[0028] figure 1 This is a schematic structural diagram of a adjustable ring inductor provided by an embodiment of the present invention, such as figure 1 As shown, the adjustable toroidal inductor of this embodiment includes: a toroidal magnetoelectric composite element 1 and a coil 2 wound on the toroidal magnetoelectric composite element 1. The ring magnetoelectric composite element 1 includes a ring piezoelectric element 11 and a ring ferromagnetic element 12. The ring piezoelectric element 11 and the ring ferromagnetic element 12 are arranged concentrically to form a concentric ring magnetoelectric composite structure.
[0029] The concentric arrangement of the annular piezoelectric element 11 and the annular ferromagnetic element 12 can be divided into the following two cases: In the first case, the outer diameter of the annular piezoelectric element 11 is equal to the inner diameter of the annular ferromagnetic element 12, and the annular piezoelectric element 11 is sleeved. Inside the toroidal ferromagnetic element 12. In the second case, the inner diameter of the annular piezoelectric element 11 is equal to the outer diameter of the annular ferromagnetic element 12, and the annular ferromagnetic element 12 is sleeved in the annular piezoelectric element 11. Under the action of an external electrostatic field, the annular piezoelectric element 11 shrinks or expands radially due to the piezoelectric effect, and the contraction or expansion of the annular piezoelectric element 11 generates mechanical stress, so that the mechanical stress is along the radial direction of the annular piezoelectric element 11. Transfer to the toroidal ferromagnetic element 12, the toroidal ferromagnetic element 12 changes the permeability and the corresponding inductance of the toroidal ferromagnetic element 12 due to the piezomagnetic effect, thereby realizing the regulation of the inductance by the electrostatic field. When a positive electric field is applied to the adjustable toroidal inductor, the inductance value of the adjustable toroidal inductor decreases significantly as the electric field increases.
[0030] Specifically, in this embodiment, the ring-shaped piezoelectric element 11 and the ring-shaped ferromagnetic element 12 are both ring-shaped. When the two are combined, the mechanical stress generated by the ring-shaped piezoelectric element 11 due to the piezoelectric effect when an electric field is applied is due to The front contact area of the ring piezoelectric element 11 and the ring ferromagnetic element 12 is large, and the mechanical normal stress transmitted by the ring piezoelectric element 11 to the ring ferromagnetic element 12 is also large. The ring ferromagnetic element 12 becomes larger due to the mechanical normal stress received. As a result, the permeability of the toroidal ferromagnetic element 12 due to the piezomagnetic effect is also large, thereby increasing the adjustable inductance of the toroidal inductance.
[0031] When the ring-shaped piezoelectric element 11 is sleeved in the ring-shaped ferromagnetic element 12, the ring-shaped piezoelectric element 11 can be connected to the ring-shaped ferromagnetic element 12 in a variety of ways. In one connection mode, the ring-shaped piezoelectric element 11 is connected to the ring-shaped ferromagnetic element 12. The element 12 is bonded by epoxy resin or co-fired to form a concentric ring magnetoelectric composite structure, so that the ring-shaped piezoelectric element 11 is sleeved in the ring-shaped ferromagnetic element 12. When a positive electric field is applied, the ring-shaped piezoelectric element 11 shrinks due to the piezoelectric effect, and the resulting mechanical stress will force the ring-shaped ferromagnetic element 12 to also shrink inward, causing the ring-shaped ferromagnetic element 12 to receive a radial and inward tensile force. As a result, compressive stress in the circumferential direction is generated in the annular ferromagnetic element 12, and due to the piezomagnetic effect, the magnetic permeability is reduced, and the inductance is also reduced correspondingly.
