Self-resonant frequency tunable on-chip transformer structure and tuning method
Through the stacked on-chip transformer and auxiliary inductor structure, the continuous adjustment of the self-resonant frequency is achieved by voltage differential tuning, which solves the limitations of the existing transformer tuning method, improves the flexibility and integration of the circuit, and is suitable for the miniaturized reconfigurable radio frequency front end in modern wireless communications.
Patent Information
- Application Number
- CN202510583887.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2025-08-08
AI Technical Summary
The existing transformer tuning methods have problems such as large parasitic parameters, limited tuning range, and complex tuning methods. They cannot flexibly adjust the self-resonant frequency, which limits its application in reconstructible circuits.
The on-chip transformer structure with a self-resonant frequency tunable is adopted. The self-resonant frequency is adjusted by stacking the first on-chip transformer, auxiliary inductor and second on-chip transformer, and the magnetic coupling principle and voltage difference tuning are used to regulate the voltage difference to adjust the self-resonant frequency.
The continuous adjustment of the self-resonant frequency of the on-chip transformer is realized, the circuit reconstruction ability is improved, the high quality factor is maintained, the interference to subsequent circuits is reduced, the circuit model analysis process is simplified, and the transformer layout area is reduced.
Smart Images
Figure CN120453024A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of tunable transformers, and in particular relates to an on-chip transformer structure with tunable self-resonant frequency and a tuning method. Background Art
[0002] The rapidly growing demand for miniaturized, reconfigurable RF front-ends in modern wireless communications has driven technological innovation in on-chip transformers. Due to their compact structure and excellent compatibility with CMOS processes, on-chip integrated transformers have become a core building block in RF integrated circuits. In specific circuits, on-chip transformers not only perform DC biasing and power distribution functions but also achieve multiple technical goals through electromagnetic coupling, including broadband impedance matching, transmission zero generation, and out-of-band noise suppression. Therefore, dynamically switching circuit operating modes by adjusting transformer parameters has become a key technical approach for building reconfigurable circuits.
[0003] Currently, tunable transformer implementations primarily employ typical approaches such as switch arrays, varactor diodes, and PIN diodes. However, these tuning methods face technical bottlenecks in standard CMOS processes: interconnect parasitic capacitance worsens system noise, and the physical size of external components limits integration density. This directly impacts traditional solutions' inability to meet the critical performance requirements of 5G / 6G communication systems for high-Q, miniaturized, and reconfigurable RF front-ends. Therefore, the following four transformer tuning methods exist in academia and industry:
[0004] In the paper "24-40GHz dual-band highly linear CMOS up-conversion mixer for mmWave 5G NR FR2 cellular applications," a directly switchable inductor is used in the transformer, which reduces complexity. However, the on-resistance during the switching process reduces the overall quality factor of the inductor / transformer.
[0005] In the literature In the present invention, MOS tubes are used to realize switchable transformers; however, the coupling coefficient and the quality factor are mutually restricted, which limits the tuning range of the switching transformer.
[0006] In the literature In this paper, multi-channel adjustable transformers generate multiple sets of inductance values by varying the phase difference of the excitation signals. Their advantage is that they provide performance similar to that of narrowband transformers while occupying a smaller area. However, multi-channel transformers have many control ports, making the control method more complex.
[0007] In the patent , switching between high-frequency and low-frequency impedance matching is simple to implement; however, the tuning range is limited and lacks flexibility.
[0008] In summary, existing research on transformer tuning methods suffers from large parasitic parameters, limited tuning range, and complex tuning methods. Furthermore, due to factors such as manufacturing process, shape and size, the transformer's self-resonant frequency and other parameters are fixed after design and manufacture, making them inflexible. This significantly limits the application of transformers in reconfigurable circuits. Summary of the Invention
[0009] In order to solve the above problems existing in the prior art, the present invention provides an on-chip transformer structure with tunable self-resonant frequency and a tuning method.
