EP0324240B1 - Symmetrischer planarer Übertrager - Google Patents

Symmetrischer planarer Übertrager Download PDF

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Publication number
EP0324240B1
EP0324240B1 EP19880311657 EP88311657A EP0324240B1 EP 0324240 B1 EP0324240 B1 EP 0324240B1 EP 19880311657 EP19880311657 EP 19880311657 EP 88311657 A EP88311657 A EP 88311657A EP 0324240 B1 EP0324240 B1 EP 0324240B1
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EP
European Patent Office
Prior art keywords
windings
conductors
winding
transformer
planar transformer
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
Application number
EP19880311657
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English (en)
French (fr)
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EP0324240A3 (en
EP0324240A2 (de
Inventor
Gordon Glen Rabjohn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nortel Networks Ltd
Original Assignee
Northern Telecom Ltd
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Filing date
Publication date
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Publication of EP0324240A2 publication Critical patent/EP0324240A2/de
Publication of EP0324240A3 publication Critical patent/EP0324240A3/en
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Publication of EP0324240B1 publication Critical patent/EP0324240B1/de
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P5/00—Coupling devices of the waveguide type
    • H01P5/08—Coupling devices of the waveguide type for linking dissimilar lines or devices
    • H01P5/10—Coupling devices of the waveguide type for linking dissimilar lines or devices for coupling balanced lines or devices with unbalanced lines or devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F21/00—Variable inductances or transformers of the signal type
    • H01F21/12—Variable inductances or transformers of the signal type discontinuously variable, e.g. tapped
    • H01F2021/125—Printed variable inductor with taps, e.g. for VCO

