US2509758A - Electrical condenser - Google Patents
Electrical condenser Download PDFInfo
- Publication number
- US2509758A US2509758A US72959A US7295949A US2509758A US 2509758 A US2509758 A US 2509758A US 72959 A US72959 A US 72959A US 7295949 A US7295949 A US 7295949A US 2509758 A US2509758 A US 2509758A
- Authority
- US
- United States
- Prior art keywords
- temperature
- dielectric
- dielectric constant
- electrical condenser
- ferrite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 claims description 14
- 229910052596 spinel Inorganic materials 0.000 claims description 4
- 239000011029 spinel Substances 0.000 claims description 4
- 239000013078 crystal Substances 0.000 description 15
- 229910000859 α-Fe Inorganic materials 0.000 description 13
- 230000005291 magnetic effect Effects 0.000 description 12
- 239000003990 capacitor Substances 0.000 description 7
- 229910001289 Manganese-zinc ferrite Inorganic materials 0.000 description 6
- JIYIUPFAJUGHNL-UHFFFAOYSA-N [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[Mn++].[Mn++].[Mn++].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Zn++].[Zn++] Chemical compound [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[Mn++].[Mn++].[Mn++].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Zn++].[Zn++] JIYIUPFAJUGHNL-UHFFFAOYSA-N 0.000 description 6
- 230000005294 ferromagnetic effect Effects 0.000 description 6
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001053 Nickel-zinc ferrite Inorganic materials 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 241000656145 Thyrsites atun Species 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 229910001308 Zinc ferrite Inorganic materials 0.000 description 1
- PGTXKIZLOWULDJ-UHFFFAOYSA-N [Mg].[Zn] Chemical compound [Mg].[Zn] PGTXKIZLOWULDJ-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- LBSAHBJMEHMJTN-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Zn].[Zn].[Zn] LBSAHBJMEHMJTN-UHFFFAOYSA-N 0.000 description 1
- 239000011162 core material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- -1 i. e. Inorganic materials 0.000 description 1
- 239000011133 lead Substances 0.000 description 1
- 238000007620 mathematical function Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G7/00—Capacitors in which the capacitance is varied by non-mechanical means; Processes of their manufacture
- H01G7/04—Capacitors in which the capacitance is varied by non-mechanical means; Processes of their manufacture having a dielectric selected for the variation of its permittivity with applied temperature
Definitions
- My invention relates to electrical condensers.
- the electrical condenser according to my invention comprises two electrodes and a dielectric of a ferromagnetic core material consisting essentially of mixed crystal ferrites of selected metal oxides.
- a ferromagnetic core material consisting essentially of mixed crystal ferrites of selected metal oxides.
- Such materials which are described in the U. S. Patents 2,452,529; 2,452,530 and 2,452,531 dated October 26, 1948 to J. L. Snoek, consist of mixed crystals of a plurality of oxides of bivalent materials mixed and reacted with iron oxide.
- Electrical condensers according to my invention exhibit an unexpectedly high capacitance for a given size, and I have found that this is due to the fact that such materials have unexpectedly high dielectric constants which are greater than 100 and in some instances of the order of 10 to 10
- my electrical condensers have the further advantage that they have a large absolute variation capacity with changes in temperature and I have found that this is due to the unusual temperature dependence of the dielectric constant of such materials.
- Fig. l is a curve indicating the dependence of the dielectric constant of the dielectric on temperature
- Fig. 2 is a capacitor according to the invention.
- the ordinates are specified in values of the dielectric constant E and the abscissae in degrees centigrade of temperature.
- the curve is a measure of the real part of the dielectric constant, an imaginary part not being shown since it in no way influences the character of the invention.
- the true dielectric constant of a material is composed of a real part and imaginary component corresponding to the real and imaginary parts of a complex argument of a mathematical function.
- the dielectric constant at temperatures below the temperature indicated as the magnetic Curie point has a value of the order of 10 and gradually perature. In' the neighborhood of the magnetic Curie temperature, the dielectric constant decreases rapidly. Quite unexpectedly I found that in the vicinity of the magnetic Curie temperature the dielectric constant rises very sharply and levels off at a lower value than the initial value of the dielectric constant at the start of the curve.