[0010] The technical problem to be solved by the present invention is achieved through the following technical solutions:
[0011] The present invention provides an on-chip transformer structure with tunable self-resonant frequency, comprising:
[0012] Auxiliary inductor;
[0013] a first on-chip transformer stacked on the auxiliary inductor;
[0014] a second on-chip transformer stacked below the auxiliary inductor;
[0015] A first dielectric layer is provided between the first on-chip transformer and the auxiliary inductor, and a second dielectric layer is provided between the second on-chip transformer and the auxiliary inductor; the first on-chip transformer, the auxiliary inductor and the second on-chip transformer all have electrical leads, the electrical leads of the first on-chip transformer and the second on-chip transformer are used to connect to a controlled source, and the electrical leads of the auxiliary inductor are used to connect to a modulation source, wherein the modulation source is used to tune the self-resonant frequency of the first on-chip transformer by regulating the voltage difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer, and to tune the self-resonant frequency of the second on-chip transformer by regulating the voltage difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the second on-chip transformer.
[0016] The present invention further provides a method for tuning the self-resonant frequency of an on-chip transformer structure with tunable self-resonant frequency, which is applied to the above-mentioned on-chip transformer structure. The method comprises:
[0017] Connecting the controlled source to the first on-chip transformer and the second on-chip transformer respectively, and connecting the modulation source to the auxiliary inductor;
[0018] When the self-resonant frequencies of the first on-chip transformer and the second on-chip transformer need to be increased, the modulation source is controlled to increase the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the first on-chip transformer, thereby increasing the self-resonant frequency of the first on-chip transformer; and the modulation source is controlled to increase the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the second on-chip transformer, thereby increasing the self-resonant frequency of the second on-chip transformer;
[0019] When it is necessary to reduce the self-resonant frequencies of the first on-chip transformer and the second on-chip transformer, the voltage difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer is reduced by regulating the modulation source to reduce the self-resonant frequency of the first on-chip transformer, and the voltage difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the second on-chip transformer is reduced by regulating the modulation source to reduce the self-resonant frequency of the second on-chip transformer.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] 1) Based on the principle of magnetic coupling, the present invention achieves continuous adjustment of the self-resonant frequency of the on-chip transformer by changing the port voltage difference, thereby improving the reconfiguration capability of the circuit;
[0022] 2) Compared to switches and varactor diodes, voltage difference tuning avoids introducing additional parasitic parameters, maintaining a high quality factor while reducing interference with subsequent circuits;
[0023] 3) The on-chip transformer, symmetrically distributed on both sides of the auxiliary inductor, adopts an equal coupling coefficient design, which not only simplifies the circuit model analysis process but also significantly improves system design efficiency;
[0024] 4) The three-layer spaced stacking structure proposed in the present invention reduces the layout area of the adjustable on-chip transformer, which is conducive to the miniaturization of the radio frequency circuit.
[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 1 is a structural diagram of an on-chip transformer structure with tunable self-resonant frequency provided by an embodiment of the present invention;
[0027] Figure 2 1 is a side view of an on-chip transformer structure with tunable self-resonant frequency provided by an embodiment of the present invention;
[0028] Figure 3 1 is a top view of an on-chip transformer structure with tunable self-resonant frequency provided by an embodiment of the present invention;
[0029] Figure 4 is another structural schematic diagram of an on-chip transformer structure with tunable self-resonant frequency provided by an embodiment of the present invention;
[0030] Figure 5 This is a structural diagram of a self-resonant frequency tuning system of an on-chip transformer structure with tunable self-resonant frequency provided by an embodiment of the present invention;
[0031] Figure 6 1 is a schematic diagram of changes in the inductance L1 value of the first on-chip transformer under exemplary conditions of different voltage differences provided by an embodiment of the present invention;
[0032] Figure 7 3 is a schematic diagram of changes in the inductance L2 value of the second on-chip transformer under exemplary conditions of different voltage differences provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0033] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.
