|Publication number||US3058078 A|
|Publication date||Oct 9, 1962|
|Filing date||Aug 7, 1958|
|Priority date||Feb 21, 1956|
|Publication number||US 3058078 A, US 3058078A, US-A-3058078, US3058078 A, US3058078A|
|Inventors||Hoh Siegfried R|
|Original Assignee||Hoh Siegfried R|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (48), Classifications (9)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Oct. 9, 1962 `s. R. HoH
LOW CAPACITANCE TRANSFORMER Original Filed Feb. 2l, 1956 I NV E N TOR. fare/5,990
kloss of essential electrical characteristics.
United tats the Air Force Original application Feb. 21, 1956, Ser. No. 567,038. Dr-
vided and this application Aug. 7, 1958, Ser. No.
4 Claims. (Cl. 336-182) (Granted under Title 35, U.S. Code (i952), sec. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.
This application forms a division of my copending application Serial No. 567,038, tiled `February 2l, 1956. The invention relates to the development of a low distributed capacitance transformer suitable for use at higher frequencies than is` possible with conventional, commercially available components.
An object of this invention is the production of a novel transformer which is of very small size without a sacrifice of elec-trical characteristics.
Another object of this invention is the production of magnetically coupled transformer which does not normally require shielding or insulation.
A further object of this invention is to provide coupling devices utilizing non-'conducting ferromagnetic ferrites or powdered iron.
A further object of this invention is the production of a novel transformer which is easily manufactured and is low in cost.
'Fliese `and other advantages, features and objects of the invention will become more apparent from the following description taken in connection with the illustrative embodiments in the accompanying drawings, wherein:
FIG. 1 shows `an end view of a miniature high-frequency transformer in section; and
FIG. 2 illustrates a top View partly in section of the embodiment of FIGURE 1.
Miniaturization of components for high frequency work is aided by the utilization of the properties of the nonconducting ferromagnetic ferrites; accordingly, the novel design of a low distributed capacitance transformer of FIGURES 1 and 2 achieve this 'desired result without a The embodiment disclosed in the gures consists of a pair of at spiral conductors 24 and 25, comprising the transformer prim-ary and secondary, in a coplanar relationship on a non-conducting `ferromagnetic ferrite disc or plate 26. Disc 26 provides the coupling between the primary and secondary. Additional ferrite discs 27 `and 28 may be provided to increase the Q of the transformer and also results in providing a shielding effect.
Conductor 24, which is a duplicate of conductor 25, shown in FIGURE 1, may be formed in many ways to conform to standard mass production techniques. For example, since a non-conducting ferromagnetic ferrite is used, conductors 24 and 25 need not be insulated, thus allowing for a closer relationship between the elements comprising the transformer. Further reduction of the spacing and transformer cost may be achieved by utilizing stampe-d sheet metal conductors `or printing the conductors ydirectly on the discs. Another method which is admirably suited for high frequency applications involves the reduction of the ferrite in the shape of the conductors to metal to forrn the conductors.
Since the stray flux of the transformer is of a very low value, shielding will not normally be required, thus aiding in the reduction of size of the transformers without sacrificing the Q factor or other electrical characteristics.
While ferromagnetic ferrites because of their high permeability are the preferred magnetic materials for the above circuit elements, powdered iron materials may also be used for low frequency applications.
Although the invention has `been described with reference to particular embodiments, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the yappended claims.
1. A trans-former for high frequency application comprising a disc of non-conducting ferromagnetic material and a pair of fiat, generally spiral shaped conductors in -a rcoplranar relationship to said disc, said conductors being in juxtaposed alignment along one surface only of said disc.
2. A device as dened in claim 1 including a pair of discs arranged to cover said conductors.
3. A transformer comprising a dat disc of magnetic material, a primary winding of a flat, generally spiral shape and a secondary winding of a dat, generally spiral shape, said windings being arranged on one side only of said `disc in a coplanar relationship.
