Inductive-capacitive filters and associated systems and methods

Abstract

To provide an inductive-capacitive filter assembly.SOLUTION: An inductive-capacitive filter includes a first insulating-conductive strip wound around a winding axis, where the first insulating-conductive strip includes a first conductive strip joined with a first insulating strip. An inductive-capacitive filter assembly includes first and second insulating-conductive strips concentrically wound around a winding axis, the first insulating-conductive strip including a first conductive strip joined with a first insulating strip, and the second insulating-conductive strip including a second conductive strip joined with a second insulating strip.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 536,806, filed July 25, 2017, which is incorporated herein by reference.

[0002] Selective electrical signal rejection is often crucial for reliable and stable operation of equipment that delivers high power radio frequency (RF) electrical signals, such as electrical signals from 10 kilohertz (kHz) to 1 gigahertz (GHz). In some applications, electrical signals must be rejected within a prescribed bandwidth, necessitating the use of band rejection filters that block electrical signals having frequencies within a certain frequency band while transmitting electrical signals or electrical energy outside the frequency band. Additionally, some applications require the delivery of electrical energy to multiple loads that have the same or different selective signal rejection requirements. In these multiple load applications, a band rejection filter for each load is required, where each band rejection filter is tuned for its specific load and where each band rejection filter does not significantly interfere with each of the other band rejection filters.

[0003] A band-stop filter ideally has a high impedance in a specified frequency band to block signals within the specified frequency band, while having a low impedance outside the frequency band to prevent undesired signal attenuation and / or inefficient transmission of electrical energy. The signal attenuation of a filter as a function of signal frequency can be referred to as the band-stop characteristic of the filter. Band-stop filters are traditionally constructed from two or more individual components, such as individual inductors and individual capacitors, placed in a parallel configuration in an electrical circuit. Individual inductors are typically formed of copper or aluminum wire wound into a coil, optionally wound around a magnetic core. Individual capacitors are typically formed of two metal plates with a dielectric material between them. The dielectric material can be ceramic, glass, mica, plastic film, or metal oxide. Summary of the Invention

[0004] In one embodiment, the inductive-capacitive filter includes a first insulating-conductive strip wound about a winding axis, where the first insulating-conductive strip includes a first conductive strip joined with a first insulating strip.

[0005] In one embodiment, the first conductive strip is wound in parallel with the first insulating strip about the winding axis.

[0006] In one embodiment, the first conductive strip is formed from a metal foil and the first insulating strip is formed from a dielectric material.

[0007] In one embodiment, the first conductive strip has a cross-sectional area with an aspect ratio of at least two.

[0008] In one embodiment, the first insulating-conductive strip forms an inner aperture, as seen when the inductive-capacitive filter is viewed in cross section along the direction of the winding axis.

[0009] In one embodiment, the inner aperture has a non-circular shape.

[0010] In one embodiment, the inductive-capacitive filter further includes a magnetic core disposed within the inner aperture.

[0011] In one embodiment, the inductive-capacitive filter further includes first and second terminals electrically coupled to opposing first and second ends, respectively, of the first conductive strip.

[0012] In one embodiment, the inductive-capacitive filter further includes one or more additional insulating-conductive strips wound about the winding axis, each additional insulating-conductive strip including a respective conductive strip wound together with a respective insulating strip.

[0013] In one embodiment, the inductive-capacitive filter assembly includes first and second insulating-conductive strips concentrically wound around a winding axis, the first insulating-conductive strip including a first conductive strip joined with the first insulating strip, and the second insulating-conductive strip including a second conductive strip joined with the second insulating strip.

[0014] In one embodiment, the first conductive strip is wound in parallel with the first insulating strip about the winding axis, and the second conductive strip is wound in parallel with the second insulating strip about the winding axis.

[0015] In one embodiment, the first insulating-conductive strip is electrically coupled to the second insulating-conductive strip.

[0016] In one embodiment, the first insulating-conductive strip is disposed within the second insulating-conductive strip as seen when the inductive-capacitive filter assembly is viewed in cross section along the direction of the winding axis.

[0017] In one embodiment, the inductive-capacitive filter assembly further includes a third insulating-conductive strip wound concentrically with the first and second insulating-conductive strips about the winding axis. The third insulating-conductive strip includes a third conductive strip joined with the third insulating strip, and each of the first, second and third insulating-conductive strips forms a respective inductive-capacitive filter. The first insulating-conductive strip is disposed within the second insulating-conductive strip as seen when the inductive-capacitive filter assembly is viewed in cross section along the winding axis, and each of the first and second insulating-conductive strips is disposed within the third insulating-conductive strip as seen when the inductive-capacitive filter assembly is viewed in cross section along the winding axis.

[0018] In one embodiment, each of the first and second conductive strips is formed from a metal foil, and each of the first and second insulating strips is formed from a dielectric material.

[0019] In one embodiment, the first conductive strip has a cross-sectional area with an aspect ratio of at least two and the second conductive strip has a cross-sectional area with an aspect ratio of at least two.

[0020] In one embodiment, each of the first and second insulating-conductive strips forms multiple turns around the winding axis.

[0021] In one embodiment, each of the first and second insulating-conductive strips forms a different respective number of turns about the winding axis.

[0022] In one embodiment, the inductive-capacitive filter assembly further includes a third insulating-conductive strip wound concentrically with the first and second insulating-conductive strips about the winding axis, the third insulating-conductive strip including a third conductive strip joined with the third insulating strip, each of the first, second and third insulating-conductive strips forming a respective inductive-capacitive filter.

[0023] In one embodiment, the electrical circuit includes any of the inductive-capacitive filters disclosed above.

[0024] In one embodiment, the opposing first and second ends of the first conductive strip are electrically coupled to different respective nodes of an electrical circuit.

[0025] In one embodiment, the electrical circuit further includes at least one of an AC power source and a DC power source electrically coupled in series with the inductive-capacitive filter of the electrical circuit and a load.

[0026] In one embodiment, the electrical circuit includes any one of the inductive-capacitive filter assemblies disclosed above, with each of the first and second insulating-conductive strips electrically coupled to a respective branch of the electrical circuit.

[0027] In one embodiment, each of the first and second insulating-conductive strips is electrically coupled between a power source and a respective electrical load. [Brief description of the drawings]

