CN220172349U - Balun and radio frequency front end module - Google Patents

Abstract

The utility model discloses a balun and a radio frequency front end module, and relates to the technical field of radio frequency. Comprising the following steps: a primary winding including a plurality of primary coils respectively provided on the plurality of metal layers, the plurality of primary coils being connected in parallel; a secondary winding including a plurality of inner secondary coils and a plurality of outer secondary coils respectively provided on the plurality of metal layers, the plurality of inner secondary coils being connected in parallel, the plurality of outer secondary coils being connected in parallel, the inner secondary coils and the outer secondary coils being connected in series on the same metal layer; the primary coil and the inner secondary coil are coupled with the narrow side of the outer secondary coil. The coils of the primary winding and the secondary winding of the balun are arranged on a plurality of metal layers, an inner secondary coil is arranged on the inner side of the primary coil, an outer secondary coil is arranged on the outer side of the primary coil, and the inner secondary coil and the outer secondary coil which are positioned on the same metal layer are coupled with the same narrow side of the primary coil, so that the balun has higher coupling degree and amplitude-phase balance.

Description

Balun and radio frequency front end module

Technical Field

The utility model relates to the technical field of radio frequency, in particular to a balun and a radio frequency front-end module.

Background

Balun (Balun, also known as a balanced feed converter or transmission line balancer) is a key component of balanced circuit layout for filters, microwave balanced mixers, frequency multipliers, push-pull amplifiers and antenna feed networks.

In the related art, the broadside-coupled balun has high coupling. However, when the broadside coupling balun is used for high-frequency signal transmission, a large parasitic capacitance exists between the primary winding and the secondary winding, so that the balun has poor phase equilibrium, and the performance of the balun cannot meet the practical application demands of people.

Disclosure of Invention

The utility model provides a balun and a radio frequency front-end module.

In a first aspect, an embodiment of the present utility model provides a balun, including: the primary winding comprises a plurality of primary coils, the plurality of primary coils are respectively arranged on a plurality of metal layers, the plurality of primary coils are connected in parallel, and the plurality of metal layers are positioned on different planes; the secondary winding comprises a plurality of inner side secondary coils and a plurality of outer side secondary coils, the inner side secondary coils and the outer side secondary coils are respectively arranged on the metal layers, each inner side secondary coil is positioned on the inner side of the primary coil on the metal layer, each outer side secondary coil is positioned on the outer side of the primary coil on the metal layer, the inner side secondary coils are connected in parallel, the outer side secondary coils are connected in parallel, and the inner side secondary coils on the same metal layer are connected in series with the outer side secondary coils; the primary coil and the inner secondary coil are coupled with the same narrow side of the layer.

Optionally, the plurality of metal layers includes a first metal layer and a second metal layer, the plurality of primary coils includes a first primary coil and a second primary coil, the plurality of inner secondary coils includes a first secondary coil and a second secondary coil, and the plurality of outer secondary coils includes a third secondary coil and a fourth secondary coil; the first primary coil is positioned on the first metal layer, the second primary coil is positioned on the second metal layer, and the first primary coil and the second primary coil are connected in parallel; the first secondary coil is positioned on the first metal layer, the second secondary coil is positioned on the second metal layer, the first secondary coil is connected with the second secondary coil in parallel, the first secondary coil is positioned on the inner side of the first primary coil, and the second secondary coil is positioned on the inner side of the second primary coil; the third secondary coil is located on the first metal layer, the fourth secondary coil is located on the second metal layer, the third secondary coil is connected with the fourth secondary coil in parallel, the third secondary coil is located on the outer side of the first primary coil, and the fourth secondary coil is located on the outer side of the second primary coil.

Optionally, the first secondary coil is connected in series with the third secondary coil through a jumper wire provided at a third metal layer, and the second secondary coil is connected in series with the fourth secondary coil through the jumper wire; the first secondary coil and the third secondary coil are coupled with the first primary coil at the same layer narrow side, and the second secondary coil and the fourth secondary coil are coupled with the second primary coil at the same layer narrow side.

Optionally, there is no overlapping area of the projection of the first primary coil located at the first metal layer and the second secondary coil and the fourth secondary coil located at the second metal layer in the vertical direction, and there is no overlapping area of the projection of the second primary coil located at the second metal layer and the first secondary coil and the third secondary coil located at the first metal layer in the vertical direction.

