RU2268520C1 - Antenna - Google Patents

Abstract

FIELD: antennae engineering, possible use for engineering of radio-based systems with signals with circular polarization.

SUBSTANCE: antenna consists of three mutually perpendicular electric vibrators with electric shoulder dimensions l_x, l_y, l_z, and combined centers and power splitter. Between outputs of power splitter and inputs of electric vibrators, phase shifters are connected. For given current distribution and direction θ,φ electric shoulder dimensions l_x, l_y, l_z of electric vibrators and vibrators excitation phase ψ_x,ψ_y,ψ_z should be satisfactory for given system of inequalities.

EFFECT: generation of ellipticity coefficient in given direction, being close to one without decrease of antenna energy.

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Description

The invention relates to antenna technology and can be used as part of radio systems using circularly polarized signals.

A turnstile antenna is known that contains two mutually perpendicular electric vibrators with combined centers and a phase shifter that provides a phase shift when the vibrators are excited by an angle of 90 degrees [1, p. 251, fig. 10.8a]. The disadvantage of this antenna is that when the direction of arrival of the useful circular polarization signal from the normal to the aperture surface of the antenna deviates, the polarization of the receiving antenna decreases.

A device is known that provides independent reception of the components of an electromagnetic wave by an orthogonal pair of vibrators forming a turnstile antenna and forming a single ellipticity coefficient at low and medium elevation angles [2]. The disadvantage of this antenna is that when the direction of arrival of the useful signal of circular polarization from the normal to the aperture surface of the antenna deteriorates, the energy characteristics of the receiving antenna deteriorate.

The closest in technical design to the proposed antenna is an antenna consisting of three mutually orthogonal vibrators with combined centers, the inputs of the electric vibrators of which are connected to the outputs of the power divider, and the electrical dimensions of the shoulders of the vibrators are selected so that in a given direction the formation of “zero” vector Beam antenna [3]. The disadvantage of this antenna is that the common-mode excitation of the vibrators does not allow its use in communication channels with circular polarization.

The invention is aimed at solving the problem of forming a single coefficient of ellipticity of the useful signal in a given direction while maintaining the energy characteristics of the antenna.

The essence of the invention lies in the fact that in an antenna system consisting of three mutually perpendicular electric vibrators with electric arm sizes l _x , l _y , l _z and combined centers, and a power divider having one input and three outputs, between the outputs of the power divider and inputs electric vibrators incorporated phase shifters, wherein for a given current distribution and direction θ, φ electrically shoulder dimensions l _x, l _y, l _z electric dipoles and excitation vibrators phase ψ _x, ψ _y, ψ _z must satisfy the inequality system Obtained based on the relationship given in [4]:

Where

F _θ (θ, φ) = (F _x (θ, φ) cosφ + F _y (θ, φ) sinφ) cosθ-F _z (θ, φ) sinθ;

F _φ (θ, φ) = F _y (θ, φ) cosφ-F _x (θ, φ) sinφ;

J _x (x), J _y (y), J _z (z) - distribution of surface currents along electric vibrators;

K _e0 is the minimum allowable ellipticity coefficient.

Figure 1 shows the proposed antenna. Figure 2 illustrates the power connection to the antenna. Figure 3 shows a cross section of the dependence of the coefficient of ellipticity within the upper hemisphere of the visible angles of the proposed antenna for the first direction specified in the table.

The table shows the electrical dimensions of the shoulders of electric vibrators and the values of the phases of excitation of the vibrators, allowing to form the ellipticity coefficient K _e > K _e0 for a number of given directions (θ, φ).

The antenna consists of three mutually perpendicular electric vibrators with aligned centers, the electrical dimensions of which are respectively equal to l _x , l _y , and l _z (figure 1). The inputs of the electric vibrators 1, 2 and 3 are connected through phase shifters 4, 5 and 6 to the outputs of the power divider 7, which has one input (figure 2). For a given current distribution and direction θ, φ, the electrical dimensions of the arms l _x , l _y , l _{z of the} electric vibrators and the phase shifts ψ _x , ψ _y , ψ _z must satisfy the system of inequalities (1) - (3) and can be chosen in the course of solving the problem of maximizing the value of K _e under additional restrictions of the form (2), (3) by any of the known methods.

The operation of the device is organized as follows.