[0028] [Figure 1] 1A-1D are respective diagrams of an inductive-capacitive filter according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the inductive-capacitive filter of FIG. [Diagram 3] 2 illustrates an approximate electrical model of the inductive-capacitive filter of FIG. 1. [Figure 4]2 is a graph illustrating impedance versus frequency for one particular embodiment of the inductive-capacitive filter of FIG. 1. [Diagram 5] FIG. 2 is a perspective view of an inductive-capacitive filter similar to the inductive-capacitive filter of FIG. 1, but having six turns instead of four, according to one embodiment. [Figure 6] 2 is a perspective view of an inductive-capacitive filter similar to that of FIG. 1, but having a larger inner aperture, according to one embodiment. [Figure 7] FIG. 2 is a perspective view of an inductive-capacitive filter similar to that of FIG. 1, but having an oval-shaped inner aperture, according to one embodiment. [Figure 8] FIG. 2 is a perspective view of an inductive-capacitive filter similar to the inductive-capacitive filter of FIG. 1, but with different insulating strips, according to one embodiment. [Figure 9] FIG. 2 is a perspective view of an inductive-capacitive filter similar to the inductive-capacitive filter of FIG. 1, but with thicker insulating strips, according to one embodiment. [Figure 10] FIG. 10 is a cross-sectional view of the inductive-capacitive filter of FIG. [Figure 11] 2 is a perspective view of an inductive-capacitive filter similar to that of FIG. 1, but with thicker conductive strips, according to one embodiment. [Figure 12] FIG. 12 is a cross-sectional view of the inductive-capacitive filter of FIG. [Figure 13] FIG. 2 is a perspective view of an inductive-capacitive filter similar to that of FIG. 1, but with wider conductive strips, according to one embodiment. [Figure 14] FIG. 2 is a perspective view of an inductive-capacitive filter assembly including two inductive-capacitive filters in a single device according to one embodiment. [Figure 15] 15 illustrates the inductive-capacitive filter assembly of FIG. 14 with first and second insulating-conductive strips electrically coupled in series, according to one embodiment. [Figure 16]16 illustrates an approximate electrical model of the inductive-capacitive filter assembly of FIG. 14 when electrically coupled as illustrated in FIG. 15. [Figure 17] 16 is a graph illustrating impedance versus frequency for one particular embodiment of the inductive-capacitive filter assembly of FIG. 14 when electrically coupled as illustrated in FIG. 15. [Figure 18] 15 illustrates the inductive-capacitive filter assembly of FIG. 14 with first and second insulating-conductive strips electrically coupled in parallel, according to one embodiment. [Figure 19] 19 is a graph illustrating impedance versus frequency for one particular embodiment of the inductive-capacitive filter assembly of FIG. 14 when electrically coupled as illustrated in FIG. 18. [Figure 20] FIG. 1 is a perspective view of two inductive-capacitive filters electrically coupled in series according to one embodiment. [Figure 21] 21 is a graph illustrating impedance versus frequency for one particular embodiment of the inductive-capacitive filter of FIG. 20 electrically coupled in series. [Figure 22] FIG. 2 is a perspective view of an inductive-capacitive filter assembly including additional insulating-conductive strips according to one embodiment. [Figure 23] FIG. 23 is a cross-sectional view of the inductive-capacitive filter assembly of FIG. 22. [Figure 24] 23 illustrates an approximate electrical model of the inductive-capacitive filter assembly of FIG. 22. [Diagram 25] 2 is a cross-sectional view of an inductive-capacitive filter similar to that of FIG. 1, but in which the width of the insulating strips is greater than the width of the conductive strips, according to one embodiment. [Figure 26] FIG. 1 illustrates a perspective view of an inductive-capacitive filter including a rod-shaped magnetic core disposed within an inner aperture according to one embodiment. [Figure 27] FIG. 13 illustrates a perspective view of another inductive-capacitive filter including an E-shaped magnetic core disposed within an inner aperture according to one embodiment. [Figure 28] FIG. 13 illustrates a perspective view of another inductive-capacitive filter including a U-shaped magnetic core disposed within an inner aperture according to one embodiment. [Figure 29] FIG. 13 illustrates a perspective view of yet another inductive-capacitive filter including a pot-shaped magnetic core disposed within an inner aperture according to one embodiment. [Diagram 30] 2 illustrates an electrical circuit including an instance of the inductive-capacitive filter of FIG. 1, according to one embodiment. [Diagram 31] 2 illustrates another electrical circuit including an instance of the inductive-capacitive filter of FIG. 1, according to one embodiment. [Diagram 32] 23 illustrates an electrical circuit including one instance of the inductive-capacitive filter assembly of FIG. 22, according to one embodiment. [Diagram 33] 15 illustrates an electrical circuit including one instance of the inductive-capacitive filter assembly of FIG. 14, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Conventional band-stop filters can generally achieve acceptable band-stop characteristics through careful design and construction. However, the individual components forming conventional band-stop filters often cause the filters to be large, expensive, and difficult to manufacture, especially for high-power applications. Furthermore, the impedance of the wires forming the individual inductors of conventional band-stop filters can significantly limit the maximum current carrying capacity of the filter, especially at high operating frequencies where the skin effect, i.e., the tendency of high-frequency currents to crowd near the outer surface of the wire, is significant. Furthermore, due to parasitic effects, including parasitic inductance and capacitance, of the individual components forming conventional band-stop filters, it can be difficult to achieve precise band-stop characteristics in conventional band-stop filters.

[0030] Applicant has developed inductive-capacitive filters and related assemblies that have the potential to overcome one or more of the above-mentioned shortcomings associated with conventional band-stop filters. Some embodiments do not require separate inductors or separate capacitors, thus facilitating small filter size, low filter cost, and ease of filter manufacture. Additionally, some embodiments are easily tunable to achieve desired band-stop characteristics during filter design and / or manufacture, thereby minimizing the number of base filter designs required to achieve precise band-stop characteristics and support various applications. Additionally, certain embodiments achieve relatively low impedance at low and high frequencies outside of a predefined frequency band, thereby helping to minimize resistive losses. Moreover, some embodiments form multiple LC filters in a single package.

[0031] FIG. 1 is a perspective view of an inductive-capacitive filter 100, which is one embodiment of a novel inductive-capacitive filter developed by the applicant. The inductive-capacitive filter 100 includes an insulating strip 108 and a conductive strip 110, collectively referred to as an insulating-conductive strip 102, wound around a winding axis 104 to form a number of turns 106. In this specification, a specific instance of an item may be referred to by using a number in parentheses (e.g., turn 106(1)), while a number without parentheses refers to any such item (e.g., turn 106). Although the inductive-capacitive filter 100 is illustrated as having four turns 106, the number of turns may vary, including full or partial turns, without departing from the scope of this specification. The conductive strip 110 is joined to the insulating strip 108 such that the conductive strip 110 is wound in parallel with the insulating strip 108 around the winding axis 104. 2 is a cross-sectional view of the inductive-capacitive filter 100 taken along line 2A-2A in FIG. 1. The insulating strip 108 is formed of a non-conductive, dielectric insulating material, such as, for example, nomex, Kapton, mylar paper, or any other material that will provide electrical insulation between the conductive strips 110. The conductive strip 110 is formed of a metal foil, such as, for example, aluminum foil, copper foil, or any other material that has low electrical resistivity. In some embodiments, the insulating strip 108 and the conductive strip 110 are formed separately and wound together to form the insulating-conductive strip 102, while in other embodiments, the insulating strip 108 and the conductive strip 110 are bonded together before the resulting insulating-conductive strip 102 is wound around the winding axis 104. For example, in certain embodiments, the insulating strip 108 is formed on the conductive strip 110 using film deposition techniques before the resulting insulating-conductive strip 102 is wound around the winding axis 104.

[0032] The conductive strip 110 has opposed first and second ends 130 and 132, respectively. A first terminal 134 is electrically coupled to the first end 130 and a second terminal 136 is electrically coupled to the second end 132. The first and second terminals 134 and 136 provide an electrical interface for the inductive-capacitive filter 100. In some embodiments, the first and second terminals 134 and 136 comprise respective aluminum or copper bus bars or wires soldered to the conductive strip 110. It is contemplated that the first and second terminals 134 and 136 may be omitted without departing from the scope of the present specification.