Optionally, the balun includes a first input end, a second input end, a first output end, and a second output end; the first primary coil comprises a first end and a second end, the second primary coil comprises a first end and a second end, the first end of the first primary coil is connected with the first input end of the balun, and the second end of the second primary coil is connected with the second input end of the balun; the first secondary coil comprises a first end and a second end, the second secondary coil comprises a first end and a second end, the third secondary coil comprises a first end and a second end, the fourth secondary coil comprises a first end and a second end, the first end of the first secondary coil and the first end of the second secondary coil are connected with the first output end of the balun, the second end of the first secondary coil is connected with the first end of the third secondary coil, the second end of the second secondary coil is connected with the first end of the fourth secondary coil, and the second end of the third secondary coil and the second end of the fourth secondary coil are connected with the second output end of the balun.

Optionally, the first output terminal of the balun is a ground terminal, the second output terminal of the balun is a signal output terminal, the first terminal of the first secondary coil and the first terminal of the second secondary coil are located within a surrounding area defined by the primary winding, and the second terminal of the third secondary coil and the second terminal of the fourth secondary coil are located outside the surrounding area defined by the primary winding.

Optionally, the midpoints of the plurality of primary coils have a center tap, the center taps of the plurality of primary coils are connected, and the center taps of the plurality of primary coils are grounded through a through hole.

Alternatively, the plurality of primary coils are connected in parallel through the through-holes, the plurality of inner secondary coils are connected in parallel through the through-holes, and the plurality of outer secondary coils are connected in parallel through the through-holes.

Optionally, the coil winding shape of the primary winding is at least one of square, octagonal, or circular with the coil winding shape of the secondary winding, and the coil winding shape of the primary winding is the same as the coil winding shape of the secondary winding.

In a second aspect, an embodiment of the present utility model provides a radio frequency front end module, including the balun.

The balun provided by the embodiment of the utility model comprises the following components: the primary winding comprises a plurality of primary coils, the plurality of primary coils are respectively arranged on a plurality of metal layers, the plurality of primary coils are connected in parallel, and the plurality of metal layers are positioned on different planes; the secondary winding comprises a plurality of inner side secondary coils and a plurality of outer side secondary coils, the inner side secondary coils and the outer side secondary coils are respectively arranged on the metal layers, each inner side secondary coil is positioned at the inner side of the primary coil on the metal layer, each outer side secondary coil is positioned at the outer side of the primary coil on the metal layer, the inner side secondary coils are connected in parallel, the outer side secondary coils are connected in parallel, and the inner side secondary coils and the outer side secondary coils on the same metal layer are connected in series; the primary coil and the inner secondary coil are coupled with the narrow side of the outer secondary coil. In the utility model, the primary winding coil and the secondary winding coil of the balun are arranged on a plurality of metal layers, the inner side of the primary winding is provided with the inner side secondary coil, the outer side of the primary winding is provided with the outer side secondary coil, and the inner side secondary coil and the outer side secondary coil which are positioned on the same metal layer are coupled with the same narrow side of the primary winding, so that parasitic capacitance between the primary winding and the secondary winding can be reduced, the balun has higher coupling degree, and the balun insertion loss can be reduced by the higher coupling degree. Meanwhile, the balun has better amplitude-phase balance by reducing parasitic capacitance between the primary winding and the secondary winding.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows a schematic structural diagram of a balun according to an embodiment of the present utility model.

Fig. 2 shows a schematic cross-sectional view of the balun provided in fig. 1 of the present utility model.

Fig. 3 shows a front view of a balun provided by another embodiment of the present utility model.

Fig. 4 shows a back view of the balun provided in fig. 3 according to the present utility model.

Fig. 5 shows a schematic circuit diagram of a balun according to an embodiment of the present utility model.

Fig. 6 is a schematic structural diagram of a rf front-end module according to an embodiment of the utility model.

Detailed Description

In order to enable those skilled in the art to better understand the present utility model, a clear and complete description of the technical solution in the present embodiment will be provided below with reference to the accompanying drawings in the present embodiment. It will be apparent that the described embodiments are only some, but not all, embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The terms "first," "second," and the like in this disclosure are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a balun 1 according to an embodiment of the utility model. The balun 1 provided by the embodiment of the present utility model will be described in detail with reference to fig. 1. The balun 1 of the present embodiment includes a primary winding 10 and a secondary winding 20.