- the condenser shown in Fig. 2 comprises a dielectric l in the form of a disc and consisting essentially of a mixed crystal ferrite as above described and electrodes 22 consisting for example of metal layers of silver, copper, gold, lead, tin or the like positioned on the dielectric by spraying, firing or the like.
- the condenser When utilizing as a dielectric the manganese-zinc ferrite above specifically described, the condenser exhibits a negative temperature coefficient of capacity over the temperature range below the magnetic Curie point, i. e. over the temperature range between 20 and C. At the magnetic Curie temperature a sharp reversal in the temperature 00- efiicient occurs and within a temperature change of approximately one degree a large change in capacitance occurs.
- capacitors would be useful for numerous applications.
- the capacitor described is useful in radio circuits as a temperature compensating capacitor for correcting undesirable frequency drift due to temperature changes of the circuit components.
- the capacitor is suitable as a, temperature responsive switch because of the abrupt change in capacitance over a small temperature rangei. e. of the order of 1 C., which it undergoes at temperatures about the magnetic Curie point.
- the magnetic Curie temperature of the ferrites can be controlled to any desired value as described by J. L. Snoek in the above-identified patents which therefore renders possible capacitors of varying characteristics each suited to a particular desired application.
- An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a ferromagnetic mixed spinel crystal ferrite material.
- An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a ferromagnetic mixed spinel crystal ferrite material having a dielectric constant greater than 100.
- An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a ferromagnetic mixed spinel crystal ferrite material having a dielectric constant of the order of 10 5.
- An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of mixed crystals of manganesezinc ferrite having a dielectric constant of the order of 10 6.
- An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of mixed crystals of manganesezinc ferrite, said dielectric having a. magnetic Curie point within the normal operating range of temperatures of the condenser and having a dielectric constant of the order of 10 7.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Soft Magnetic Materials (AREA)
- Magnetic Ceramics (AREA)
Description
May 30, 1950 F. BROCKMAN 2,509,758
ELECTRICAL CONDENSER Filed Jan. 26, 1949 100000 [DIELECTRIC CONSTANT i vs.
TEMPERATURE soooo MAGNETIC 40000 CURIE POINT TEMPERATURE 1N DEGREES CENTIGRADE FIGJ CAPACITOR DIELECTRIC CDNSTITUTED BY A MIXED CRYSTAL FERRITE FIG-2 FRANK BROCKMAH INVENTOR AGENT Y Patented May 30,
ELECTRICAL CONDENSER Frank Brockman. Dobbs Ferry, N. Y., assignor to Philips Laboratories, Inc., Irvington on Hudson,
Application January 26, 1949, Serial No. 72,959
8 Claims. 1
My invention relates to electrical condensers.
It is an object of my invention to provide a new and novel electrical condenser.
It is a further object of my invention to provide a temperature responsive electrical condenser having improved characteristics.
These and further objects of my invention will appear as the specification progresses.
The electrical condenser according to my invention comprises two electrodes and a dielectric of a ferromagnetic core material consisting essentially of mixed crystal ferrites of selected metal oxides. Such materials, which are described in the U. S. Patents 2,452,529; 2,452,530 and 2,452,531 dated October 26, 1948 to J. L. Snoek, consist of mixed crystals of a plurality of oxides of bivalent materials mixed and reacted with iron oxide.
Electrical condensers according to my invention exhibit an unexpectedly high capacitance for a given size, and I have found that this is due to the fact that such materials have unexpectedly high dielectric constants which are greater than 100 and in some instances of the order of 10 to 10 In addition, my electrical condensers have the further advantage that they have a large absolute variation capacity with changes in temperature and I have found that this is due to the unusual temperature dependence of the dielectric constant of such materials.
' decreases until it nears the magnetic Curie tem- In order that the invention may be more clearly understood and carried into effect, it will now be described with reference to the accompanying drawing in which:
Fig. l is a curve indicating the dependence of the dielectric constant of the dielectric on temperature; and
Fig. 2 is a capacitor according to the invention.
