Feedback circuit, multi-port low-noise amplifier and radio frequency front-end module

Abstract

The invention relates to the technical field of amplifiers, and discloses a feedback circuit, a multi-port low noise amplifier and a radio frequency front end module, the feedback circuit comprises a first extension part, a second extension part, a first connection part and an inductor main body; at least two connecting ends are arranged on the first extension part at intervals, and different connecting ends are respectively connected with the first amplification units corresponding to different radio frequency input ports in the multi-port low-noise amplifier; the first connection part is connected with one end of the first extension part and the first end of the second extension part, the first extension part and the second extension part are oppositely arranged, and when current is accessed, the current direction of the first extension part is opposite to that of the second extension part. And the difference between amplification gains of different radio frequency input ports is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of amplifier technology, and in particular to a feedback circuit, a multi-port low noise amplifier and a radio frequency front-end module. BACKGROUND

[0002] In the current multi-port low noise amplifier (LNA) design, in order to support the application of multiple frequency bands, face the increasingly complex carrier aggregation (CA) requirements, in order to meet various complex use scenarios, some radio frequency (RF) inputs of the low noise amplifier are designed to be multiplexed.

[0003] The port multiplexing circuit of the multi-port low noise amplifier in the related scheme has an independent transconductance (gm) amplification unit for each RF input, and any one transconductance amplification unit is connected to a cascode amplification unit through a secondary switch to realize frequency band switching. Each RF input of each frequency band has an independent transconductance amplification unit, and the first to Nth RF inputs and the corresponding transconductance amplification units are selected to be connected to the cascode amplification unit through the switch to realize multiplexing of multiple frequency bands.

[0004] This scheme avoids the insertion loss caused by the input switch and has good noise coefficient performance, but in the inductance layout design of the feedback circuit, due to the different distribution positions of the transconductance amplification units corresponding to different RF inputs, the distances from the inductance connection end connected to the source of different transconductance amplification units to the end of the inductance are different, resulting in different inductance values accessed by different transconductance amplification units, that is, the inductance values accessed by the feedback circuit to different transconductance amplification units are different, so the multi-port low noise amplifier has the problem of unbalanced inductance values provided by the feedback circuit, resulting in inconsistent amplification gains of different RF inputs. SUMMARY

[0005] Therefore, the present application provides a feedback circuit, a multi-port low noise amplifier and a radio frequency front-end module to solve or partially solve the technical problem of unbalanced inductance values provided by the feedback circuit in the related scheme.

[0006] The technical solutions of the present application are as follows: In a first aspect, the present application provides a feedback circuit applied to a multi-port low noise amplifier, comprising: an inductor, the inductor comprising a first extension, a second extension, a first connecting portion and an inductor main body; the first extension is provided with at least two connection terminals at intervals, different connection terminals are connected with different first amplification units corresponding to different radio frequency input ports in the multi-port low noise amplifier respectively; the first connecting portion is connected with one end of the first extension and a first end of the second extension respectively, the first extension and the second extension are oppositely arranged, when current is connected, the current direction of the first extension and the current direction of the second extension are opposite, the magnetic induction lines generated by the first extension and the magnetic induction lines generated by the second extension are partially offset, so that the inductance values of the connection terminal parts of the first extension to the second end of the inductor main body are equal; the first end of the inductor main body is connected with the second extension, and the second end of the inductor main body is connected with a ground terminal.

[0007] The feedback circuit of the present application connects one end of the first extension and the first end of the second extension through the first connecting portion, so that the first extension and the second extension are opposite, when current is connected, the current direction of the first extension and the current direction of the second extension are opposite, according to the right-hand rule, the magnetic induction lines generated by the first extension and the magnetic induction lines generated by the second extension will partially offset, because the longer the connection terminal part from the first extension to the second end of the inductor main body, the more the magnetic induction lines offset, so that the inductance values of the connection terminal parts of the first extension to the second end of the inductor main body are equal, thereby making the inductance values of the first amplification units connected by different radio frequency input ports in the multi-port low noise amplifier equal, solving the problem of unbalanced inductance value provided by the feedback circuit, reducing the difference between the amplification gains of different radio frequency input ports.

[0008] Optionally, the projection of any connection terminal on the first extension along a first direction is located on the second extension, and the first direction is perpendicular to the extension direction of the second extension.

[0009] In this way, since the projection of the connection terminal on the first extension along the first direction is located on the second extension, the interaction effect of the first extension and the second extension when generating a magnetic field can be enhanced.

[0010] Optionally, the inductor further comprises a third extension part and a second connecting part; the third extension part is provided with at least two connection ends at intervals, and different connection ends are connected with different first amplification units corresponding to different radio frequency input ports of the multi-port low noise amplifier respectively; two ends of the second connecting part are connected with a second end of the second extension part and one end of the third extension part respectively, and the second extension part and the third extension part are oppositely arranged; when current is connected, the current direction of the second extension part is opposite to the current direction of the third extension part, and the magnetic induction lines generated by the second extension part and the third extension part partially offset each other, so that the inductance values of the connection line parts from the at least two connection ends on the third extension part to the second end of the inductor main body are equal.

[0011] In this mode, the number of connection ends is expanded by symmetrical arrangement, which can better meet the port number requirement of the multi-port low noise amplifier.

[0012] Optionally, the inductor main body comprises a first connecting part and a coil part, a first end of the first connecting part is connected with the second extension part, a second end of the first connecting part is connected with a first end of the coil part, and a second end of the coil part is connected with the ground end.