The balun 1 is a device for converting unbalanced signals into balanced signals or converting balanced signals into unbalanced signals by utilizing electromagnetic mutual induction, and the two balanced output phases are 180 degrees different to realize voltage, current and impedance transformation. Balun 1 may be used in push-pull amplifiers, broadband antennas, balanced mixers, balanced multipliers and modulators, phase shifters, and any circuit configuration where it is desirable to transmit equal amplitude and 180 degrees phase difference over two lines.

In the present embodiment, the primary winding 10 includes a plurality of primary coils 11, and the plurality of primary coils 11 are respectively disposed on a plurality of metal layers, which are in different planes. The number of primary coils 11 in the primary winding 10 is at least two, and the metal layer may be a metal layer on the substrate or a metal layer on the chip, which is not limited herein.

Further, the secondary winding 20 includes a plurality of inner secondary coils 21 and a plurality of outer secondary coils 22, the number of the inner secondary coils 21 in the secondary winding 20 is at least two, the number of the outer secondary coils 22 in the secondary winding 20 is at least two, and the number of the inner secondary coils 21 and the number of the primary coils 11 and the number of the outer secondary coils 22 and the number of the primary coils 11 in the balun 1 may be equal. The plurality of inner secondary coils 21 and the plurality of outer secondary coils 22 are respectively arranged on the plurality of metal layers, each inner secondary coil 21 is positioned on the inner side of the primary coil 11 on the metal layer, each outer secondary coil 22 is positioned on the outer side of the primary coil 11 on the metal layer, namely, the inner side and the outer side of the primary coil 11 in each metal layer are respectively provided with the secondary coils. Fig. 1 shows the coil circuit arrangement of the primary winding 10 and the secondary winding 20 of the balun 1 in one metal layer, and the coil circuit arrangement of the primary winding 10 and the secondary winding 20 in the remaining metal layers is identical to the metal layer.

Alternatively, the plurality of primary coils 11 are connected in parallel, the plurality of inner secondary coils 21 are connected in parallel, the plurality of outer secondary coils 22 are connected in parallel, and the inner secondary coils 21 and the outer secondary coils 22 on the same metal layer are connected in series. The inner side and the outer side of the primary coil 11 in each metal layer are respectively provided with a secondary coil, and the inner side secondary coil 21 and the outer side secondary coil 22 which are positioned on the same metal layer are coupled with the same layer narrow side of the primary coil 11, so that the coupling degree between the primary winding 10 and the secondary winding 20 is improved, the coupling coefficient of the balun 1 is improved in the embodiment, and the insertion loss of the balun 1 can be reduced due to the higher coupling degree. The coils of the plurality of metal layers may be connected in parallel by through holes, that is, the plurality of primary coils 11 of the balun 1 are connected in parallel by through holes, the plurality of inner secondary coils 21 are connected in parallel by through holes, and the plurality of outer secondary coils 22 are connected in parallel by through holes.

As shown in fig. 2, fig. 2 shows a schematic cross-sectional view of the balun 1 provided in fig. 1 according to the present utility model. In this embodiment, the primary winding 10 and the secondary winding 20 of the balun 1 are disposed on a plurality of metal layers, and the inner side of the primary winding 11 of the primary winding 10 in the same metal layer is provided with the inner side secondary winding 21 of the secondary winding 20, and the outer side of the primary winding 11 is provided with the outer side secondary winding 22, so that the balun 1 has a higher coupling degree by adopting the same-layer narrow-side coupling mode between the primary winding 10 and the secondary winding 20. Compared with the prior art in which the balun 1 adopts upper and lower layers of broadside coupling, in this embodiment, when the balun 1 is coupled with a layer of broadside, there is no overlapping area in the projection between the primary winding 10 coil and the secondary winding 20 coil in the vertical direction, and the gap between the primary winding 10 coil and the secondary winding 20 coil is larger, so that the parasitic capacitance between the primary winding 10 coil and the secondary winding 20 coil can be reduced.

It should be noted that the parasitic capacitance between the primary winding 10 and the secondary winding 20 is a non-ideal factor, i.e., should not be present in the ideal balun 1. The ideal balun 1 is magnetic coupling, and the parasitic capacitance directly brings about electric coupling from the primary winding 10 to the secondary winding 20, and the electric coupling causes a phase difference of balun input or output to deviate by 180 degrees, and the relative amplitude deviates from the ideal amplitude, so that the amplitude-phase balance of the balun 1 is influenced.