4. A device las defined in claim 3 including a pair of llat discs of magnetic material arranged in a coplanar relationship to cover said primary and secondary.
References Cited in the file of this patent UNITED STATES PATENTS 2,114,031 Rust et al. Apr. 12, 1938 2,474,988 Sargrove July 5, 1949 2,850,707 Wroblewski et al Sept. 2, 1958 2,910,662 Rex Oct. 27, 1959 National Bureau of 1947, particularly pp.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2114031 *||Aug 8, 1935||Apr 12, 1938||Rca Corp||Remotely controllable radio and similar high frequency receivers|
|US2474988 *||Aug 16, 1944||Jul 5, 1949||Sargrove John Adolph||Method of manufacturing electrical network circuits|
|US2850707 *||Apr 15, 1954||Sep 2, 1958||Sylvania Electric Prod||Electromagnetic coils|
|US2910662 *||Jun 29, 1956||Oct 27, 1959||Harold B Rex||Printed transformer|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4059493 *||Apr 29, 1976||Nov 22, 1977||Cities Service Company||Anode, anode basket and method of packaging anodes|
|US4246446 *||Dec 19, 1978||Jan 20, 1981||Pioneer Electronic Corporation||Moving coil pick-up with coils printed on opposite sides of waver|
|US4517540 *||Mar 28, 1980||May 14, 1985||Mcdougal John A||Spiral windings|
|US5126714 *||Dec 20, 1990||Jun 30, 1992||The United States Of America As Represented By The Secretary Of The Navy||Integrated circuit transformer|
|US5300911 *||Oct 9, 1992||Apr 5, 1994||International Business Machines Corporation||Monolithic magnetic device with printed circuit interconnections|
|US5781077 *||Jan 28, 1997||Jul 14, 1998||Burr-Brown Corporation||Reducing transformer interwinding capacitance|
|US7376212||Dec 22, 2004||May 20, 2008||Silicon Laboratories Inc.||RF isolator with differential input/output|
|US7421028||Jun 3, 2004||Sep 2, 2008||Silicon Laboratories Inc.||Transformer isolator for digital power supply|
|US7447492||Jun 3, 2004||Nov 4, 2008||Silicon Laboratories Inc.||On chip transformer isolator|
|US7460604||Feb 23, 2005||Dec 2, 2008||Silicon Laboratories Inc.||RF isolator for isolating voltage sensing and gate drivers|
|US7545059||Feb 9, 2007||Jun 9, 2009||Analog Devices, Inc.||Chip-scale coils and isolators based thereon|
|US7577223||Jun 30, 2007||Aug 18, 2009||Silicon Laboratories Inc.||Multiplexed RF isolator circuit|
|US7650130||Nov 27, 2007||Jan 19, 2010||Silicon Laboratories Inc.||Spread spectrum isolator|
|US7683654||Dec 27, 2007||Mar 23, 2010||Analog Devices, Inc.||Signal isolators using micro-transformers|
|US7692444||Jul 6, 2006||Apr 6, 2010||Analog Devices, Inc.||Signal isolators using micro-transformers|
|US7719305||Jan 22, 2008||May 18, 2010||Analog Devices, Inc.||Signal isolator using micro-transformers|
|US7737871||Jun 30, 2008||Jun 15, 2010||Silicon Laboratories Inc.||MCU with integrated voltage isolator to provide a galvanic isolation between input and output|
|US7738568||Jun 30, 2007||Jun 15, 2010||Silicon Laboratories Inc.||Multiplexed RF isolator|
|US7821428||Jun 30, 2008||Oct 26, 2010||Silicon Laboratories Inc.||MCU with integrated voltage isolator and integrated galvanically isolated asynchronous serial data link|
|US7856219||Jun 28, 2007||Dec 21, 2010||Silicon Laboratories Inc.||Transformer coils for providing voltage isolation|