[0033] The conductive strip 110 has a cross-sectional area 112 when viewed in a plane parallel to each of the winding axis 104 and the radial axis 114. The radial axis 114 is perpendicular to the winding axis 104 and extends away from the winding axis 104. The cross-sectional area 112 has an aspect ratio of a width 116 divided by a thickness 118, where the width 116 is the width of the conductive strip 110 parallel to the winding axis 104 and the thickness 118 is the thickness of the conductive strip 110 parallel to the radial axis 114. In some embodiments, the aspect ratio is at least 2, i.e., the width 116 is at least twice the thickness 118, to minimize proximity and skin effects when the conductive strip 110 is carrying high frequency signals. As discussed above, skin effect refers to the tendency of high frequency currents to crowd near the outer surface of a conductor, while proximity effect refers to the magnetic field generated by current flowing through one conductor that induces circulating currents through one or more other nearby conductors. In certain embodiments, thickness 118 is 0.10 inches or less and width 116 is at least 0.5 inches or more to achieve a large cross-sectional area 112, which promotes low AC resistance and low DC resistance at frequencies outside the bandstop filter frequency band of inductive-capacitive filter 100.

[0034] Adjacent portions of the conductive strip 110 create capacitance, and the conductive strip 110 creates inductance when connected to an electrical circuit. As a result, the inductive-capacitive filter 100 has the electrical characteristics of a parallel inductive-capacitive filter. FIG. 3 illustrates an approximate electrical model 300 of the inductive-capacitive filter 100 as viewed from the first and second terminals 134 and 136, where a capacitor 302 is electrically coupled in parallel with an inductive branch 304. The inductive branch 304 includes an inductor 306 electrically coupled in series with a resistor 308. The capacitor 302 represents the capacitance of the adjacent portions of the conductive strip 110, the inductor 306 represents the inductance of the conductive strip 110, and the resistor 308 represents the resistance of the conductive strip 110. Thus, the inductive-capacitive filter 100 has the ability to operate as a band-stop filter without the use of separate inductors or separate capacitors, thus facilitating small filter size, low filter cost and ease of filter manufacture. The inductive-capacitive filter 100 has a bandwidth of approximately

number

[0035] 4 is a graph 400 illustrating impedance versus frequency for one particular embodiment of the inductive-capacitive filter 100. As is evident from FIG. 4, this particular embodiment has a resonant frequency of about 14.65 megahertz (MHz), at which the impedance of the filter is approximately 30,000 ohms. The impedance decreases rapidly as the frequency moves away from the resonant frequency, so the inductive-capacitive filter has a low impedance at frequencies away from the resonant frequency, helping to minimize undesirable signal attenuation.

[0036] It should be noted that although the electrical model 300 of Figure 3 illustrates each of the capacitor 302, inductor 306, and resistor 308 as being separate elements for simplicity of illustration, each of these components represents a distributed element. Additionally, it should be noted that the model 300 does not take into account higher order effects, such as leakage current through the capacitor 302. For example, although the conductive strip 110 may be designed to achieve a finite resistance in an application where a particular resistive attenuation is desired, it is expected that the inductive-capacitive filter 100 will typically be designed to promote a low resistance of the conductive strip 110 to minimize resistive losses within the inductive-capacitive filter 100.

[0037] The resonant frequency of the inductive-capacitive filter 100 can be varied during its design and / or manufacture, thus enabling a single basic design to achieve precise band-stop characteristics and / or support multiple applications. For example, the resonant frequency of the inductive-capacitive filter 100 can be varied by varying the number of turns 106 formed around the winding axis 104. In particular, increasing the number of turns 106 increases the inductance of the inductive-capacitive filter 100, and increasing the inductance lowers the resonant frequency of the inductive-capacitive filter 100, as can be determined from Equation 1 above. FIG. 5 is a perspective view of an inductive-capacitive filter 500 similar to the inductive-capacitive filter 100 of FIG. 1, but having six turns 106 instead of four turns 106. Thus, the inductive-capacitive filter 500 will have a lower resonant frequency than the inductive-capacitive filter 100. 5, to promote clarity of illustration, only two instances of turns 106 are labeled. It should be pointed out that each turn 106 does not necessarily have to be a complete turn, in other words, the first and / or last turns 106 may be partial turns, thereby allowing for continuous variation of the band-stop characteristics during design and / or manufacturing of the inductive-capacitive filter 100.

[0038] The insulating-conductive strips 102 form inner apertures 120 and 520 in each of the inductive-capacitive filters 100 and 500, as viewed in cross section along the direction of the winding axis 104. The band-stop characteristics of the capacitive filters 100 and 500 can be varied by varying the size and / or shape of the inner apertures 120 and 520 in addition to or instead of varying the number of turns 106. For example, FIG. 6 is a perspective view of an inductive-capacitive filter 600 similar to the inductive-capacitive filter 100 of FIG. 1, but having an inner aperture 620 that is larger than the inner aperture 120, as viewed in cross section along the direction of the winding axis 104. Increasing the size of the inner aperture increases the cross-sectional area of ​​the magnetic flux path, and therefore the inductance. Such an increase in inductance decreases the resonant frequency and increases the impedance at the resonant frequency. As a result, inductive-capacitive filter 600 has a lower resonant frequency and a higher peak impedance than inductive-capacitive filter 100 .

[0039] As another example, FIG. 7 is a perspective view of an inductive-capacitive filter 700 similar to the inductive-capacitive filter of FIG. 1, but with an inner aperture 720 having an oval shape instead of a circular shape, as seen when viewed in cross section along the direction of the winding axis 104. Although the inner aperture 720 has the same circumference as the inner aperture 120 of FIG. 1, the inner aperture 720 has a smaller area than the inner aperture 120, as seen when viewed in cross section along the direction of the winding axis 104. As a result, the inductive-capacitive filter 700 has a higher resonant frequency and a smaller peak impedance than the inductive-capacitive filter 100. It is contemplated that any of the inductive-capacitive filters disclosed herein can be modified to have different inner aperture shapes without departing from the scope of the present specification. For example, it is contemplated that the inductive-capacitive filter 700 can be modified in such a way that the inner aperture 720 has a different non-circular shape, such as a rectangular shape, a triangular shape, or even an irregular shape.

[0040] It is contemplated that the material and / or thickness of the insulating strip 108 can be modified in any of the inductive-capacitive filters disclosed herein, for example to adjust the band-stop characteristics. Increasing the dielectric constant of the insulating strip 108 will lower both the resonant frequency and the peak impedance of the inductive-capacitive filter. For example, FIG. 8 is a perspective view of an inductive-capacitive filter 800 similar to the inductive-capacitive filter 100 of FIG. 1, except that the insulating strip 108 has been replaced with an insulating strip 808. The insulating strip 808 has a higher dielectric constant than the insulating strip 108. As a result, the inductive-capacitive filter 800 will have a lower resonant frequency and a lower peak impedance than the inductive-capacitive filter 100. On the other hand, by replacing the insulating strip 108 with an insulating strip having a lower dielectric constant than the insulating strip 108, the resonant frequency and the peak impedance of the inductive-capacitive filter 100 will be increased.