Based on this, the balun 1 of the present embodiment reduces the parasitic capacitance between the primary winding 10 and the secondary winding 20 in the balun 1 while having a higher coupling degree, and the reduction of the parasitic capacitance between the windings makes the balun 1 less interfering with signals in the signal transmission process, so that good amplitude balance and phase balance characteristics of the balun 1 are maintained. Therefore, the differential signal of the balun 1 can be close to an ideal amplitude phase state in the signal transmission process, so that the balun 1 of the embodiment has good amplitude phase balance and keeps low synthesis loss.

Note that, in the balun 1 of the present embodiment, the coil winding shape of the primary winding 10 and the coil winding shape of the secondary winding 20 are at least one of square, octagonal, or circular, and the coil winding shape of the primary winding 10 and the coil winding shape of the secondary winding 20 are not limited herein.

The balun 1 of the embodiment of the utility model comprises: a primary winding 10, the primary winding 10 including a plurality of primary coils 11, the plurality of primary coils 11 being disposed on a plurality of metal layers, respectively, and the plurality of primary coils 11 being connected in parallel, the plurality of metal layers being in different planes; a secondary winding 20, the secondary winding 20 including a plurality of inside secondary coils 21 and a plurality of outside secondary coils 22, the plurality of inside secondary coils 21 and the plurality of outside secondary coils 22 being respectively disposed on a plurality of metal layers, each inside secondary coil 21 being located inside the primary coil 11 on the metal layer, each outside secondary coil 22 being located outside the primary coil 11 on the metal layer, the plurality of inside secondary coils 21 being connected in parallel, the plurality of outside secondary coils 22 being connected in parallel, the inside secondary coils 21 on the same metal layer being connected in series with the outside secondary coils 22; the primary coil 11 and the inner secondary coil 21 and the outer secondary coil 22, which are located in the same metal layer, are coupled with the narrow sides of the layers. Based on the above, the primary winding 10 and the secondary winding 20 of the balun 1 are arranged on a plurality of metal layers, the inner side of the primary winding 11 is provided with an inner side secondary winding 21, the outer side is provided with an outer side secondary winding 22, the inner side secondary winding 21 and the outer side secondary winding 22 which are positioned on the same metal layer are coupled with the same layer narrow side of the primary winding 11, and the primary winding 10 and the secondary winding 20 are coupled by adopting the same layer narrow side, so that the balun 1 has higher coupling degree, and the insertion loss of the balun 1 is reduced; meanwhile, the parasitic capacitance between the primary winding 10 and the secondary winding 20 in the balun 1 is reduced, and the reduction of the parasitic capacitance between the windings enables the balun 1 to have better amplitude-phase balance.

Referring to fig. 3, fig. 3 is a front view of a balun according to another embodiment of the present utility model. As shown in fig. 3, the balun of the present embodiment includes a primary winding 10 and a secondary winding 20.

In the present embodiment, when the primary winding 10 and the secondary winding 20 in the balun are disposed on the first metal layer, the primary winding 10 is provided with the first primary coil 12 in the first metal layer, and the secondary winding 20 is provided with the first secondary coil 23 and the third secondary coil 25 in the first metal layer.

Alternatively, the first secondary coil 23 is located inside the first primary coil 12, and the third secondary coil 25 is located outside the first primary coil 12. The first secondary coil 23 is connected in series with the third secondary coil 25 by a jumper 40 provided at the third metal layer, and the first secondary coil 23 and the third secondary coil 25 are coupled with the first primary coil 12 at the same layer narrow side. The connection between the inner secondary winding and the outer secondary winding in the secondary winding 20 by the jumper 40 is not limited herein.

As shown in fig. 4, fig. 4 shows a back view of the balun provided by fig. 3 of the present utility model. Specifically, when the primary winding 10 and the secondary winding 20 in the balun are disposed on the second metal layer, the primary winding 10 is provided with the second primary coil 13 in the second metal layer, and the secondary winding 20 is provided with the second secondary coil 24 and the fourth secondary coil 26 in the second metal layer.

Alternatively, the second secondary coil 24 is located inside the second primary coil 13, and the fourth secondary coil 26 is located outside the second primary coil 13. The second secondary coil 24 is connected in series with the fourth secondary coil 26 by a jumper 40 provided at the third metal layer, and the second secondary coil 24 and the fourth secondary coil 26 are coupled with the second primary coil 13 at the same layer narrow side.