[0034] The present invention provides an on-chip transformer structure with tunable self-resonant frequency, comprising:
[0035] Auxiliary inductor;
[0036] a first on-chip transformer stacked on the auxiliary inductor;
[0037] a second on-chip transformer stacked below the auxiliary inductor;
[0038] A first dielectric layer is provided between the first on-chip transformer and the auxiliary inductor, and a second dielectric layer is provided between the second on-chip transformer and the auxiliary inductor. The first on-chip transformer, the auxiliary inductor, and the second on-chip transformer all have electrical leads. The electrical leads of the first on-chip transformer and the second on-chip transformer are used to connect to a controlled source, and the electrical leads of the auxiliary inductor are used to connect to a modulation source. The modulation source is used to tune the self-resonant frequency of the first on-chip transformer by regulating the voltage difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer, and to tune the self-resonant frequency of the second on-chip transformer by regulating the voltage difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the second on-chip transformer. Specifically, the voltage difference is negatively correlated with the inductance value, and the voltage difference is positively correlated with the self-resonant frequency.
[0039] In the present invention, both the controlled source and the modulation source are AC power supplies, and both the amplitude and phase of the modulation source are adjustable. Specifically, the modulation source is used to regulate the amplitude ratio between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer / the second on-chip transformer by regulating only the amplitude of the voltage between the electrical lead-out terminals of the auxiliary inductor, so as to tune the self-resonant frequency of the first on-chip transformer / the second on-chip transformer; the modulation source is also used to regulate the phase difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer / the second on-chip transformer by regulating only the phase of the voltage between the electrical lead-out terminals of the auxiliary inductor, so as to tune the self-resonant frequency of the first on-chip transformer / the second on-chip transformer; the modulation source is also used to regulate the amplitude ratio and phase difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer / the second on-chip transformer by regulating the amplitude and phase of the voltage between the electrical lead-out terminals of the auxiliary inductor, so as to tune the self-resonant frequency of the first on-chip transformer / the second on-chip transformer.
[0040] In some embodiments, the thickness of the first dielectric layer is the same as the thickness of the second dielectric layer. Exemplarily, the dielectric layer is a silicon dioxide layer. The shapes of the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are all symmetrical, and the shapes of the first on-chip transformer are the same as the shapes of the second on-chip transformer. Exemplarily, the shapes of the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer can all be circular or symmetrical polygons, such as quadrilaterals, hexagons, octagons, etc. For example, the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are all a single metal layer, and the metal of the metal layer is copper. Then, the on-chip transformer structure with tunable self-resonant frequency is composed of three stacked metal layers, wherein the first metal layer is the first on-chip transformer, the second metal layer is the auxiliary inductor, and the third metal layer is the second on-chip transformer. Furthermore, the spacing between the first metal layer and the second metal layer is equal to the spacing between the second metal layer and the third metal layer.
[0041] For example, Figure 1 This is a structural schematic diagram of an on-chip transformer structure with tunable self-resonant frequency provided by the present invention; Figure 2 1 is a side view of an on-chip transformer structure with tunable self-resonant frequency provided by the present invention; Figure 3 FIG. 1 is a top view of the on-chip transformer structure with tunable self-resonant frequency provided by the present invention. Figure 1 、 2As shown in Figure 3, the on-chip transformer structure with tunable self-resonant frequency is composed of a first on-chip transformer, an auxiliary inductor, and a second on-chip transformer stacked on top of each other. The orange structure represents the first on-chip transformer, the red structure represents the auxiliary inductor, and the green structure represents the second on-chip transformer. The shapes of the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are all octagonal, and the structures on both sides of each octagon are electrical leads. Figure 1 、 2 As shown in Figure 3, the layout area of the self-resonant frequency tunable on-chip transformer structure is small and can be used for miniaturization of radio frequency circuits to improve the integration scale.
