CN218124668U - Radio frequency front end module - Google Patents

Abstract

The utility model discloses a radio frequency front end module, including base plate, first electric capacity, set up the first balun on the base plate, first balun includes primary winding and secondary winding, primary winding includes first primary coil section and second primary coil section; a second end of the first primary coil segment is connected to a first end of the first capacitor, and a second end of the first capacitor is connected to a first end of the second primary coil segment; the first end and the second end of the secondary winding are arranged on the periphery of the first balun, and the first capacitor is arranged close to the first end and the second end of the secondary winding. The technical scheme can flexibly adjust the position of the first capacitor and reduce the loss of the radio frequency front-end module.

Description

Radio frequency front end module

Technical Field

The utility model relates to a radio frequency technology field especially relates to a radio frequency front end module.

Background

Radio frequency, microwave, and millimeter wave integrated circuits are critical to the functioning of wireless communication, radar, and imaging systems. Integrated circuit designs at these frequencies require the use of on-chip passive electrical components such as resistors, inductors, capacitors, and transformers. Transformers or balun devices are commonly used in wireless communication.

At present, when the balun is applied to the radio frequency front end module, in order to ensure the bandwidth performance of the radio frequency front end module, the loss of the radio frequency front end module is increased, that is, the loss cannot be reduced while the bandwidth performance of the radio frequency front end module is ensured, so that the overall performance of the radio frequency front end module is affected.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a radio frequency front end module to solve the problem that can't reduce the loss when guaranteeing the bandwidth performance of radio frequency front end module.

A radio frequency front end module comprises a substrate, a first capacitor and a first balun arranged on the substrate, wherein the first balun comprises a primary winding and a secondary winding, and the primary winding comprises a first primary coil section and a second primary coil section; a second end of the first primary coil segment is connected to a first end of the first capacitor, and a second end of the first capacitor is connected to a first end of the second primary coil segment; the first end and the second end of the secondary winding are arranged on the periphery of the first balun, and the first capacitor is arranged close to the first end and the second end of the secondary winding.

Furthermore, the radio frequency front-end module further comprises a first chip, a first end of the secondary winding is connected with the first chip, and a second end of the secondary winding is connected with a ground terminal.

Further, a first switch is disposed in the first chip, a first end of the first switch is connected to a first end of the secondary winding, and a second end of the first switch is coupled to the signal output terminal.

Further, the first capacitor is disposed on the substrate in a region between the first end and the second end of the secondary winding.

Further, the first capacitor is arranged in the first chip; the first capacitor is arranged in the first chip; the first end of the first capacitor is connected with the second end of the first primary coil section through a first bridging line, and the second end of the first capacitor is connected with the first end of the second primary coil section through a second bridging line.

Furthermore, a second change-over switch is arranged in the first chip; the second change-over switch is connected in parallel with the first capacitor.

Further, the first chip further comprises a second capacitor, and the second capacitor is connected in series with the second change-over switch.

Further, the first primary coil segment is of a different length than the second primary coil segment.

Further, the secondary winding and the primary winding are located in the same metal layer of the substrate.

Further, the first end of the first primary coil segment is a first input end of the first balun; a second end of the second primary coil segment is a second input of the first balun; the first end of the first primary coil section is taken as a starting point, the wiring direction of the first primary coil section is taken as a first direction, the first end of the second primary coil section is taken as a starting point, and the wiring direction of the second primary coil section is taken as a second direction; the first direction is opposite to the second direction;

the secondary winding comprises a first secondary coil section and a second secondary coil section; the first end of the first secondary coil section is a first output end of the first balun, the second end of the first secondary coil section is connected with the first end of the second secondary coil section, and the second end of the second secondary coil section is a second output end of the first balun; taking a first end of the first secondary coil section as a starting point, a wiring direction of the first secondary coil section as a first direction, and taking a second end of the second secondary coil section as a starting point, the wiring direction of the second secondary coil section as a second direction; the first direction is opposite to the second direction;

wherein the first direction is clockwise and the second direction is counterclockwise; or the first direction is a counterclockwise direction, and the second direction is a clockwise direction.