Further, the first primary coil 12 and the second primary coil 13 in the primary winding 10 are connected in parallel. In the secondary winding 20, a first secondary coil 23 is connected in parallel with a second secondary coil 24, and a third secondary coil 25 is connected in parallel with a fourth secondary coil 26.

It should be noted that, there is no overlapping area between the projections of the first primary coil 12 located in the first metal layer and the second secondary coil 24 and the fourth secondary coil 26 located in the second metal layer in the vertical direction, and there is no overlapping area between the projections of the second primary coil 13 located in the second metal layer and the first secondary coil 23 and the third secondary coil 25 located in the first metal layer in the vertical direction. That is, the primary winding 10 and the secondary winding 20 of which the coils are in the same layer are not overlapped in the vertical direction, and the primary winding 10 and the secondary winding 20 of which the coils are in different metal layers are also not overlapped in the vertical direction.

In the present embodiment, by disposing the primary winding 10 and the secondary winding 20 on two metal layers, the inner side and the outer side of the first primary winding 12 in the first metal layer are respectively provided with a first secondary winding 23 and a third secondary winding 25 coupled with the same layer narrow side thereof, and the first secondary winding 23 is connected in series with the third secondary winding 25; the inner side and the outer side of the second primary coil 13 in the second metal layer are respectively provided with a second secondary coil 24 and a fourth secondary coil 26 which are coupled with the same side, and the second secondary coil 24 and the fourth secondary coil 26 are connected in series, so that the balun has higher coupling degree, parasitic capacitance between the primary winding 10 and the secondary winding 20 of the balun is reduced, and the amplitude-phase balance of the balun is improved.

Further, the center point of the first primary coil 12 and the center point of the second primary coil 13 each have a center tap 14, and the center tap 14 of the first primary coil 12 is connected to the center tap 14 of the second primary coil 13 and grounded through a through hole, so the balun of the present embodiment can further improve balance by providing the grounded center tap 14 in the primary winding 10 and provide the balun with a better common mode rejection degree.

The coils in the primary winding 10 and the secondary winding 20 may be formed of metal wires having a certain length and width, and the smaller the line width of the coil, the larger the inductance of the coil when the material and length of the metal wires constituting the coil are fixed. In at least one embodiment, the impedance transformation that can be achieved by the balun is related to the number of turns or inductance of the primary winding 10 and the secondary winding 20 of the balun. In the case where the number of turns or inductance of the primary winding 10 is unchanged, the number of turns or inductance of the secondary winding 20 increases, and the turns ratio between the secondary winding 20 and the primary winding 10 of the balun increases, so that the impedance conversion ratio achievable by the balun increases. Conversely, in the case where the number of turns or inductance of the secondary winding 20 is unchanged, the number of turns or inductance of the primary winding 10 increases, and the turns ratio between the secondary winding 20 and the primary winding 10 of the balun decreases accordingly, so does the impedance conversion ratio that the balun can achieve. Compared with the balun in the related art in which the primary winding 10 coil and the secondary winding 20 coil are broadside coupled in upper and lower layers, since the primary winding 10 coil and the secondary winding 20 coil in the same metal layer are broadside coupled in the same layer, in the embodiment, when the line width of the primary winding 10 coil or the secondary winding 20 coil of the balun is adjusted, only the line width of the primary winding 10 or only the line width of the secondary winding 20 can be adjusted, so that the adjustment of impedance is realized, and the line widths of the primary winding 10 and the secondary winding 20 do not need to be adjusted at the same time. In the related art, since the primary winding 10 and the secondary winding 20 are broadside coupled in the upper and lower layers, if only the line width of the primary winding 10 is adjusted or only the line width of the secondary winding 20 is adjusted, the coupling degree is affected although the adjustment of the impedance can be also achieved. In this embodiment, the primary winding 10 and the secondary winding 20 are both coupled by the same layer and narrow side, so that the influence on the coupling between the primary winding 10 and the secondary winding 20 of the balun is small, and the balun of the present utility model is convenient for arbitrarily setting the impedance ratio of the primary winding 10 and the secondary winding 20 by adjusting the line width of the coil, thereby obtaining the balun with any required impedance ratio.

Optionally, the balun comprises a first input 31, a second input 32, a first output 33 and a second output 34. In a specific embodiment, as shown in fig. 5, fig. 5 shows a schematic circuit diagram of a balun according to an embodiment of the present utility model.