[0042] In some embodiments, based on the fact that the thickness of the first dielectric layer is the same as the thickness of the second dielectric layer, and the shapes of the first on-chip transformer and the second on-chip transformer are symmetrical and identical, the inductance value of the first on-chip transformer and the inductance value of the second on-chip transformer are also the same. In this way, the on-chip transformers symmetrically distributed on both sides of the auxiliary inductor are designed with equal coupling coefficients, which not only simplifies the circuit model analysis process but also significantly improves the design efficiency of the system.
[0043] In some embodiments, the inductance values of the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are all the same.
[0044] In some embodiments, the first on-chip transformer and the second on-chip transformer are both one-turn or multi-turn inductors, and the auxiliary inductor is a one-turn or multi-turn inductor; for example, the first on-chip transformer and the second on-chip transformer are both one-turn inductors, and the auxiliary inductor is also a one-turn inductor; for another example, the first on-chip transformer and the second on-chip transformer are both n-turn inductors, and the auxiliary inductor is a one-turn inductor, where n is a positive integer greater than 1; for another example, the first on-chip transformer and the second on-chip transformer are both 1-turn inductors, and the auxiliary inductor is an n-turn inductor; for another example, the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are all n-turn inductors.
[0045] In some embodiments, the direction in which the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are stacked on each other is a first direction, and the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer each have two electrical leads, wherein the two electrical leads of the first on-chip transformer and the two electrical leads of the second on-chip transformer are located on the same side and are adjacent to each other up and down along the first direction, and the two electrical leads of the auxiliary inductor are located on opposite sides of the two electrical leads of the first on-chip transformer and the second on-chip transformer, wherein the first electrical lead of the auxiliary inductor is axially symmetrical with the first electrical lead of the first on-chip transformer and the first electrical lead of the second on-chip transformer, and the second electrical lead of the auxiliary inductor is axially symmetrical with the second electrical lead of the first on-chip transformer and the second electrical lead of the second on-chip transformer; the first electrical lead of the first on-chip transformer and the first electrical lead of the second on-chip transformer are both used to connect to a controlled source, the first electrical lead of the auxiliary inductor is used to connect to a modulation source, and the second electrical lead of the first on-chip transformer, the second electrical lead of the second on-chip transformer, and the second electrical lead of the auxiliary inductor are all used to be grounded. For example, Figure 4 is another structural schematic diagram of the on-chip transformer structure with tunable self-resonant frequency provided by the present invention; Figure 5 This is a structural diagram of a self-resonant frequency tuning system of an on-chip transformer structure with tunable self-resonant frequency provided by the present invention. Figure 2 、 4 As shown in Figures 5 and 6, the first electrical terminal of the first on-chip transformer is S2, the first electrical terminal of the second on-chip transformer is S3, the first electrical terminal of the auxiliary inductor is S1, the second electrical terminal of the first on-chip transformer is D2, the second electrical terminal of the second on-chip transformer is D3, and the second electrical terminal of the auxiliary inductor is D1. S3 and S2 are both used to connect to the controlled source, S1 is used to connect to the modulation source, and D1, D2, and D3 are all used to connect to ground (GND). The modulation source can be used to control the voltage difference between the voltage V1 between the two electrical terminals of the auxiliary inductor and the voltage V2 between the two electrical terminals of the first on-chip transformer and the voltage V3 between the two electrical terminals of the second on-chip transformer, so that the on-chip transformer and the auxiliary inductor are coupled to each other under the action of voltages V1, V2, and V3, thereby achieving self-resonant frequency tuning of the on-chip transformer. Specifically, as mentioned above, by regulating the modulation source to change the amplitude and / or phase of the voltage V1, the amplitude ratio and / or phase difference between V1 and V2 and V3 can be regulated, thereby coupling the auxiliary inductor and the on-chip transformer to each other, thereby achieving the effect of tuning the inductance of the transformer. Since the change in the inductance of the transformer will cause the self-resonant frequency to change (the inductance of the transformer is negatively correlated with the self-resonant frequency), the self-resonant frequency of the transformer can be tuned.
