Transformer and method of forming

Abstract

A transformer and a method of forming are disclosed. Comprising a coaxial cable portion and a printed circuit board (PCB) trace portion is wound around the magnetic core. The coaxial cable portion defines a portion of a primary winding and a portion of a secondary winding. The PCB trace portion includes a first set of PCB traces and a second set of PCB traces to define another portion of the primary winding, and a third set of PCB traces and a fourth set of PCB traces to define another portion of the secondary winding. The set of third and fourth PCB traces are electrically coupled through a set of conductive vias. The third PCB trace, the fourth PCB trace, and the set of conductive vias circumferentially surround at least a portion of the first PCB trace and the second PCB trace.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to inductors, and more particularly to a transformer using coaxial cable and printed circuit board (PCB) technology. BACKGROUND

[0002] A power transformer is an inductive device that typically consists of a pair of coils or windings having a number of turns wrapped around a ferromagnetic core. The pair of coils includes a primary winding through which a current is directed and a secondary winding that is electrically isolated from the primary winding. A magnetic field generated by the current flow in the primary winding inductively couples to the secondary winding, and variations in the magnetic field induce a current flow in the secondary winding. The ferromagnetic core provides a low reluctance path for the magnetic field. The magnitude of the induced current flow depends on the ratio of the number of turns in the primary winding to the number of turns in the secondary winding. SUMMARY

[0003] Technical Solution 1. A transformer, comprising:

[0004] a multilayer printed circuit board (PCB) having a first face and an opposite second face and a set of dielectric layers disposed between the first face and the second face, the set of dielectric layers including a first layer and a second layer, the first layer having a first PCB trace and a second PCB trace defined thereon, the second layer having a set of third PCB traces defined thereon, the first PCB trace and the second PCB trace being oppositely spaced from the third PCB traces;

[0005] a set of first vias extending from the first face to and coupled to the first PCB trace;

[0006] a set of second vias extending from the first face to and electrically coupled to the second PCB trace;

[0007] a toroidal magnetic core defining a bore, the toroidal magnetic core coupled to the first face;

[0008] a set of coaxial conductors extending longitudinally through the bore, each coaxial conductor having a first conductive element circumferentially surrounded by and electrically isolated from a second conductive element and respectively defining a first end and an opposite second end;

[0009] a primary winding comprising a set of primary winding turns, each primary winding turn comprising a respective first conductive element of at least one of the coaxial conductors, a respective portion of the first PCB trace, and a respective portion of the second PCB trace, the respective first conductive element being coupled at a respective first end to the respective portion of the first PCB trace by a respective first via, and being coupled at a respective second end to the respective portion of the second PCB trace by a respective second via;

[0010] a secondary winding comprising a set of secondary winding turns, each secondary winding turn comprising a respective second conductive element of each of the coaxial conductors; and

[0011] a set of third vias extending from the first face to and coupled to the third PCB trace;

[0012] wherein the respective outer second conductive element is coupled at the respective first end to a respective portion of the third PCB trace by a respective third via, and is further coupled at the respective second end to the third PCB trace by another respective third via.

[0013] Technical Solution 2. The transformer of any preceding technical solution, wherein each of the set of primary winding turns is electrically coupled in parallel with respect to one another, and each of the set of secondary winding turns is electrically coupled in series with one another.

[0014] Technical Solution 3. The transformer of any preceding technical solution, wherein each of the set of primary winding turns is electrically coupled in series with respect to one another, and each of the set of secondary winding turns is electrically coupled in parallel with one another.

[0015] Technical Solution 4. The transformer of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1 :T, and wherein the set of third PCB traces comprises a number N of third PCB traces, wherein the number N is equal to T.

[0016] Technical Solution 5. The transformer of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of T: 1, and wherein the set of third PCB traces comprises a number N of third PCB traces, wherein the number N is equal to T.

[0017] Technical Solution 6. The transformer of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1 : 1.

[0018] TECHNICAL SOLUTION 7. The transformer of any preceding technical solution, wherein the set of dielectric layers further comprises a third layer having a set of fourth PCB traces defined thereon, each fourth PCB trace opposing at least a portion of at least one of the first and second PCB traces,

[0019] wherein the first and second PCB traces are disposed between and spaced apart from respective portions of the third and fourth PCB traces, and

[0020] wherein the set of third vias extending from the first face to the third PCB traces further extend to respective ones of the fourth PCB traces and electrically couple each fourth PCB trace with a respective one of the third PCB traces.

[0021] TECHNICAL SOLUTION 8. The transformer of any preceding technical solution, wherein portions of respective third PCB traces, portions of respective fourth PCB traces, and respective subsets of the set of third vias cooperatively circumferentially surround at least a portion of one of the first and second PCB traces.

[0022] TECHNICAL SOLUTION 9. The transformer of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1 :T, and wherein the set of third PCB traces comprises a number N of third PCB traces and the set of fourth PCB traces comprises the number N of fourth PCB traces, wherein the number N is equal to T.

[0023] TECHNICAL SOLUTION 10. The transformer of any preceding technical solution, wherein each primary winding turn is circumferentially surrounded by a portion of a respective secondary winding turn.

[0024] TECHNICAL SOLUTION 11. A method of forming a transformer, comprising:

[0025] A multi-layer printed circuit board is formed having a first face and an opposite second face and a set of dielectric layers disposed between the first face and the second face, the set of dielectric layers including: a first layer having a first PCB trace and a second PCB trace defined thereon; a first via extending from the first face to the first PCB trace and coupled to the first PCB trace; a second via extending from the first face to the second PCB trace and electrically coupled to the second PCB trace; a second layer having a set of third PCB traces defined thereon, the first and second PCB traces being oppositely spaced from the third PCB traces; and a set of third vias extending from the first face to the third PCB traces and electrically coupled to the third PCB traces;

[0026] An annular magnetic core defining a bore is coupled to the first face;

[0027] A set of coaxial conductors is disposed longitudinally through the bore, each coaxial conductor including a first conductive element circumferentially surrounded by and electrically insulated from a second conductive element and respectively defining a first end and a second end;

[0028] A primary winding is formed including a set of primary winding turns, each primary turn including a respective first conductive element of at least one of the set of coaxial conductors, a portion of a respective first PCB trace, and a respective portion of the second PCB trace, the respective first conductive element being coupled at a respective first end to the respective portion of the first PCB trace by a respective first via and at a respective second end to the respective portion of the second PCB trace by a respective second via; and

[0029] A secondary winding is formed including a set of secondary winding turns, each secondary turn including a respective second conductive element of at least one of the set of coaxial conductors and a portion of a respective third PCB trace, the respective second conductive element being coupled at the respective first end to the respective portion of the third PCB trace by a respective third via and at the respective second end further coupled to the third PCB trace by another respective third via.

[0030] Technical Solution 12. The method of any preceding technical solution, further comprising electrically coupling the set of primary winding turns in parallel with respect to one another and electrically coupling the set of secondary winding turns in series with one another.

[0031] TECHNICAL SOLUTION 13. The method of any preceding technical solution, further comprising electrically coupling the set of primary winding turns in series with respect to one another, and electrically coupling the set of secondary winding turns in parallel with one another.

[0032] TECHNICAL SOLUTION 14. The method of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1 :T, and wherein the set of third PCB traces comprises a number N of third PCB traces, wherein the number N is equal to T.