Referring to the drawing, I have shown in Fig. l the temperature dependence of the dielectric constant of a particular mixed crystal ferrite, i. e., manganese-zinc ferrite the constituent components of which consist for example of about 23 mol per cent manganese oxide, about 25 mol per cent zinc oxide and about 52 mol per cent iron oxide. Although the invention will be described with reference to this particular material, I wish it to be understood that other mixed crystal ferrites described in the above-identified patents are suitable for the invention, e. g. copperzinc ferrite, magnesium-zinc ferrite, coppercadmium ferrite and nickel-zinc ferrite.
Referring to Fig. 1, the ordinates are specified in values of the dielectric constant E and the abscissae in degrees centigrade of temperature.
It should be noted that the curve is a measure of the real part of the dielectric constant, an imaginary part not being shown since it in no way influences the character of the invention. To those familiar in the art, it is known that at higher frequencies, e. g. above one megacycle, the true dielectric constant of a material is composed of a real part and imaginary component corresponding to the real and imaginary parts of a complex argument of a mathematical function.
It will be seen from the curve that the dielectric constant at temperatures below the temperature indicated as the magnetic Curie point, has a value of the order of 10 and gradually perature. In' the neighborhood of the magnetic Curie temperature, the dielectric constant decreases rapidly. Quite unexpectedly I found that in the vicinity of the magnetic Curie temperature the dielectric constant rises very sharply and levels off at a lower value than the initial value of the dielectric constant at the start of the curve.
The Curie point of a magnetic material is that temperature above which the magnetic material has a negligible permeability and for all practical purposes is no longer ferromagnetic. The Curie point of ferromagnetic mixed crystal ferrite materials to which the present invention is directed can be controlled over a wide range of temperatures as set forth in the above noted patents and therefore the temperature at which the dielectric constant of the materials exhibits a sharp drop in value as well as the slope of the change in dielectric constant with temperature over a given operating temperature range can similarly be controlled.
The condenser shown in Fig. 2 comprises a dielectric l in the form of a disc and consisting essentially of a mixed crystal ferrite as above described and electrodes 22 consisting for example of metal layers of silver, copper, gold, lead, tin or the like positioned on the dielectric by spraying, firing or the like. When utilizing as a dielectric the manganese-zinc ferrite above specifically described, the condenser exhibits a negative temperature coefficient of capacity over the temperature range below the magnetic Curie point, i. e. over the temperature range between 20 and C. At the magnetic Curie temperature a sharp reversal in the temperature 00- efiicient occurs and within a temperature change of approximately one degree a large change in capacitance occurs.
Such capacitors would be useful for numerous applications. For example. the capacitor described is useful in radio circuits as a temperature compensating capacitor for correcting undesirable frequency drift due to temperature changes of the circuit components. Furthermore the capacitor is suitable as a, temperature responsive switch because of the abrupt change in capacitance over a small temperature rangei. e. of the order of 1 C., which it undergoes at temperatures about the magnetic Curie point.
Where a large capacitance per unit volume is desired. the unexpectedly high dielectric constant of the material makes these condensers particularly useful.
As above noted the magnetic Curie temperature of the ferrites can be controlled to any desired value as described by J. L. Snoek in the above-identified patents which therefore renders possible capacitors of varying characteristics each suited to a particular desired application.
While I have thus described my invention with specific examples and applications, I do not wish to be limited solely thereto as other modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.
What I claim is:
1. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a mixed spine] crystal ferrite material.
2. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a ferromagnetic mixed spinel crystal ferrite material.
3. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a ferromagnetic mixed spinel crystal ferrite material having a dielectric constant greater than 100.
4. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of a ferromagnetic mixed spinel crystal ferrite material having a dielectric constant of the order of 10 5. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of mixed crystals of manganesezinc ferrite having a dielectric constant of the order of 10 6. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of mixed crystals of manganesezinc ferrite, said dielectric having a. magnetic Curie point within the normal operating range of temperatures of the condenser and having a dielectric constant of the order of 10 7. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of mixed crystals of manganesezinc ferrite, said dielectric having a magnetic Curie point at about C. and having a dielectric constant of the order of 10 8. An electrical condenser comprising a pair of electrodes and a dielectric therebetween consisting essentially of mixed crystals of manganesezinc ferrite, said dielectric having a magnetic Curie point at about 160 C. and exhibiting a sharp rise in the value of the dielectric constant at the said temperature, said dielectric having a dielectric constant of the order of 10 FRANK BROCKMAN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Snoek .'Oct. 26, 1948
Claims (1)
1. AN ELECTRICAL CONDENSER COMPRISING A PAIR OF ELECTRODES AND A DIELECTRIC THEREBETWEEN CONSISTING ESSENTIALLY OF A MIXED SPINEL CRYSTAL FERRITE MATERIAL.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72959A US2509758A (en) | 1949-01-26 | 1949-01-26 | Electrical condenser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72959A US2509758A (en) | 1949-01-26 | 1949-01-26 | Electrical condenser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2509758A true US2509758A (en) | 1950-05-30 |
Family
ID=22110822
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US72959A Expired - Lifetime US2509758A (en) | 1949-01-26 | 1949-01-26 | Electrical condenser |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2509758A (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2611094A (en) * | 1950-02-16 | 1952-09-16 | Harold B Rex | Inductance-capacitance resonance circuit |
| DE1103222B (en) * | 1958-07-30 | 1961-03-23 | Itt | Method of manufacturing dielectric material |
| US2992990A (en) * | 1956-01-05 | 1961-07-18 | Richard G Parker | Soft magnetic material |
| US3002137A (en) * | 1957-09-04 | 1961-09-26 | Sprague Electric Co | Voltage dependent ceramic capacitor |
| US3003967A (en) * | 1959-09-23 | 1961-10-10 | Kearfott Company Inc | Method for increasing the effective permeability of manganese ferrites |
| DE1116821B (en) * | 1954-07-02 | 1961-11-09 | Siemens Ag | Arrangement for stabilizing electrical switching elements or electrical circuit arrangements to a certain temperature |
| DE1125340B (en) * | 1959-04-07 | 1962-03-08 | Itt | Method of manufacturing dielectric material |
| DE1177538B (en) * | 1958-06-12 | 1964-09-03 | Itt | Method of manufacturing dielectric material |
| DE1177998B (en) * | 1960-03-30 | 1964-09-10 | Itt | Method of manufacturing dielectric material |
| DE1177999B (en) * | 1960-03-30 | 1964-09-10 | Itt | Method of manufacturing dielectric material |
| DE1180847B (en) * | 1956-03-28 | 1964-11-05 | Siemens Ag | Device for changing the apparent resistance of a capacitor |
| US3268744A (en) * | 1964-04-16 | 1966-08-23 | Ibm | High capacitance microelectronic decoupling device with low shunt resistance at high frequencies |
| US3434120A (en) * | 1965-10-14 | 1969-03-18 | Foxboro Co | Capacitive memory storage device employing magnetizable material as a dielectric |
| DE1300055B (en) * | 1959-01-19 | 1969-07-24 | Internat Telephone & Telegraph | Method of manufacturing dielectric material |
| US4807085A (en) * | 1987-05-28 | 1989-02-21 | Iwasaki Electric Co., Ltd. | Nonlinear capacitor for generating high-voltage pulses |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2306555A (en) * | 1940-05-23 | 1942-12-29 | Research Corp | Method for frequency control |