[0013] In this mode, the coil part can be arranged at a suitable position in the layout of the multi-port low noise amplifier through the first connecting part, and the coil part can be arranged away from the first extension part, the second extension part and the third extension part, so as to reduce the influence of the coil part on the magnetic field of the first extension part, the second extension part and the third extension part.

[0014] Optionally, when the distance between the coil part and the second extension part is greater than a first threshold value and the first connecting part is perpendicular to the second extension part, the connection position of the first connecting part and the second extension part is located at the center position of the second extension part.

[0015] In this mode, the coil part has less influence on the magnetic field of the first extension part and the third extension part, and the influence on both sides is basically the same, so when the connection position of the first connecting part and the third extension part is located at the center position of the second extension part, the inductance values of the connection line parts from the connection ends on the first extension part to the second end of the inductor main body and the inductance values of the connection line parts from the connection ends on the third extension part to the second end of the inductor main body are equal.

[0016] Optionally, when the distance between the coil part and the second extension part is less than a second threshold value, the connection position of the first connecting part and the second extension part is deviated towards the first extension part or the third extension part.

[0017] In this way, the coil part is close to the second extension part, and the magnetic field of the first extension part and / or the third extension part is offset or enhanced, the connection position of the first connection part and the second extension part is deviated to the first extension part or the third extension part, the magnetic field coupling of the coil part is reduced by the different connection distances on two sides, and the inductance value of the connection end on the first extension part to the connection part of the second end of the inductance main body is equal to the inductance value of the connection end on the third extension part to the connection part of the second end of the inductance main body.

[0018] Optionally, the first connection part and the second extension part are perpendicular, and the deviation direction of the connection position of the first connection part and the second extension part is opposite to the current direction of the wire closest to the second extension part in the coil part.

[0019] In this way, when the first connection part and the second extension part are perpendicular, the wire closest to the second extension part in the coil part has a weakening effect on the magnetic field coupling of the second extension part opposite to it, and therefore the connection position of the first connection part and the second extension part needs to be deviated to a direction opposite to the current direction of the wire closest to the second extension part in the coil part, so as to offset the weakening effect of the magnetic field coupling.

[0020] Optionally, the first connection part is deviated to the first extension part or the third extension part, the current direction of the wire closest to the second extension part in the coil part is opposite to the current direction of the deviated extension part, and the connection position of the first connection part and the second extension part is deviated to a direction away from the deviated extension part.

[0021] In this way, the first connection part can be deviated to the first extension part or the third extension part according to the layout of the inductance part, and if the current direction of the wire closest to the second extension part in the coil part is opposite to the current direction of the deviated extension part, the coupling effect of the coil part has a weakening effect on the inductance value of the connection end connected to the deviated extension part, and therefore the connection position of the first connection part and the second extension part is deviated to a direction away from the deviated extension part, so as to increase the inductance value of the connection end connected to the deviated extension part and ensure that the inductance values of the connection ends connected to the two extension parts are equal.

[0022] Optionally, the first connection part is deviated to the first extension part or the third extension part, the current direction of the wire closest to the second extension part in the coil part is opposite to the current direction of the deviated extension part, and the connection position of the first connection part and the second extension part is deviated to a direction away from the deviated extension part.

[0023] In this way, the coupling effect of the coil part has a strengthening effect on the inductance value of the connection end connected to the deviated extension part, and therefore the connection position of the first connection part and the second extension part is deviated to a direction close to the deviated extension part, so as to reduce the inductance value of the connection end connected to the deviated extension part and ensure that the inductance values of the connection ends connected to the two extension parts are equal.

[0024] Optionally, the distance between the first extension and the second extension is between 15 μm and 25 μm.

[0025] In this way, when the distance between the first extension and the second extension is between 15 μm and 25 μm, the inductance values of the connection ends of different positions on the first extension can be equalized.

[0026] Optionally, the second end of the coil part is connected to the ground end through the first switch, the third end of the coil part is connected to the ground end through the second switch, and the third end of the coil part is located between the first end of the coil part and the second end of the coil part.

[0027] In this way, according to the amplification gain requirement, the first switch and the second switch can be controlled to be closed or opened, so as to change the inductance value, and the flexibility of the feedback circuit is improved.

[0028] Optionally, the coil part comprises a first coil and a second coil, the first end of the first coil is connected to the second end of the first connection part, the second end of the first coil is connected to the first end of the second coil through the second connection part, the second connection part is connected to the ground end through the third switch, and the second end of the second coil is connected to the ground end through the fourth switch.

[0029] In this way, according to the amplification gain requirement, the third switch and the fourth switch can be controlled to be closed or opened, so as to change the inductance value, the flexibility of the feedback circuit is improved, and by adopting the arrangement of two coils, the change amount of the inductance value can be larger.

[0030] In a second aspect, the present application provides a multi-port low-noise amplifier, comprising at least two radio frequency input ports and the feedback circuit according to any one of the first aspect of the present application, each radio frequency input port is connected with a first amplification unit, and the sources of the at least two first amplification units are connected with at least two connection ends in the feedback circuit respectively.

