RU169506U1 - SUPER HIGH FREQUENCY FERRITE FILTER - Google Patents

Abstract

The utility model relates to radio electronics and microwave technology, and more specifically to electrically tunable waveguide filters containing miniature spherical samples magnetized by an electromagnet made of monocrystalline ferrites as resonators. The microwave filter contains two rectangular waveguides intersecting at right angles, separated along wide walls by a dividing wall with communication holes, opposite which spherical ferrite resonators, an electromagnet with pole tips are installed, while short-circuit walls are made along the longitudinal symmetry axes of the intersecting waveguides in the center of each waveguide which form four short-circuited waveguides. The technical result is the simultaneous transmission of two signals. 4 s.p. f-ly, 8 ill.

Description

The invention relates to radio electronics and microwave technology, and more particularly, to waveguide filters electrically tunable in frequency, containing miniature spherical samples magnetized by an electromagnet as resonators made of single-crystal ferrites.

Waveguide filter designs are promising for short wavelengths of the microwave range, where the dimensions and mass of the waveguides are small, and the use of coaxial transmission lines is difficult. Moreover, in these filters, along with ferrite resonators (FRs) made of iron-garnet garnet and lithium spinel, hexaferrite single crystals are used that have large fields of crystallographic anisotropy, which reduces the size of the electromagnet and the current consumption.

Known microwave ferrite filter millimeter wavelengths (see B.M. Lebed, V.A. Lavrovich, I.O. Khokhlyshev. - Ferrite filters and their application, M, reviews on electronic technology, Ser. 1, Microwave electronics, 10, 1982), which includes two rectangular waveguides that are connected along wide walls at right angles, separated by a thin partition with a communication hole and short-circuited near the communication hole. On both sides of the partition opposite the communication hole made at the intersection of the longitudinal axes of the waveguides, there are RFs, one in each waveguide. In the known filter, which contains two RFs, directly interconnected with each other through an opening in the partition, and also mutually orthogonal waveguides, the out-of-band obstacle is substantially increased (up to 50 dB in the frequency band 26-37.5 GHz of the 7.2 × 3 cross-section of the waveguide, 4 mm ² ), frequency selectivity (up to 12 dB / oct), the level of spurious resonances decreases (up to -25 dB).

In the known microwave ferrite filter, with increasing frequency and, consequently, decreasing the cross section of a rectangular waveguide, transmission losses increase from 4 to 8 dB, and the barrage outside the band decreases from 50 to 35 dB. If necessary, in order to increase the barrage, especially at high frequencies, the number of FRs can be increased in the known filter to three. For this, instead of a thin (0.1 mm) partition, it is necessary to use a thicker (≈0.5 mm) partition, in which a third spherical RF is placed in the communication hole. However, this increases the gap between the pole pieces of the electromagnet, which increases the mass, dimensions and current of the electromagnet.

A known filter on rectangular waveguides (see application W02008068025, IPC Н01Р-001/203 Н01Р-001/218, published June 12, 2008), comprising a housing in which two tunable spherical RFs are located that are located on two filter arms. At least one of the filter arms contains a substrate on which a slit line is drawn extending in the direction of electrical connection of the filter. Two filter arms are connected by a communication hole, and spherical ferrite resonators are located inside each of the two filter arms on two sides of the communication hole.

The disadvantages of the known filter are the complexity and complexity of manufacturing, lower barrage due to the lack of orthogonality of microwave magnetic fields in the RF distribution area, and the impossibility of transmitting two or more signals simultaneously.

Known waveguide magnetically tunable filter (see application W0200803483, IPC Н01Р-001/203 Н01Р-001/218, published January 10, 2008), which includes a housing in which two tunable spherical RFs are located that are located on two filter arms. Two filter arms are connected by a communication hole, and spherical ferrite resonators are located inside each of the two filter arms on two sides of the communication hole. One of the filter arms contains a layer on which a coplanar line is drawn extending in the direction of electrical connection of the filter.

The disadvantages of the known filter is the complexity in manufacturing, the inability to transmit simultaneously two signals. The use of two separate filters to solve this problem increases the size and power consumption of the electronic system.

