RU2758663C1 - Multichannel filter with spatial selection based on a two-dimensional magnon crystal - Google Patents

Abstract

FIELD: microwave radio engineering.SUBSTANCE: invention relates to microwave radio engineering, in particular to devices on magnetostatic waves, and can be used as a power divider of a wave beam. The microwave signal filter contains a ferromagnetic film made of iron-yttrium garnet, which has the shape of a rectangle, the input and output converters of magnetostatic waves located on it, a number of holes are formed in the film, placed with the same period. The filter contains a second row of holes in the film, identical to the first and forming a two-dimensional magnon crystal with the first row, while the rows of holes are arranged symmetrically relative to the central axis of the rectangle along its edges, and the period of the holes is 350-400 mcm.EFFECT: ability to control the operating mode when transmitting information by changing the amplitude and phase of the spin wave.3 cl, 6 dwg

Description

The invention relates to microwave radio engineering, in particular to devices based on magnetostatic waves, and can be used as a power divider of a wave beam.

A device based on a magnonic crystal is known (US 10033078, IPC H01F10 / 32, publ. 24.07.2018) containing a waveguide with a spin wave, a magnon crystal structure in a waveguide with a spin wave, and a magnetoelectric cell functionally associated with the crystal structure of a magnon. The structure is adapted for selective filtering of the spectral component of the spin wave. The magnetoelectric cell contains an electrode for controlling the spectral component of the spin wave through a control voltage-dependent interaction between the magnetoelectric cell and the magnetic property of the magnon crystal.

The disadvantage of this device is the impossibility of complete transfer of the energy of the spin wave to one of the arms.

A frequency filter based on a magnonic crystal is known for controlling the frequency of spin waves (WO 2009145579, IPC H03H2 / 00, publ. 03.12.2009). The device consists of a waveguide based on a thin magnetic film. The waveguide has three sections, one of which is a periodic structure - a magnonic crystal formed by periodically changing the width or thickness of a ferromagnetic film. The disadvantage of this device is the inability to control the properties of the spectrum of spin waves by changing the control parameters.

The closest to the patented device is a multichannel microwave signal filter (see RF patent 2706441, H01P1 / 215, publ. controlling external magnetic field. The structure is formed by a film of yttrium iron garnet (YIG) and has the shape of a rectangle, on the short edges of which two local dividing paths are symmetrically made along the long axis in the body of the YIG film to form four areas for placing transducers of surface magnetostatic waves. A magnon crystal is formed between the ends of the dividing tracks along the long axis of the rectangle, which is a set of holes in the film, placed with the same period selected from the condition for the formation of a Bragg band gap in the range of wave numbers from 100 cm ^-1 to 300 cm ^-1 .

The problem to be solved by the invention is to construct a multi-channel filter with spatial selection based on a two-dimensional magnon crystal.

The technical result consists in the ability to control the mode of operation when transmitting information by changing the amplitude and phase of the spin wave.

The problem is solved by the fact that in a microwave signal filter containing a ferromagnetic film of yttrium iron garnet in the shape of a rectangle, the input and output converters of magnetostatic waves located on it, a number of holes located with the same period in the film along the line of the longitudinal axis of the rectangle, according to solution, it contains a second row of holes in the film, identical to the first, and forms a two-dimensional magnon crystal with the first row, while the rows of holes are located symmetrically relative to the central axis of the rectangle along its edges, and the period of the holes is 350-400 microns.

The microwave filter can have 40 holes, 20 in each row, the diameter of the holes in the film is 200 µm, and the distance between the centers of the holes is 400 µm.

The invention is illustrated by drawings, where:

fig. 1 is a schematic representation of a microwave;

fig. 2 - microwave, side view;

fig. 3 - spectral characteristics of the dependence of the transmission coefficient of the wave on the frequency at the outputs of the converters 6, 7, 8;

fig. 4-6 - maps of the intensity of the MSW propagating in the structure under study, at various values of the frequency, obtained by numerical modeling.

In the drawings, the numbers indicate:

1 - microstrip antenna (input transducer),

2 - a film of yttrium iron garnet (YIG),

3 - holes,

4 - magnonic crystal (microwave),

5 - non-magnetic substrate,

6, 7, 8 - output transducers of surface magnetostatic waves (MSW),

9, 10, 11 - spectral characteristics at the output of converters 6, 7, 8, respectively.

The microwave signal filter contains (Figs. 1 and 2) an input converter 1, a rectangular yttrium-iron garnet film 2, in which two rows of holes are made along the long axis of the rectangle 3. In this case, the set of holes in the film forms a two-dimensional magnon crystal 4 ( microwave). Holes 3 are placed with the same period of 350 - 400 microns. The input transducer 1 and the YIG film 2 are placed on a non-magnetic substrate 5 made of GGG. On film 2 there are output converters ПМСВ 6,7.8. The structure is placed in a magnetic field. The source of the magnetic field is not shown in the drawing.

General dimensions of a rectangular waveguide: length w = 8000 μm, width d = 940 μm, thickness h = 10 μm. The area width is a = 400 μm, the length of the magnon crystal 4 is S = 7800 μm, the hole diameter is b = 200 μm, and the region between the arrays of holes is e = 1500 μm.

The principle of operation of the patented filter is that the input microwave signal, the frequency of which must lie in the frequency range determined by the magnitude of the external constant magnetic field, is fed to the input transducer 1. Then the signal is converted into an MSSW propagating along the microwave. In such a system, the transfer of spin waves from the region between the arrays of holes into the microwave is observed. In the graphs in FIG. 4-6 shows how the intensity of the propagation of a spin wave varies with frequency. Therefore, by changing the frequency of the signal, you can achieve the maximum performance of the device.

The frequencies are selected based on the graph shown in FIG. 3. It can be seen from the spectrum that the main signal propagation occurs at frequencies in the range from 4.9 to 5.6 GHz, and the signal propagates most actively at frequencies of 5.1 and 5.5 GHz. Consequently, the performance of the device at these frequencies will be maximum.

Further, in FIG. Figures 4-6 show the intensity maps of the MSW propagating in the structure under study, for frequencies in the range from 4.9 to 5.6 GHz, obtained by numerical modeling.

From the spectral characteristics it can be seen that the signal arriving at the converters 7, 8 differs from the signal arriving at the converter 6, therefore, the filter can be controlled by changing the frequency value.

Thus, the presented data confirm the achievement of the technical result, which consists in constructing a controlled microwave power filter with the ability to transmit information by changing the phase and amplitude of the spin wave.

The second row of holes makes it possible to create three channels with good signal. As shown in FIG. 3, the signal passes actively in all three channels with spectral characteristics 9, 10, 11. This increases the efficiency of the signal and will improve its transmission in the microwave.

Claims (3)

1. A microwave signal filter containing a ferromagnetic film of yttrium iron garnet in the shape of a rectangle, the input and output transducers of magnetostatic waves located on it, a number of holes are formed in the film, located with the same period, characterized in that it contains a second row of holes in the film, identical to the first and forming a two-dimensional magnonic crystal with the first row, while the rows of holes are arranged symmetrically relative to the central axis of the rectangle along its edges, and the period of the holes is 350-400 microns. 2. The microwave filter according to claim 1, characterized in that the diameter of the holes in the film is 200 µm, and the distance between the centers of the holes is 400 µm. 3. The microwave filter according to claim 1, characterized in that it has 40 holes of 20 in each row.

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