|US7902627||Mar 30, 2009||Mar 8, 2011||Silicon Laboratories Inc.||Capacitive isolation circuitry with improved common mode detector|
|US7920010||Nov 10, 2009||Apr 5, 2011||Analog Devices, Inc.||Signal isolators using micro-transformers|
|US8049573||Jun 30, 2007||Nov 1, 2011||Silicon Laboratories Inc.||Bidirectional multiplexed RF isolator|
|US8064872||Jun 24, 2008||Nov 22, 2011||Silicon Laboratories Inc.||On chip transformer isolator|
|US8169108||Mar 31, 2008||May 1, 2012||Silicon Laboratories Inc.||Capacitive isolator|
|US8198951||Mar 30, 2009||Jun 12, 2012||Silicon Laboratories Inc.||Capacitive isolation circuitry|
|US8441325||Jun 30, 2009||May 14, 2013||Silicon Laboratories Inc.||Isolator with complementary configurable memory|
|US8451032||Dec 22, 2010||May 28, 2013||Silicon Laboratories Inc.||Capacitive isolator with schmitt trigger|
|US8736343||Mar 31, 2011||May 27, 2014||Analog Devices, Inc.||Signal isolators using micro-transformers|
|US9293997||Mar 14, 2013||Mar 22, 2016||Analog Devices Global||Isolated error amplifier for isolated power supplies|
|US20050269657 *||Jun 3, 2004||Dec 8, 2005||Timothy Dupuis||On chip transformer isolator|
|US20050271147 *||Jun 3, 2004||Dec 8, 2005||Timothy Dupuis||Transformer isolator for digital power supply|
|US20050271148 *||Dec 22, 2004||Dec 8, 2005||Timothy Dupuis||RF isolator with differential input/output|
|US20050271149 *||Feb 23, 2005||Dec 8, 2005||Timothy Dupuis||RF isolator for isolating voltage sensing and gate drivers|
|US20060250155 *||Jul 6, 2006||Nov 9, 2006||Baoxing Chen||Signal isolators using micro-transformers|
|US20080013635 *||Jun 28, 2007||Jan 17, 2008||Silicon Laboratories Inc.||Transformer coils for providing voltage isolation|
|US20080025450 *||Jun 30, 2007||Jan 31, 2008||Silicon Laboratories Inc.||Multiplexed rf isolator circuit|
|US20080030080 *||Feb 9, 2007||Feb 7, 2008||Baoxing Chen||Chip-scale coils and isolators based thereon|
|US20080119142 *||Nov 27, 2007||May 22, 2008||Silicon Laboratories Inc.||Spread spectrum isolator|
|US20080136442 *||Jan 22, 2008||Jun 12, 2008||Baoxing Chen||Signal isolator using micro-transformers|
|US20080267301 *||Jun 30, 2007||Oct 30, 2008||Silicon Laboratories Inc.||Bidirectional multiplexed rf isolator|
|US20080317106 *||Jun 30, 2008||Dec 25, 2008||Silicon Laboratories Inc.||Mcu with integrated voltage isolator and integrated galvanically isolated asynchronous serial data link|
|US20090027243 *||Jun 30, 2008||Jan 29, 2009||Silicon Laboratories Inc.||Mcu with integrated voltage isolator to provide a galvanic isolation between input and output|
|US20090243028 *||Mar 30, 2009||Oct 1, 2009||Silicon Laboratories Inc.||Capacitive isolation circuitry with improved common mode detector|
|US20100052826 *||Jun 30, 2009||Mar 4, 2010||Silicon Laboratories Inc.||Isolator with complementary configurable memory|
|US20100134139 *||Nov 10, 2009||Jun 3, 2010||Analog Devices, Inc.||Signal isolators using micro-transformers|
|US20110175642 *||Mar 31, 2011||Jul 21, 2011||Analog Devices, Inc.||Signal isolators using micro-transformers|
|WO1991007765A1 *||Aug 22, 1990||May 30, 1991||Motorola, Inc.||A planar transformer and a splitter/combiner using same|
|U.S. Classification||336/182, 336/221, 336/232, 336/200, 336/220, 336/83|