[0032] When the ring-shaped ferromagnetic element 12 is sleeved in the ring-shaped piezoelectric element 11, the ring-shaped ferromagnetic element 12 can be connected to the ring-shaped piezoelectric element 11 in a variety of ways. In one connection mode, the ring-shaped ferromagnetic element 12 is connected to the ring-shaped piezoelectric element 11. The element 11 is bonded by epoxy resin or co-fired to form a concentric circular magnetoelectric composite structure, so that the ring-shaped ferromagnetic element 12 is sleeved in the ring-shaped piezoelectric element 11. It should be noted that the ring piezoelectric element 11 and the ring ferromagnetic element 12 are not limited to the above two ways to form a concentric circular ring magnetoelectric composite structure. The ring piezoelectric element 11 and the ring ferromagnetic element 12 may also be connected in other ways. When an electric field is applied, the ring-shaped piezoelectric element 11 shrinks due to the piezoelectric effect, and the mechanical stress generated will squeeze the ring-shaped ferromagnetic element 12 and shrink the ring-shaped ferromagnetic element 12, causing the ring-shaped ferromagnetic element 12 to receive radial and inward pressure. Due to the piezomagnetic effect of the toroidal ferromagnetic element 12, the magnetic permeability changes, so that the inductance also changes accordingly.
[0033] In this embodiment, the material of the ring-shaped piezoelectric element 11 can be any one of the following materials: lead zirconate titanate piezoelectric ceramics, barium titanate piezoelectric ceramics, lead magnesium niobate-lead titanate piezoelectric ceramics, or single Crystal, lead magnesium niobate-lead zirconate titanate piezoelectric ceramics or single crystals, lead zinc niobate-lead titanate piezoelectric ceramics or single crystals, and potassium sodium niobate-based lead-free piezoelectric ceramics. The material of the toroidal ferromagnetic element 12 can be manganese-zinc ferrite or iron-based amorphous alloy, but the present invention is not limited to this. The toroidal piezoelectric element 11 and the toroidal ferromagnetic element 12 can also be made of materials other than those listed above. Other piezoelectric materials and ferromagnetic materials.
[0034] In this embodiment, the coil 2 can be evenly wound on the toroidal magneto-electric composite element 1, and the ends of the coil 2 are reserved as terminals for adjustable toroidal inductance. The material of the coil 2 can be enameled wire. Of course, the coil 2 can also be any existing coil, which is not limited in the present invention.
[0035] The adjustable toroidal inductor provided in this embodiment consists of a toroidal piezoelectric element with piezoelectric effect and a toroidal ferromagnetic element with piezomagnetic effect to form a toroidal magneto-electric composite element, and a ring-shaped magneto-electric composite structure Coil composition. Under the action of an external electrostatic field, the ring piezoelectric element shrinks or expands radially due to the piezoelectric effect, and the generated mechanical stress is transferred to the ring ferromagnetic element along the radial direction of the ring piezoelectric element. The magnetic effect causes the permeability and the corresponding inductance of the ring ferromagnetic element to change, thereby realizing the regulation of the inductance by the electrostatic field. Moreover, the adjustable toroidal inductor provided in this embodiment adopts a concentric composite structure of a toroidal piezoelectric element and a toroidal ferromagnetic element, so that the positive contact area and normal stress of the piezoelectric element and the ferromagnetic element are increased, and the piezoelectric element can reduce Greater mechanical stress is transferred to the ferromagnetic element, thereby increasing the adjustable range of the adjustable ring inductance.
[0036] Further, on the basis of the adjustable ring inductance provided in the first embodiment, a pair of electrodes are provided on the upper and lower surfaces of the ring piezoelectric element 11, and the ring piezoelectric element 11 is polarized in a direction perpendicular to the radial direction of the ring piezoelectric element 11. That is, the ring-shaped piezoelectric element 11 is polarized in its thickness direction. Alternatively, the inner and outer surfaces of the ring-shaped piezoelectric element 11 are provided with a pair of electrodes, and the ring-shaped piezoelectric element 11 is polarized along the radial direction of the ring-shaped piezoelectric element 11. In addition, a wire is set on each electrode, and the wire is used as the control voltage terminal 3 of the adjustable toroidal inductance, and a forward voltage or a reverse voltage is applied to both ends of the adjustable toroidal inductance through the control voltage terminal 3.