[0041] Increasing the thickness 122 (FIG. 2) of the insulating strip 108 increases both the resonant frequency value and the peak impedance of the inductive-capacitive filter. For example, FIG. 9 is a perspective view of an inductive-capacitive filter 900 similar to the inductive-capacitive filter 100 of FIG. 1, except that the insulating strip 108 is replaced with an insulating strip 908. FIG. 10 is a cross-sectional view of the inductive-capacitive filter 900 taken along line 10A-10A of FIG. 9. The insulating strip 908 has a thickness 922 that is greater than the thickness 122 of the insulating strip 108. As a result, the inductive-capacitive filter 900 has a lower capacitance, a higher resonant frequency, and a higher maximum impedance than the inductive-capacitive filter 100.

[0042] It is contemplated that the material and / or thickness of the conductive strip 110 may be modified in any of the inductive-capacitive filters disclosed herein, for example to adjust the band-stop characteristics. For example, FIG. 11 is a perspective view of an inductive-capacitive filter 1100 similar to the inductive-capacitive filter 100, but with the conductive strip 110 replaced by a conductive strip 1100. FIG. 12 is a cross-sectional view of the inductive-capacitive filter 1100 taken along line 12A-12A of FIG. 11. The conductive strip 1110 has a thickness 1118 that is greater than the thickness 118 of the conductive strip 110. As a result, the inductive-capacitive filter 1100 has a lower DC resistance and a lower low-frequency AC resistance than the inductive-capacitive filter 100.

[0043] The conductive strip 1110 has opposing first and second ends 1130 and 1132, respectively. A first terminal 1134 is electrically coupled to the first end 1130, and a second terminal 1136 is electrically coupled to the second end 1132. The first and second terminals 1134 and 1136 provide an electrical interface for the inductive-capacitive filter 1100. In some embodiments, the first and second terminals 1134 and 1136 comprise respective aluminum or copper bus bars or wires soldered to the conductive strip 1110. It is contemplated that the first and second terminals 1134 and 1136 may be omitted without departing from the scope of the present specification.

[0044] It is contemplated that the width of any insulating-conductive strip of the inductive-capacitive filters disclosed herein may likewise be modified to adjust the band-stop characteristics. For example, increasing the width 124 (FIG. 1) of the insulating-conductive strip 102 increases the surface area of ​​the adjacent portions of the conductive strip 110, thereby increasing the capacitance of the inductive-capacitive filter 100 and decreasing the inductance of the filter, resulting in a lower resonant frequency value and a smaller peak impedance. Furthermore, increasing the width 124 of the insulating-conductive strip also decreases the DC and low frequency AC resistance of the inductive-capacitive filter 100, thereby promoting the inductive-capacitive filter 100's ability to transmit electrical energy with minimal losses. FIG. 13 is a perspective view of an inductive-capacitive filter 1300 similar to the inductive-capacitive filter 100 of FIG. 1, but with the insulating-conductive strip 102 replaced by an insulating-conductive strip 1302. Insulating-conductive strip 1302 is similar to insulating-conductive strip 102, but has a width 1324 that is greater than width 124 of insulating-conductive strip 102. As a result, inductive-capacitive filter 1300 has a lower resonant frequency value, a lower peak impedance, and a lower resistance than inductive-capacitive filter 100.

[0045] It is contemplated that any two or more of the inductive-capacitive filters disclosed herein may be combined to form an inductive-capacitive filter assembly including two inductive-capacitive filters in a single device, for example, to achieve band-stop filtering across two or more frequency bands. For example, FIG. 14 is a perspective view of an inductive-capacitive filter assembly 1400 including a first insulating-conductive strip 1402 and a second insulating-conductive strip 1403 wound concentrically about a winding axis 1404. The first insulating-conductive strip 1402 is disposed within the second insulating-conductive strip 1403, as can be seen when the inductive-capacitive filter assembly 1400 is viewed in cross section along the direction of the winding axis 1404. The first insulating-conductive strip 1402 forms a first inductive-capacitive filter 1405, and the second insulating-conductive strip 1403 forms a second inductive-capacitive filter 1407, such that the inductive-capacitive assembly 1400 includes two inductive-capacitive filters in a single device. The first insulating-conductive strip 1402 includes a first conductive strip joined with a first insulating strip, where the first conductive strip is similar to the conductive strip 110, and the first insulating strip is similar to the insulating strip 108. The first conductive strip and the first insulating strip are not labeled in FIG. 14 to facilitate clarity of illustration. Similarly, the second insulating-conductive strip 1403 includes a second conductive strip (not labeled) and a second insulating strip (not labeled), which are also similar to the conductive strip 110 and the insulating strip 108, respectively.

[0046] The band-stop characteristics can be varied during the design and / or manufacture of the inductive-capacitive filter assembly 1400, for example, by (1) varying the number of turns of the first insulating-conductive strip 1402 and / or the second insulating-conductive strip 1403, (2) varying the size and / or shape of the inner aperture 1420 of the inductive-capacitive filter assembly 1400, (3) varying the thickness and / or dielectric properties of the insulating strips, (4) varying the thickness of the conductive strips, and / or (5) varying the width 1424 of the insulating-conductive strips 1402 and 1403, in a manner similar to that discussed above with respect to Figures 1-13. Additionally, although the insulating-conductive strips 1402 and 1403 are illustrated as forming three and four turns, respectively, the number of turns formed by the insulating-conductive strips 1402 and 1403 may be varied without departing from the scope of the present specification. Additionally, the inductive-capacitive filter assembly 1400 may be modified to include one or more additional insulating-conductive strips such that all of the insulating-conductive strips are wound concentrically around the winding axis 1404 without departing from the scope of the present specification.

[0047] The inductive-capacitive filters of the inductive-capacitive filter assembly 1400 are optionally electrically coupled in series or parallel. For example, FIG. 15 illustrates an inductive-capacitive filter assembly 1400 in which a first insulating-conductive strip 1402 is electrically coupled in series with a second insulating-conductive strip 1403 by an electrical conductor 1502. A first terminal 1534 is electrically coupled to a first end of the first insulating-conductive strip 1402, and a second terminal 1536 is electrically coupled to a second end of the second insulating-conductive strip 1403. The first and second terminals 1534 and 1536 provide an electrical interface for the inductive-capacitive filter assembly 1400. In some embodiments, the first and second terminals 1534 and 1536 include respective aluminum or copper bus bars or wires. It is contemplated that the first and second terminals 1534 and 1536 may be omitted without departing from the scope of the present specification. 16 illustrates an approximate electrical model 1600 of the inductive-capacitive filter assembly 1400 electrically coupled as illustrated in FIG. 15 as viewed from the first and second terminals 1534 and 1536. A capacitor 1604 represents the capacitance of the first insulating-conductive strip 1402, an inductor 1606 represents the inductance of the first insulating-conductive strip 1402, and a resistor 1608 represents the resistance of the first insulating-conductive strip 1402. A capacitor 1610 represents the capacitance of the second insulating-conductive strip 1403, an inductor 1612 represents the inductance of the second insulating-conductive strip 1403, and a resistor 1614 represents the resistance of the first insulating-conductive strip 1403.