The radio frequency front end module comprises a substrate, a first capacitor and a first balun arranged on the substrate, wherein the first balun comprises a primary winding and a secondary winding, and the primary winding comprises a first primary coil section and a second primary coil section; a second end of the first primary coil segment is connected to a first end of the first capacitor, and a second end of the first capacitor is connected to a first end of the second primary coil segment; the first end and the second end of the secondary winding are arranged on the periphery of the first balun, and the first capacitor is arranged close to the first end and the second end of the secondary winding. In this embodiment, the first end and the second end of the secondary winding are disposed at the periphery of the first balun, and the first capacitor is disposed near the first end and the second end of the secondary winding, so that the performance of the rf front-end module is ensured, and the position of the first capacitor can be flexibly adjusted, thereby improving the integration level of the rf front-end module and reducing the loss of the rf front-end module.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a radio frequency front end module according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of an rf front-end module according to an embodiment of the present invention.

In the figure: 10. a substrate; 20. a first capacitor; 30. a first balun; 31. a primary winding; 311. a first primary coil segment; 312. a second primary coil segment; 32. a secondary winding; 321. a first secondary coil section; 322. a second secondary coil section; 40. a first chip; 50. a second chip; 60. and supplying power to the power supply end.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated throughout the same reference numerals to indicate same elements for clarity.

It will be understood that when an element or layer is referred to as being "on …," "adjacent …," "connected to" or "coupled to" another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on …," "directly adjacent …," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatial relationship terms such as "under …", "under …", "under …", "over …", "over", and the like, may be used herein for ease of description to describe the relationship of one element or feature to other elements or features shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "under …" and "under …" may include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present invention, the following description will provide detailed structures and steps for illustrating the technical solutions provided by the present invention. The preferred embodiments of the present invention are described in detail below, however, other embodiments of the present invention are possible in addition to these detailed descriptions.

The present embodiment provides a radio frequency front end module, as shown in fig. 1, including a substrate 10, a first capacitor 20, and a first balun 30 disposed on the substrate 10, where the first balun 30 includes a primary winding 31 and a secondary winding 32, the primary winding 31 includes a first primary coil segment 311 and a second primary coil segment 312; the second terminal of the first primary coil segment 311 is connected to the first terminal of the first capacitor 20, and the second terminal of the first capacitor 20 is connected to the first terminal of the second primary coil segment 312; first and second ends of the secondary winding 32 are disposed about the first balun 30, and the first capacitor 20 is disposed proximate the first and second ends of the secondary winding 32.

The radio frequency front end module also comprises a power amplifying circuit. Alternatively, the power amplification circuit may be a push-pull power amplification circuit, a doherty power amplification circuit, or other amplification circuit involving conversion of a radio frequency signal. Alternatively, the conversion of the radio frequency signal may be to convert an unbalanced radio frequency signal into two balanced radio frequency signals, or to convert two balanced radio frequency signals into an unbalanced radio frequency signal. In this embodiment, a push-pull power amplifier circuit is taken as an example for description.

In one embodiment, the rf front end module includes a substrate 10 and a first balun 30 disposed on the substrate 10. Alternatively, the first balun 30 may be applied in a front-stage conversion circuit of the push-pull power amplification circuit, or in a rear-stage conversion circuit of the push-pull power amplification circuit.

As an example, the rf front end module includes a pre-conversion circuit and a second chip 50. Optionally, the second chip 50 is a push-pull power amplifier chip. The pre-conversion circuit comprises the first balun 30 in the above described embodiment. The push-pull power amplification chip includes a first power amplifier M1 and a second power amplifier M2. A first input terminal of the first balun 30 is connected to the signal input terminal of the rf front-end module, and is configured to receive the first rf signal, and a second input terminal of the first balun 30 is grounded. A first output terminal of the first balun 30 is connected to an input terminal of the first power amplifier M1, and a second output terminal of the first balun 30 is connected to an output terminal of the first power amplifier M1. The first balun 30 is configured to convert the first rf signal, output a first rf input signal to the first power amplifier M1, and output a second rf input signal to the second power amplifier M2. The first power amplifier M1 is configured to amplify a first rf input signal and output a first rf amplified signal. The second power amplifier M2 is configured to amplify the second rf input signal and output a second rf amplified signal.

As another example, as shown in fig. 2, the rf front-end module includes a post-stage conversion circuit and a second chip 50. Optionally, the second chip 50 is a push-pull power amplifier chip. The latter stage conversion circuit comprises the first balun 30 in the above described embodiment. The push-pull power amplification chip includes a first power amplifier M1 and a second power amplifier M2. A first input end of the first balun 30 is connected to an input end of the first power amplifier M1, a second input end of the first balun 30 is connected to an input end of the second power amplifier M2, a first output end of the first balun 30 is an output node of the post-stage conversion circuit, and a second end of the first balun 30 is grounded. The first balun 30 is configured to convert the first rf amplified signal output by the first power amplifier M1 and the second rf amplified signal output by the second power amplifier M2, and output an rf output signal.