Definitions

  • This invention relates to planar transformers, and is particularly but not exclusively concerned with balanced monolithic transformers for use at microwave frequencies, for example in a double balanced mixer of a microwave radio receiver.
  • U.K. patent application No. 2,084,809 published April 15, 1982 and entitled "Printed Circuit Transformers” discloses a planar transformer for use in mixers in VHF applications.
  • a primary track is arranged between two secondary tracks, forming a center tapped secondary, on a printed circuit board.
  • the primary track and each secondary track has only three-quarters of a turn, and the design appears to be limited to transformers with less than one turn for each track.
  • This transformer provides for solder bridges to be added for trimming the transformer by changing the effective lengths of the secondary tracks; such manual trimming is undesirable in a manufacturing environment, and can not easily be achieved with smaller transformers designed for operation at gigahertz frequencies.
  • An object of this invention is to provide an improved planar transformer.
  • a planar transformer comprising two windings each having at least one turn, the two windings comprising interleaved spiral conductors arranged in substantially a single plane, characterized in that the conductors of the windings cross one another whereby each winding is symmetrical about a line passing through center points of both of the windings, and a center tap connection is provided to the center point of at least one of the windings.
  • the interleaved conductors of the two windings of the transformer are arranged to cross one another to achieve symmetry of each winding with respect to a center point of the winding, at which point a center tap connection can be made. Because of the symmetry of the winding, this center tap is optimally positioned, and the two halves of the winding are inductively and capacitively balanced, for all frequencies within a very broad frequency range.
  • One or both of the windings may have more than one turn, with typically the number of turns of the two windings being substantially the same.
  • the two windings preferably have substantially the same physical arrangement in said plane.
  • the two windings may be substantially identical to one another, with one winding rotated and translated in said plane with respect to the other winding, whereby the conductors of the two windings are interleaved and connections can be conveniently made thereto. If each winding has n turns, then in such a transformer the conductors of the windings may typically cross one another at a number of 4n-2 locations.
  • one winding may have substantially one more turn than the other winding, and the crossings of the conductors may comprise two fewer crossings than there are total turns of the two windings together, each crossing comprising a cross-over between conductors in different turns of the same winding.
  • Each winding may have an integer number of turns, but this is not necessarily the case, and the windings may alternatively have non-integer numbers of turns.
  • embodiments of the invention are described below in which each winding has a number (2p+1)/2 turns, where p is a positive integer, which can provide advantageous arrangements in certain circumstances.
  • the conductors of the windings and the crossings therebetween are arranged in such manner that any two adjacent conductors comprise one conductor of each winding; in other words conductors of the two windings alternate with one another when considered in order from within to outside the turns of the windings.
  • both windings may be center tapped.
  • the transformer may include means for connecting an unbalanced circuit between one end and the center tap connection of one of the windings and for allowing the other end of this one of the windings to remain electrically floating. This arrangement compensates for imbalances due to circuits connected in use to the transformer, for improved operation.
  • the conductors of the windings comprise conductors supported by and spaced from a surface of a substrate, whereby said plane is spaced from said surface of the substrate.
  • each crossing between conductors of the windings conveniently comprises a conductor supported by and spaced from the surface of the substrate and a conductor on the surface of the substrate.
  • a known form of monolithic transformer consists of two spiral windings 10 and 12, respectively primary and secondary windings, each of which is shown as having two turns.
  • the two spiral windings are substantially identical to one another, but one is rotated and translated in relation to the other to produce the form shown.
  • a significant application for such a monolithic transformer is in microwave radio receivers, at frequencies of several gigahertz, and in particular in balanced circuits such as a double balanced mixer in which such transformers may be used for coupling radio frequency and local oscillator signals.
  • a center tap for the secondary winding 12 in Fig. 1 might be somewhere in the region of the point marked C.
  • determining the position of the center tap for this winding is difficult, and the center tap position can not be optimal for all frequencies and does not result in balancing of the two halves of the secondary winding.
  • These drawbacks arise from the facts that the turn radius varies throughout the winding, so that the inductance per turn increases greatly from the inside to the outside of the spiral and the inductance per unit length increases slightly, and interwinding capacitance varies in a manner which is difficult to calculate.
  • the center tap position is frequency-dependent and may be a compromise between different positions required for inductive and capacitive balancing.
  • Fig. 2 shows a monolithic transformer, comprising a primary winding 14 and center tapped secondary winding 16 each having a single turn, in which the above disadvantages are avoided.
  • each winding comprises a spiral inwardly to a central point and then outwardly again, the winding being symmetrical on each side of this central point.
  • This central point for example the point CT in Fig. 2 for the winding 16, clearly defines for the winding a center tapping point which is independent of frequency and which ensures that the winding halves on each side of it are inductively and capacitively equal.