[0033] TECHNICAL SOLUTION 15. The method of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of T: 1, and wherein the set of third PCB traces comprises a number N of third PCB traces, wherein the number N is equal to T.

[0034] TECHNICAL SOLUTION 16. The method of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1 : 1.

[0035] TECHNICAL SOLUTION 17. The method of any preceding technical solution, wherein the set of dielectric layers further comprises a third layer having a set of fourth PCB traces defined thereon, each fourth PCB trace opposing at least a portion of at least one of the first and second PCB traces,

[0036] wherein the first and second PCB traces are disposed between and spaced apart from the third and fourth PCB traces, and

[0037] wherein the set of third vias extending from the first face to the third PCB traces further extend to a respective one of the fourth PCB traces and electrically couple each fourth PCB trace with a respective third PCB trace.

[0038] TECHNICAL SOLUTION 18. The method of any preceding technical solution, wherein a portion of a respective third PCB trace, a portion of a respective fourth PCB trace, and a respective subset of the set of third vias cooperatively circumferentially encircle at least a portion of one of the first and second PCB traces.

[0039] Technical Solution 19. The method of any preceding technical solution, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1 :T, and wherein the set of third PCB traces comprises a number N of third PCB traces, the set of fourth PCB traces comprises the number N of fourth PCB traces, wherein the number N is equal to T.

[0040] Technical Solution 20. The method of any preceding technical solution, wherein each primary winding turn is circumferentially surrounded by a portion of a secondary winding turn. BRIEF DESCRIPTION OF DRAWINGS

[0041] The complete and enabling disclosure of this description, including the best mode thereof, to one of ordinary skill in the art at the time of the making of the application as set forth in the specification, including claims, appended drawings and drawings, is set forth in the specification of the description, which is exemplified in the drawings, wherein:

[0042] Figure 1 An isometric view of a conventional transformer is depicted.

[0043] Figure 2 A perspective view of a conventional coaxial cable is depicted.

[0044] Figure 3 A transformer according to various aspects described herein is depicted.

[0045] Figure 4 A schematic block diagram of a transformer according to various aspects described herein is depicted. Figure 3

[0046] Figure 5 A schematic block diagram of another exemplary transformer according to various aspects described herein is depicted.

[0047] Figure 6 A schematic diagram of a portion of a transformer according to various aspects described herein is depicted. Figure 5

[0048] Figure 7 A flow diagram of a method of forming a transformer according to various aspects described herein is depicted. DETAILED DESCRIPTION

[0049] The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the accompanying drawings attached hereto are not necessarily to scale and are merely intended to aid in description of the aspects associated with the present disclosure. Additionally, the number and placement of various components in the drawings is not intended to limit the aspects associated with the present disclosure and can be varied. For example, while various components have been illustrated as being separate components, aspects of the present disclosure are not so limited and components can be combined or divided.

[0050] ​​Aspects of the disclosure can be implemented in any environment, device, or method for an electrical filter, regardless of the function performed by the device or method.

[0051] As used herein, the term "set" or a "set" of elements can be any number of elements, including only one.

[0052] As used herein, the term "upstream" refers to a direction opposite the direction of current flow, and the term "downstream" refers to a direction in the same direction as current flow. Thus, an "upstream" end of an element is opposite a "downstream" end of the element.

[0053] Additionally, while terms such as "voltage," "current," and "power" can be used herein, it will be apparent to those skilled in the art that these terms can be interrelated when aspects of a circuit or circuit operation are described.

[0054] Connection references (e.g., attach, couple, connect, and join) are to be construed broadly and can include intermediate members between the elements, as well as relative movement between elements, unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other. In non-limiting examples, a connection or disconnection can be selectively configured to provide, enable, disable, etc. an electrical connection between respective elements. Additionally, as used herein, an "electrical connection" or "electrically coupled" can include a wired or wireless connection. The example figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures herein can vary.

[0055] As used herein, the term "conductivity" refers to a property of a material that allows charge or current to flow therethrough. Further, as used herein, the term "electrical conductor" or "conductive element" refers to a material or structure that exhibits a relatively high electrical conductivity (e.g., greater than about 10 -7 Siemens / meter (S / m)). Unless otherwise stated, as used herein, the terms "conductive," "conductor," "conductivity," and the like refer to electrical properties of a material or structure. For example, the term "conductor" refers to an electrical conductor.

[0056] As used herein, the term "insulative" refers to a property of a material that resists the flow of charge or current therethrough. Further, as used herein, the term "insulator" or "insulation" refers to a material that exhibits a low electrical conductivity (e.g., less than about 10 -8 Siemens / meter (S / m)). Unless otherwise stated, as used herein, the terms "insulative," "insulator," and the like refer to electrical insulation.

[0057] As used herein, the term "inductance" is a relative measure of the tendency of a conductive material to resist a change in current flowing therethrough. Inductance can be expressed as a ratio of voltage to a rate of change of current. In the International System of Units (SI), the unit of inductance is the henry (H).

[0058] As used herein, the term "cable" refers to an electrical transmission line or conductor that operates to conduct current in an inclusive manner between discrete devices, electrical components, or other conductors (e.g., PCB traces) within a circuit or component. As used herein, the term "coaxial cable" refers to a conductive cable having an inner conductor that is circumferentially surrounded by a concentric outer conductor or conductive shield, where the inner and outer conductors are separated by a dielectric or insulating material. Non-limiting examples of cables include wires, coaxial cables, bus bars, or combinations thereof. As used herein, the terms "cable," "coaxial cable" are not intended to be so broadly construed as to include PCB traces.

[0059] As used herein, the term "trace" or "printed circuit board trace," "PCB trace," or the like refers to a planar conductive line or conductor integrally defined on a layer of a PCB. As used herein, the terms "trace" and "PCB trace" are not intended to be so broadly construed as to include cables or wires.

[0060] As used herein, the term "via" or "conductive via" refers to an electrically conductive path defined between different layers of a PCB. For example, a via can be disposed as an aperture or hole defined through a layer of a PCB and traversing two or more adjacent layers. The via can be internally covered with a conductive material such as copper (e.g., by a plating process, staking, or by inserting a small tube of conductive material) to form an electrical path in the insulating material separating the layers of the PCB. As used herein, a via can include a through via (e.g., which extends through a layer of a PCB including both opposing outer surfaces of the PCB), a buried via (e.g., which extends entirely inside the PCB without connection to both opposing outer surfaces of the PCB), or a blind via (e.g., which extends from one outer surface of the PCB through one or more inner layers without extending to the opposing outer surface of the PCB).

[0061] A conventional inductor is a passive electrical component that stores electrical energy in a magnetic field when current flows through the magnetic field. An inductor typically includes an insulated wire wound into a coil or winding. When the current flowing through the coil changes direction (e.g., AC current), a time-varying magnetic field induces an electromotive force (emf) or voltage in the conductor, as described by Faraday's Law of Induction. An inductor is characterized by an inductance value. For example, a conventional inductor has an inductance value typically in the range from 1 μΗ (10 -6 H) to 20 H. Typically, an inductor has a magnetic core (e.g., a ferrite core) inside the coil that serves to increase the magnetic field and thus the inductance.