[0037] The embodiment of the present invention will briefly introduce the manufacturing method of the adjustable toroidal inductor. The structure of the adjustable toroidal inductor is as follows: figure 1 As shown, in this embodiment, the ring-shaped piezoelectric element 11 uses a ring-shaped lead zirconate titanate ceramic sheet, the ring-shaped ferromagnetic element 12 uses a manganese-zinc ferrite ring, and the surface of the ring-shaped piezoelectric element 11 is provided with a silver electrode, and the ring-shaped piezoelectric element 11 is provided with a silver electrode. The material model of the acid lead ceramic sheet is PZT-5H (Pb(Zr,Ti)O3, abbreviated as PZT). The outer diameter of the ring-shaped piezoelectric element 11 is 15mm (mm), the inner diameter is 5mm, and the thickness is 1mm. The electric element 11 is polarized in a direction perpendicular to its radial direction, that is, in its thickness direction. The initial permeability of the manganese-zinc ferrite ring is 5000, its outer diameter is 25mm, the inner diameter is 15mm (the same as the outer diameter of the ring-shaped lead zirconate titanate ceramic sheet), and the thickness is also 1mm.
[0038] In the first step, lead zirconate titanate ceramics are prepared into ring-shaped piezoelectric elements 11 with an outer diameter of 15 mm, an inner diameter of 5 mm, and a thickness of 1 mm. Silver electrodes are fired on the upper and lower surfaces of the ring piezoelectric elements 11, and then a high-voltage DC power supply is used to It is polarized along the thickness direction, and 120°C silicone oil is used during the polarization treatment, and the polarization treatment electric field is 3kV/cm. There are many methods for polarization treatment of lead zirconate titanate ceramics. Here is just a common example to illustrate. Finally, a wire is respectively welded on the upper and lower electrode surfaces of the ring piezoelectric element 11 as a terminal for controlling the control voltage of the ring inductance. It is also possible to fabricate electrodes on the inner and outer ring surfaces of the annular piezoelectric element 11 and polarize them in the radial direction.
[0039] The second step is to prepare the manganese-zinc ferrite ring into a ring-shaped ferromagnetic element 12 with an outer diameter of 25mm, an inner diameter of 15mm, and a thickness of 1mm. Use fine sandpaper on the outer ring edge of the ring piezoelectric element 11 and the inner ring of the ring ferromagnetic element 12. The ring wall is properly polished, and then the ring piezoelectric element 11 and the ring ferromagnetic element 12 are tightly bonded with epoxy resin (West system 105/206) to form the ring magnetoelectric composite element 1. The whole process is completed at room temperature and cured for 24 hours.
[0040] In the third step, after the ring magnetoelectric composite element 1 is formed, N turns of the coil 2 are evenly wound on the ring magnetoelectric composite element 1, and the head and tail ends are set aside as the terminals for the adjustable ring inductance.
[0041] Through the above three steps, the production of the adjustable toroidal inductor is completed. The adjustable toroidal inductor has a simple structure and simple manufacturing process. It can be applied to power management, power filters, inverters, and pressure in the field of wireless systems in the field of power electronics. Controlled oscillator, dynamic matching network, etc.
[0042] The following examples illustrate the testing process of the adjustable toroidal inductance provided by the present invention. First, connect the terminal of the adjustable toroidal inductance to the LCR meter or impedance analyzer, and then use a DC power supply according to the polarization direction of the toroidal piezoelectric element 11. By applying a forward voltage to the control voltage terminal 3 of the adjustable toroidal inductance, the inductance of the adjustable toroidal inductance and the change rule of the adjustable amount with the applied electric field of the present invention can be obtained. Normally, the forward voltage is applied. , Due to negative voltage easily lead to depolarization of piezoelectric ceramics. figure 2 It is a schematic diagram of the change of the inductance value of the adjustable toroidal inductor with the applied electric field, such as figure 2 As shown, under the action of an external positive electric field, the inductance value of the adjustable toroidal inductor of the present invention decreases with the increase of the electric field, and shows a good linear relationship. image 3 It is a schematic diagram of the change of the adjustable amount of the adjustable ring inductance with the applied electric field, such as image 3 As shown, under the action of an electric field of 5kV/cm, an adjustable amount of 65% can be obtained, which increases the control range of the magnetoelectric adjustable inductance.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. range.