Known microwave filter ferrite (see patent US 4888569, IPC P0131.128, published 12.19.1989), which coincides with this decision for the largest number of essential features and adopted for the prototype. The prototype filter includes two short-circuited parallel waveguides intersected along wide walls at right angles by a third waveguide, short-circuited at both ends. The wide wall of the third waveguide, dividing it from the first two waveguides, is made in the form of a thin partition with two communication holes at the ends, against which the FR are installed.

The advantages of the prototype filter are a high barrage outside the passband (≈70-75 dB) with not very high resonant transmission loss (12-14 dB). The main disadvantage of the known filter is the inability to transmit simultaneously two signals. In addition, there is parasitic leakage of the signal at a frequency that is resonant for a third waveguide short-circuited on both sides.

The objective of this technical solution is to develop a microwave ferrite filter controlled by one electromagnet, which would ensure the simultaneous transmission of two signals.

This object is achieved in that the microwave filter contains two rectangular waveguides intersecting at right angles, separated along wide walls by a separating partition with communication holes, spherical RF opposite the communication holes and an electromagnet. New in the microwave ferrite filter is the implementation of short-circuiting walls along the longitudinal axis of symmetry of the waveguides at the center of intersection of each waveguide, forming four short-circuited waveguides.

Pole lugs can be placed in recesses made in the wide walls of the waveguides.

In each short-circuited waveguide, along their longitudinal axes of symmetry, rectangular dielectric inserts with an upper facet beveled towards the distal end and facing the corresponding ferrite resonator with an oblique end face can be installed on a wide wall.

The dividing wall can be made both thin (t≈0.1 mm) and thick (t≈0.5 mm). In the second case, a DF can be installed in the communication hole of the thickened partition, and a two-channel filter from a two-cavity filter turns into a three-cavity filter.

The present utility model is illustrated in the drawing, where:

in FIG. 1 shows a simplified illustration of a real microwave ferrite filter without the upper part of an electromagnet (top view) with a cutout in the region of intersection of rectangular waveguides;

in FIG. 2 shows a side view of a real microwave ferrite filter with a longitudinal section along the inputs of the signal transmission channels;

in FIG. 3 shows, on an enlarged scale, a sectional view of cylindrical sampling in one of the pole pieces opposite to the RF of one of the signal transmission channels;

in FIG. 4 shows, on an enlarged scale in section, the performance of cylindrical samples in two pole pieces opposite the FR of one of the signal transmission channels;

in FIG. 5 shows a simplified longitudinal section of the placement of dielectric beveled rectangular inserts in the present filter along the longitudinal symmetry axes of each waveguide;

in FIG. 6 shows a side view of a real filter with a thick separating partition, in the communication holes of which two additional FRs are placed one at a time;

in FIG. 7 shows a top view of a lower rectangular waveguide with a short-circuit wall, two FRs and with a wide wall oriented at a right angle to the intersected upper waveguide;

in FIG. Figure 8 shows a partition separating rectangular waveguides intersecting at right angles with two communication holes.