  • the symmetry of the transformer and its windings is produced by providing interchanged positions or cross-overs of the conductors of the windings.
  • the cross-overs 18, at each of which the winding conductors cross one another but do not join or contact one another, can be formed in any convenient manner such as that described later below.
  • Fig. 3(a) illustrates another monolithic transformer having primary and secondary windings 14 and 16 each of which has two turns.
  • the transformer of Fig. 3(a) includes not only the two cross-overs 18 but a further four, similar, cross-overs 20.
  • the even number of turns results in the point CT on the secondary winding being at the right-hand side, as illustrated, of the transformer, i.e. on the same side of the transformer as secondary winding connections 22.
  • these connections 22 include symmetrically-arranged conductors 24 forming a connection to the center tap point CT. The conductors 24 cross the conductors of the windings 14 and 16 in the same manner as for the cross-overs 18 and 20.
  • Fig. 3(a) provides a closely matched and balanced transformer with a single-ended input (connections 30) and a double-ended or push-pull output (connections 22).
  • a transformer is well suited for use in a double balanced mixer of a microwave radio receiver.
  • the primary winding 14 may instead, or as well, be center tapped in a similar manner,
  • Fig. 3(a) has a disadvantage in that different turns of each winding 14 or 16 run adjacent one another over parts of their lengths, rather than the conductors of the two different windings always being adjacent one another. As a result, there is some reduction in coupling between the windings. This disadvantage is avoided by the alternative arrangement shown in Fig. 3(b).
  • rings of the windings numbered from the innermost ring (ring 1) to the outermost ring (ring 4), designated R1 to R4 in each of Figs. 3(a) and 3(b). It should be appreciated, however, that these designations do not refer to turns or conductors of the windings themselves, because each ring is made up of different parts of both windings 14 and 16.
  • the cross-overs 18 are between horizontal conductors in the rings R1 and R2, and two of the cross-overs 20 are between horizontal conductors in the rings R3 and R4. The same applies to the transformer of Fig. 3(b).
  • the other two cross-overs are between vertical conductors in the rings R2 and R3, with primary winding connections 30 and the secondary winding connections 22 to vertical conductors in the ring R4.
  • cross-overs 26 are provided between vertical conductors in non-adjacent rings R2 and R4, and the primary winding connections 30 and secondary connections 22 are made to conductors in the ring R3, as shown via optional cross-overs 28.
  • any two adjacent conductors in the transformer of Fig. 3(b) comprise one conductor of each winding.
  • Fig. 3(c) illustrates a modified form of the transformer of Fig. 3(b); the cross-overs 18, 20, 26 and 28 are identical, and only the paths of the conductors of the windings 14 and 16 between the cross-overs are changed. Obviously other arrangements of the conductors, including rectangular, circular, and octagonal arrangements, may be provided in a similar manner.
  • the arrangements of the transformers of Figs. 2, 3(a), 3(b), and 3(c) can be modified and extended to provide arbitrary numbers of turns and different rearrangements of cross-overs and connections.
  • the center taps could be provided on an outer ring, and the connections to the ends of the windings could be made on an inner ring, rather than being the other way round as shown.
  • the primary and secondary windings 14 and 16 are identical to one another. Generally, rearrangements which retain such identity will still provide two cross-overs for the first turn, and four cross-overs for each subsequent turn, of the windings, so that transformers with primary and secondary windings each of 1, 2, 3, 4... turns will have respectively 2, 6, 10, 14... cross-overs, or more generally windings of n turns will have 4n-2 cross-overs.
  • Figs. 4(a), 4(b), and 4(c) illustrate alternative transformer arrangements in accordance with embodiments of the invention, in which the above-described symmetry with respect to a central line A-A is maintained, with consequent maintenance of the advantages provided by such symmetry, but in which the primary winding 14 and the secondary winding 16 are not identical.
  • the arrangements shown in these figures generally have fewer cross-overs in all, the cross-overs being between non-adjacent rather than adjacent rings, and can facilitate the provision of different turns ratios between the numbers of turns of the primary and secondary windings.
  • the primary winding 14 has one turn and the secondary winding 16 has two turns, with a cross-over 26 between the secondary winding rings R1 and R3.
  • the secondary winding end connections 22 are taken from the outer ring R3, and the primary winding connections 30 are taken from the ring R2, via an optional cross-over 28.
  • the primary winding 14 has two turns, in rings R1 and R3, with a cross-over 26 therebetween and connections 30 to the ring R1.
  • other circuitry not shown, may be provided in known manner within the ring R1.
  • the secondary winding 14 also has two turns, in rings R2 and R4, with a cross-over 26 therebetween and connections 22 to the ends of the winding 14 in the ring R4.
  • the primary winding 14 has three turns, in rings R1, R3, and R5, with a cross-over 26 between the rings R1 and R3 and another cross-over 26 between the rings R3 and R5, and connections 30 in the ring R5.
  • the secondary winding 16 has two turns, in rings R2 and R4, with a cross-over 26 therebetween, connections 22 to the ends of the winding in the ring R4, and a center tap connection to the point CT in the ring R2 via symmetrical conductors 24.
  • the transformers of Figs. 4(a) to 4(c) can be extended in a similar manner with more turns in the windings and more cross-overs 26. Generally, there will be two fewer cross-overs 26 than the total number of turns in the primary and secondary windings. In other words, if the primary winding 14 has n p turns and the secondary winding 16 has n s turns, with
  • ⁇ 1, then the number n c of cross-overs 26 is given by the equation n c n p +n s -2.
  • Figs. 2 to 4 all have primary and secondary windings with integral numbers of turns, but the invention is not limited in this respect.