Specifically, the balun includes a primary winding 10, a secondary winding 20, a first input 31, a second input 32, a first output 33, and a second output 34. The first end of the primary winding 10 is connected to the first input 31, the second end of the primary winding 10 is connected to the second input 32, the first end of the secondary winding 20 is connected to the first output 33, the second end of the primary winding 10 is connected to the second output 34, the first output 33 of the balun is a ground terminal, and the second output 34 of the balun is a signal output terminal. In other embodiments, the primary winding 10 in balun is connected to the first output 33 and the second output 34, and the secondary winding 20 is connected to the first input 31 and the second input 32, without limitation.

In the present embodiment, the first primary coil 12 in the primary winding 10 includes a first end and a second end, the second primary coil 13 includes a first end and a second end, and the first end of the first primary coil 12 is connected to the first input terminal 31 of the balun, and the second end of the second primary coil 13 is connected to the second input terminal 32 of the balun. The first secondary winding 23 of the secondary winding 20 includes a first end and a second end, the second secondary winding 24 includes a first end and a second end, the third secondary winding 25 includes a first end and a second end, and the fourth secondary winding 26 includes a first end and a second end. The first end of the first secondary coil 23 and the first end of the second secondary coil 24 are connected to the first output end 33 of the balun, the second end of the first secondary coil 23 is connected to the first end of the third secondary coil 25, the second end of the second secondary coil 24 is connected to the first end of the fourth secondary coil 26, and the second end of the third secondary coil 25 and the second end of the fourth secondary coil 26 are connected to the second output end 34 of the balun.

Optionally, the first end of the first secondary coil 23 and the first end of the second secondary coil 24 are located within the surrounding area defined by the primary winding 10, and the second end of the third secondary coil 25 and the second end of the fourth secondary coil 26 are located outside the surrounding area defined by the primary winding 10.

It should be noted that, in the present embodiment, the second end of the third secondary coil 25 and the second end of the fourth secondary coil 26 are connected to the second output end 34 of the balun, the second output end 34 of the balun is a signal output end, and the second end of the third secondary coil 25 and the second end of the fourth secondary coil 26 are located outside the surrounding area defined by the primary winding 10, and at this time, the balun may be directly connected when connected to an external electronic component. In other embodiments, the first output 33 of the balun is a signal output, the second output 34 of the balun is a ground, the first end of the first secondary coil 23 and the first end of the second secondary coil 24 in the balun are connected to the signal output, and the first end of the first secondary coil 23 and the first end of the second secondary coil 24 are located within the surrounding area defined by the primary winding 10, where the signal output of the balun needs to be connected to an external electronic component through a jumper 40 when the balun is connected to the external electronic component.

In this embodiment, the primary winding 10 and the secondary winding 20 are disposed on multiple metal layers, the inner side of the primary winding 11 is provided with an inner side secondary winding 21, the outer side is provided with an outer side secondary winding 22, and the inner side secondary winding and the outer side secondary winding on the same metal layer are both coupled with the same layer narrow side of the primary winding, so that the balun has higher coupling degree, parasitic capacitance between the primary winding 10 and the secondary winding 20 of the balun can be reduced, and the amplitude-phase balance of the balun is improved; at the same time, the balance is further improved by arranging a grounded center tap 14 in the coil of the primary winding 10, and the balun has a better common mode rejection degree; in addition, in the present embodiment, when the line width of the coil in the primary winding 10 or the secondary winding 20 of the balun is adjusted, the influence on the performance of the balun is small, so that the impedance ratio of the primary winding 10 to the secondary winding 20 can be arbitrarily set by adjusting the line width.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a rf front-end module 2 according to an embodiment of the utility model. As shown in fig. 6, the rf front-end module 2 provided in this embodiment includes the balun 1 of the above embodiment.

In some specific embodiments, the balun 1 may be applied to a radio frequency front end module 2, where the radio frequency front end module 2 is an element that integrates two or more discrete devices such as a radio frequency switch, a low noise amplifier, a filter, a duplexer, a power amplifier, etc. into a single module, so as to improve the integration level and hardware performance, and reduce the size. Specifically, the present utility model relates to a method for manufacturing a semiconductor device. A radio frequency front-end module can be applied to 4G and 5G communication equipment such as smart phones, tablet computers, smart watches and the like.