[0062] When an AC voltage is applied across an inductor (e.g., a primary winding), a self-induced emf (e.g., voltage) is generated due to the changing magnetic field around the turns of the winding. When an emf is induced into an adjacent winding (e.g., a secondary winding) disposed within the same magnetic field, the emf is said to be induced by mutual induction. Typically, "mutual induction" refers to an electrical parameter between two magnetically coupled windings (e.g., a first winding and a second winding linked by a common magnetic flux) and defines the ratio of the time-varying magnetic flux produced by the first winding that is induced into the second winding.

[0063] Inductors that store energy and transfer energy between windings are sometimes referred to as transformers or coupled inductors. Unless otherwise indicated, in this disclosure, the term "transformer" can include coupled inductors.

[0064] A conventional transformer typically includes two separate coils or sets of windings (e.g., inductors). The two separate coils generally have different numbers of individual "turns" of respective insulated conductors wound around the same ferromagnetic core to have magnetic coupling between them. Typically, transformers have a gapless ferromagnetic core, while coupled inductors employ a gapped core. The two coils are generally referred to as a primary winding and a secondary winding. Typically, the primary winding is energized by a source, and the secondary winding is connected to a load.

[0065] For example, Figure 1 An isometric view of a conventional transformer 20 is depicted. The transformer includes a primary winding 21, a secondary winding 22, and an annular magnetic core 25 defining a hole 26. A first set of turns (primary winding turns 21a) is typically wound around a first side of the magnetic core 25 and through the hole 26 to collectively define the primary winding 21. A second set of turns (secondary winding turns 22a) is typically wound around an opposite second side of the magnetic core 25 and through the hole 26 to collectively define the secondary winding 22.

[0066] When an input voltage Vin is applied across the primary winding 21, an output voltage Vo is induced across the secondary winding 22. The efficiency of the mutual induction or magnetic coupling can be quantified as the "coupling coefficient" of the transformer, through which power is transferred from the primary winding 21 to the secondary winding 22 of the transformer 20. Generally, the coupling coefficient can be defined as the ratio of the number of magnetic flux paths common to both windings to the number of magnetic flux paths in the windings. The better the primary winding 21 and the secondary winding 22 are magnetically coupled, the more efficient the electromagnetic induction between them. If the primary winding 21 and the secondary winding 22 are perfectly magnetically coupled (e.g., all of the magnetic flux generated by the primary winding 21 penetrates the coils of the secondary winding 22), the coupling coefficient is equal to 1. If the primary winding 21 and the secondary winding 22 are not coupled (e.g., the primary winding 21 and the secondary winding 22 are completely shielded from each other), the coupling coefficient is equal to 0. The coupling coefficient can depend on the structural design of the transformer 20. For example, an important factor that affects the coupling coefficient is the position of the primary winding 21 and the secondary winding 22 relative to each other. For example, if the primary winding 21 and the secondary winding 22 are wound on top of each other, and every magnetic flux path from the primary winding 21 intersects a magnetic flux path from the secondary winding 22, the coupling coefficient is equal to 1. If any flux is lost, the coupling coefficient is less than 1. Incomplete magnetic coupling between the primary winding 21 and the secondary winding 22 (e.g., less than all of the magnetic flux generated by the primary winding 21 penetrates the coils of the secondary winding 22) results in a reduction of the voltage induced in the secondary winding 22. Incomplete coupling appears as a self-inductance in series with the respective ohmic resistance of the primary winding 21 or the secondary winding 22, and is referred to as "leakage inductance." Leakage inductance is due to magnetic flux not linking with every turn of the incompletely coupled set of windings. The coupling coefficient of a typical transformer is in the range from 0.950 to 0.990.

[0067] In many conventional transformers, the number of primary winding turns 21a in the primary winding 21 is different from the number of secondary winding turns 22a in the secondary winding 22. This difference in the number of primary winding turns 21a and secondary winding turns 22a is generally referred to as the turns ratio of the transformer 20. Typically, the turns ratio is defined as the ratio of the number of primary winding turns 21a in the primary winding 21 to the number of secondary winding turns 22a in the secondary winding 22. The turns ratio can indicate the ratio of the input voltage Vin applied across the primary winding 21 to the output voltage Vo induced across the secondary winding 22. The turns ratio is typically expressed as "Np:Ns," where Np is equal to the number of primary winding turns 21a and Ns is equal to the number of secondary winding turns 22a.

[0068] A transformer 20 having a greater number of secondary winding turns 22a than primary winding turns 21a is referred to as a step-up transformer. The step-up transformer 20 has a secondary or output voltage Vo that is higher than the primary or input voltage Vin. A transformer 20 having a greater number of primary winding turns 21a than secondary winding turns 22a is referred to as a step-down transformer. The step-down transformer has an output voltage Vo that is lower than its input voltage Vin.

[0069] While conventional transformers 20 typically use conventional insulated wires or cables to form the primary winding turns 21a and the secondary winding turns 22a, such transformers 20 can exhibit undesirably high leakage inductance due to the inherent gap between the discrete insulated wires forming the primary winding turns 21a of the primary winding 21 and the discrete insulated wires forming the secondary winding turns 22a of the secondary winding 22. One known technique to reduce this inherent gap is to use conventional coaxial cables to form the primary winding turns 21a and the secondary winding turns 22a. For example, some known transformers 20 have coaxial cables (with the inner conductor arranged as the primary winding 21 and the outer conductor arranged as the secondary winding 22) that are wound around a former (not shown) and wrapped by a toroidal core (not shown). However, such transformers 20 can have limited applicability because the turns ratio of these coaxial cable transformers is then necessarily limited to 1 : 1.

[0070] It would be desirable to provide a transformer that has an improved coupling coefficient (e.g., greater than 0.990) or reduced leakage inductance compared to conventional transformers while also enabling turns ratios that are not limited to 1 : 1.

[0071] Figure 2 A conventional coaxial cable 150 is illustrated in FIG. 1. The coaxial cable 150 has a first end 150a and a second end 150b that is diametrically opposite. The coaxial cable 150 can include an elongated central first conductive element 151 (e.g., a copper wire) or primary conductor that is circumferentially surrounded by a first electrically insulating layer 153. The first electrically insulating layer 153 can be circumferentially surrounded by an elongated, generally tubular second conductive element 152. In some examples, the second conductive element 152 can be a jacket, a shield, a woven braid, etc. In non-limiting aspects, a second electrically insulating layer 154 circumferentially surrounds the second conductive element. The first conductive element 151 and the second conductive element 152 extend from the first end 150a to the second end 150b of the coaxial cable 150. It will be appreciated that, Figure 2 The coaxial cable 150 is depicted with respective portions of the first electrically insulating layer 153, the second conductive element 152, and the second electrically insulating layer 154 at the first end 150a omitted for clarity.

[0072] While for ease of description and understanding, Figure 2The first conductive element 151 is depicted as having a generally circular cross-section, but in various examples, the first conductive element 151 can have any desired cross-section, including, for example, oval, rectangular, and polygonal, without departing from the scope of the present disclosure. Additionally, while the first conductive element 151 is depicted as a single conductor or strand, in other aspects, the first conductive element 151 can include any desired number of conductors (e.g., twisted wires), without departing from the scope of the present disclosure. Figure 2 The first conductive element 151 is depicted as a single conductor or strand, but in other aspects, the first conductive element 151 can include any desired number of conductors (e.g., twisted wires), without departing from the scope of the present disclosure.