[0046] The present invention also provides a method for tuning the self-resonant frequency of an on-chip transformer structure with tunable self-resonant frequency. The method is applied to the above-mentioned on-chip transformer structure, and the method comprises:
[0047] S1. Connect the first on-chip transformer and the second on-chip transformer to controlled sources respectively, and connect the auxiliary inductor to a modulation source.
[0048] S2. When it is necessary to increase the self-resonant frequency of the first on-chip transformer and the second on-chip transformer, the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the first on-chip transformer is increased by regulating the modulation source to increase the self-resonant frequency of the first on-chip transformer, and the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the second on-chip transformer is increased by regulating the modulation source to increase the self-resonant frequency of the second on-chip transformer.
[0049] In some embodiments, the amplitude of the voltage between the electrical leads of the auxiliary inductor can be increased by increasing the amplitude of the modulation source, the amplitude ratio between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer can be increased by increasing the amplitude of the voltage between the electrical leads of the auxiliary inductor, and the self-resonant frequency of the first on-chip transformer / the second on-chip transformer can be increased by increasing the amplitude ratio between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer.
[0050] In some embodiments, the phase of the voltage between the electrical leads of the auxiliary inductor can be increased by increasing the phase of the modulation source, the phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer can be increased by increasing the phase of the voltage between the electrical leads of the auxiliary inductor, and the self-resonant frequency of the first on-chip transformer / the second on-chip transformer can be increased by increasing the phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer.
[0051] In some embodiments, the amplitude and phase of the voltage between the electrical leads of the auxiliary inductor can be increased by simultaneously increasing the amplitude and phase of the modulation source, the amplitude ratio and phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer can be increased by increasing the amplitude and phase of the voltage between the electrical leads of the auxiliary inductor, and the self-resonant frequency of the first on-chip transformer / the second on-chip transformer can be increased by increasing the amplitude ratio and phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer.
[0052] S3. When it is necessary to reduce the self-resonant frequency of the first on-chip transformer and the second on-chip transformer, the voltage difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer is reduced by regulating the modulation source to reduce the self-resonant frequency of the first on-chip transformer, and the voltage difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the second on-chip transformer is reduced by regulating the modulation source to reduce the self-resonant frequency of the second on-chip transformer.
[0053] In some embodiments, the amplitude of the voltage between the electrical leads of the auxiliary inductor can be reduced by reducing the amplitude of the modulation source, the amplitude ratio between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer can be reduced by reducing the amplitude of the voltage between the electrical leads of the auxiliary inductor, and the self-resonant frequency of the first on-chip transformer / the second on-chip transformer can be reduced by reducing the amplitude ratio between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer.
[0054] In some embodiments, the phase of the voltage between the electrical leads of the auxiliary inductor can be increased by reducing the phase of the modulation source, the phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer can be reduced by reducing the phase of the voltage between the electrical leads of the auxiliary inductor, and the self-resonant frequency of the first on-chip transformer / the second on-chip transformer can be reduced by reducing the phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer.
[0055] In some embodiments, the amplitude and phase of the voltage between the electrical leads of the auxiliary inductor can be reduced by simultaneously reducing the amplitude and phase of the modulation source, the amplitude ratio and phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer can be reduced by reducing the amplitude and phase of the voltage between the electrical leads of the auxiliary inductor, and the self-resonant frequency of the first on-chip transformer / the second on-chip transformer can be reduced by reducing the amplitude ratio and phase difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer / the second on-chip transformer.
[0056] The above structure and method provided by the present invention have the following advantages:
[0057] 1) Tuning methods using varactor diodes are limited by large parasitic parameters, a narrow tuning range, and the inability to continuously adjust. This invention firstly avoids the introduction of parasitic parameters by using a voltage difference tuning method based on magnetic coupling, effectively improving the quality factor while reducing interference with subsequent circuits. Secondly, because the voltage difference can be varied continuously and over a wide range, it enables flexible, broadband on-chip transformer tuning.