| US2443094A (en) * | 1946-12-18 | 1948-06-08 | Rca Corp | Frequency multiplier network |
| US2452529A (en) * | 1941-10-24 | 1948-10-26 | Hartford Nat Bank & Trust Co | Magnet core |
| US2452530A (en) * | 1943-05-15 | 1948-10-26 | Hartford Nat Bank & Trust Co | Magnetic core |
-
1949
- 1949-01-26 US US72959A patent/US2509758A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2306555A (en) * | 1940-05-23 | 1942-12-29 | Research Corp | Method for frequency control |
| US2452529A (en) * | 1941-10-24 | 1948-10-26 | Hartford Nat Bank & Trust Co | Magnet core |
| US2452530A (en) * | 1943-05-15 | 1948-10-26 | Hartford Nat Bank & Trust Co | Magnetic core |
| US2443094A (en) * | 1946-12-18 | 1948-06-08 | Rca Corp | Frequency multiplier network |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2611094A (en) * | 1950-02-16 | 1952-09-16 | Harold B Rex | Inductance-capacitance resonance circuit |
| DE1116821B (en) * | 1954-07-02 | 1961-11-09 | Siemens Ag | Arrangement for stabilizing electrical switching elements or electrical circuit arrangements to a certain temperature |
| US2992990A (en) * | 1956-01-05 | 1961-07-18 | Richard G Parker | Soft magnetic material |
| DE1180847B (en) * | 1956-03-28 | 1964-11-05 | Siemens Ag | Device for changing the apparent resistance of a capacitor |
| US3002137A (en) * | 1957-09-04 | 1961-09-26 | Sprague Electric Co | Voltage dependent ceramic capacitor |
| DE1177538B (en) * | 1958-06-12 | 1964-09-03 | Itt | Method of manufacturing dielectric material |
| DE1103222B (en) * | 1958-07-30 | 1961-03-23 | Itt | Method of manufacturing dielectric material |
| DE1300055B (en) * | 1959-01-19 | 1969-07-24 | Internat Telephone & Telegraph | Method of manufacturing dielectric material |
| DE1125340B (en) * | 1959-04-07 | 1962-03-08 | Itt | Method of manufacturing dielectric material |
| US3003967A (en) * | 1959-09-23 | 1961-10-10 | Kearfott Company Inc | Method for increasing the effective permeability of manganese ferrites |
| DE1177999B (en) * | 1960-03-30 | 1964-09-10 | Itt | Method of manufacturing dielectric material |
| DE1177998B (en) * | 1960-03-30 | 1964-09-10 | Itt | Method of manufacturing dielectric material |
| US3268744A (en) * | 1964-04-16 | 1966-08-23 | Ibm | High capacitance microelectronic decoupling device with low shunt resistance at high frequencies |
| US3434120A (en) * | 1965-10-14 | 1969-03-18 | Foxboro Co | Capacitive memory storage device employing magnetizable material as a dielectric |
| US4807085A (en) * | 1987-05-28 | 1989-02-21 | Iwasaki Electric Co., Ltd. | Nonlinear capacitor for generating high-voltage pulses |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2509758A (en) | Electrical condenser | |
| US2685568A (en) | Soft ferromagnetic mixed ferrite material | |
| US3886077A (en) | Garnet structure ferrimagnetic material having a saturation magnetisation less than 1000 gauss for microwave applications | |
| JPH0255883B2 (en) | ||
| JPS61215255A (en) | Dielectric ceramic composition | |
| JPS5873908A (en) | High frequency dielectric porcelain composition | |
| US3030307A (en) | Ferrite material containing lithium and aluminum oxides | |
| GB849827A (en) | Improvements in circuit elements for electronic data storage systems or the like | |
| US2982731A (en) | Modified nickel ferrite | |
| JP4761175B2 (en) | Low-loss ferrite and magnetic core using the same | |
| US3035927A (en) | Ceramic dielectric compositions | |
| EP0523608B1 (en) | Dielectric ceramic composition | |
| US3103442A (en) | Ceramic dielectric compositions | |
| JPH0160928B2 (en) | ||
| SU396731A1 (en) | VARIABLE CAPACITOR | |
| JPH0376770B2 (en) | ||
| US5346638A (en) | Oxide magnetic material | |
| SU637880A1 (en) | Ferrite material | |
| JPS59121157A (en) | High frequency magnetic material | |
| JPH0228306A (en) | Power supply | |
| US3006853A (en) | Square loop cadmium-nickel ferrites | |
| JPH0376771B2 (en) | ||
| US2864712A (en) | High voltage ceramic dielectric | |
| JPS5914214A (en) | Dielectric porcelain composition | |
| JP2918077B2 (en) | Dielectric porcelain composition |