[0031] In a third aspect, the present application provides a radio frequency front-end module, comprising the multi-port low-noise amplifier according to the second aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly express the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0033] Figure 1 The circuit schematic diagram of a multi-port low-noise amplifier in the related art; Figure 2This is a circuit schematic of another multi-port low-noise amplifier in the related technology; Figure 3 This is a schematic diagram of the feedback circuit of a multi-port low-noise amplifier in related technologies; Figure 4 This is a schematic diagram of the structure of a feedback circuit in an embodiment of the present invention; Figure 5 This is a schematic diagram of the electromagnetic cancellation principle of a feedback circuit in an embodiment of the present invention; Figure 6 This is a schematic diagram of the electromagnetic cancellation principle of another feedback circuit in an embodiment of the present invention; Figure 7 This is a schematic diagram of another feedback circuit in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of another feedback circuit in an embodiment of the present invention; Figure 12 This is a simulation result diagram of the inductance when the distance between the first extension and the second extension is different in an embodiment of the present invention; Figure 13 This is a schematic diagram of the inductor structure of a feedback circuit in an embodiment of the present invention; Figure 14 for Figure 13 Simulation results of the inductor in the feedback circuit; Figure 15 This is a schematic diagram of the inductor structure of another feedback circuit in an embodiment of the present invention; Figure 16 for Figure 14 Simulation results of the inductor in the feedback circuit; Figure 17 This is a schematic diagram of the inductor structure of another feedback circuit in an embodiment of the present invention; Figure 18 for Figure 14 Simulation results of the inductor in the feedback circuit; Figure 19 This is a circuit schematic diagram of a multi-port low-noise amplifier in an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1, first extension; 2, first connection; 3, second extension; 4, third extension; 5, inductance body; 51, first connection; 52, coil part; 521, first coil; 522, second coil; 523, second connection; s1, first switch; s2, second switch; s3, third switch; s4, fourth switch; Ls1, first connection end; Ls2, second connection end. DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] In the description of the present application, it should be noted that the terms "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements; it can be wireless connection, or it can be wired connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0038] The conventional two kinds of multi-port low noise amplifiers are shown in Figure 1 and Figure 2 As shown in Figure 1 , the first input uses a single-pole multi-throw switch (Single Pole N Throw, SPNT) to switch the input band; as shown in Figure 2 , the second one has an independent transconductance (transconductance, gm) amplification unit for each radio frequency input port, and through a secondary switch, any one transconductance amplification unit is connected to a cascode amplification unit to realize the switching of the frequency band. Each frequency band has an independent transconductance amplification unit, and the first to Nth radio frequency input ports and the corresponding transconductance amplification units are selected by switching to access the cascode amplification unit, thereby realizing the multiplexing of multiple frequency bands.

[0039] The first multi-port low noise amplifier has the characteristics of simple circuit and small size, but has the disadvantages of switch insertion loss of input, noise figure (NF) deterioration, and increase of input to ground parasitic capacitance due to the presence of off state capacitance (Coff), which increases the difficulty of input matching and degrades the input return loss.

[0040] The second multi-port low noise amplifier avoids the switch insertion loss of the radio frequency input port and has good noise figure performance. However, in the inductor layout design of the feedback circuit, due to the different distribution positions of the transconductance amplification units corresponding to different radio frequency input ports, the distances from the inductor connection ends connected to the sources of different transconductance amplification units to the inductor ends are different, resulting in different inductance values of the inductors connected to different transconductance amplification units, for example, Figure 3 The distance from the inductor connection end connected to the field effect transistor of the transconductance amplification unit connected to the radio frequency input port RF1 to the inductor end is greater than the distance from the inductor connection end connected to the field effect transistor corresponding to the radio frequency input port RF2 to the inductor end, resulting in different inductance values of the inductors connected to the transconductance amplification units corresponding to different radio frequency input ports in the feedback circuit, thereby causing inconsistent amplification gains of different radio frequency input ports.

[0041] In view of the problem of inconsistent amplification gains of different radio frequency input ports of the second multi-port low noise amplifier, the feedback circuit provided by the embodiment of the present application utilizes the electromagnetic cancellation principle to reduce the inductance value difference of the inductors connected to the transconductance amplification units corresponding to the radio frequency input ports, so that the amplification gains of different radio frequency input ports to the input signal tend to be consistent.

[0042] As shown in Figure 4 The feedback circuit provided by the embodiment of the present application is applied to a multi-port low noise amplifier and includes: An inductor includes a first extension 1, a second extension 3, a first connecting part 2, and an inductor main body 5. At least two connection ends are arranged on the first extension 1 at intervals, and different connection ends are connected to first amplification units corresponding to different radio frequency input ports in the multi-port low noise amplifier, respectively. The two ends of the first connecting part 2 are connected to one end of the first extension 1 and the first end of the second extension 3, respectively. The first extension 1 and the second extension 3 are oppositely arranged. When current is connected, the current direction of the first extension 1 is opposite to the current direction of the second extension 3. The magnetic induction lines generated by the first extension 1 and the second extension 3 are partially canceled, so that the inductance values of the connection lines from the at least two connection ends on the first extension 1 to the second end of the inductor main body 5 are equal. The first end of the inductance body 5 is connected with the first extension part 3, and the second end of the inductance body 5 is connected with the ground end.

[0043] Specifically, the first extension part 1 and the second extension part 3 can all adopt the structure of a straight line, a broken line or a wavy line. The connecting ends arranged on the first extension part 1 can be two, three or four, etc. The number of the connecting ends can be set according to actual requirements, and the connecting ends can be arranged at equal distances or at unequal distances.

[0044] In the embodiment of the present application, the "equal inductance value" can be understood as that the difference between the two inductance values is greater than a set minimum value. The set minimum value can be set according to actual accuracy requirements. For example, when the difference between the two inductance values is less than 0.5 pH, the two inductance values are considered equal.

