SU1741204A1 - Magnet antenna - Google Patents

Abstract

Usage: Antenna technology for receiving and processing signals. SUMMARY OF THE INVENTION: The magnetic antenna comprises a ferromagnetic core with a pump winding and a signal winding. Two low-pass filters, two high-pass filters, two concentrated selection filters, three controllable dividers and a dc generator were introduced. The ferromagnetic core is made in the form of an isotropic flat disk. The possibility of electronic control of the antenna pattern in the azimuthal plane has been achieved. 3 ill., 1 tab.

Description

The invention relates to antenna technology and is intended to receive and process signals.

A known magnetic antenna comprising a core of ferromagnetic material, a pump winding and a signal one. However, such an antenna does not allow operational control of the radiation pattern, since the arrangement of the windings allows only one azimuthal direction of the characteristic directional pattern (DN) of such antennas - the figure eight, moreover, this antenna has a large manufacturing complexity due to the complex two-window structure of the core, in addition, the antenna is The three-circuit design — pumping, signaling, and coupling circuits — which increases the labor intensity of production and prevents the control of the DD her orientation.

The closest to the present invention is a ferrozond used as a magnetic antenna and containing a ferromagnetic core placed on

it is mutually orthogonal to the signal winding and the pump winding, the pump generator, but such an antenna, despite the orthogonality of the arrangement of the windings, has all the disadvantages of the analog.

The purpose of the invention is to provide the possibility of electronic control of the radiation pattern in the azimuthal plane.

The goal is achieved by introducing two low-pass filters (LPF), two high-pass filters (HPF), two concentrated selection filters (FSS), the first, second and third controlled dividers (UD) and DC generator into the magnetic antenna. The output of which is connected to the input of the first DD, the outputs of which are connected via the LPF to the outputs of the signal winding and the pump winding, the output of the pump generator is connected to the input of the second DD, the outputs of which are connected via an HPF with the outputs of the signal winding and the pump winding red connected through first and second inputs FSS

(L

WITH

-h

hO

about

s

The third CA, the output of which is the output of the magnetic antenna, while the ferromagnetic core is made in the form of a flat disk of an isotropic ferromagnetic material.

FIG. 1 shows a core with windings located on it; in fig. 2 - structural diagram of the proposed magnetic antenna; in fig. 3 - rotation of the magnetic axis of the antenna (MOA).

The magnetic antenna consists of a core 1 and pump windings 2 and a signal 3 (see Fig. 1) made on it, two identical low-pass filters (LPF) 4 and 5, the first controlled divider 6, the DC generator 7, two filters equal high frequencies (HPF) 8 and 9, second controlled splitter (UD) 10, alternator 11, two identical filters of concentrated selection (FSS) 12 and 13, third controlled splitter (UD) 14.

Magnetic antenna works as follows.

A constant current supplied through the low-pass filter 4.5 and a controlled divider (UD) b (all three dividers can be made in the form of a potentiometer) from the DC generator 7 to the pump winding 2 and signal 3, serves to magnetize the core and control magnetic axis of the antenna (MOA). Considering the axis of the pump winding 2 for x, and the axis of the signal winding 3 for y, we have

expression

 /

tg y / lu / px,

where y is the angle of MOA;

/, у «у - projections of dynamic permeability along the axis m.

To rotate the MOA by 360 °, it is only necessary to use a controlled divider 6, which, using weights, can rotate the axis by 180 °, after which the polarity of the current supplied to the pump windings 2 and signal 3 is achieved. 360 °. In accordance with the obvious and known positions of the parametric theory, the vector of the intensity of the incident field H will be projected onto the MOA, i.e. The azimuthal angle of arrival of the incident wave will vary in accordance with the rotation of the MOA, the penetration of high-frequency oscillations along the direct-current path is prevented by the low-pass filter. The presence of a constant field acting on the core leads to the possibility of working on the first harmonic of the pump field (parametric constant displacements).

The pumping field is induced by alternating current flowing from divider 10 and highpass filter 8,

9 (which prevent the passage of direct current), and with the help of a controlled divider, it is induced so that the vector field HF is perpendicular to the vector of the constant field B0. Most often, a simple sinusoidal oscillation with a frequency is used as a pump (He.