Alternatively, the first and second power amplifiers M1 and M2 may be BJT transistors (e.g., HBT transistors) or field effect transistors.

In one embodiment, the first power amplifier M1 is an HBT transistor. The base of the first power amplifier M1 is an input terminal, the collector of the first power amplifier M1 is an output terminal, and the transmitter of the first power amplifier M1 is grounded.

The second power amplifier M2 is an HBT transistor. The base of the second power amplifier M2 is an input terminal, the collector of the second power amplifier M2 is an output terminal, and the transmitter of the second power amplifier M2 is grounded.

In a particular embodiment, the first balun 30 includes a primary winding 31 and a secondary winding 32, the primary winding 31 including a first primary coil segment 311 and a second primary coil segment 312. The first end of the first primary coil segment 311 is a first input end of the first balun 30, the second end of the first primary coil segment 311 is connected to the first pad, the first end of the second primary coil segment 312 is connected to the second pad, and the second end of the second primary coil segment 312 is a second input end of the first balun 30. A first end of the secondary winding 32 is a first output terminal of the first balun 30, and a second end of the secondary winding 32 is a second output terminal of the first balun 30.

The present embodiment is exemplified by the case that the first end of the first capacitor 20 is connected to the second end of the first primary coil section 311 through a first pad, and the second end of the first capacitor 20 is connected to the second end of the first primary coil section 311 through a second pad. Specifically, the rf front-end module further includes a first capacitor 20, a first end of the first capacitor 20 is coupled to the first pad, a second end of the first capacitor 20 is coupled to the second pad, a first end and a second end of the secondary winding 32 are disposed at the periphery of the first balun 30, and the first capacitor 20 is disposed near the first end and the second end of the secondary winding 32. In this embodiment, the second end of the first primary coil section 311 is connected to the first pad, the first end of the second primary coil section 312 is connected to the second pad, the first end of the first capacitor 20 is coupled to the first pad, the second end of the first capacitor 20 is coupled to the second pad, and the first primary coil section 311, the first capacitor 20 and the second primary coil section 312 participate in impedance matching of the push-pull power amplifying circuit in the rf front-end module.

It should be noted that, in the related art, in order to ensure balanced symmetry of the push-pull power amplifying circuit, the first capacitor 20 needs to be disposed at the midpoint of the primary winding 31, so that the first capacitor 20 has the same length as the transmission lines of the first input terminal and the second input terminal of the first and primary windings 31. The position of the first capacitor 20 is relatively limited, and the position of the first capacitor 20 generally depends on the positions of the first input terminal and the second input terminal of the primary winding 31.

However, in the present embodiment, since the first primary coil section 311, the first capacitor 20 and the second primary coil section 312 form a loop, and only a capacitive element, such as the first capacitor 20, is included between the first primary coil section 311 and the second primary coil section 312, no additional circuit, such as a ground terminal, affecting the virtual ground position between the first primary coil section 311 and the second primary coil section 312 is added. Therefore, in the present embodiment, the arrangement position of the first capacitor 20 can be flexibly adjusted, and although the lengths of the first primary coil section 311 and the second primary coil section 312 are different, the virtual ground position between the first primary coil section 311 and the second primary coil section 312 is not affected, and the balance of the push-pull power amplifying circuit is not affected. The present embodiment can flexibly adjust the setting position of the first capacitor 20, and is not limited by the setting positions of the first input end and the second input end of the primary winding 31, and even if the lengths of the first capacitor 20 and the first input end and the second input end of the primary winding 31 are different, that is, the lengths of the first primary coil section 311 and the second primary coil section 312 are different, the balance cannot be damaged, and the performance of the rf front-end circuit cannot be affected.

In a specific embodiment, since in the practical application process, it is generally necessary to adjust the capacitance between the first primary coil section 311 and the second primary coil section 312 according to the practical situation, so as to perform impedance matching on the push-pull power amplifying circuit according to the practical situation. For example, according to the operation mode of the push-pull power amplifier circuit, the capacitance between the first primary coil section 311 and the second primary coil section 312 is adjusted correspondingly to ensure the impedance matching of the push-pull power amplifier circuit in different operation modes. Alternatively, the operation mode may be an operation frequency band of the push-pull power amplifying circuit, or a power mode of the push-pull power amplifying circuit, and the like. For example: when the push-pull power amplifying circuit operates in different operating frequency bands, the operating frequency band may be a high frequency band, a middle frequency band or a low frequency band. When the push-pull power amplification circuit operates in a different power mode, the power mode may be a High Power Mode (HPM) or a Low Power Mode (LPM).