[0045] Figure 4 The structure of the inductance in the embodiment of the present application is shown in the figure. The number of the connecting ends on the first extension part 1 is two, which are a first connecting end Ls1 and a second connecting end Ls2. The first connecting end Ls1 and the second connecting end Ls2 are respectively connected with the source of the field effect transistor in the first amplification unit corresponding to different radio frequency input ports in the multi-port low-noise amplifier.

[0046] According to the actual circuit layout space, as shown in the figure, Figure 4 the connecting position of the inductance body 5 and the second extension part 3 can be located on the side of the second extension part 3 facing the first extension part 1; or, as shown in the figure, Figure 7 the connecting position of the inductance body 5 and the second extension part 3 can be located on the side of the second extension part 3 away from the first extension part 1.

[0047] The length of the connecting line part of the first connecting end Ls1 to the second end of the inductance body 5 is less than the length of the connecting line part of the second connecting end Ls2 to the second end of the inductance body 5. In inductance design, the longer the transmission line is, the greater the inductance value is. Therefore, without considering the magnetic induction line offset, the inductance value of the first connecting end Ls1 to the second end of the inductance body 5 is less than the inductance value of the second connecting end Ls2 to the second end of the inductance body 5.

[0048] In the embodiment of the present application, the first extension part 1 and the second extension part 3 are connected by the first connecting part 2, so that the first extension part 1 and the second extension part 3 are arranged oppositely, and when current is accessed, the current direction of the first extension part 1 is opposite to that of the second extension part 3. According to the right-hand rule, the magnetic induction lines generated by the first extension part 1 and the second extension part 3 will partially cancel each other, and the longer the connecting line part from the connecting end to the second end of the inductor main body 5, the more the magnetic induction lines cancel each other. That is, when the second connecting end Ls2 is connected to the first amplification unit to access current, the first extension part 1 generates more magnetic induction lines to cancel the magnetic induction lines generated by the second extension part 3 than when the first connecting end Ls1 is connected to the first amplification unit.

[0049] In combination Figure 5 and Figure 6 As shown in FIG. 1, the closer the distance S1 between the first extension part 1 and the second extension part 3, the more the magnetic field lines cancel each other, and the greater the degree of cancellation. After the width W1 of the first extension part 1 and the width W2 of the second extension part 3 are determined, the degree of cancellation of the magnetic field lines can be adjusted by adjusting the distance S1 between the first extension part 1 and the second extension part 3, and then the inductance values of the connecting line parts of the first connecting end Ls1 to the inductor main body 5 and the second connecting end Ls2 to the inductor main body 5 are adjusted, so that the inductance values of the connecting line parts of the first connecting end Ls1 to the inductor main body 5 and the second connecting end Ls2 to the inductor main body 5 are equal. Since the first connecting end Ls1 and the second connecting end Ls2 share the same inductor main body 5, the inductance values of the connecting line parts of the first connecting end Ls1 to the second end of the inductor main body 5 and the second connecting end Ls2 to the second end of the inductor main body 5 are also equal, that is, the inductance values accessed by the first connecting end Ls1 and the second connecting end Ls2 are equal.

[0050] Further, the distance between the first extension part 1 and the second extension part 3 is between 15 μm and 25 μm. When the distance between the first extension part 1 and the second extension part 3 is between 15 μm and 25 μm, the inductance values accessed by the connecting ends at different positions on the first extension part 1 can be equal. Wherein the widths of the first extension part 1 and the second extension part 3 are different, the distance between the first extension part 1 and the second extension part 3 will also change. For example, the widths of the first extension part 1 and the second extension part 3 are both 10 μm, and when the distance between the first extension part 1 and the second extension part 3 is 20 μm, the inductance values accessed by the connecting ends at different positions on the first extension part 1 are equal. Or, the widths of the first extension part 1 and the second extension part 3 are both 12 μm, and then the distance between the first extension part 1 and the second extension part 3 can be appropriately increased to 24 μm or 25 μm, so that the inductance values accessed by the connecting ends at different positions on the first extension part 1 are equal.

[0051] In an embodiment, the inductance value of the feedback circuit is verified by simulation software. Figure 12 As shown in FIG. 1, the widths of the first extension 1, the first connecting portion 2 and the third connecting portion are all 10 μm, when the distance S1 between the first extension 1 and the second extension 3 is 30 μm, the inductance value of the connecting portion of the first connecting end Ls1 to the inductance body 5 is equal to 178.1 pH, and the inductance value of the connecting portion of the second connecting end Ls2 to the inductance body 5 is equal to 188.5 pH; when the distance S1 between the first extension 1 and the second extension 3 is 20 μm, the inductance value of the connecting portion of the first connecting end Ls1 to the inductance body 5 is equal to 169.0 pH, and the inductance value of the connecting portion of the second connecting end Ls2 to the inductance body 5 is equal to 170.3 pH, which can be considered as the inductance values of the two connecting ends are equal; when the distance S1 between the first extension 1 and the second extension 3 is 10 μm, the inductance value of the connecting portion of the first connecting end Ls1 to the inductance body 5 is equal to 152.3 pH, and the inductance value of the connecting portion of the second connecting end Ls2 to the inductance body 5 is equal to 170.3 pH.

[0052] The feedback circuit of the embodiment of the present application makes the inductance values of the connecting portions of the at least two connecting ends on the first extension 1 to the second end of the inductance body 5 equal by using the magnetic field line offset principle, so that the inductance values of the first amplification units connected by different radio frequency input ports in the multi-port low noise amplifier are equal, thereby solving the problem of unbalanced inductance value provided by the feedback circuit and reducing the difference between the amplification gains of different radio frequency input ports.