  • Figs. 5(a) to 5(d) illustrate alternative forms of transformer with non-integral numbers of turns of the primary and secondary windings. More particularly, in these figures each winding has (2p+1)/2 turns, where p is a positive integer.
  • Each of these figures illustrates a transformer having a primary winding 14 with a center tap point CP and terminals 30a and 30b, a secondary winding 16 with a center tap point CT and terminals 22a and 22b, cross-overs which for clarity are not referenced, and a line of symmetry A-A.
  • each of the windings 14 and 16 has one-and-a-half turns, but the coupling therebetween is not optimal because, as in the transformer of Fig. 3(a), different turns of each winding 14 or 16 run adjacent one another over parts of their lengths.
  • the windings 14 and 16 are rearranged so that any two conductors running adjacent one another belong to different windings, whereby the coupling between the windings is improved from that of Fig. 5(a), in the same manner that the coupling of the transformer of Fig. 3(b) is improved from that of Fig. 3(a).
  • Fig. 5(c) illustrates a modified form of the transformer of Fig.
  • Fig. 5(b) illustrates a transformer in which the primary winding 14 has two-and-a-half turns, whereas the secondary winding 16 has one-and-a-half turns.
  • the non-integral number of turns of each winding 14 or 16 results in the terminals 30a, 30b or 22a, 22b being on opposite sides of the transformer.
  • This may be of advantage in such circuits as balanced amplifiers in which the two terminals of each winding are connected to respective amplifier units, in that the amplifier units may be arranged on each side of the transformer in an integrated circuit with a balanced layout.
  • Fig. 6 illustrates a transformer having an unbalanced input to a primary winding 14 and a balanced output from a center-tapped secondary winding 16.
  • the secondary winding center tap CT is grounded, as is one end of the primary winding 14, and an input signal 32 is supplied to the other end of the primary winding.
  • An in-phase output signal 34 and an anti-phased output signal 36 are derived from the ends of the secondary winding 16.
  • Fig. 6 also shows by broken line connections capacitances 38 and 40 between the ends of the windings 14 and 16; these capacitances represent inter-winding capacitances of the transformer between the windings 14 and 16, which give rise to the balancing problem.
  • the capacitance 38 is connected between points at which signal voltages are in phase, whereas the capacitance 40 is connected on one side to ground and on the other side to a signal voltage. Consequently, the capacitance 40 is subjected to a different and greater signal voltage than the capacitance 38, and this leads to a considerably asymmetry in the transformer frequency response for the two output signals 34 and 36.
  • FIG. 7 A solution to this problem is illustrated in Fig. 7.
  • the primary winding 14 is also center tapped and the center tap is grounded, the signal 32 being supplied to one end of the primary winding and the other end being left floating. Consequently, an anti-phased signal 42 is induced at this floating end, which is thus in phase with the anti-phased output signal 36.
  • the dummy or floating half of the primary winding 14 thus serves to compensate for the effects of the inter-winding capacitances.
  • Fig. 8 illustrates the transformer of Fig. 3(b) modified in accordance with the principles of Fig. 7.
  • a center point CP of the primary winding 14 is connected via symmetrical conductors 44 to one of the primary winding connections 30, the other of which is connected to one end of the primary winding 14.
  • the other end 46 of the primary winding is left floating. Otherwise, the transformer of Fig. 8 is as described above with reference to Fig. 3(b).
  • the transformer is formed using so-called air bridge technology on a suitable substrate, which may comprise glass, ceramic, or other insulating material.
  • a suitable substrate which may comprise glass, ceramic, or other insulating material.
  • the transformer was formed on a gallium arsenide substrate, on which other components of a dual gate field effect transistor double balanced mixer for operation at frequencies up to about 8GHz were also formed, with the transformer windings 14 and 16 themselves occupying a square area with a side length of about 300 ⁇ m.
  • the square connections 22 and 30 in Fig. 9 represent connection pad terminations on such a substrate, which is referenced 48 in Fig. 10.
  • conductors 50 are elevated above the surface of the substrate 48 for reduced capacitance, and are supported periodically along their lengths on conductive posts 52 which appear as small squares in Fig. 9.
  • Fig. 9 does not represent all of the posts 52 which would be present along the lengths of the conductors 50.
  • a conductor 54 is provided directly on the surface of the substrate 48 extending between two posts 52 which are interconnected thereby. Except for such cross-over conductors 54, the connections 22 and 30, the conductors 24 and 44, the posts 52, and a conductor 56, all of the transformer conductors are constituted by the elevated conductors 50.
  • the substrate conductors 54 are initially deposited on the substrate in the desired pattern, then a photoresist layer is applied and the posts 52 and conductors 50 are deposited in the desired pattern, and then the photoresist is removed to leave the form of structure illustrated in Fig. 10.
  • the conductive parts may conveniently be of gold, with the substrate conductors 54 having a thickness of about 0.4 ⁇ m, the conductors 50 having a thickness of about 1 to 2 ⁇ m, and the air gaps between the conductors 50 and 54 having a thickness of about 1 to 2 ⁇ m.
  • the substrate conductor 56 interconnects the bases of posts 52 at the center taps CP and CT, and is connected (although the connections can not be seen in Fig. 9 as they underlie the elevated conductors 50) to the conductors 44 and 24, which are in turn grounded via respective connections 30 and 22.
  • the two conductors 44 are shown interconnected in Fig. 9; they may instead be connected to individual connection pads for grounding separately.
  • transformers in accordance with the invention can also be constructed directly on a substrate and using dielectric cross-overs rather than using air bridge technology as described above.