[0073] Figure 3 is an isometric view of a non-limiting aspect of a transformer 200 having a primary winding 201 and a secondary winding 202. The transformer 200 includes a multi-layer PCB 210 having a first face 210a spaced apart from a second face 210b. A toroidal ferromagnetic core 220 is coupled to the first face 210a of the PCB 210. In non-limiting aspects, the ferromagnetic core 220 can be coupled to the first face 210a using a strip 222. In other non-limiting aspects, the ferromagnetic core 220 can be coupled to the first face 210a using a clamp, a fastener, an adhesive, or a combination thereof. The ferromagnetic core 220 defines a hole 225 therethrough. While the hole 225 is depicted as being circular, in other aspects, the hole 225 can have any desired shape, including, for example, oval, rectangular, and polygonal, without departing from the scope of the present disclosure. Figure 3 The exemplary aspect depicted in FIG. 2 depicts the transformer 200 having a toroidal ferromagnetic core 220 without a gap, but in other aspects, the ferromagnetic core 220 can include a gap (e.g., to form a coupled inductor). A first set of coaxial cables 250 are arranged to extend through the hole and are coupled to the PCB 210 at a first end 250a and a second end 250b. In non-limiting aspects, the coaxial cables 250 can be coupled to the PCB 210 using connectors 256. In other aspects, the coaxial cables 250 can be coupled to the PCB 210 using a soldered connection.

[0074] Figure 4 is a block diagram depicting a cross-section of a portion of another non-limiting aspect of a transformer 300, with the ferromagnetic core 220 omitted for clarity Figure 3The transformer 300 includes a primary winding 201 and a secondary winding 202. The primary winding 201 and the secondary winding 202 are each defined by a respective coaxial cable portion (formed by the set of coaxial cables 250) and a respective PCB portion (e.g., trace) formed on the PCB 210. For example, each coaxial cable 250 can include a respective first conductive element 251 (e.g., copper wire) or primary conductor. Each coaxial cable 250 can be circumferentially surrounded by a first electrically insulating layer 253. The first electrically insulating layer 253 can be circumferentially surrounded by a second conductive element 252 that is generally tubular. In some examples, the second conductive element 252 can be a jacket, a shield, a woven braid, or the like. In non-limiting aspects, a second electrically insulating layer 254 circumferentially surrounds the second conductive element 252. The first conductive element 251 and the second conductive element 252 extend from a first end 250a to a second end 250b of the coaxial cable 250.

[0075] The primary winding 201 can include a respective primary cable portion 251a and a respective primary PCB trace portion 251b. The secondary winding 202 can include a respective secondary cable portion 252a and a respective secondary PCB trace portion 252b. The first conductive element 251 of each coaxial cable 250 can form the respective primary cable portion 251a of the primary winding 201, and the second conductive element 252 of each coaxial cable 250 can form the respective secondary cable portion 252a of the secondary winding 202.

[0076] The PCB 210 can be a multi-layer PCB 210 and can include a set of layers 230. For example, in non-limiting aspects, the PCB 210 can include a first layer 230a and a second layer 230b. The first layer 230a and the second layer 230b can be planar and formed of an insulating or dielectric material. The first layer 230a and the second layer 230b can be oppositely (e.g., parallelly) arranged between the first face 210a and the second face 210b. The first PCB trace 211 and the second PCB trace 212 can be disposed on the first layer 230a. The second PCB trace 212 is spaced apart from the first PCB trace 211 on the first layer 230a. A set of first vias 215 can be coupled to the first PCB trace 211. The set of first vias 215 can extend from the first PCB trace 211 to the first face 210a. A set of second vias 216 can be coupled to the second PCB trace 212. The set of second vias 216 can extend from the second PCB trace 212 to the first face 210a.

[0077] The respective first conductive element 251 of each coaxial cable 250 can be coupled to a respective first via 215 at the first end 250a and to a respective second via 216 at the second end 250b. For example, in non-limiting aspects, the respective primary cable portion 251a of each coaxial cable 250 can be coupled to the respective first via 215 and second via 216 via a solder connection (omitted for clarity). In some aspects, the respective primary cable portion 251a can be coupled to the respective first via 215 and second via 216 via a respective connector 256 Figure 3 ) in non-limiting aspects. The first PCB trace 211, second PCB trace 212, first via 215, and second via 216 can cooperatively form a primary PCB trace portion 251b.

[0078] The second layer 230b can have a set of third PCB traces 213 disposed thereon. The set of third PCB traces 213 includes a predetermined number ("N") of third PCB traces 213. The first PCB trace 211 and second PCB trace 212 can be oppositely spaced from the respective third PCB traces 213. Likewise, the first via 215 and second via 216 are spaced from the third PCB traces 213. A set of third vias 217 can be electrically coupled to the third PCB traces 213. In non-limiting aspects, the third vias 217 can extend to the first face 210a. The third PCB traces 213 and third vias 217 can cooperatively form a secondary PCB trace portion 252b.

[0079] The respective secondary cable portion 252a of each coaxial cable 250 can be coupled to a respective third via 217 at the first end 250a and to another respective third via 217 at the second end 250b. For example, in non-limiting aspects, the respective secondary cable portion 252a of each coaxial cable 250 can be coupled to the respective third via 217 via a solder connection. In some aspects, the respective secondary cable portion 252a can be coupled to the respective third via 217 via a respective connector 256 Figure 3 ) in non-limiting aspects.

[0080] While Figure 4 The second layer 230b is depicted with the third PCB traces 213 disposed between the first layer 230a and the first face 210a, other aspects are not so limited. In other aspects, the first layer 230a can be disposed between the second layer 230b and the first face 210a without departing from the scope of the present disclosure. Additionally, although not shown, it is contemplated that in non-limiting aspects, a subset of the third vias 217 can extend between the first face 210a and the second face 210b.

[0081] Figure 5is a cross-sectional block diagram of portions of another exemplary aspect of the transformer 400, with the ferromagnetic core 220 omitted for clarity. Figure 5 The aspects depicted in Figure 4 are similar to those of Figure 4 and the same reference numbers refer to the same components. Figure 5 One significant difference between the aspects depicted in Figure 5 the aspects depicted in

[0082] In non-limiting aspects, the third layer 230c can be planar and formed of an insulating or dielectric material. The first layer 230a, the second layer 230b, and the third layer 230c are spaced apart (e.g., parallel) from one another between the first face 210a and the second face 210b. In non-limiting aspects, the first layer 230a can be sandwiched or disposed between the second layer 230b and the third layer 230c.

[0083] The first PCB traces 211 and the second PCB traces 212 are disposed on the first layer 230a, with the second PCB traces 212 spaced apart from the first PCB traces 211 on the first layer 230a. The first vias 215 and the second vias 216 are spaced apart from the third PCB traces 213. The set of first vias 215 are coupled to and extend from the first PCB traces 211 to the first face 210a. The set of second vias 216 are coupled to and extend from the second PCB traces 212 to the first face 210a. The respective first conductive elements 251 of each coaxial cable 250 can be coupled to the respective first via 215 at the first end 250a and to the respective second via 216 at the second end 250b. For example, in non-limiting aspects, the respective primary cable portion 251a of each coaxial cable 250 can be coupled to the respective first via 215 and second via 216 via a soldered connection. In some aspects, the respective primary cable portion 251a can be coupled to the respective first via 215 and second via 216 via a connector (not shown).

