RU177528U1 - SUPER HIGH FREQUENCY FERRITE FILTER - Google Patents

Abstract

The utility model relates to electronic microwave technology, namely, to ferrite multilink filters, the resonant frequency of which is linearly tuned by the magnetic field. The microwave ferrite filter contains a non-magnetic casing located in the gap of the electromagnet, at least two spherical ferrite resonators (FRs) mounted on heat-conducting cermet rods in the resonator chambers of the non-magnetic casing. DFs are electromagnetically coupled to the input and output transmission lines by means of single-wound single-loop communication elements (WES) shorted to the housing, and DFs are connected by double WES, short-circuited at their free ends and interconnected by conductors. Single and double wind farms, intersecting in pairs, cover the FR. Conductors in the second channels of the non-magnetic case are connected capacitors with a capacity of 3-20 pF, closed to a non-magnetic case. The microwave ferrite filter has an expanded passband while providing strength and stability of the filter's electrical parameters to mechanical stress, and ensuring its maintainability. 2 s.p. f-ly, 3 ill.

Description

The utility model relates to electronic microwave technology, namely, to ferrite multilink filters, the resonant frequency of which is linearly tuned by a magnetic field, for example, by changing the current in an electromagnet magnetizing single crystal ferrite resonators (FR) in the form of miniature polished spheres.

Known microwave (microwave) ferrite filter (see patent US 7557678, IPC Н01Р 1/218, published 07.07.2009), comprising a housing of non-magnetic material located in the gap of the electromagnet, several spherical RFs located in the resonant chambers of the non-magnetic housing. The FRs are electromagnetically coupled by winding communication elements located in a non-magnetic body, the ends of which are soldered in the recesses of the non-magnetic body to the mass of the non-magnetic body.

In the known microwave ferrite filter, the accuracy of the manufacture of communication coils and their placement in resonance chambers is ensured. However, in the known microwave filter, a sufficiently high vibration resistance and vibration resistance, impact resistance and impact resistance when operating in the low part of the decimeter (meter) wavelength range are not provided. This is due to the fact that in this wavelength range, single and double coiled communication elements (WES) are not made in the form of half loops having a 180 ° coverage angle, but are made in the form of one and a half to two, three full loops having a coverage angle of 540 ° and above. Bulky double wind farms are a weak link in the filter design. Under the influence of vibration and shock, they can be displaced by insignificant distances relative to the center of the RF, which causes a change in the electrical parameters of the microwave ferrite filter, and in the process of vibration, the output signal is modulated.

Known microwave ferrite filter (see patent US 6255918, IPC Н01Р 7/00, published 07.07.2009), containing a non-magnetic housing with a resonant chamber located in the gap of the electromagnet, a spherical single-crystal FR mounted on the rod, single turn communication elements, holder for rod with a single-crystal FR, which is attached to the body. In the known microwave ferrite filter, the single crystal FR is rigidly fixed relative to the housing by means of a holder in order to reduce the displacements of the single crystal FR relative to communication elements fixed to the housing when exposed to vibration.

A disadvantage of the known microwave ferrite filter is its insufficiently high stability and strength with respect to vibration and shock loads when operating in the low part of the decimeter (meter) wavelength range, since wind turbines made in the form from one and a half to two, three full loops can be shifted by insignificant the distance relative to the center of the single-crystal FR, which causes a change in the electrical parameters of the known microwave ferrite filter, also in the process of vibration, the modulation of the output Nogo signal. This disadvantage is especially evident when using more than one RF.

Known microwave ferrite filter (see patent RU 128785, IPC Н01Р 1/00, published May 27, 2013), containing a non-magnetic housing located in the gap of the electromagnet, at least two spherical single-crystal ferrite resonators mounted on heat-conducting ceramic rods in resonant chambers non-magnetic enclosure. In the two resonance chambers, through the first channels in a non-magnetic case, the input and output segments of the transmission lines are respectively drawn. The central conductors of the transmission lines are loaded on single-wound single-wound communication elements short-circuited on a non-magnetic case, spherical single-crystal ferrite resonators are electromagnetically connected to each other using double-wound communication elements, short-circuited on a non-magnetic case at the free ends and connected by conductors of long L <passed through the second channels of the non-magnetic case λ / 4, where λ is the wavelength in the working decimeter, centimeter, millimeter filter tuning range. Single and double winding coupling elements pairwise orthogonally spherical single-crystal ferrite resonators. A local roughness is made on the surface of at least one of the polished FRs. This eliminates spurious loss emissions in the passband of the filter in known frequency ranges determined by the saturation magnetization used.