Considering the frequency of the incident wave W and taking into account the first harmonic system operation, we have in the output spectrum frequencies a) + (Op (with (On)); larger in amplitude than others in the same spectrum. FSS 12 are tuned to one of these frequencies , 13 into the output circuits, and with the help of the weighting factors selected by the third controlled divider 14, the output circuit establishes a mode in which the axis of the quasi-output winding — the total vector B2c is perpendicular to the vector Bn.

In accordance with the canons of the parametric theory, the output emf of a magnetic antenna will be calculated by the formula:

eЈ -1S Nfio e / 4 Nn (d / d t) cos / 1 fi (d HH / dt) cos /

+

fig - slna sin / 3

J

(l cosacos. where Hn is the intensity of the falling floor; Hn is the intensity of the pumping floor;

/ 4 d В / Хио d Е), уИ B / (u0 H) are the main components of the dynamic permeability tensor of the ferromagnetic core / i, Hi (t), called the differential and normal permeability, respectively (an asterisk indicates the need to take into account the demagnetizing factor );

S is the equivalent cross-sectional area of the core;

W is the number of turns of the signal winding;

E is the unbalance factor characterizing the non-identity of half-elements magnetic.

filament antennas; a ./3 Nn, Ј angles between vectors;

° j is the unit vector defining the direction of the axis of the signal winding;

i0 4л 10 7Гн / м; Ј 1 - construction factor.

In this case, when the magnetic bias field B0 is sufficient to saturate the core, if the field of the incident wave is absent, then at the inputs of the third controlled divider, under the action of pumping, an emf of doubled frequency occurs. If the value of the useful signal field (incident wave) is different from zero, then only in the spectrum of the output EMF does it carry useful information.

To clarify the principle of antenna rotation, as functions of MOA, consider the image of limiting cases for the synthesis of MOA on the proposed antenna with right windings (i.e., windings are made in a clockwise direction). Denote the winding numbers 2 and 3 (see Fig. ZD-g).

As can be seen from FIG. 3 a-d in each case while maintaining polarity on the windings and changing the amplitude of the direct current from O to max and vice versa (on the corresponding windings) MOA, and accordingly the DN of the magnetic antenna (since Im MOA in the optimal case, i.e. at the maximum output current of the antenna). Thus, a smooth and synchronous change of the amplitudes of And and h - one current to increase, and the other to decrease, with the corresponding polarity of the windings, gives the rotation of MOA by 360 ° (and, accordingly, the DN of the magnetic antenna). We illustrate it this way - the location of the MOA in the quadrants of FIG. 3 d possible under the conditions of table. one.

Those. when the polarity of the windings of the antenna (Fig. 3 d) in accordance with the table. and a smooth change in the amplitudes of the currents And and la, the MOA will be in the quadrant indicated in the table. The vector Hn the pumping floor should be perpendicular to the MOA. The orientation of the HH is depleted in the same way as the MOA using weights.

In addition to the possibility of operational control of the DN with a rotation of the characteristic figure of 360 °. This magnetic antenna has the following advantages over other types and types of antennas:

- allows to carry out the magnetization reversal of the core (component B0t (x, y) of the field of constant magnetic bias) more efficiently with the help of the pump field, since this reduces the power consumed by the magnetic antenna, unlike other variants, which in turn

leads to a decrease in noise level;

-Barkhausen jumps are reduced, since the tilting of rigid magnetization vectors is more qualitatively carried out by the transverse field;

- the sensitivity threshold of the magnetic antenna is reduced;

-simplifies its manufacture.

In the proposed device, the quality of reception of the useful signal is increased and the manufacturability of this antenna is improved.

Claims (1)

Magnetic Antenna Containing a Ferromagnetic Core with Placed on it is mutually orthogonal to the signal winding and the pump winding, a pump generator, characterized in that, in order to enable electronic control of the radiation pattern in azimuth plane, two low-pass filters (LPF), two high-pass filters (HPF), two filters of concentrated selection (FSS), the first, second and third controlled dividers (UD) and a DC generator, the output of which is connected to the input of the first DD, the outputs of which through the low-pass filter are connected to the outputs of the signal winding and the pump winding, the output of the pump generator is connected to the input Second UD, the outputs of which are connected via HPF with the outputs of the signal winding and pump winding, which, in turn, are connected through the first and second FSS to the inputs of the third UD, the output of which is the output of the magnetic antenna, while the ferromagnetic core is made in the form of a flat disk of isotropic ferromagnetic material. / / H FIG. one  L / V / h Fl 2 55  four