[0084] The second layer 230b has a predetermined number (designated as "N") of third PCB traces 213 disposed thereon. Additionally, the third layer 230c can have the set of fourth PCB traces 214 disposed thereon. The set of fourth PCB traces 214 includes a predetermined number ("N") of fourth PCB traces 214. Each fourth PCB trace 214 can be opposingly spaced from a respective third PCB trace 213. The first PCB traces 211 and the second PCB traces 212 can be disposed between and opposingly spaced from the respective third PCB traces 213 and the respective fourth PCB traces 214. The second conductive element 252 of each coaxial cable 250 can be coupled to a respective third via 217 at the respective first end 250a and the second end 250b. Each respective third via 217 can be coupled to a respective third PCB trace 213 and a respective fourth PCB trace 214.

[0085] In non-limiting aspects, the set of third vias 217 can electrically couple the third PCB traces 213 and the fourth PCB traces 214. At least a subset of the third vias 217 can extend to the first face 210a. In non-limiting aspects, another subset of the third vias 217 can extend between the first face 210a and the second face 210b. As such, the third PCB traces 213, the fourth PCB traces 214, and at least portions of the set of third vias 217 cooperatively arranged to circumferentially surround portions of at least one of the first PCB traces 211 or the second PCB traces 212. The number of third vias 217 can be selected to surround a predetermined length of at least one of the first PCB traces 211 or the second PCB traces 212. The respective second conductive element 152 of each coaxial cable 250 is coupled to the third PCB traces 213 and the fourth PCB traces 214 through the third vias 217. For example, the respective secondary cable portion 252a of each coaxial cable 250 can be coupled to at least one respective third via 217 at the first end 250a and to another at least one respective third via 217 at the second end 250b. In non-limiting aspects, the respective secondary cable portion 252a of each coaxial cable 250 can be coupled to the respective third via 217 via a soldered connection. In some aspects, the respective secondary cable portion 252a can be coupled to the respective third via 217 via a connector (not shown). Thus, as shown in FIG. 2, the respective secondary cable portion 252a of each coaxial cable 250 can be coupled to the respective third via 217 at the first end 250a and the second end 250b. In non-limiting aspects, the respective secondary cable portion 252a of each coaxial cable 250 can be coupled to the respective third via 217 at the first end 250a and the second end 250b via a soldered connection. In some aspects, the respective secondary cable portion 252a can be coupled to the respective third via 217 via a connector (not shown). Figure 5As illustrated in the middle diagram, the first conductive element 251 of the coaxial cable 250 is circumferentially surrounded by the second conductive element 252, and the first PCB trace 211 and the second PCB trace 212 are likewise circumferentially surrounded by the third PCB trace 213, the fourth PCB trace 214, and the respective portions of the set of third vias 217. By arranging the respective primary cable portions 251a of the primary winding 201 to be circumferentially surrounded by the secondary cable portions 252a, and further arranging the primary PCB trace portions 251b of the primary winding 201 to be circumferentially surrounded by the secondary PCB trace portions 252b of the secondary winding 202, a higher coupling coefficient can be achieved compared to conventional transformers.

[0086] Figure 6 is Figure 5 a diagram of a portion of the PCB 210. Figure 6 between Figure 5 one notable difference is that while Figure 5 the primary cable portions 251a and the secondary cable portions 252a are depicted in a two-dimensional format, and the primary PCB trace portions 251b and the secondary PCB trace portions 252b are depicted in a two-dimensional format, Figure 6 the primary cable portions 251a and the secondary cable portions 252a are depicted in a solid line schematic format, and the primary PCB trace portions 251b and the secondary PCB trace portions 252b are depicted in a dashed line format. Another notable difference is that Figure 6 includes a portion of the ferromagnetic core 220 coupled to the first face 210a of the PCB 210, with the remainder of the ferromagnetic core 220 omitted for clarity.

[0087] As illustrated in the middle diagram, the first conductive element 251 of the coaxial cable 250 is circumferentially surrounded by the second conductive element 252, and the first PCB trace 211 and the second PCB trace 212 are likewise circumferentially surrounded by the third PCB trace 213, the fourth PCB trace 214, and the respective portions of the set of third vias 217. By arranging the respective primary cable portions 251a of the primary winding 201 to be circumferentially surrounded by the secondary cable portions 252a, and further arranging the primary PCB trace portions 251b of the primary winding 201 to be circumferentially surrounded by the secondary PCB trace portions 252b of the secondary winding 202, a higher coupling coefficient can be achieved compared to conventional transformers. Figure 6 As illustrated in the middle diagram, the first conductive element 251 of the coaxial cable 250 is circumferentially surrounded by the second conductive element 252, and the first PCB trace 211 and the second PCB trace 212 are likewise circumferentially surrounded by the third PCB trace 213, the fourth PCB trace 214, and the respective portions of the set of third vias 217. By arranging the respective primary cable portions 251a of the primary winding 201 to be circumferentially surrounded by the secondary cable portions 252a, and further arranging the primary PCB trace portions 251b of the primary winding 201 to be circumferentially surrounded by the secondary PCB trace portions 252b of the secondary winding 202, a higher coupling coefficient can be achieved compared to conventional transformers. Figure 6 In non-limiting aspects, and as illustrated in the middle diagram of FIG. 2, the first primary winding turn 203a, the second primary winding turn 203b, and the third primary winding turn 203c can be electrically coupled in parallel to one another.

[0088] The secondary winding 202 includes a set of secondary winding turns 205, which are designated as a first secondary winding turn 205a, a second secondary winding turn 205b, and a third secondary winding turn 205c. In non-limiting aspects, the first secondary winding turn 205a, the second secondary winding turn 205b, and the third secondary winding turn 205c can include a corresponding secondary cable portion 252a (shown in solid format) and a corresponding secondary PCB trace portion 252b (shown in dashed format). The corresponding secondary PCB trace portion 252b can include portions of the third PCB trace 213, the fourth PCB trace 214, the third via 217, and combinations thereof. The set of third vias 217 can be arranged to extend from the first side 210a and couple to the secondary PCB trace portion 252b such that portions of the first PCB trace 211 and the second PCB trace 212 are circumferentially surrounded by corresponding portions of the third PCB trace 213, the fourth PCB trace 214, and the set of third vias 217. Each respective secondary cable portion 252a may be coupled to a respective third via 217 at a first end 250a and to another respective third via 217 at a second end 250b.

[0089] In non-limiting aspects, and as Figure 6 As shown in FIG, the first primary winding turn 203a, the second primary winding turn 203b, and the third primary winding turn 203c can be electrically coupled to each other in parallel. In a non-limiting aspect, the first secondary winding turn 205a, the second secondary winding turn 205b, and the third secondary winding turn 205c can be electrically coupled to each other in series. In a non-limiting aspect, the primary winding turns 203a, 203b, 203c are coupled in parallel. When so arranged, with the primary winding turns (203a), (203b), (203c) electrically coupled in series and the secondary winding turns (205a), (205b), (205c) electrically coupled in parallel, a transformer 200, 300, 400 having a turns ratio of 1:3 can be arranged.