[0058] 2) The switching tuning method has the disadvantage of large layout area. The present invention can continuously obtain multiple equivalent inductance values without adding additional components, effectively improving the circuit integration and reconfiguration capability.
[0059] 3) To address the problem of complex implementation and lack of flexibility of multi-channel transformers based on the phase difference of the excitation signal, the tuning method of the present invention is independent of other circuit modules and can be designed independently, with high independence and universality, and improves the efficiency of early design.
[0060] 4) The present invention proposes a three-layer stacked on-chip transformer structure, which overcomes the problem of large transformer layout area; at the same time, the reuse of on-chip transformers can greatly reduce the device area.
[0061] The effectiveness of the present invention is illustrated below through some experimental data.
[0062] For example, Figure 6 1 is a schematic diagram of changes in the inductance L1 of the first on-chip transformer under different voltage differences provided by an embodiment of the present invention; Figure 7 Schematic diagram of the change of the inductance L2 value of the second on-chip transformer under different voltage differences provided by the embodiment of the present invention. Figure 6 、 7 In the figure, the horizontal axis represents the operating frequency of the inductor, the vertical axis represents the corresponding inductance value, and the curve represents the change curve of the inductance; Figure 6 、 7 The black dotted line in the figure indicates that the inductance value is 0, and the intersection frequency with the inductance change curve is the self-resonant frequency. Figure 6 As shown in the figure, in modulation mode, when the voltage difference between the first on-chip transformer and the auxiliary inductor increases from 0.1 to 2.2, the self-resonant frequency of the inductor L1 of the first on-chip transformer increases from 30.7 GHz to 47.7 GHz due to the magnetic coupling effect, and the applicable frequency range of the inductor is expanded by 17.0 GHz. Figure 7 As shown, when the voltage difference between the second on-chip transformer and the auxiliary inductor increases from 0.1 to 2.2, the self-resonant frequency of the inductor L2 of the second on-chip transformer increases from 31.1 GHz to 47.5 GHz, and the applicable frequency range of the inductor is expanded by 16.4 GHz.
[0063] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.
[0064] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.
[0065] In the specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.
[0066] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.
Claims
1. An on-chip transformer structure with tunable self-resonant frequency, characterized in that: include: Auxiliary inductor; a first on-chip transformer stacked on the auxiliary inductor; a second on-chip transformer stacked below the auxiliary inductor; A first dielectric layer is provided between the first on-chip transformer and the auxiliary inductor, and a second dielectric layer is provided between the second on-chip transformer and the auxiliary inductor; the first on-chip transformer, the auxiliary inductor and the second on-chip transformer all have electrical leads, the electrical leads of the first on-chip transformer and the second on-chip transformer are used to connect to a controlled source, and the electrical leads of the auxiliary inductor are used to connect to a modulation source, wherein the modulation source is used to tune the self-resonant frequency of the first on-chip transformer by regulating the voltage difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the first on-chip transformer, and to tune the self-resonant frequency of the second on-chip transformer by regulating the voltage difference between the voltage between the electrical leads of the auxiliary inductor and the voltage between the electrical leads of the second on-chip transformer.
2. The on-chip transformer structure according to claim 1, characterized in that: The thickness of the first dielectric layer is the same as that of the second dielectric layer. The shapes of the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are all symmetrical. Moreover, the shape of the first on-chip transformer is the same as that of the second on-chip transformer.
3. The on-chip transformer structure according to claim 1, wherein: The first on-chip transformer and the second on-chip transformer have the same inductance value.