[0053] In some embodiments, the projections of any connecting end on the first extension 1 along the first direction are all located on the second extension 3, and the first direction is perpendicular to the extension direction of the second extension 3.

[0054] The projections of the connecting ends on the first extension 1 along the first direction are all located on the second extension 3, which can make the current on the second extension 3 flow through the connecting ends at different positions, thereby enhancing the interaction effect of the first extension 1 and the second extension 3 when generating a magnetic field, enhancing the offset degree of the magnetic field lines, and the farther the connecting end from the first connecting portion 2, the greater the enhancement effect when the current is connected, thereby more conveniently realizing the same inductance.

[0055] In some embodiments, the inductor further comprises a third extension 4 and a second connecting portion; the third extension 4 is provided with at least two connection ends at intervals; two ends of the second connecting portion are connected with a second end of the second extension 3 and an end of the third extension 4 respectively, the second extension 3 and the third extension 4 are parallel, when current is connected, the current direction of the second extension 3 and the current direction of the third extension 4 are opposite, the magnetic induction lines generated by the second extension 3 and the magnetic induction lines generated by the third extension 4 partially offset, so that the inductance values of the connection lines from the at least two connection ends of the third extension 4 to the second end of the inductor body 5 are equal.

[0056] Specifically, the first connecting portion 2 and the second connecting portion have the same structure, both of which adopt a "U" type structure or a "F" type structure. Through the "U" type structure or the "F" type structure, the first extension 1 and the third extension 4 can be parallel to the second extension 3 respectively, and the first extension 1 and the third extension 4 both overlap the second extension 3 in the first direction, which is beneficial to realize that when current exists, the current direction of the first extension 1 and the current direction of the second extension 3 are opposite, and the current direction of the third extension 4 and the current direction of the second extension 3 are opposite.

[0057] It should be understood that, due to the limitation of layout design, the arc part in the "U" type structure is obtained by chamfering, that is, the arc part in the "U" type structure is actually composed of one or more mutually connected broken lines.

[0058] In an example, the second extension 3 is a smooth line segment, the first extension 1 and the third extension 4 are symmetrically arranged with respect to the central perpendicular line of the second extension 3, and there is a certain interval between the first extension 1 and the third extension 4 to facilitate the connection of the second extension 3 with the inductor body 5.

[0059] In another example, as shown in Figure 6 , the second extension 3 is provided with a stepped structure between the first extension 1 and the third extension 4, which can make the inductor flexibly arranged at different positions of the layout.

[0060] In the present embodiment, by increasing the third extension, the number of connection ends can be expanded, which can better meet the port number requirement of the multi-port low noise amplifier.

[0061] In some embodiments, the inductor body 5 comprises a first connecting portion 51 and a coil portion 52, a first end of the first connecting portion 51 is connected with the second extension 3, a second end of the first connecting portion 51 is connected with a first end of the coil portion 52, and a second end of the coil portion 52 is connected with a ground end.

[0062] Specifically, the first connecting portion 51 can be a straight line segment structure or a broken line structure.

[0063] The coil part 52 is composed of a plurality of coils, and each coil is sequentially connected by a plurality of fold line segments.

[0064] According to the actual circuit layout space, the connection position of the first connecting part 51 and the second extending part 3 can be located on the side of the second extending part 3 away from the first extending part 1, or the connection position of the first connecting part 51 and the second extending part 3 can be located on the side of the second extending part 3 facing the first extending part 1.

[0065] The first connecting part 51 can make the coil part 52 arranged in a suitable position in the multi-port low noise amplifier layout, and can make the coil part 52 away from the first extending part 1, the second extending part 3 and the third extending part 4, and reduce the influence of the coil part 52 on the magnetic field of the first extending part 1, the second extending part 3 and the third extending part 4.

[0066] In some embodiments, the second end of the coil part 52 is connected through the first switch s1 and the ground terminal, the third end of the coil part 52 is connected through the second switch s2 and the ground terminal, and the third end of the coil part 52 is located between the first end of the coil part 52 and the second end of the coil part 52.

[0067] Specifically, the third end of the coil part 52 is located at the middle point of the overall wiring distance of the coil part 52, when the first switch s1 is closed and the second switch s2 is opened, the entire coil part 52 is connected to the circuit, and the inductance value is large, when the second switch s2 is closed and the first switch s1 is opened, only the front half of the coil part 52 is connected to the circuit, and the inductance value is small. Therefore, according to the demand of amplification gain, the first switch s1 and the first switch s1 are controlled to be closed or opened, so as to change the inductance value connected, and improve the flexibility of the feedback circuit.

[0068] In some embodiments, in combination with Figure 8 and Figure 9 As shown, the coil part 52 includes a first coil 521 and a second coil 522, the first end of the first coil 521 is connected to the second end of the first connecting part 51, the second end of the first coil 521 is connected to the first end of the second coil 522 through a second connecting part, the second connecting part is connected to the ground terminal through a third switch s3, and the second end of the second coil 522 is connected to the ground terminal through a fourth switch s4.

[0069] Specifically, the first connecting part 51 can be an extending part or a fold line segment. The first coil 521 and the second coil 522 are connected in series.

[0070] When the third switch s3 is open and the fourth switch s4 is closed, both the first coil 521 and the second coil 522 are connected to the circuit, and the inductance value is large. When the third switch s3 is closed and the fourth switch s4 is open, only the first coil 521 is connected to the circuit, and the inductance value is small. Therefore, according to the demand of the amplification gain, the third switch s3 and the fourth switch s4 can be controlled to be closed or open, so as to change the inductance value connected, improve the flexibility of the feedback circuit, and through the setting of two coils, the change amount of the inductance value can be larger.