Depicted in FIG. 1, FIG. 2, this microwave ferrite filter contains two rectangular waveguides 1, 2 intersecting at right angles, separated by wide walls 3 by a dividing wall 4 with communication holes 5, spherical resonators 6 located near short-circuit walls 7 opposite the communication holes 5, electromagnet 8 with pole tips 9 Short-circuiting walls 7 are made along the longitudinal axis of symmetry of the waveguides 1, 2 at the center of intersection of each waveguide, forming four short-circuited waveguides 10, 11, 12, 13. The pole pieces 9 in order to ensheniya working air gap and, consequently, reduce the power consumption and size of electromagnet 8 may be placed in recesses 14 in the walls of the broad waveguide filter in the placement of both pairs FF 6 (see. FIG. 3). If you need to create the necessary detuning of the resonant frequencies of the FR 6 in the channels of the short-circuited waveguides 10, 12 and 11, 13, you can use metal gaskets placed opposite one of the signal transmission channels at the junction of the upper and lower parts of the pole pieces 9. If this method is not very effective, adjusting the resonant frequencies of the signal transmission channels, it is possible to make a cylindrical recess 15 in one or both of the pole pieces embedded in the wide walls of the waveguides FF 6 9 opposite one of the signal channels (FIG. 3, FIG. 4). In order to increase the concentration of the microwave field in the RF 6, which are slightly offset from the longitudinal axis of symmetry in each short-circuited waveguide 10, 11, 12, 13, it is possible to arrange rectangular dielectric inserts 16 with the upper face oblique to the distal end 17 along the longitudinal axis of symmetry of each waveguide, and facing the opposite end 18 to the corresponding FR 6 (that is, having a triangle shape in longitudinal section) (see Fig. 5). The dielectric inserts 16 can be made with dimensions in cross section that provide the maximum contraction in them of the microwave field of rectangular short-circuited waveguides 10, 11, 12, 13, that is, they can act as dielectric waveguides placed in a metal screen. Moreover, for rectangular short-circuited waveguides 10, 11, 12, 13, not only the height (as in the case of waveguides without dielectric beveled rectangular liners) can be reduced, but also the width. This allows, if necessary, to reduce the dimensions of this microwave filter.

The dividing wall 4 can be thickened, and two additional RF 19 can be placed one at a time in the communication holes 5 of this wall 4 (see Fig. 6). This allows a two-cavity two-channel filter to be converted into a three-cavity two-channel filter having a higher obstacle outside the passband.

This filter works as follows. The microwave signal entering the input of the waveguide 1 excites the FR 6 located in the short-circuited waveguide 10 and is reradiated in the passband of the FR 6 through the communication hole 5 in the dividing wall 4 in the FR 6 located in the short-circuited waveguide 12. The FR 6 located in the short-circuited waveguide 10 has the same resonant frequency as the DF in the short-circuited waveguide 12, which ensures their coupling. The FR in the short-circuited waveguide 12 excites an electromagnetic wave, which is fed to the output of the short-circuited waveguide 12. The resonant frequencies of the FR 6 in both short-circuited waveguides 10, 12 are aligned, since they are under the same pair of pole tips 9 of the electromagnet 8, on the same axial line. Signals whose frequencies do not lie in the passband of the FR 6 practically do not pass from the input short-circuited waveguide 10 to the output short-circuited waveguide 12. The transmission losses of these signals are determined by the filter barrage outside the pass-band. The second signal transmission channel, formed by the short-circuited waveguides 11, 13, works in a similar way, where the input short-circuited waveguide is waveguide 11 and the output one is 13. FR 6, located in these waveguides opposite the communication hole 5 have resonant frequencies matching the resonant frequencies of FR 6 short-circuited waveguides 10, 12, as they are under the influence of magnetic fields generated by the same pair of pole pieces 9.

FR 6, 19 in this filter can be mounted both on ceramic-metal holders and oriented along the “thermal axes”, and in dielectric cartridges, similar to how they are installed in the prototype filter.

Claims (5)

1. Microwave ferrite filter containing two rectangular waveguides intersecting at right angles, separated along wide walls by a separating partition with communication holes, opposite which are mounted spherical ferrite resonators, an electromagnet with pole tips, characterized in that along the longitudinal axis of symmetry of the waveguides in the center of intersection each waveguide has short-circuiting walls that form four short-circuited waveguides. 2. The filter according to claim 1, characterized in that the pole pieces are located in recesses made in the wide walls of the waveguides. 3. The filter according to claim 1, characterized in that in one or both of the pole pieces a cylindrical recess is made externally along the axis of the arrangement of ferrite resonators and communication holes. 4. The filter according to claim 1, characterized in that in each short-circuited waveguide along their longitudinal axes of symmetry, tetrahedral dielectric inserts are installed on the wide wall with the upper face tapered to the distal end and facing the corresponding ferrite resonator with the opposite end. 5. The filter according to claim 1, characterized in that the dividing wall is thickened and additional ferrite resonators are placed in the communication holes.

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