dynamic (adjustable) amplitude-phase distribution (AFR) on the antenna aperture.

A design of two multimode elements orthogonally built into each other, each of which contains a frame with a current (7), the perimeter of which is longer than the wavelength (source of magnetic field formation) and a multimode emitter with linear dimensions greater than the wavelength (source of electric field formation) (L ), combined by a common input / output (6), are an example of solving one of the most relevant tasks of the present time.

Creation of small-sized ultra-wideband antenna emitters (elements) with increased transmitted power and increased gain.

каждый, которые объединены общим входом/выходом.In the General case, the radiating aperture of the antenna system is formed by M emitters (radiation sources of electric and magnetic fields) with linear dimensions greater than the wavelength and several points of excitation

each, which are combined by a common input / output.

Since the dimensions of each of the emitters in the antenna are larger than the wavelength, it is ultra-wideband, multimode. Moreover, its amplitude-phase distribution (AFR) can be both regulated (if it is excited by both even and odd modes, the ratio of amplitudes and phases of which can be controlled), and constant (controlled, but unregulated) (if it is excited only by odd modes) in this case, as a result of interference, only the main mode is retained at its aperture, all higher modes are suppressed due to the symmetry of the structure, which allows the formation of a superdirectional pattern with a high gain and a low level of side lobes .

The results of mathematical modeling of the spatial pattern of the omnidirectional antenna in the microwave range are presented in FIG. 4, they almost completely coincide with the measurement results on physical models. The cross-sections of the spatial pattern in the principal planes — azimuth and elevation — are shown in FIG. 5, 6.

From the above results it follows that an omnidirectional antenna designed on the described principles is characterized by a gain (gain) G = 6.9 dB and an input impedance Z = (60.5 + j9.4) Ohm, which is almost purely active. Standard turnstile antennas [2] from Hertz dipoles with radiation in the horizontal plane have KU G≤3 dB and input impedance Z = (75 + J42.5) Ohm.

From the foregoing, it becomes obvious that the tasks posed in the development of this technical solution are completely solved by the proposed design of an omnidirectional antenna, which implements dynamic AFR at the aperture, which makes it quite easy to solve the problems of obtaining a circular beam pattern, expanding the bandwidth and matching it with free space and with feeding feeder. The present invention is a very advanced microstrip antenna, performed using modern technology of printed circuit boards, characterized by compactness, low weight and high adaptability. This antenna will find wide application in electrical engineering.

Claims (1)

An omnidirectional antenna with a set of emitters and an excitation system, made in the form of a lattice structure with element sizes greater than the wavelength, characterized in that the emitters are located on the screen side of the dielectric plate, made in the form of a set of metallization fragments (plates) in the form of polygons and arranged so that between their vertices there are slots, the distances between which are more than half the wavelength, and the excitation system is executed on the back of the plate in the form of a set of conductors, with one con Each of these conductors, located opposite the slots on the screen side of the plate, is superimposed on it and connected to the metallization of the adjacent polygon, and the rest are interconnected and form the antenna input / output.

Images