[0048] Figure 17 is a graph 1700 illustrating impedance versus frequency for one particular embodiment of an inductive-capacitive filter assembly 1400 in which the first insulating-conductive strip 1402 is electrically coupled in series with the second insulating-conductive strip 1403 as illustrated in Figure 15. As is apparent from Figure 17, this particular embodiment has a first resonant frequency 1702 of about 5.7 MHz and a second resonant frequency 1704 of about 15.6 MHz. The first resonant frequency 1702 is a resonant frequency associated with the second inductive-capacitive filter 1407 and the second resonant frequency 1704 is a resonant frequency associated with the first inductive-capacitive filter 1405. The peak impedance of the first inductive-capacitive filter 1405 is approximately 6,200 ohms at the second resonant frequency 1704 , and the peak impedance of the second inductive-capacitive filter 1407 is approximately 22,000 ohms at the first resonant frequency 1702 .

[0049] Figure 18 illustrates an inductive-capacitive filter assembly 1400 in which a first insulating-conductive strip 1402 is electrically coupled in parallel with a second insulating-conductive strip 1403 by electrical conductors 1802 and 1804, and Figure 19 is a graph 1900 showing impedance versus frequency for one particular embodiment of an inductive-capacitive filter assembly 1400 in which a first insulating-conductive strip 1402 is electrically coupled in parallel with a second insulating-conductive strip 1403 as illustrated in Figure 18. As is evident from Figure 19, this particular embodiment has a resonant frequency 1902 of 8.6 MHz and a peak impedance at resonant frequency 1902 of approximately 6,600 ohms.

[0050] 20 is a perspective view of a first inductive-capacitive filter 2000 and a second inductive-capacitive filter 2001 electrically coupled in series by an electrical conductor 2026. Additional electrical conductors 2028 and 2030 provide an electrical interface for the first and second inductive-capacitive filters 2000 and 2001, respectively. The first inductive-capacitive filter 2000 includes a first insulating-conductive strip 2002 and the second inductive-capacitive filter 2001 includes a second insulating-conductive strip 2003. The first insulating-conductive strip 2002 includes an insulating strip 2008 wound in parallel with a conductive strip 2010 around a winding axis 2004, and the second insulating-conductive strip 2003 includes an insulating strip 2009 wound in parallel with a conductive strip 2011 around a winding axis 2005. First insulating-conductive strip 2002 and second insulating-conductive strip 2003 each have a configuration similar to one or more of the insulating-conductive strips described above with respect to Figures 1-19, for example. The band-stop characteristics can be varied during the design and / or manufacture of inductive-capacitive filters 2000 and / or 2001, for example, in a manner similar to that discussed above with respect to FIGS. 1-19, by, for example, (1) varying the number of turns of first insulating-conductive strip 2002 and / or second insulating-conductive strip 2003, (2) varying the size and / or shape of inner apertures 2020 and 2021 of inductive-capacitive filters 2000 and / or 2001, (3) varying the thickness and / or dielectric properties of insulating strip 2008 and / or insulating strip 2009, (4) varying the thickness of conductive strip 2010 and / or conductive strip 2011, and / or (5) varying width 2024 and / or width 2025 of first and second insulating-conductive strips 2002 and 2003, respectively.Additionally, although the first and second insulating-conductive strips 2002 and 2003 are illustrated as forming three and four turns 2006 and 2007, respectively, the number of turns of the first and second insulating-conductive strips 2002 and 2003 may be varied without departing from the scope of the present specification. To promote clarity in the illustration, only some instances of turns 2006 and 2007 are labeled in FIG. 20. Furthermore, the inductive-capacitive filters 2000 and / or 2001 may be modified to include one or more additional insulating-conductive strips outside the scope of the present specification. Moreover, it is contemplated that the first inductive-capacitive filter 2000 and the second inductive-capacitive filter 2001 may be electrically coupled in parallel without departing from the scope of the present specification.

[0051] FIG. 21 is a graph 2100 illustrating impedance versus frequency for one particular embodiment of the inductive-capacitive filters 2000 and 2001 of FIG. 20, electrically coupled in series. As is evident from FIG. 21, this particular embodiment has a first resonant frequency 2102 of about 2 MHz and a second resonant frequency 2104 of about 26.6 MHz. The first resonant frequency 2102 is the resonant frequency associated with the second inductive-capacitive filter 2101, and the second resonant frequency 2104 is the resonant frequency associated with the first inductive-capacitive filter 2000. The peak impedance of the first inductive-capacitive filter 2000 is about 39,240 ohms at the second resonant frequency 2104, and the peak impedance of the second inductive-capacitive filter 2001 is about 16,095 ohms at the first resonant frequency 2102.

[0052] It is contemplated that any of the inductive-capacitive filters described above may be modified to include one or more additional insulating-conductive strips. For example, FIG. 22 is a perspective view of an inductive-capacitive filter assembly 2200 including three insulating-conductive strips 2202, and FIG. 23 is a cross-sectional view of the inductive-capacitive filter assembly 2200 taken along line 23A-23A in FIG. 22. Each insulating-conductive strip 2202 is similar to insulating-conductive strip 102. In particular, the first insulating-conductive strip 2202(1) includes a first conductive strip 2210(1) joined with a first insulating strip 2208(1), the second insulating-conductive strip 2202(2) includes a second conductive strip 2210(2) joined with a second insulating strip 2208(2), and the third insulating-conductive strip 2202(3) includes a third conductive strip 2210(3) joined with a third insulating strip 2208(3). In some embodiments, each conductive strip 2210 includes opposing first and second terminals (not shown) electrically coupled to opposing ends of the conductive strip. To promote illustrative clarity, only some instances of the insulating-conductive strip 2202, insulating strip 2208, and conductive strip 2210 are labeled in FIG. 23 . It is contemplated that the number of insulating-conductive strips 2202 can vary without departing from the scope of the present specification.

[0053] Each conductive strip 2210 may be used, for example, as a separate channel of a multi-channel bandstop filter, where each channel has similar bandstop characteristics. The bandstop characteristics may be varied during the design and / or manufacture of the inductive-capacitive filter assembly 2200, for example, by (1) varying the number of turns 2206 of the insulating-conductive strip 2202, (2) varying the size and / or shape of the inner aperture 2220 of the inductive-capacitive filter assembly 2200, (3) varying the thickness and / or dielectric properties of the insulating strip 2208, (4) varying the thickness of the conductive strip 2210, and / or (5) varying the width 2224 of the insulating-conductive strip 2202, in a manner similar to that discussed above with respect to Figures 1-21. To promote illustrative clarity, only two instances of turns 2206 are labeled in Figure 22.

[0054] The inductive-capacitive filter assembly 2200 has an approximate electrical model similar to that of FIG. 3 in an application where the conductive strips 2210 are electrically coupled in parallel. In contrast, FIG. 24 illustrates an approximate electrical model 2400 of the inductive-capacitive filter assembly 2000 when the conductive strips 2210 are not electrically coupled in parallel. In this application, the inductive-capacitive filter assembly 2200 forms three channels 2402, 2404, and 2406 corresponding to the insulating-conductive strips 2202(1), 2202(2), and 2202(3), respectively, such that each insulating-conductive strip 2202 forms a respective inductive-capacitive filter. A capacitor 2408, an inductor 2410, and a resistor 2412 represent the capacitance, inductance, and resistance of the channel 2402, respectively. Capacitor 2414, inductor 2416, and resistor 2418 represent the capacitance, inductance, and resistance of channel 2404, respectively. Capacitor 2420, inductor 2422, and resistor 2424 represent the capacitance, inductance, and resistance of channel 2406. Capacitor 2426 represents the capacitive coupling between channel 2402 and channel 2404, capacitor 2428 represents the capacitive coupling between channel 2404 and channel 2406, and capacitor 2430 represents the capacitive coupling between channel 2402 and channel 2406. Although electrical model 2400 of FIG. 24 illustrates each component as a separate element for simplicity of illustration, each of these components represents a distributed element. Additionally, model 2400 does not take into account higher order effects such as leakage current through a capacitor, capacitance of an inductor, or inductance of a capacitor.