4. The on-chip transformer structure according to claim 1, wherein: The direction in which the first on-chip transformer, the auxiliary inductor, and the second on-chip transformer are stacked on each other is a first direction. The first on-chip transformer, the auxiliary inductor, and the second on-chip transformer each have two electrical leads, wherein the two electrical leads of the first on-chip transformer and the two electrical leads of the second on-chip transformer are located on the same side and are adjacent to each other in the upper and lower directions along the first direction, and the two electrical leads of the auxiliary inductor are located on opposite sides of the two electrical leads of the first on-chip transformer and the second on-chip transformer, wherein the first electrical lead of the auxiliary inductor is adjacent to the first electrical lead of the first on-chip transformer. The first electrical lead-out terminal of the auxiliary inductor and the first electrical lead-out terminal of the second on-chip transformer are all axially symmetrical, and the second electrical lead-out terminal of the auxiliary inductor is axially symmetrical with the second electrical lead-out terminal of the first on-chip transformer and the second electrical lead-out terminal of the second on-chip transformer; the first electrical lead-out terminal of the first on-chip transformer and the first electrical lead-out terminal of the second on-chip transformer are both used to connect to a controlled source, the first electrical lead-out terminal of the auxiliary inductor is used to connect to a modulation source, and the second electrical lead-out terminal of the first on-chip transformer, the second electrical lead-out terminal of the second on-chip transformer and the second electrical lead-out terminal of the auxiliary inductor are all used to be grounded.
5. The on-chip transformer structure according to claim 1, wherein: The controlled source and the modulation source are both AC power sources, and the amplitude and phase of the modulation source are adjustable.
6. The on-chip transformer structure according to claim 1, wherein: The voltage difference is negatively correlated with the inductance value, and is positively correlated with the self-resonant frequency.
7. The on-chip transformer structure according to claim 1, wherein: The first on-chip transformer and the second on-chip transformer are both one-turn or multi-turn inductors, and the auxiliary inductor is one-turn or multi-turn inductor.
8. The on-chip transformer structure according to claim 1, wherein: The modulation source is used to adjust the amplitude ratio and / or phase difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the first on-chip transformer / the second on-chip transformer by adjusting the amplitude and / or phase of the voltage between the electrical lead terminals of the auxiliary inductor, so as to tune the self-resonant frequency of the first on-chip transformer / the second on-chip transformer.
9. A method for tuning the self-resonant frequency of an on-chip transformer structure with tunable self-resonant frequency, characterized in that: Applied to the on-chip transformer structure according to any one of claims 1 to 8, the method comprises: Connecting the controlled source to the first on-chip transformer and the second on-chip transformer respectively, and connecting the modulation source to the auxiliary inductor; When the self-resonant frequencies of the first on-chip transformer and the second on-chip transformer need to be increased, the modulation source is controlled to increase the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the first on-chip transformer, thereby increasing the self-resonant frequency of the first on-chip transformer; and the modulation source is controlled to increase the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the second on-chip transformer, thereby increasing the self-resonant frequency of the second on-chip transformer; When it is necessary to reduce the self-resonant frequencies of the first on-chip transformer and the second on-chip transformer, the voltage difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer is reduced by regulating the modulation source to reduce the self-resonant frequency of the first on-chip transformer, and the voltage difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the second on-chip transformer is reduced by regulating the modulation source to reduce the self-resonant frequency of the second on-chip transformer.
10. The self-resonant frequency tuning method according to claim 9, wherein: The increasing the voltage difference between the voltage between the electrical lead terminals of the auxiliary inductor and the voltage between the electrical lead terminals of the first on-chip transformer by regulating the modulation source to increase the self-resonant frequency of the first on-chip transformer includes: The amplitude and / or phase of the voltage between the electrical lead-out terminals of the auxiliary inductor are increased by regulating the modulation source; the amplitude ratio and / or phase difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer are increased by increasing the amplitude ratio and / or phase difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer; and the self-resonant frequency of the first on-chip transformer is increased by increasing the amplitude ratio and / or phase difference between the voltage between the electrical lead-out terminals of the auxiliary inductor and the voltage between the electrical lead-out terminals of the first on-chip transformer.