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  • Coils Or Transformers For Communication (AREA)

Claims (14)

  1. Planarer Übertrager mit zwei Wicklungen (14, 16), die jeweils zumindestens eine Windung aufweisen, wobei die beiden Wicklungen ineinander verschachtelte spiralförmige Leiter aufweisen, die im wesentlichen in einer einzigen Ebene angeordnet sind,
    dadurch gekennzeichnet, daß die Leiter der Wicklungen einander kreuzen (18), wodurch jedes Wicklung symmetrisch zu einer Linie (A-A) ist, die durch die Mittelpunkte der beiden Wicklungen verläuft, und daß ein Mittelanzapfungsanschluß (CT) an den Mittelpunkt von zumindestens einer der Wicklungen vorgesehen ist.
  2. Planarer Übertrager nach Anspruch 1, bei dem zumindestens eine der Wicklungen mehr als eine Windung aufweist.
  3. Planarer Übertrager nach Anspruch 1 oder 2, bei dem die Überkreuzungen der Leiter zwei Überkreuzungen weniger als die Gesamtzahl der Windungen der beiden Wicklungen zusammen umfassen.
  4. Planarer Übertrager nach Anspruch 3, bei dem jede Überkreuzung eine Überkreuzung (26) zwischen Leitern in unterschiedlichen Windungen der gleichen Wicklung umfaßt.
  5. Planarer Übertrager nach einem der Ansprüche 1 bis 4, bei dem eine Wicklung im wesentlichen eine Windung mehr als die andere Wicklung aufweist.
  6. Planarer Übertrager nach Anspruch 1, bei dem jede der Wicklungen mehr als eine Windung aufweist.
  7. Planarer Übertrager nach Anspruch 1 oder 6, bei dem die beiden Wicklungen im wesentlichen die gleiche Anzahl von Windungen aufweisen.
  8. Planarer Übertrager nach Anspruch 7, bei dem die beiden Wicklungen im wesentlichen die gleiche körperliche Anordnung in der genannten Ebene aufweisen.
  9. Planarer Übertrager nach Anspruch 8, bei dem jede Wicklung n Windungen aufweist und die Leiter der Wicklung einander an einer Anzahl von 4n-2 Stellen überkreuzen.
  10. Planarer Übertrager nach einem der Ansprüche 1 bis 9, bei dem die Leiter der Wicklungen und die Überkreuzungen zwischen diesen in einer derartigen Weise angeordnet sind, daß jeweilige zwei benachbarte Leiter einen Leiter jeder Wicklung umfassen.
  11. Planarer Übertrager nach einem der Ansprüche 1 bis 10, der Mittelanzapfungsanschlüsse (CT, CP) an die Mittelpunkte beider Wicklungen einschließt.
  12. Planarer Übertrager nach Anspruch 11, der Einrichtungen (30) zum Anschluß einer unsymmetrischen Schaltung zwischen einem Ende und dem Mittelanzapfungsanschluß (CP) einer der Wicklungen (14) einschließt, wobei das andere Ende dieser einen der Wicklungen elektrisch schwimmend gelassen wird.
  13. Planarer Übertrager nach einem der Ansprüche 1 bis 12, bei dem die Leiter der Wicklungen Leiter (50) umfassen, die auf einer Oberfläche eines Substrates (48) und mit Abstand von dieser gehaltert sind, so daß die genannte Ebene von der Oberfläche des Substrates einen Abstand aufweist.
  14. Planarer Übertrager nach Anspruch 13, bei dem jede Überkreuzung zwischen Leitern der Wicklungen einen Leiter (50), der auf der Oberfläche des Substrates (48) und in Abstand von dieser gehaltert ist, und einen Leiter (54) auf der Oberfläche des Substrates umfaßt.
EP19880311657 1988-01-15 1988-12-09 Symmetrischer planarer Übertrager Expired - Lifetime EP0324240B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA000556685A CA1278051C (en) 1988-01-15 1988-01-15 Balanced planar transformers
CA556685 1988-01-15