The above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be appreciated by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not drive the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims (10)

1. A balun, characterized in that it comprises:

the primary winding comprises a plurality of primary coils, the plurality of primary coils are respectively arranged on a plurality of metal layers, the plurality of primary coils are connected in parallel, and the plurality of metal layers are positioned on different planes;

the secondary winding comprises a plurality of inner side secondary coils and a plurality of outer side secondary coils, the inner side secondary coils and the outer side secondary coils are respectively arranged on the metal layers, each inner side secondary coil is positioned on the inner side of the primary coil on the metal layer, each outer side secondary coil is positioned on the outer side of the primary coil on the metal layer, the inner side secondary coils are connected in parallel, the outer side secondary coils are connected in parallel, and the inner side secondary coils on the same metal layer are connected in series with the outer side secondary coils;

the primary coil and the inner secondary coil are coupled with the same narrow side of the layer.

2. The balun of claim 1, wherein the plurality of metal layers comprises a first metal layer and a second metal layer, the plurality of primary coils comprises a first primary coil and a second primary coil, the plurality of inner secondary coils comprises a first secondary coil and a second secondary coil, and the plurality of outer secondary coils comprises a third secondary coil and a fourth secondary coil;

the first primary coil is positioned on the first metal layer, the second primary coil is positioned on the second metal layer, and the first primary coil and the second primary coil are connected in parallel;

the first secondary coil is positioned on the first metal layer, the second secondary coil is positioned on the second metal layer, the first secondary coil is connected with the second secondary coil in parallel, the first secondary coil is positioned on the inner side of the first primary coil, and the second secondary coil is positioned on the inner side of the second primary coil;

the third secondary coil is located on the first metal layer, the fourth secondary coil is located on the second metal layer, the third secondary coil is connected with the fourth secondary coil in parallel, the third secondary coil is located on the outer side of the first primary coil, and the fourth secondary coil is located on the outer side of the second primary coil.

3. Balun according to claim 2, characterized in that the first secondary coil is connected in series with the third secondary coil by means of a jumper provided at a third metal layer, and the second secondary coil is connected in series with the fourth secondary coil by means of the jumper;

the first secondary coil and the third secondary coil are coupled with the first primary coil at the same layer narrow side, and the second secondary coil and the fourth secondary coil are coupled with the second primary coil at the same layer narrow side.

4. Balun according to claim 2, characterized in that there is no overlap of the projections of the first primary coil at the first metal layer and the second secondary coil and the fourth secondary coil at the second metal layer in the vertical direction, and there is no overlap of the projections of the second primary coil at the second metal layer and the first secondary coil and the third secondary coil at the first metal layer in the vertical direction.

5. Balun according to claim 2, characterized in that it comprises a first input, a second input, a first output and a second output;

the first primary coil comprises a first end and a second end, the second primary coil comprises a first end and a second end, the first end of the first primary coil is connected with the first input end of the balun, and the second end of the second primary coil is connected with the second input end of the balun;

the first secondary coil comprises a first end and a second end, the second secondary coil comprises a first end and a second end, the third secondary coil comprises a first end and a second end, the fourth secondary coil comprises a first end and a second end, the first end of the first secondary coil and the first end of the second secondary coil are connected with the first output end of the balun, the second end of the first secondary coil is connected with the first end of the third secondary coil, the second end of the second secondary coil is connected with the first end of the fourth secondary coil, and the second end of the third secondary coil and the second end of the fourth secondary coil are connected with the second output end of the balun.

6. Balun according to claim 5, characterized in that,

the first output end of the balun is a grounding end, the second output end of the balun is a signal output end, the first end of the first secondary coil and the first end of the second secondary coil are located in a surrounding area defined by the primary winding, and the second end of the third secondary coil and the second end of the fourth secondary coil are located outside the surrounding area defined by the primary winding.

7. Balun according to any one of claims 1-6, characterized in that the midpoints of the plurality of primary coils are each provided with a center tap, the center taps of the plurality of primary coils are connected, and the center taps of the plurality of primary coils are grounded through vias.

8. Balun according to any one of claims 1-6, characterized in that the plurality of primary coils are connected in parallel by means of through holes, the plurality of inner secondary coils are connected in parallel by means of through holes, and the plurality of outer secondary coils are connected in parallel by means of through holes.

9. Balun according to any of claims 1-6, characterized in that the coil winding shape of the primary winding is at least one of square, octagonal or circular with the coil winding shape of the secondary winding, which is identical to the coil winding shape of the secondary winding.

10. A radio frequency front end module comprising a balun according to any one of claims 1 to 9.