[0090] While non-limiting aspects are illustrated and described as having three primary winding turns 203a, 203b, 203c and three secondary winding turns 205a, 205b, 205c for ease of description and understanding, other aspects are not so limited. Other non-limiting aspects can have any desired number of primary winding turns 203a, 203b, 203c and a desired number of secondary winding turns 205a, 205b, 205c without departing from the scope of the present disclosure. In this manner, transformers 200, 300, 400 having any desired turns ratio can be arranged. For example, the predetermined number N of third PCB traces 213 and fourth PCB traces 214 can be determined based on a desired turns ratio of the transformer 200, 300, 400. In non-limiting aspects, for a particular transformer 200, 300, 400 having a turns ratio of 1 :T, the predetermined number N of third PCB traces 213 can be equal to T. For example, for a particular transformer having a turns ratio of 1 :3, the number N of third PCB traces 213 and the number N of fourth PCB traces 214 can be equal to 3. In some non-limiting aspects, the primary winding turns 203a, 203b, 203c and the secondary winding turns 205a, 205b, 205c can be arranged to define a turns ratio of 1 :T, where the number N of first PCB traces 211 and the number N of second PCB traces 212 are equal to T. Conversely, in other non-limiting aspects, the primary winding turns 203a, 203b, 203c and the secondary winding turns 205a, 205b, 205c are arranged to define a turns ratio of T: 1, where the number N of first PCB traces 211 and the number N of second PCB traces 212 are equal to T.

[0091] Additionally, while non-limiting aspects are illustrated and described as the primary winding turns 203a, 203b, 203c being coupled in parallel and the secondary winding turns 205a, 205b, 205c being coupled in series for ease of description and understanding, other aspects are not so limited. In other non-limiting aspects, the primary winding turns 203a, 203b, 203c can be coupled in series or in parallel. In still other non-limiting aspects, the secondary winding turns 205a, 205b, 205c can be coupled in series or in parallel.

[0092] It will be appreciated that, since the respective primary cable portions 251a of the first primary winding turn 203a, the second primary winding turn 203b, and the third primary winding turn 203c comprise respective first conductive elements 251 of the respective coaxial cables 250 Figure 5 ), and the respective secondary cable portions 252a of the first secondary winding turn 205a, the second secondary winding turn 205b, and the third secondary winding turn 205c comprise respective second conductive elements 252 of the respective coaxial cables 250 Figure 5), so the respective secondary cable portion 252a of the first secondary winding turn 205a, the second secondary winding turn 205b, and the third secondary winding turn 205c circumferentially encircles the respective primary cable portion 251a of the first primary winding turn 203a, the second primary winding turn 203b, and the third primary winding turn 203c.

[0093] Each of the first primary winding turn 203a, the second primary winding turn 203b, and the third primary winding turn 203c can be cooperatively defined by a respective portion of the first PCB trace 211, a respective portion of the second PCB trace 212, and a respective first conductive element 251 of the at least one coaxial cable 250. The first primary winding turn 203a, the second primary winding turn 203b, and the third primary winding turn 203c each include a respective primary cable portion 251a and a respective primary PCB trace portion 251b. The first secondary winding turn 205a, the second secondary winding turn 205b, and the third secondary winding turn 205c each include a respective secondary cable portion 252a and a secondary PCB trace portion 252b.

[0094] Figure 7 A method 600 of forming a transformer 200, 300, 400 is depicted. Although described in terms of transformers, it will be appreciated that the method 600 can be applicable to other devices including inductors and coupled inductors. While the method 600 is described herein in terms of transformers 200, 300, 400 for ease of understanding, other aspects are not so limited, and the method 600 can be implemented with any transformer without departing from the scope of the present disclosure. Figures 2 to 6 The method 600 is described in terms of transformers 200, 300, 400 for ease of understanding, other aspects are not so limited, and the method 600 can be implemented with any transformer without departing from the scope of the present disclosure.

[0095] The transformer 200, 300, 400 can include a primary winding 201 and a secondary winding 202. The primary winding 201 can include a respective primary cable portion 251a and a respective primary PCB trace portion 251b. The secondary winding 202 can include a respective secondary cable portion 252a and a respective secondary PCB trace portion 252b. The first conductive element 251 of each coaxial cable 250 can form the respective primary cable portion 251a of the primary winding 201, and the second conductive element 252 of each coaxial cable 250 can form the respective secondary cable portion 252a of the secondary winding 202.

[0096] The method 600 can begin at 605 by forming a multi-layer PCB 210. The multi-layer PCB 210 can include a first face 210a spaced apart from a second face 210b. The PCB 210 can include the set of layers 230. For example, in non-limiting aspects, the PCB 210 can include a first layer 230a and a second layer 230b. The first layer 230a and the second layer 230b can be planar and formed of an insulating or dielectric material. The first layer 230a and the second layer 230b can be arranged opposite (e.g., parallel) to each other between the first face 210a and the second face 210b. A first PCB trace 211 and a second PCB trace 212 can be disposed on the first layer 230a. The second PCB trace 212 is spaced apart from the first PCB trace 211 on the first layer 230a. The set of first vias 215 can be coupled to the first PCB trace 211. The set of first vias 215 can extend from the first PCB trace 211 to the first face 210a. The set of second vias 216 can be coupled to the second PCB trace 212. The set of second vias 216 can extend from the second PCB trace 212 to the first face 210a.

[0097] The respective first conductive element 251 of each coaxial cable 250 can be coupled to a respective first via 215 at a first end 250a and to a respective second via 216 at a second end 250b. The first PCB trace 211, the second PCB trace 212, the first via 215, and the second via 216 can cooperatively form a primary PCB trace portion 251b.

[0098] In non-limiting aspects, the second layer 230b can have a set of third PCB traces 213 disposed thereon. The set of third PCB traces 213 can include a predetermined number “N” of third PCB traces 213. The first PCB trace 211 and the second PCB trace 212 can be spaced apart opposite respective third PCB traces 213. The set of third vias 217 can be electrically coupled to the third PCB traces 213. In non-limiting aspects, the third vias 217 can extend to the first face 210a. In non-limiting aspects, a subset of the third vias 217 can extend between the first face 210a and the second face 210b. The third PCB traces 213 and the third vias 217 can cooperatively form a secondary PCB trace portion 252b.

[0099] In non-limiting aspects, the first via 215 can extend from the first face 210a to and be electrically coupled to the first PCB trace 211, the second via 216 extends from the first face 210a to and be electrically coupled to the second PCB trace 212, the second layer 230b has a number N of third PCB traces 213 defined thereon, the first and second PCB traces 211, 212 are oppositely spaced from the third PCB traces 213, and the set of conductive third vias 217 extend from the first face 210a to and be electrically coupled to the third PCB traces 213.

[0100] The method can include coupling, at 610, the annular ferromagnetic core 220 defining the aperture 225 to the first face 210a. In non-limiting aspects, the ferromagnetic core 220 can be coupled to the first face 210a using the strip 222. In other non-limiting aspects, the ferromagnetic core 220 can be coupled to the first face 210a using a clamp, a fastener, an adhesive, or a combination thereof. The method 600 can include arranging, at 615, a set of coaxial cables 250 longitudinally through the aperture 225. In non-limiting aspects, each coaxial cable 250 can include a first conductive element 251 circumferentially surrounded by a second conductive element 252 and electrically insulated therefrom, and defining a first end 250a and an opposite second end 250b, respectively.

[0101] The method can include forming, at 620, the primary winding 201 including a set of primary winding turns 203. In non-limiting aspects, each primary winding turn 203 can include a respective first conductive element 251 of at least one coaxial cable 250, a portion of the respective first PCB trace 211, and a respective portion of the second PCB trace 212, the respective first conductive element 251 being coupled to the first PCB trace 211 at the respective first end 250a by a respective first via 215 and to the respective portion of the second PCB trace 212 at the respective second end 250b by a respective second via 216.