Publications (3)

Publication Number Publication Date
EP0324240A2 EP0324240A2 (de) 1989-07-19
EP0324240A3 EP0324240A3 (en) 1990-07-25
EP0324240B1 true EP0324240B1 (de) 1994-10-12

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Application Number Title Priority Date Filing Date
EP19880311657 Expired - Lifetime EP0324240B1 (de) 1988-01-15 1988-12-09 Symmetrischer planarer Übertrager

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EP (1) EP0324240B1 (de)
JP (1) JP2938082B2 (de)
CA (1) CA1278051C (de)
DE (1) DE3851831T2 (de)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2652210B1 (fr) * 1989-09-20 1995-06-16 Alcatel Radiotelephone Circuit de modulation en phase et en amplitude.
FI91930C (fi) * 1991-03-19 1994-08-25 Nokia Mobile Phones Ltd Piirilevymuuntaja ja sen käyttö
FR2819938B1 (fr) 2001-01-22 2003-05-30 St Microelectronics Sa Dispositif semi-conducteur comprenant des enroulements constituant des inductances
DE10261385B4 (de) * 2002-12-30 2007-05-16 Newlogic Technologies Ag Monolithisch integrierter Transformator
JP4507508B2 (ja) * 2003-05-08 2010-07-21 パナソニック株式会社 インダクタ装置およびその製造方法
EP1478045B1 (de) * 2003-05-16 2012-06-06 Panasonic Corporation Gegeninduktionsschaltung
JP4664619B2 (ja) * 2003-05-16 2011-04-06 パナソニック株式会社 相互誘導回路
US8217747B2 (en) * 2004-06-23 2012-07-10 Nxp B.V. Planar inductor
KR100777394B1 (ko) * 2006-05-17 2007-11-19 삼성전자주식회사 진폭 불균형을 개선하기 위한 온­칩 트랜스포머 밸룬
JP2009064963A (ja) * 2007-09-06 2009-03-26 Nec Electronics Corp 電子デバイス
JP4893616B2 (ja) * 2007-12-25 2012-03-07 セイコーエプソン株式会社 インダクタ
US7714679B2 (en) * 2008-01-29 2010-05-11 Hittite Microwave Corporation Spiral coupler
US8860180B2 (en) * 2012-10-26 2014-10-14 Xilinx, Inc. Inductor structure with a current return encompassing a coil
DE102013101768A1 (de) * 2013-02-22 2014-08-28 Intel Mobile Communications GmbH Transformator und elektrische Schaltung
US20160284461A1 (en) * 2015-03-28 2016-09-29 Intel IP Corporation Tuning inductance ratio of a passive device
FR3049758B1 (fr) 2016-03-30 2018-04-27 Stmicroelectronics Sa Transformateur de puissance du type symetrique-dissymetrique a topologie completement equilibree

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1271230B (de) * 1966-01-13 1968-06-27 Telefunken Patent Hochfrequenz-Symmetriertransformator
US4080585A (en) * 1977-04-11 1978-03-21 Cubic Corporation Flat coil transformer for electronic circuit boards
JPS5464192A (en) * 1978-08-03 1979-05-23 Daido Maruta Finishing Printing method
JPS5837972B2 (ja) * 1979-08-31 1983-08-19 株式会社明電舎 スコット結線変圧器
GB2084809B (en) * 1980-10-01 1984-01-18 Communications Patents Ltd Printed circuit transformers
JPS58215392A (ja) * 1982-06-08 1983-12-14 Sanyo Electric Co Ltd 透明フイルムへの画像記録方法

Also Published As

Publication number Publication date
JPH027406A (ja) 1990-01-11
DE3851831D1 (de) 1994-11-17
EP0324240A3 (en) 1990-07-25
JP2938082B2 (ja) 1999-08-23
EP0324240A2 (de) 1989-07-19
DE3851831T2 (de) 1995-02-09
CA1278051C (en) 1990-12-18

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