[0071] In some embodiments, when the distance between the coil part 52 and the second extension part 3 is greater than the first threshold value and the first connection part 51 is perpendicular to the second extension part 3, the connection position of the first connection part 51 and the second extension part 3 is located at the center position of the second extension part 3.

[0072] Specifically, the first threshold value can be set according to the actual magnetic field influence range of the coil part 52, for example, the first threshold value can be set to 500 μm, 600 μm, etc. When the distance between the coil part 52 and the second extension part 3 is greater than the first threshold value and the first connection part 51 is perpendicular to the second extension part 3, the magnetic field influence of the coil part 52 on the first extension part 1 and the third extension part 4 is small, and the influence on both sides is basically the same, and the coupling influence of the coil part 52 on the first extension part 1 and the third extension part 4 can be ignored. Therefore, when the connection position of the first connection part 51 and the third extension part 4 is located at the center position of the second extension part 3, it can be ensured that the inductance value of the connection end on the first extension part 1 to the wire part of the second end of the inductance main body 5 is equal to the inductance value of the connection end on the third extension part 4 to the wire part of the second end of the inductance main body 5.

[0073] It should be understood that the distance between the coil part 52 and the second extension part 3 is the length of the projection of the wire connecting the second end of the first connection part 51 to the first end of the inductance main body 5 in the first direction.

[0074] In combination Figure 13 and Figure 14As shown, when the distance between the coil part 52 and the second extension part 3 is greater than 600 μm, the inductance transmission line width is 10 μm, the distance S1 between the first extension part 1 and the second extension part 3 is 19 μm, the distance between the first connecting part 51 and the first extension part 1 is 58.21 μm, and the first extension part and the third extension part are symmetrically arranged, the inductance values of the feedback circuit are verified by simulation software, the inductance value L15 of the connecting line part of the first connecting end Ls1 to the inductance main body 5 is equal to 168.8288 pH, the inductance value L25 of the connecting line part of the second connecting end Ls2 to the inductance main body 5 is equal to 168.4947 pH, the inductance value L35 of the connecting line part of the third connecting end Ls3 to the inductance main body 5 is equal to 168.4515 pH, and the inductance value L45 of the connecting line part of the fourth connecting end Ls4 to the inductance main body 5 is equal to 168.7755 pH, which can be regarded as the inductance values of the four connecting ends being equal.

[0075] In some embodiments, when the distance between the coil part 52 and the second extension part 3 is less than the second threshold value, the connecting position of the first connecting part 51 and the second extension part 3 is deviated towards the first extension part 1 or the third extension part 4.

[0076] Specifically, the second threshold value can be set according to the actual magnetic field influence range of the coil part 52, for example, the second threshold value can be set to 500 μm, 600 μm, etc. When the distance between the coil part 52 and the second extension part 3 is small, for example, the distance is less than 500 μm, the magnetic field coupling of the coil part 52 will cause the inductance values of the connecting ends on the first extension part 1 and the third extension part 4 to be different, therefore, it is necessary to adjust the connecting position of the first connecting part 51 and the second extension part 3 to deviate towards the first extension part 1 or the third extension part 4, so that the inductance values of the connecting ends on the first extension part 1 and the third extension part 4 are the same.

[0077] In the design of inductance, the connecting position of the first connecting part 51 and the second extension part 3 is first adjusted to make the inductance values of the connecting ends on the first extension part 1 and the third extension part 4 equal, and then the distances of the first extension part 1 and the second extension part 3 and the distances of the second extension part 3 and the third extension part 4 are adjusted respectively to make the inductance values of the connecting ends on the first extension part 1 equal and the inductance values of the connecting ends on the third extension part 4 equal. In other examples, the distance can be adjusted first and then the connecting position can be adjusted.

[0078] Specifically, when the first connecting part 51 and the second extension part 3 are not deviated vertically, the deviated direction of the connecting position of the first connecting part 51 and the second extension part 3 is opposite to the current direction of the wire closest to the second extension part 3 of the coil part 52.

[0079] When the first connecting part 51 and the second extension part 3 are perpendicular, the trace closest to the second extension part 3 in the coil part 52 weakens the inductance value of the magnetic field coupling to the second extension part 3 opposite to it. Therefore, it is necessary to shift the connection position of the first connecting part 51 and the second extension part 3 in the opposite direction to the current direction of the trace closest to the second extension part 3 in the coil part 52 to counteract the weakening effect of the magnetic field coupling.

[0080] In one example, such as Figure 15 As shown, the first connecting part 51 and the second extension part 3 are perpendicular. The current direction of the trace closest to the second extension part 3 in the coil part 52 (i.e., the bottommost trace) is to the left (i.e., the current direction of the coil part 52 is clockwise). The distance S1 between the first extension part 1 and the second extension part 3 is 20μm, and the distance S2 between the third extension part 4 and the second extension part 3 is 21.8μm. The connection position of the first connecting part 51 and the second extension part 3 is offset to the right. When the distance between the first connecting part 51 and the first extension part 1 is 50μm, and the distance between the first connecting part 51 and the third extension part 4 is 45μm, the inductance value of the feedback circuit is verified by simulation software, and the simulation results are as follows. Figure 16 As shown, the inductance value L15 of the connection between the first connection terminal Ls1 and the inductor body 5 is equal to 387.5 pH, the inductance value L25 of the connection between the second connection terminal Ls2 and the inductor body 5 is equal to 387.2 pH, the inductance value L35 of the connection between the third connection terminal Ls3 and the inductor body 5 is equal to 387.1 pH, and the inductance value L45 of the connection between the fourth connection terminal Ls4 and the inductor body 5 is equal to 387.2 pH. These can be considered as the inductance values ​​connected to the four connection terminals being equal.