[0102] The method can include forming, at 630, the secondary winding 202 including a set of secondary winding turns 205. In non-limiting aspects, each secondary winding turn 205 can include a respective second conductive element 252 of at least one coaxial cable 250 of the set of coaxial conductors 250 and a portion of the respective third PCB trace 213. The respective second conductive element 252 can be coupled to the respective portion of the third PCB trace 213 at the respective first end 250a by a respective third via 217 and further coupled to the third PCB trace 213 at the respective second end 250b by another respective third via 217.

[0103] In non-limiting aspects of the method 600, forming the primary winding 201 can include electrically coupling the primary winding turns 203 in parallel with respect to one another. In other non-limiting aspects, forming the primary winding 201 can include electrically coupling the primary winding turns 203 in series with respect to one another.

[0104] In non-limiting aspects of the method 600, forming the secondary winding 202 can include electrically coupling the secondary winding turns 205 in parallel with respect to one another. In other non-limiting aspects, forming the secondary winding 202 can include electrically coupling the secondary winding turns 205 in series with respect to one another.

[0105] In non-limiting aspects of the method 600, forming the primary winding 201 at 620 and forming the secondary winding 202 at 630 can include arranging the primary winding turns 203 and the secondary winding turns 205 to define a turn ratio of 1 :T. In non-limiting aspects, the number N of third PCB traces 213 can equal T. In other non-limiting aspects, forming the primary winding 201 at 620 and forming the secondary winding 202 at 630 can include arranging the primary winding turns 203 and the secondary winding turns 205 to define a turn ratio of T: 1. In non-limiting aspects, the number N of third PCB traces 213 equals T.

[0106] In still other non-limiting aspects, forming the primary winding 201 at 620 and forming the secondary winding 202 at 630 can include arranging the primary winding turns 203 and the secondary winding turns 205 to define a turn ratio of 1 :T, where the set of primary winding turns 203 and the set of secondary winding turns 205 each include a number T of turns. In some non-limiting aspects, the primary winding turns 203a, 203b, 203c and the secondary winding turns 205a, 205b, 205c can be arranged to define a turn ratio of 1 :T, where the number N of first PCB traces 211 and the number of second PCB traces 212 equals T. Conversely, in other non-limiting aspects, the three primary winding turns 203a, 203b, 203c and the secondary winding turns 205a, 205b, 205c are arranged to define a turn ratio of T: 1, where the number N of first PCB traces 211 and the number N of second PCB traces 212 equals T.

[0107] In non-limiting aspects, the set of layers 230 can include a dielectric third layer 230c having a number N of fourth PCB traces 214 defined thereon, each fourth PCB trace 214 opposing at least a portion of at least one of the first and second PCB traces 211, 212. In such non-limiting aspects, the first and second PCB traces 211, 212 can be disposed between and spaced apart from the third and fourth PCB traces 213, 214. In some aspects, the set of conductive third vias 217 extending from the first face 210a to the third PCB traces 213 can further extend to a respective one of the set of fourth PCB traces 214 and electrically couple each fourth PCB trace 214 with a respective one of the third PCB traces 213.

[0108] In non-limiting aspects of the method 600, the portion of the respective third PCB trace 213, the portion of the respective fourth PCB trace 214, and the respective subset of third vias 217 cooperatively circumferentially surround at least a portion of one of the first and second PCB traces 211, 212.

[0109] In non-limiting aspects, forming the primary winding 201 at 620 and the secondary winding 202 at 630 can include arranging the primary winding turns 203 and the secondary winding turns 205 to define a turn ratio of 1 :T. In such non-limiting aspects, the number N of third PCB traces 213 can be equal to T, and the number N of fourth PCB traces 214 can be equal to T.

[0110] In non-limiting aspects of the method 600, each primary winding turn 203 can be circumferentially surrounded by a portion of a secondary winding turn 205.

[0111] While the present disclosure has been described with reference to one or more exemplary aspects, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular aspect(s) disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all aspects falling within the scope of the appended claims.

[0112] To the extent not already described, the different features and structures of the various aspects can be used with each other in any

[0113] This written description uses examples to disclose aspects of the disclosure (including best modes), and also to enable any person skilled in the art to practice aspects of the disclosure (including making and using any devices or systems and performing any incorporated methods). The patentable scope of the disclosure is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent

[0114] Further aspects of the disclosure are provided by the subject matter of the following clauses:

[0115] A transformer comprising: a multilayer printed circuit board (PCB) having a first face and an opposite second face and a set of dielectric layers disposed between the first face and the second face, the set of dielectric layers including a first layer and a second layer, the first layer having a first PCB trace and a second PCB trace defined thereon, the second layer having a set of third PCB traces defined thereon, the first PCB trace and the second PCB trace being oppositely spaced from the third PCB traces;

[0116] a set of first vias extending from the first face to and electrically coupled to the first PCB trace; a set of second vias extending from the first face to and electrically coupled to the second PCB trace; a toroidal magnetic core defining a bore, the toroidal magnetic core coupled to the first face; a set of coaxial conductors extending longitudinally through the bore, each coaxial conductor having a first conductive element circumferentially surrounded by and electrically insulated from a second conductive element, and respectively defining a first end and an opposite second end; a primary winding comprising a set of primary winding turns, each primary winding turn comprising a respective first conductive element of at least one coaxial conductor, a respective portion of the first PCB trace, and a respective portion of the second PCB trace, the respective first conductive element coupled at the respective first end to the respective portion of the first PCB trace by a respective first via, and coupled at the respective second end to the respective portion of the second PCB trace by a respective second via; a secondary winding comprising a set of secondary winding turns, each secondary winding turn comprising a respective second conductive element of each coaxial conductor; and a set of third vias extending from the first face to and coupled to the third PCB trace; wherein the respective outer second conductive elements are coupled at the respective first end to the respective portion of the third PCB trace by a respective third via, and further coupled at the respective second end to the third PCB trace by another respective third via.

[0117] The transformer according to any preceding Clause, wherein each of the set of primary winding turns are electrically coupled in parallel with respect to one another, and each of the set of secondary winding turns are electrically coupled in series with one another.

[0118] The transformer according to any preceding Clause, wherein each of the set of primary winding turns are electrically coupled in series with respect to one another, and each of the set of secondary winding turns are electrically coupled in parallel with one another.

[0119] The transformer according to any preceding Clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1 :T, and wherein the set of third PCB traces comprises a number N of third PCB traces, wherein the number N is equal to T.

[0120] The transformer according to any preceding Clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of T: 1, and wherein the set of third PCB traces comprises a number N of third PCB traces, wherein the number N is equal to T.

[0121] The transformer according to any preceding Clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1 : 1.

[0122] The transformer according to any preceding Clause, wherein the set of dielectric layers further comprises a third layer having a set of fourth PCB traces defined thereon, each fourth PCB trace opposing at least a portion of at least one of the first and second PCB traces, wherein the first and second PCB traces are disposed between and spaced apart opposite respective portions of the third and fourth PCB traces, and wherein the set of third vias extending from the first face to the third PCB traces further extend to respective ones of the fourth PCB traces and electrically couple each fourth PCB trace (214) with a respective one of the third PCB traces.

[0123] The transformer according to any preceding Clause, wherein portions of respective third PCB traces, portions of respective fourth PCB traces, and respective subsets of the set of third vias cooperatively circumferentially encircle at least portions of one of the first and second PCB traces.