[0055] Although the insulating and conductive strips have a common width in the illustrations of Figures 1, 2, 5-15, 18, 20, 22 and 23, the width of the insulating strips and the width of the conductive strips need not be the same. For example, Figure 25 is a cross-sectional view similar to Figure 2 of an inductive-capacitive filter 2500 similar to the inductive-capacitive filter of Figure 1, but including an insulating strip 2508 instead of insulating strip 108. Insulating strip 2508 has a width 2516 that is greater than the width of conductive strip 110, for example to reduce the likelihood of accidental shorting of adjacent sections of conductive strip 110.

[0056] Inductive-capacitive filters 100, 500, 600, 700, 800, 900, 1100, 1300, 1405, 1407, 2000, 2001, 2200 and 2500 do not have an explicit magnetic core, or in other words, these inductive-capacitive filters have an "air" core. However, it is believed that any of the inductive-capacitive filters disclosed herein can be modified to include an explicit magnetic core formed of a magnetic material, including but not limited to ferrite magnetic material or iron powder magnetic material. The magnetic core, which may form either a partial or complete magnetic flux path, affects the resonant frequency of the inductive-capacitive filter. In particular, the inductance increases with decreasing reluctance of the magnetic flux path of the inductive-capacitive filter, and increasing the inductance decreases the resonant frequency of the filter. As a result, the resonant frequency of an inductive-capacitive filter with a given magnetic core can be adjusted by varying the permeability of the magnetic material forming the magnetic core, such that the resonant frequency decreases with increasing permeability of the magnetic material.

[0057] FIG. 26 illustrates a perspective view of an inductive-capacitive filter 2600 similar to the inductive-capacitive filter 100 of FIG. 1, but further including a rod-shaped magnetic core 2628 disposed within the inner aperture 120. The rod-shaped magnetic core 2628 forms only a partial magnetic flux path, or in other words, the rod-shaped magnetic core 2628 does not form a closed path around the resonating strip 102. Nevertheless, the rod-shaped magnetic core 2628 significantly reduces the magnetic resistance of the magnetic flux path of the inductive-capacitive filter 2600, so that the inductive-capacitive filter 2600 has a lower resonant frequency than the inductive-capacitive filter 100 of FIG. 1. The first and second terminals 134 and 136 are not shown in FIG. 26 to promote clarity of illustration.

[0058] Each of Figures 27-29 illustrates a respective embodiment of an inductive-capacitive filter in which the magnetic core forms a complete magnetic flux path, or in other words, the magnetic core forms a closed path around the insulating-conductive strips of the inductive-capacitive filter. In particular, Figure 27 illustrates a perspective view of an inductive-capacitive filter 2700 similar to the inductive-capacitive filter 100 of Figure 1, but further including a magnetic core 2728. The magnetic core 2728 included an inner post (not visible in Figure 27) that extends through the inner aperture 120 and an outer portion that connects the opposing ends of the inner post. In some embodiments, the magnetic core 2728 is formed of two "E-shaped" cores, and in some other embodiments, the magnetic core 2728 is formed of an "I-shaped" core and an "E-shaped" core. Magnetic core 2728 provides a magnetic flux path of lower reluctance than magnetic core 2628 of Figure 26, and therefore inductive-capacitive filter 2700 of Figure 27 has a lower resonant frequency than inductive-capacitive filter 2600 of Figure 26. First and second terminals 134 and 136 are not shown in Figure 27 to promote clarity of illustration.

[0059] FIG. 28 illustrates a perspective view of an inductive-capacitive filter 2800 similar to the inductive-capacitive filter of FIG. 1, but further including a magnetic core 2828. In some embodiments, the magnetic core 2828 is formed of two "U-shaped" cores, and in some embodiments, the magnetic core 2828 is formed of an "I-shaped" core and a "U-shaped" core. The magnetic core 2828 provides a magnetic flux path with lower reluctance than the magnetic core 2628 of FIG. 26, and thus the inductive-capacitive filter 2800 of FIG. 28 has a lower resonant frequency than the inductive-capacitive filter 2600 of FIG. 26. The first and second terminals 134 and 136 are not shown in FIG. 28 to promote clarity of illustration.

[0060] Figure 29 illustrates a perspective view of an inductive-capacitive filter 2900 similar to the inductive-capacitive filter of Figure 1, but further including a magnetic core 2928. The magnetic core 2928 is similar to the magnetic core 2728 of Figure 27, but has a rounded outer portion connecting opposing ends of an inner post (not visible in Figure 29) that extends through the inner aperture 120. In some embodiments, the magnetic core 2928 is formed of two pot cores. Magnetic core 2928 provides a lower reluctance magnetic flux path than either magnetic core 2628 of Figure 26, magnetic core 2728 of Figure 27, or magnetic core 2828 of Figure 28, and thus inductive-capacitive filter 2900 of Figure 29 has a lower resonant frequency than either inductive-capacitive filter 2600 of Figure 26, inductive-capacitive filter 2700 of Figure 27, or inductive-capacitive filter 2800 of Figure 28. First and second terminals 134 and 136 are not shown in Figure 29 to promote clarity of illustration.

[0061] One possible application of the inductive-capacitive filters disclosed herein is in electrical circuits, for example to implement a band-stop filter that blocks signals having frequencies within a certain frequency band around the resonant frequency of the filter while transmitting signals away from the resonant frequency. For example, FIG. 30 illustrates an electrical circuit 3000 including an example of an inductive-capacitive filter 100 electrically coupled in series with an alternating current (AC) power source 3002 and a load 3004. The circuit 3000 is, for example, part of a semiconductor processing system. In some embodiments, the power source 3002 represents an AC electric grid (e.g., one operating at 50 or 60 Hertz), an AC generator, an inverter, an oscillator, an audio amplifier, or a radio frequency amplifier, and the load 3004 represents a linear load (e.g., a resistive, inductive, and / or capacitive load) or a nonlinear load (e.g., a switching power supply load). In the electrical circuit 3000, the first end 130 of the conductive strip 110 of the inductive-capacitive filter 100 is electrically coupled to a power source 3002 via a first terminal 134 at a first node 3006, and the second end 132 of the conductive strip 110 is electrically coupled to a load 3004 via a terminal 136 at a second node 3008. Thus, the first and second ends 130 and 132 of the conductive strip 110 are electrically coupled to different respective nodes 3006 and 3008 of the electrical circuit 3000. In this particular application, the inductive-capacitive filter 100 blocks transmission of signals within a particular frequency band close to the resonant frequency of the filter 100 to prevent transmission of undesired signals generated, for example, by the power source 3002 or the load 3004. The inductive-capacitive filter 100 may be tuned, for example, to have a resonant frequency close to or equal to the frequency of the unwanted signal such that the inductive-capacitive filter 100 has a high impedance at this frequency, thereby substantially blocking transmission of the unwanted signal within the electrical circuit 3000.