[0081] When the first connecting portion 51 deflects toward the first extension portion 1 or the third extension portion 4, the inductive coupling of the coil portion 52 will cause the inductance value connected to the connecting end on the first extension portion 1 to be different from the inductance value connected to the connecting end on the third extension portion 4. At this time, depending on the deflection direction of the first connecting portion 51 and the direction of current flow, shifting the connection position of the first connecting portion 51 and the second extension portion 3 toward the first extension portion 1 or the third extension portion 4 can also make the inductance value connected to the connecting end on the first extension portion 1 and the inductance value connected to the connecting end on the third extension portion 4 equal.

[0082] Specifically, when the current direction of the trace closest to the second extension 3 in the coil portion 52 is opposite to the current direction of the deflected extension, the connection position of the first connection portion 51 and the second extension 3 shifts away from the deflected extension. Here, the "deflected extension" refers to the extension (first extension 1 or third extension 4) that is closest to the coil portion 52 in the direction perpendicular to the second extension 3 after the first connection portion 51 is deflected.

[0083] According to the inductor layout requirements, the first connection portion 51 can be deflected toward the first extension portion 1 or the third extension portion 4. At this time, if the current direction of the trace closest to the second extension portion 3 in the coil portion 52 is opposite to the current direction of the deflected extension portion, the coupling effect of the coil portion 52 has a weakening effect on the inductance value connected to the connection terminal on the deflected extension portion. Therefore, the connection position of the first connection portion 51 and the second extension portion 3 is shifted away from the deflected extension portion to reduce the inductance value connected to the connection terminal on the deflected extension portion, ensuring that the inductance values ​​connected to the connection terminals on the two extension portions are equal.

[0084] like Figure 10 As shown, the first connecting part 51 deflects toward the third extension part 4, and the current in the coil part 52 closest to the second extension part 3 is opposite to that in the third extension part 4 (at this time, the current direction of the coil part 52 is clockwise). Inductive coupling weakens the inductance. The connection position of the first connecting part 51 and the second extension part 3 is shifted away from the deflected extension part, thereby making the inductance value connected to the connection end on the two extension parts equal.

[0085] In one example, the first connecting portion 51 is deflected and adjusted toward the third extension portion 4, such as... Figure 17 As shown, when the distance between the first connecting part 51 and the first extension part 1 is 45.5 μm, and the distance from the first connecting part 51 to the third extension part 4 is 50 μm, the inductance value of the feedback circuit is verified by simulation software, and the simulation results are as follows. Figure 18 As shown, the inductance value L25 of the connection portion from the second connection terminal Ls2 to the inductor body 5 is equal to 463.1 pH, and the inductance value L35 of the connection portion from the third connection terminal Ls3 to the inductor body 5 is equal to 463.4 pH. These can be considered as the inductance values ​​connected to the connection terminals on the first extension 1 and the third extension 4 being equal.

[0086] When the current direction of the trace closest to the second extension 3 in the coil section 52 is the same as the current direction of the deflected extension, the coupling effect of the coil section 52 enhances the inductance value connected to the connection terminal on the deflected extension. Therefore, the connection position of the first connection section 51 and the second extension 3 is shifted towards the direction closer to the deflected extension to reduce the inductance value connected to the connection terminal on the deflected extension and ensure that the inductance values ​​connected to the connection terminals on the two extensions are equal.

[0087] like Figure 11 As shown, when the current in the trace closest to the second extension 3 of the coil section 52 is the same as that in the deflected extension (at this time, the current direction of the coil section 52 is counterclockwise), the inductive coupling plays a role in enhancing the inductance, and the connection position of the first connection section 51 and the second extension 3 is shifted away from the deflected extension.

[0088] In the embodiment, the coil part 52 can offset or enhance the magnetic field of the first extension part 1 and / or the third extension part 4, and the connection position of the first connecting part 51 and the second extension part 3 can be deviated to the first extension part 1 or the third extension part 4. The magnetic field coupling influence of the coil part 52 can be reduced by the different connection distances on two sides, so that the inductance value of the connection end on the first extension part 1 to the connection part of the second end of the inductance main body 5 is equal to the inductance value of the connection end on the third extension part 4 to the connection part of the second end of the inductance main body 5.

[0089] The embodiment of the present application also provides a multi-port low noise amplifier, as shown in the figure, the multi-port low noise amplifier comprises at least two radio frequency input ports and a feedback circuit like any one of the embodiments of the present application, each radio frequency input port is connected with a first amplification unit, and the sources of the at least two first amplification units are connected with at least two connection ends in the feedback circuit respectively. Figure 19

[0090] Specifically, the first amplification unit adopts a transconductance amplification unit, the transconductance amplification unit comprises a first field effect transistor, the gate of the first field effect transistor is connected with a corresponding radio frequency input port RFN, and the source of the first field effect transistor is connected with a corresponding connection end in the feedback circuit.

[0091] The multi-port low noise amplifier also comprises a common source common gate amplification unit, the drain of each first field effect transistor is connected with the common source common gate amplification unit through a corresponding switch, so that double amplification is realized.

[0092] The multi-port low noise amplifier of the embodiment of the present application can make the inductance values of the first amplification units connected by different radio frequency input ports equal, solve the problem of unbalanced inductance values provided by the feedback circuit, and reduce the difference between the amplification gains of different radio frequency input ports.