[0124] The transformer according to any preceding Clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1 :T, and wherein the set of third PCB traces comprises a number N of third PCB traces and the set of fourth PCB traces comprises a number N of fourth PCB traces, wherein the number N is equal to T.

[0125] The transformer according to any preceding Clause, wherein each primary winding turn is circumferentially encircled by a portion of a respective secondary winding turn.

[0126] A method of forming a transformer, comprising: forming a multilayer printed circuit board having a first face and an opposite second face and a set of dielectric layers disposed between the first face and the second face, the set of dielectric layers including: a first layer having a first PCB trace and a second PCB trace defined thereon; a first via extending from the first face to the first PCB trace and coupled to the first PCB trace; a second via extending from the first face to the second PCB trace and electrically coupled to the second PCB trace; a second layer having a set of third PCB traces defined thereon, the first and second PCB traces being oppositely spaced from the third PCB traces; and a set of third vias extending from the first face to the third PCB traces and electrically coupled to the third PCB traces; coupling an annular magnetic core defining a bore to the first face; disposing a set of coaxial conductors longitudinally through the bore, each coaxial conductor including a first conductive element circumferentially surrounded by a second conductive element and electrically insulated therefrom, and respectively defining a first end and a second end; forming a primary winding including a set of primary winding turns, each primary turn including a respective first conductive element of at least one of the set of coaxial conductors, a portion of the respective first PCB trace, and a respective portion of the second PCB trace, the respective first conductive element being coupled to the respective portion of the first PCB trace at the respective first end by the respective first via, and coupled to the respective portion of the second PCB trace at the respective second end by the respective second via; and forming a secondary winding including a set of secondary winding turns, each secondary turn including a respective second conductive element of at least one of the set of coaxial conductors, and a portion of the respective third PCB trace, the respective second conductive element being coupled to the respective portion of the third PCB trace at the respective first end by the respective third via, and further coupled to the third PCB trace at the respective second end by another respective third via.

[0127] The method according to claim 11, further comprising electrically coupling the set of primary winding turns in parallel with respect to one another, and electrically coupling the set of secondary winding turns in series with one another.

[0128] The method according to any preceding clause, further comprising electrically coupling the set of primary winding turns in series with respect to one another, and electrically coupling the set of secondary winding turns in parallel with one another.

[0129] The method according to any preceding clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1 :T, and wherein the set of third PCB traces includes a number N of third PCB traces, wherein the number N is equal to T.

[0130] The method of any preceding clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of T: 1, and wherein the set of third PCB traces includes a number N of third PCB traces, where the number N is equal to T.

[0131] The method of any preceding clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1: 1.

[0132] The method of any preceding clause, wherein the set of dielectric layers further includes a third layer having a set of fourth PCB traces defined thereon, each fourth PCB trace opposing at least a portion of at least one of the first and second PCB traces, wherein the first and second PCB traces are disposed between and spaced apart from the third and fourth PCB traces, and wherein the set of third vias extending from the first face to the third PCB traces further extend to a respective one of the fourth PCB traces and electrically couple each fourth PCB trace with the respective third PCB trace.

[0133] The method of any preceding clause, wherein the portion of the respective third PCB trace, the portion of the respective fourth PCB trace, and the respective subset of the set of third vias cooperatively circumferentially encircle at least the portion of one of the first and second PCB traces.

[0134] The method of any preceding clause, wherein the set of primary winding turns and the set of secondary winding turns are arranged to define a turn ratio of 1: T, and wherein the set of third PCB traces includes a number N of third PCB traces, the set of fourth PCB traces includes a number N of fourth PCB traces, where the number N is equal to T.

[0135] The method of any preceding clause, wherein each primary winding turn is circumferentially encircled by a portion of a secondary winding turn.

Claims

1. A transformer, comprising: a multilayer printed circuit board (PCB) having a first side and an opposing second side and a set of dielectric layers disposed between the first side and the second side, the set of dielectric layers including a first layer and a second layer, the first layer having a first PCB trace and a second PCB trace defined thereon, the second layer having a set of third PCB traces defined thereon, the first PCB trace and the second PCB trace being spaced apart from the third PCB trace; a set of first vias extending from the first side to the first PCB trace and coupled to the first PCB trace; a set of second vias extending from the first side to the second PCB trace and electrically coupled to the second PCB trace; a toroidal core defining a bore, the toroidal core coupled to the first face; a set of coaxial conductors extending longitudinally through the aperture, each coaxial conductor having a first conductive element circumferentially surrounded by and electrically insulated from a second conductive element and respectively defining a first end and an opposite second end; a primary winding comprising a set of primary winding turns, each primary winding turn comprising a respective first conductive element of at least one coaxial conductor, a respective portion of the first PCB trace, and a respective portion of the second PCB trace, the respective first conductive element being coupled to the respective portion of the first PCB trace at a respective first end through a respective first via and coupled to the respective portion of the second PCB trace at a respective second end through a respective second via; a secondary winding comprising a set of secondary winding turns, each secondary winding turn comprising a respective second conductive element of each coaxial conductor; as well as a set of third vias extending from the first side to and coupled to the third PCB trace; The corresponding external second conductive element is coupled to the corresponding portion of the third PCB trace through a corresponding third via at the corresponding first end, and is further coupled to the third PCB trace through another corresponding third via at the corresponding second end.

2. The transformer according to claim 1, wherein: Each of the set of primary winding turns is electrically coupled in parallel with respect to one another, and each of the set of secondary winding turns is electrically coupled in series with one another.

3. The transformer according to claim 1, wherein: Each of the set of primary winding turns is electrically coupled in series with respect to one another, and each of the set of secondary winding turns is electrically coupled in parallel with one another.

4. The transformer according to claim 1, wherein: The set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1:T, and wherein the set of third PCB traces includes a number N of third PCB traces, wherein the number N is equal to T.

5. The transformer according to claim 1, wherein: The set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of T:1, and wherein the set of third PCB traces includes N number of third PCB traces, wherein the number N is equal to T.

6. The transformer according to claim 1, wherein: The set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1:

1.

7. The transformer according to claim 1, wherein: the set of dielectric layers further comprising a third layer having a set of fourth PCB traces defined thereon, each fourth PCB trace opposing at least a portion of at least one of the first PCB trace and the second PCB trace, wherein the first PCB trace and the second PCB trace are disposed between and relatively spaced from corresponding portions of the third PCB trace and the fourth PCB trace, and wherein the set of third vias extending from the first side to the third PCB traces further extend to a corresponding one of the fourth PCB traces and electrically couple each fourth PCB trace (214) to a corresponding one of the third PCB traces.

8. The transformer according to claim 7, wherein: Portions of the respective third PCB traces, portions of the respective fourth PCB traces, and a respective subset of the set of third vias cooperatively circumferentially surround at least a portion of one of the first PCB trace and the second PCB trace.

9. The transformer according to claim 7, wherein: The set of primary winding turns and the set of secondary winding turns are arranged to define a turns ratio of 1:T, and wherein the set of third PCB traces includes a number N of third PCB traces, and the set of fourth PCB traces includes a number N of fourth PCB traces, wherein the number N is equal to T.

10. The transformer according to claim 7, wherein: Each primary winding turn is circumferentially surrounded by a portion of a corresponding secondary winding turn.

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