[0062] The AC power source 3002 may be replaced with a direct current (DC) power source without departing from the scope of the present specification. For example, Figure 31 illustrates an electrical circuit 3100 similar to the electrical circuit 3000 of Figure 30, but where the AC power source 3002 is replaced with a direct current (DC) power source 3102. The DC power source 3102 may be, for example, a DC power bus, a power supply, a battery, or one or more solar cells.

[0063] In a particular embodiment, the load 3004 is a power supply that generates an AC output signal at frequency f1 for powering an external circuit (not shown). The power supply is sensitive to noise from the DC power source 2802 or the AC power source 3002 having frequency f1, and the inductive-capacitive filter 100 is appropriately tuned to block transmission of signals having frequency f1.

[0064] The electrical circuits 3000 and 3100 may be modified to replace the inductive-capacitive filter 100 with any of the other inductive-capacitive filters disclosed herein without departing from the scope of the present specification. Additionally, the topology of the electrical circuits 3000 and 2100 may be modified without departing from the scope of the present specification. For example, the electrical circuit 3000 may be modified such that the inductive-capacitive filter 100 is electrically coupled in parallel with each of the power source and load 3104 to shunt all signals except those having frequencies close to the resonant frequency of the inductive-capacitive filter 100.

[0065] 32 illustrates one example of an inductive-capacitive filter assembly 2200, an electrical circuit 3200 including an AC power source 3202, a first load 3204, a second load 3206, and a third load 3208. A first channel 2402 of the inductive-capacitive filter assembly 2200 is electrically coupled between the first load 3204 and the AC power source 3202 in a first branch 3210 of the electrical circuit 3200, a second channel 2404 of the inductive-capacitive filter assembly 2200 is electrically coupled between the second load 3206 and the AC power source 3202 in a second branch 3212 of the electrical circuit 3200, and a third channel 2406 of the inductive-capacitive filter assembly 2200 is electrically coupled between the third load 3208 and the AC power source 3202 in a third branch 3208 of the electrical circuit 3200. Circuit 3200 is, for example, part of a semiconductor processing system. AC power source 3202 may be replaced with a DC power source without departing from the scope of this specification.

[0066] In a particular embodiment, the first load 3204 is a first power supply generating an AC output signal at a first frequency f1 for powering an external circuit (not shown), the second load 3206 is a second power supply generating an AC output signal at a second frequency f2 for powering an external circuit (not shown), and the third load 3208 is a third power supply generating an AC output signal at a third frequency f3 for powering an external circuit (not shown). The first, second and third power supplies are sensitive to noise from the AC power source 3202 having frequencies f1, f2 and f3, respectively. Thus, in this application, the first channel 2402 of the inductive-capacitive filter 2200 is tuned to block transmission of signals having a frequency f1, the second channel 2404 of the inductive-capacitive filter 2200 is tuned to block transmission of signals having a frequency f2, and the third channel 2406 of the inductive-capacitive filter 2200 is tuned to block transmission of signals having a frequency f3.

[0067] 33 illustrates an electrical circuit 3300 including one example of an inductive-capacitive filter assembly 1400, an AC power source 3302, and a load 3304. The first and second inductive-capacitive filters 1405 and 1407 of the assembly 1400 are electrically coupled in series with the AC power source 3302 and the load 3304. The circuit 3300 is, for example, part of a semiconductor processing system. The AC power source 3302 may be replaced with a DC power source without departing from the scope of this specification.

[0068] In a particular embodiment, the load 3304 is sensitive to noise from the AC power source 3302 having a frequency f1 and to noise from the AC power source 3302 having a frequency f2. Thus, in this application, the first inductive-capacitive filter 1405 is tuned to block transmission of signals having a frequency f1, and the second inductive-capacitive filter 1407 is tuned to block transmission of signals having a frequency f2.

[0069] Changes may be made to the inductive-capacitive filters, systems and related methods described above, outside the scope of this specification. It should therefore be noted that the matter contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover the generic and specific features described herein, as well as all statements of the scope of such filters, methods and systems that may be linguistically said to fall therebetween. The invention disclosed in this specification includes the following aspects. [Aspect 1] In inductive-capacitive filters, a first insulating-conductive strip wound about a winding axis; The first insulating-conductive strip includes a first conductive strip joined with a first insulating strip, the inductive-capacitive filter. [Aspect 2] 2. The inductive-capacitive filter of claim 1, wherein the first conductive strip is wound in parallel with the first insulating strip about the winding axis. [Aspect 3] the first conductive strip is formed of a metal foil; the first insulating strip is formed of a dielectric material; 2. The inductive-capacitive filter of embodiment 1. Aspect 4 2. The inductive-capacitive filter of embodiment 1, wherein the first conductive strip has a cross-sectional area with an aspect ratio of at least two. Aspect 5 2. The inductive-capacitive filter of claim 1, wherein the first insulating-conductive strip forms an inner aperture as seen when the inductive-capacitive filter is viewed in cross section along the direction of the winding axis. Aspect 6 6. The inductive-capacitive filter of claim 5, wherein the inner aperture has a non-circular shape. Aspect 7 6. The inductive-capacitive filter of embodiment 5, further comprising a magnetic core disposed in the inner aperture. Aspect 8 2. The inductive-capacitive filter of embodiment 1, further comprising first and second terminals electrically coupled to opposing first and second ends, respectively, of the first conductive strip. Aspect 9 2. The inductive-capacitive filter of embodiment 1, further comprising one or more additional insulating-conductive strips wound about the winding axis, each additional insulating-conductive strip comprising a respective conductive strip wound together with a respective insulating strip. Aspect 10 a winding axis including first and second insulating-conductive strips wound concentrically about the winding axis; the first insulating-conductive strip includes a first conductive strip joined with a first insulating strip; the second insulating-conductive strip comprises a second conductive strip joined with a second insulating strip; Inductive-capacitive filter assembly. Aspect 11 the first conductive strip is wound around the winding axis in parallel with the first insulating strip; the second conductive strip is wound around the winding axis in parallel with the second insulating strip; 11. The inductive-capacitive filter assembly of embodiment 10. Aspect 12 11. The inductive-capacitive filter assembly of claim 10, wherein the first insulating-conductive strip is electrically coupled to the second insulating-conductive strip. Aspect 13 11. The inductive-capacitive filter assembly of claim 10, wherein the first insulating-conductive strip is disposed within the second insulating-conductive strip as seen when the inductive-capacitive filter assembly is viewed in cross section along a winding axis. Aspect 14 a third insulating-conductive strip wound concentrically with the first and second insulating-conductive strips about the winding axis; the third insulating-conductive strip includes a third conductive strip joined with a third insulating strip; each of the first, second and third insulating-conductive strips forms a respective inductive-capacitive filter; the first insulating-conductive strip is disposed within the second insulating-conductive strip as seen in a cross-section of the inductive-capacitive filter assembly along the winding axis; each of the first and second insulating-conductive strips is disposed within the third insulating-conductive strip as seen in a cross-section of the inductive-capacitive filter assembly along the winding axis; 11. The inductive-capacitive filter assembly of embodiment 10. Aspect 15 each of the first and second conductive strips is formed of a metal foil; each of the first and second insulating strips is formed of a dielectric material; 11. The inductive-capacitive filter assembly of embodiment 10. Aspect 16 the first conductive strip has a cross-sectional area with an aspect ratio of at least 2; the second conductive strip has a cross-sectional area with an aspect ratio of at least 2; 11. The inductive-capacitive filter assembly of embodiment 10. Aspect 17 11. The inductive-capacitive filter assembly of claim 10, wherein each of the first and second insulating-conductive strips forms multiple turns around the winding axis. Aspect 18 11. The inductive-capacitive filter assembly of embodiment 10, wherein each of the first and second insulating-conductive strips forms a different respective number of turns around a winding axis. Aspect 19 a third insulating-conductive strip wound concentrically with the first and second insulating-conductive strips about the winding axis; the third insulating-conductive strip includes a third conductive strip joined with a third insulating strip; each of the first, second and third insulating-conductive strips forms a respective inductive-capacitive filter; 11. The inductive-capacitive filter assembly of embodiment 10. Aspect 20 2. An electric circuit comprising the inductive-capacitive filter of embodiment 1. Aspect 21 21. The electrical circuit of embodiment 20, wherein opposing first and second ends of the first conductive strip are electrically coupled to different respective nodes of the electrical circuit. Aspect 22