The Cartesian coordinate system is selected so that the electric vibrator 1 is oriented along the OX axis, the electric vibrator 2 is along the OY axis, and the electric vibrator 3 is along the OZ axis (Fig. 1). The input of the power divider 7 receives a modulated high-frequency signal from the generator. At the outputs of the power divider 7 are formed three identical in amplitude and phase of the signal. Each of the signals is phase shifted using phase shifters 4-6 by the amount ψ _x , ψ _y , ψ _z, respectively. The generated signals excite electric vibrators 1, 2 and 3. In a given direction θ, φ, the quantity K _e > K _e0 can be formed if inequalities (1) - (3) are satisfied. The values of the components of the vector pattern F _θ (θ, φ) and F _φ (θ, φ) are determined by the superposition of the vector potentials F _x (θ, φ), F _y (θ, φ) and F _z (θ, φ). In this case, the choice of the electrical dimensions of the arms of the vibrators determines the amplitude values of the vector potentials, and the phase shifts introduced by the phase shifters determine the phase values of the vector potentials. This means that the vector from these six parameters will completely determine the magnitude of the ellipticity coefficient. Moreover, conditions (2), (3) follow from the physical meaning of the desired parameters, and condition (1) is the criterion for choosing an acceptable solution.

The table shows the values of the electrical dimensions of the shoulders l _x , l _y , l _{z of the} electric vibrators 1, 2 and 3 and the phase shifts ψ _x , ψ _y , ψ _z , allowing the formation of K _e > K _e0 for the case of a sinusoidal distribution of currents in given directions in upper half-plane. In the lower half-plane, the vector antenna bottom with K _e > K _e0 can be formed for the same l _x , l _y , l _z , but θ and φ will increase by π.

Table No. p / p Zero Direction Nam, Degrees Electrical dimensions of emitters, X Phase Shifts, Degrees θ φ l _x l _y l _z ψ _x ψ _y ψ _z one 35 35 0.825 0.313 0.345 -4,133 69,090 -77,662 2 45 35 0.719 0 0.328 15,543 65,517 -118,066 3 25 35 1,104 0.362 0.337 -3.854 73,208 -77,589 four 35 fifteen 1,141 0.325 0.327 0.752 70,452 -96.081 5 35 115 0.683 0.182 0.265 -0.763 82,641 -99,670

Figure 3 shows a cross section of the dependence of the coefficient of ellipticity within the upper hemisphere of the visible angles of the proposed antenna for the first direction specified in the table.

Thus, the obtained technical result achieved by introducing into the antenna, consisting of three mutually perpendicular electric vibrators with electric arm sizes l _x , l _y , l _z and combined centers and a power divider, between the outputs of the power divider and the inputs of the electric vibrators of the phase shifters, providing phase shift signals of the same power, consists in the formation in a given direction of the ellipticity coefficient close to unity without reducing the antenna power.

Information sources

1. Problems of antenna technology / Ed. L.D. Bahrakh, D.I. Voskresensky. - M .: Radio and communications, 1988 .-- p.277.

2. Auth. testimonial. 1376146 (USSR). Phased antenna array with circular polarization of the field / E.P. Abrakin, L.L. Bazeyan and A.I. Brazhenko // 1988, Bull. fig. Number 7.

3. Patent No. 2080713 (RF). Antenna / D.D. Gabrielyan, S.E. Mishchenko, V.V. Shatsky // 1997, Bull. fig. No. 15, 6 H 01 Q 21/24.

4. Gostyukhin V.L., Grineva K.I., Trusov V.N. Problems of designing active headlights using a computer / Ed. V.L. Gostyukhina. - M .: Radio and communications, 1983. - p. 248.

Claims (1)

An antenna consisting of three mutually perpendicular electric vibrators with electric arm sizes l _x , l _y , l _z and combined centers, a power divider having one input and three outputs, characterized in that phase shifters are connected between the outputs of the power divider and the inputs of electric vibrators, and for a given current distribution and direction θ, φ, the electric dimensions of the arms l _x , l _y , l _z , electric vibrators and the excitation phases of the vibrators ψ _x , ψ _y , ψ _z , must satisfy the system of inequalities:

l _x >0; l _y >0; l _z >0; 0 ° ≤ψ _x <360 °; 0 ° ≤ψ _y <360 °; 0 ° ≤ψ _z <360 °, Where

F _θ (θ, φ) = (F _x (θ, φ) cosφ + F _y (θ, φ) sinφ) cosθ-F _z (θ, φ) sinθ; F _φ (θ, φ) = F _y (θ, φ) cosφ-F _x (θ, φ) sinφ;

J _x (x), J _y (y), J _z (z) - distribution of surface currents along electric vibrators; To _e0 - the minimum allowable value of the coefficient of ellipticity.

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