In the known microwave ferrite filter, parasitic outliers of losses in the passband of the filter in the known frequency ranges determined by the used saturation magnetization of the RF are eliminated. However, the known microwave ferrite filter does not provide a sufficiently high vibration resistance and vibration resistance, impact resistance and impact resistance when operating in the low part of the decimeter (meter) wavelength range.

A known microwave ferrite filter (see RU 154064, IPC Н01Р 1/218, published on 08/10/2015), which coincides with this decision by the largest number of essential features and adopted as a prototype. The known microwave ferrite filter prototype contains a non-magnetic housing located in the gap of the electromagnet, at least two spherical single-crystal ferrite resonators mounted on heat-conducting ceramic rods in the resonance chambers of a non-magnetic housing. The input and output segments of the transmission line, respectively, the central conductors of which are loaded on single-wound single-loop communication elements short-circuited on the non-magnetic case, are respectively drawn into two resonance chambers through the first channels in the non-magnetic case. Spherical single-crystal ferrite resonators are electromagnetically connected to each other using double-wound coupling elements, short-circuited to the non-magnetic casing at the free ends and connected by conductors passed through the second channels of the non-magnetic casing, single and double-wound coupling elements pairwise orthogonally enclose spherical single-crystal ferrite resonators, second conductors the channels of the non-magnetic body are enclosed in inserted dielectric bushings made of silicon -ethnic sealant with a dielectric constant ε _r is not more than 2.5 and the dielectric loss tangent of tgδ not more than 0.01, the width b _in mm, the height h _in mm, the length L _in mm, and the radius of the dielectric sleeve _in R , mm, its internal channel selected from the ratios:

b _in = b _to ;

h _in = h _to ;

L _in ≤L _to ;

R _in = R _n;

b _to , h _to , L _to - respectively the width, height and length of each of the second channels, mm;

R _p - the radius of each conductor in the second channels, mm

The choice of the width, height, length of the dielectric sleeve and the radius of its inner channel from the above ratios is due to the need to exclude the formation of gaps between the conductor and the surface of the inner channel of the dielectric sleeve, as well as between the outer surface of the dielectric sleeve and the surface of the second channel. As a result, after the sealant has cured, the dielectric sleeve reliably fixes the conductors in the second channels of the non-magnetic casing, which significantly reduces the possibility of biasing the double wind farms relative to the RF, and, consequently, the electrical parameters of the microwave ferrite filter are more resistant to mechanical stress. At the same time, in the well-known microwave ferrite filter, free access to the FR and surrounding wind farms is provided, which allows them to be repaired if necessary.

A disadvantage of the known filter prototype, as additional studies have shown in the low-frequency part of the microwave range (meter and long wavelength centimeter range), is not wide enough bandwidth. This happens despite the use of multi-turn communication elements having a FR coverage angle of 360 ° to 720 ° and higher, and the use of large diameter FRs.

The objective of this technical solution was the creation of such a microwave ferrite filter, which would have an expanded passband while providing strength and stability of the filter's electrical parameters to mechanical stress, and ensuring its maintainability.

The problem is solved by the fact that the microwave filter contains a non-magnetic housing located in the gap of the electromagnet, at least two spherical single-crystal FRs mounted on heat-conducting cermet rods in the resonant chambers of the non-magnetic body. The input and output sections of the transmission line, respectively, the central conductors of which are loaded onto single single-ended wind farms short-circuited on the non-magnetic case, are drawn into two resonance chambers through the first channels in the non-magnetic case. Spherical single-crystal RFs are electromagnetically connected to each other using double wind farms, short-circuited to a non-magnetic casing at the free ends and connected by conductors passed through the second channels of the non-magnetic casing. Single and double wind farms span orthogonally spherical single-crystal DF in pairs. New in the microwave ferrite filter is the connection to the conductors in the second channels of the non-magnetic casing of capacitors with a capacity of 3-20 pF, closed to the non-magnetic casing.

Capacitors can be shorted to a non-magnetic housing, for example, by soldering.

Capacitors can be made of ceramic.

The range of capacitance of 3-20 pF capacitors is due to the fact that when the capacitance is less than 3 pF, the filter does not show the bandwidth expansion due to the low capacitance of the capacitors, and when the capacitance is more than 20 pF, the capacitors have high reactance at high frequencies, in As a result, they shorten the circuit and introduce additional losses.