However, since the capacitance value of the first capacitor 20 is fixed, and the capacitance value cannot be switched according to different operation modes, the first capacitor 20 is disposed near the first end and the second end of the secondary winding 32, and since the first end of the secondary winding 32 is connected to the subsequent circuit (the first chip 40), the capacitance value between the first primary coil section 311 and the second primary coil section 312 can be switched by using the switch on the first chip 40 to connect to the first capacitor 20. Since the position of the first chip 40 on the substrate 10 is usually relatively fixed. Difficult nimble adjustment, consequently, in order to avoid bringing into too big loss, the transmission line when guaranteeing to be connected with components and parts on first electric capacity 20 and the first chip 40 can not the overlength, and the position of the first electric capacity 20 of nimble adjustment can be realized to this application, makes first electric capacity 20 near the first end and the second end setting of secondary winding 32 to the realization adopts shorter transmission line can reach the purpose of being connected with components and parts on first electric capacity 20 and the first chip 40, in order to reduce the loss that the transmission line between first chip 40 and the first electric capacity 20 brought. Alternatively, the transmission line may be a bridge line, for example.

In an embodiment, the first balun 30 is applied to a post-stage conversion circuit of the push-pull power amplifier circuit. A first end of the first primary coil segment 311 is connected to an input terminal of the first power amplifier M1, a second end of the first primary coil segment 311 is connected to an input terminal of the second power amplifier M2, a first end of the secondary winding 32 is a first output terminal of the first balun 30, a second end of the secondary winding 32 is a second output terminal of the first balun 30, the first end and the second end of the secondary winding 32 are disposed at the periphery of the first balun 30, and the first capacitor 20 is disposed near the first end and the second end of the secondary winding 32. In the present embodiment, since the first end of the secondary winding 32 is the first output end of the first balun 30, the second end of the secondary winding 32 is the second output end of the first balun 30, the first end of the secondary winding 32 is generally connected to the rear stage circuit (the first chip 40), and the second end of the secondary winding 32 is grounded. The latter stage output circuit may be, for example, an output impedance matching circuit or other circuits for receiving the rf output signal, or may be a switch circuit. Therefore, the first end and the second end of the secondary winding 32 are arranged at the periphery of the first balun 30, and the first capacitor 20 is arranged close to the first end and the second end of the secondary winding 32, so that the first capacitor 20 is close to the first chip 40, and the purpose of connecting the first capacitor 20 with the component on the first chip 40 can be achieved by using a short transmission line, so that the loss caused by the transmission line between the first chip 40 and the first capacitor 20 is reduced.

In the present embodiment, the rf front end module includes a substrate 10, a first capacitor 20, and a first balun 30 disposed on the substrate 10. The first balun 30 comprises a primary winding 31 and a secondary winding 32. The primary winding 31 includes a first primary coil section 311 and a second primary coil section 312. A second terminal of the first primary coil section 311 is connected to a first pad, a first terminal of the first capacitor 20 is coupled to the first pad, a first terminal of the second primary coil section 312 is connected to a second pad, and a second terminal of the first capacitor 20 is coupled to the second pad; first and second ends of the secondary winding 32 are disposed about the first balun 30, and the first capacitor 20 is disposed proximate the first and second ends of the secondary winding 32. In this embodiment, the first end and the second end of the secondary winding 32 are disposed at the periphery of the first balun 30, and the first capacitor 20 is disposed near the first end and the second end of the secondary winding 32, so that the purpose of connecting the first capacitor 20 and the component on the first chip 40 can be achieved by using a shorter transmission line, the loss caused by the transmission line between the first chip 40 and the first capacitor 20 is reduced, and the loss of the rf front-end module is reduced while the bandwidth performance of the rf front-end module is ensured.

Optionally, the rf front-end module further includes a power supply end 60, and the power supply end 60 is disposed in a middle region surrounded by the coils of the first balun 30, so as to reduce an occupied area of the power supply end 60 and reduce loss of the rf front-end module. The power supply terminal 60 is connected to a first terminal of the first primary coil terminal and a second terminal of the second secondary coil section 322, and is respectively configured to supply power to the first power amplifier M1 and the second power amplifier M2 in the push-pull power amplifier chip.

In one embodiment, as shown in fig. 1, a first end of the secondary winding 32 is connected to the first chip 40 via a first end, and a second end of the secondary winding 32 is connected to a ground end.