[0023] The electric circuit of embodiment 21, further comprising at least one of an AC power source and a DC power source electrically coupled in series with the inductive-capacitive filter of embodiment 1 and a load. Aspect 23 11. The inductive-capacitive filter assembly of claim 10, an electrical circuit, wherein each of the first and second insulating-conductive strips is electrically coupled to a respective branch of the electrical circuit. Aspect 24 24. The electric circuit of embodiment 23, wherein each of the first and second insulating-conductive strips is electrically coupled between a power source and a respective electrical load.

Claims

1. 1. An inductive-capacitive filter assembly comprising: a first insulating-conductive strip and a second insulating-conductive strip; Each of the first insulating-conductive strip and the second insulating-conductive strip comprises: (a) a first insulating strip joined to a first conductive strip and a second insulating strip joined to a second conductive strip; (b) (i) a first terminal end of the first insulating-conductive strip is connected to a power source; (ii) a second terminal end of the first insulating-conductive strip is connected to a first terminal end of the second insulating-conductive strip by an electrical conductor; and (iii) a second terminal end of the second insulating-conductive strip is connected to a load, the inductive-capacitive filter assembly being wound in series about a common winding axis to block signals at frequencies centered about a first resonant frequency associated with the first insulating-conductive strip and a second resonant frequency associated with the second insulating-conductive strip. Inductive-capacitive filter assembly.

2. the first insulating-conductive strip and the second insulating-conductive strip are layered together and wound about the winding axis; the band-stop characteristic of each of the first insulating-conductive strip and the second insulating-conductive strip is tuned to one of the frequencies in response to one or more of a number of turns of the insulating-conductive strip, a size and shape of an inner aperture of the inductive-capacitive filter assembly, a dielectric property and a thickness of the insulating strip, a thickness of the conductive strip, a width of the insulating-conductive strip, and combinations thereof; 2. The inductive-capacitive filter assembly of claim 1.

3. Each conductive strip comprises a metal foil; Each insulating strip comprises a dielectric material.

2. The inductive-capacitive filter assembly of claim 1.

4. the conductive strip has a radial axis perpendicular to and extending away from the winding axis; 2. The inductive-capacitive filter assembly of claim 1, wherein a cross-section of each of the conductive strips has a cross-sectional shape with an aspect ratio of at least 2 when viewed in a plane parallel to each of the winding axis and the radial axis.

5. 2. The inductive-capacitive filter assembly of claim 1, wherein the first insulating-conductive strip and the second insulating-conductive strip form an inner aperture, as seen when the inductive-capacitive filter assembly is viewed in cross-section along the direction of the winding axis.

6. 6. The inductive-capacitive filter assembly of claim 5, wherein the inner aperture has a size and non-circular shape that contributes in part to tuning the inductive-capacitive filter assembly to the first resonant frequency and the second resonant frequency.

7. 6. The inductive-capacitive filter assembly of claim 5, further comprising a magnetic core disposed in the inner aperture that partially tunes the inductive-capacitive filter assembly to the first resonant frequency and the second resonant frequency.

8. 2. The inductive-capacitive filter assembly of claim 1, wherein the first conductive strip and the second conductive strip have different respective numbers of turns about a winding axis, the number of turns contributing to tuning the first resonant frequency and the second resonant frequency.

9. 1. An inductive-capacitive filter assembly comprising: a first insulating-conductive strip and a second insulating-conductive strip; Each of the first insulating-conductive strip and the second insulating-conductive strip comprises: (a) a first insulating strip joined to a first conductive strip and a second insulating strip joined to a second conductive strip; (b) (i) a first conductor connects a first terminal end of the first insulating-conductive strip to a first terminal end of the second insulating-conductive strip; (ii) a second conductor connects a second terminal end of the first insulating-conductive strip to a second terminal end of the second insulating-conductive strip; (iii) the first terminal ends of the first insulating-conductive strip and the second insulating-conductive strip are connected to a power source; and (iv) the second terminal ends of the first insulating-conductive strip and the second insulating-conductive strip are connected to a load, the inductive-capacitive filter assembly being wound in parallel about a common winding axis such that the inductive-capacitive filter assembly blocks signals at frequencies centered about a first resonant frequency associated with the first insulating-conductive strip and a second resonant frequency associated with the second insulating-conductive strip. Inductive-capacitive filter assembly.

10. the first insulating-conductive strip and the second insulating-conductive strip are layered together and wound about the winding axis; the band-stop characteristic of each of the first insulating-conductive strip and the second insulating-conductive strip is tuned to one of the frequencies in response to one or more of a number of turns of the insulating-conductive strip, a size and shape of an inner aperture of the inductive-capacitive filter assembly, a dielectric property and a thickness of the insulating strip, a thickness of the conductive strip, a width of the insulating-conductive strip, and combinations thereof; 10. The inductive-capacitive filter assembly of claim 9.

11. Each conductive strip comprises a metal foil; Each insulating strip comprises a dielectric material.

10. The inductive-capacitive filter assembly of claim 9.

12. the conductive strip has a radial axis perpendicular to and extending away from the winding axis; 10. The inductive-capacitive filter assembly of claim 9, wherein a cross-section of each of the conductive strips has a cross-sectional shape with an aspect ratio of at least 2 when viewed in a plane parallel to each of the winding axis and the radial axis.

13. 10. The inductive-capacitive filter assembly of claim 9, wherein the first insulating-conductive strip and the second insulating-conductive strip form an inner aperture, as seen when the inductive-capacitive filter assembly is viewed in cross-section along the direction of the winding axis.

14. 14. The inductive-capacitive filter assembly of claim 13, wherein the inner aperture has a size and non-circular shape that contributes in part to tuning the inductive-capacitive filter assembly to the first resonant frequency and the second resonant frequency.

15. 14. The inductive-capacitive filter assembly of claim 13, further comprising a magnetic core disposed in the inner aperture that partially tunes the inductive-capacitive filter assembly to the first resonant frequency and the second resonant frequency.

16. 2. The inductive-capacitive filter assembly of claim 1, wherein each of the first conductive strip and the second conductive strip forms a different respective number of turns about a winding axis, the number of turns contributing to tuning the first resonant frequency and the second resonant frequency, respectively.

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