[0093] The embodiment of the present application also provides a radio frequency front end module, which comprises the multi-port low noise amplifier in the above-mentioned embodiments of the present application.

[0094] The embodiment of the present application also provides a feedback circuit design method, which is applied to optimizing the feedback circuit in any one of the above-mentioned embodiments of the present application, and comprises the following steps. Adjusting the distance between the first extension part 1 and the second extension part 3, so that the inductance values of the connection parts of at least two connection ends on the first extension part 1 to the inductance main body 5 are equal; Adjusting the distance between the second extension part 3 and the third extension part 4, so that the inductance values of the connection parts of at least two connection ends on the third extension part 4 to the inductance main body 5 are equal; ​The connection position of the first connecting part 51 and the second extending part 3 is adjusted, so that the inductance value of the connection end on the first extending part 1 to the inductance value of the connection end on the second extending part 3 to the second end of the inductance body 5 is the same.

[0095] It should be understood that the order of the above steps can be that the distance between the first extending part 1 and the second extending part 3 is adjusted first, and then the distance between the second extending part 3 and the third extending part 4 is adjusted, and then the connection position of the first connecting part 51 and the second extending part 3 is adjusted, or the connection position of the first connecting part 51 and the second extending part 3 is adjusted first, and then the distance between the first extending part 1 and the second extending part 3 is adjusted, and then the distance between the second extending part 3 and the third extending part 4 is adjusted.

[0096] According to the above steps, the feedback circuit of any one of the above embodiments of the present application can be optimized, so that the inductance value of the connection end on the first extending part 1 and the third extending part 4 is equal, and the problem of imbalance of the inductance value provided by the feedback circuit is solved, and the difference between the amplification gains of different radio frequency input ports is reduced.

[0097] Although the example embodiments and their advantages have been described in detail, those skilled in the art can make various changes, substitutions and modifications to these embodiments without departing from the spirit of the present application and the scope of protection defined, and such modifications and variations fall within the scope defined.

Claims

1. A feedback circuit applied to a multi-port low noise amplifier, characterized in that, The application relates to an inductor, which comprises a first extension, a second extension, a first connecting part and an inductor body. At least two connecting ends are arranged on the first extension at intervals, and different connecting ends are connected with different first amplification units corresponding to different radio frequency input ports of a multi-port low-noise amplifier. The two ends of the first connecting part are connected with one end of the first extension and the first end of the second extension, and the first extension and the second extension are oppositely arranged. The first end of the inductor body is connected with the second extension, and the second end of the inductor body is connected with a grounding end. The projection of any connecting end on the first extension along a first direction is located on the second extension, and the first direction is perpendicular to the extension direction of the second extension.

2. The feedback circuit of claim 1, wherein, The inductor further comprises a third extension and a second connecting part.

3. The feedback circuit of claim 1, wherein, At least two connecting ends are arranged on the third extension at intervals, and different connecting ends are connected with different first amplification units corresponding to different radio frequency input ports of a multi-port low-noise amplifier. The two ends of the second connecting part are connected with the second end of the second extension and one end of the third extension, and the second extension and the third extension are oppositely arranged. The first end of the inductor body is connected with the second extension, and the second end of the inductor body is connected with a grounding end.

4. The feedback circuit of claim 3, wherein, When the distance between the coil part and the second extension is greater than a first threshold value and the first connecting part is perpendicular to the second extension, the connecting position of the first connecting part and the second extension is located at the center position of the second extension.

5. The feedback circuit of claim 4, wherein, When the distance between the coil part and the second extension is less than a second threshold value, the connecting position of the first connecting part and the second extension is deviated towards the first extension or the third extension.

6. The feedback circuit of claim 4, wherein, The first connecting part is deviated towards the first extension or the third extension, the current direction of the wire closest to the second extension in the coil part is opposite to the current direction of the deviated extension, and the connecting position of the first connecting part and the second extension is deviated towards the direction away from the deviated extension.

7. The feedback circuit of claim 6, wherein, ​ 8. The feedback circuit of claim 6, wherein, ​ 9. The feedback circuit of claim 6, wherein, The first connecting part is deflected to the first extending part or the third extending part, the current direction of the wire of the coil part closest to the second extending part is the same as the current direction of the deflected extending part, and the connecting position of the first connecting part and the second extending part is offset to the direction close to the deflected extending part.

10. The feedback circuit of claim 4, wherein, The distance between the first extending part and the second extending part is between 15 μm and 25 μm.

11. The feedback circuit of claim 4, wherein, The second end of the coil part is connected with the ground end through a first switch, the third end of the coil part is connected with the ground end through a second switch, and the third end of the coil part is located between the first end of the coil part and the second end of the coil part.

12. The feedback circuit of claim 4, wherein, The coil part comprises a first coil and a second coil, the first end of the first coil is connected with the second end of the first connecting part, the second end of the first coil is connected with the first end of the second coil through a second connecting part, the second connecting part is connected with the ground end through a third switch, and the second end of the second coil is connected with the ground end through a fourth switch.

13. A multi-port low noise amplifier, characterized by, The feedback circuit comprises at least two radio frequency input ports and at least two first amplification units, each radio frequency input port is connected with one first amplification unit, and the sources of the at least two first amplification units are connected with at least two connecting ends in the feedback circuit respectively.

14. A radio frequency front end module, comprising: The multi-port low-noise amplifier comprises the multi-port low-noise amplifier according to claim 13.

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