The present utility model is illustrated in the drawing, where

in FIG. 1 shows the design of this microwave ferrite filter, shown for clarity, without the upper part of the electromagnet;

in FIG. 2 shows on an enlarged scale the central part of a non-magnetic case with resonant chambers (view A);

in FIG. 3 shows an equivalent electrical circuit of the present filter.

The microwave ferrite filter (see Fig. 1, Fig. 2) contains a non-magnetic body 1 located in the gap of the electromagnet 2, three single-crystal FR 3 in the form of miniature polished spheres. FR 3 are mounted on heat-conducting cermet rods 4, respectively, in the resonance chambers 5, 6, 7 of the non-magnetic housing 1. In the two extreme resonator chambers 5, 7 through the first channels 8, 9 in the non-magnetic housing 1 are the input and output segments of the transmission line, respectively, central conductors 10, 11 of which are loaded onto a single wind farm 12, 13 short-circuited to a non-magnetic housing 1, surrounding the extreme FR 3. FR 3 are connected to each other by double wind turbines 14, 15 short-circuited to a non-magnetic housing 1 at the free ends and connected short conductors 18, 19 of small length L, passed through the second channels 16, 17 of the non-magnetic housing 1, for example, L <λ / 4, where λ is the wavelength in the low-frequency part of the microwave range (decimeter) of the filter tuning. Conductors 18, 19 pass through the second channels 16, 17 respectively between chambers 5, 6 and 6, 7. Single wind farms 12, 13 and double wind turbines 14, 15 pairwise orthogonally enclose RF 3 in each of the resonance chambers 5, 6, 7. Spherical single-crystal FR 3 by rotation of the heat-conducting cermet rods 4 are oriented during tuning of the microwave ferrite filter in isotropic directions and magnetized by a magnetic field H perpendicular to the plane of FIG. 1, created by the electromagnet 2 along the isotropic direction (along the “thermal axis”), in order to ensure the stability of the resonant frequency and parameters of the microwave ferrite filter in a wide range of frequencies and temperatures. In this case, the ceramic-metal rods 4 are passed through radiators 20, on which thermistors 21 are installed, connected to a voltage source of 26 ± 3 V (not shown in the drawing). Conductors 18, 19 in the second channels 16, 17 of the non-magnetic case 1 (see Fig. 2) are connected through miniature, for example, ceramic capacitors 22 with a capacity of 3-20 pF to the non-magnetic case 1, for example, by soldering. The equivalent electrical circuit of the proposed filter (see Fig. 3) represents a circuit for three FRs, tuned by the magnetic field H of the electromagnet to the resonant frequency fp., Associated with segments of the input 10, 11 and the input line by single wind farms 12,13. The double WES 14, 15 together with the capacitors 22 form low-Q resonators 23, increasing the coupling between the FR 3 and the double WES 14, 15, and, therefore, expanding the bandwidth of the microwave ferrite filter.

In accordance with this utility model, prototypes of two three-resonator microwave ferrite filters in the decimeter wavelength range (400-600 MHz) were made using ceramic capacitors with a capacity of 10 pF with an accuracy of 5% and without the use of capacitors. Bandwidth expansion was achieved in a real filter with ceramic capacitors up to 50%. At a frequency of 520 MHz, the bandwidth was increased from 10 MHz to 15 MHz. At the same time, the microwave filter was resistant to mechanical stress and allowed, if necessary, to repair it.

Claims (3)

1. Microwave ferrite filter containing a non-magnetic casing located in the gap of the electromagnet, at least two spherical single-crystal ferrite resonators mounted on heat-conducting cermet rods in the resonance chambers of the non-magnetic casing, in two of which, respectively, the input and output segments of the transmission line, the central conductors of which are loaded on single-turn single-wound elements short-circuited on a non-magnetic case ides, spherical single-crystal ferrite resonators are electromagnetically connected to each other using double-wound coupling elements, short-circuited to the non-magnetic casing at the free ends and connected by conductors passed through the second channels of the non-magnetic casing, single and double-wound coupling elements pairwise orthogonally enclose spherical single-crystal ferrite resonators, characterized in that 3-20 pF capacitors are connected to the conductors in the second channels of the non-magnetic case, closed hollow on a non-magnetic housing. 2. The filter according to claim 1, characterized in that the capacitors are closed to a non-magnetic housing by soldering. 3. The filter according to claim 1, characterized in that the capacitors are made of ceramic.

Images