In the present embodiment, the first end of the secondary winding 32 is connected to the first chip 40, and therefore, the capacitance value between the first primary coil section 311 and the second primary coil section 312 can be switched by connecting the first capacitor 20 with the switch on the first chip 40. Since the position of the first chip 40 on the substrate 10 is generally fixed, it is not easy to flexibly adjust. Therefore, in order to avoid bringing excessive loss, the transmission line is not too long when the transmission line is connected with the first capacitor 20 and the component on the first chip 40, the position of the first capacitor 20 can be flexibly adjusted, so that the first capacitor 20 is close to the first end and the second end of the secondary winding 32, and the purpose of connecting the first capacitor 20 and the component on the first chip 40 by using a short transmission line can be achieved, so that the loss caused by the transmission line between the first chip 40 and the first capacitor 20 is reduced. Alternatively, the transmission line may be, for example, a bridge line.

In an embodiment, a first switch K1 is disposed in the first chip 40, a first end of the first switch K1 is connected to a first end of the secondary winding 32, and a second end of the first switch K1 is coupled to a signal output end.

As an example, a first terminal of the first switch K1 is connected to a first terminal of the secondary winding 32, and a second terminal of the first switch K1 is coupled to the signal output terminal. When the first switch K1 is turned on, the rf front-end module outputs the rf output signal, and when the first switch K1 is turned off, the rf front-end module does not output the rf output signal.

In this embodiment, a first switch K1 is disposed in the first chip 40, a first end of the first switch K1 is connected to a first end of the secondary winding 32, and a second end of the first switch K1 is coupled to the signal output end, so that the first chip 40 switches an output state of the rf output signal of the rf front-end module, and the first capacitor 20 is close to the first chip 40, thereby reducing loss caused by the transmission line between the first chip 40 and the first capacitor 20.

Alternatively, the first capacitor 20 may be directly disposed on the substrate 10, or the first capacitor 20 may be disposed within the first chip 40.

Alternatively, the first chip 40 may be an SOI (Silicon On Insulator, silicon technology, SIO) chip, a gallium arsenide chip, a CMOS chip, or the like. Preferably, the first chip 40 may be an SOI chip, and the Q value of the first capacitor 20 may be increased by integrating the first capacitor 20 in the first chip 40.

In an embodiment, the first capacitor 20 is disposed on the substrate 10 in a region between the first end and the second end of the secondary winding 32. Since the first end and the second end of the secondary winding 32 are disposed at the periphery of the first balun 30, and the first end and the second end of the secondary winding 32 just form a vacant region, the first capacitor 20 is located in the region between the first end and the second end of the secondary winding 32, so that the integration degree of the rf front-end module can be improved while the loss is reduced. Especially when the primary winding 31 and the secondary winding 32 are coupled in the same layer, the arrangement position of the first capacitor 20 is relatively limited, and is limited by the winding manner of the secondary winding 32 and the primary winding 31, so that the integration level of the rf front-end module can be further improved and the loss of the rf front-end module can be reduced by arranging the first end and the second end of the secondary winding 32 at the periphery of the first balun 30 and arranging the first capacitor 20 in the region between the first end and the second end of the secondary winding 32.

In one embodiment, the first capacitor 20 is disposed in the first chip 40; a first end of the first capacitor 20 is connected to a second end of the first primary coil segment 311 through a first bridge line, and a second end of the first capacitor 20 is connected to a first end of the second primary coil segment 312 through a second bridge line.

Specifically, the first capacitor 20 is disposed within the first chip 40; a first terminal of the first capacitor 20 is connected to the fourth pad of the first chip 40 and a second terminal of the first capacitor 20 is connected to the fifth pad of the first chip 40. The fourth pad of the first chip 40 is connected to the first pad through a first bridge, the first pad is connected to the second end of the first primary coil segment 311, the fifth pad of the first chip 40 is connected to the second pad through a second bridge, and the second pad is connected to the first end of the second primary coil segment 312.

In a specific embodiment, the first capacitor 20 is integrated in the first chip 40, a first terminal of the first capacitor 20 is connected to the fourth bonding pad of the first chip 40, and a second terminal of the first capacitor 20 is connected to the fifth bonding pad of the first chip 40. The fourth pad of the first chip 40 is connected to the first pad through a first bridge, and the fifth pad of the first chip 40 is connected to the second pad through a second bridge. In the present embodiment, the first capacitor 20 is integrated in the first chip 40 to improve a quality factor (Q) value of the first capacitor 20, so as to optimize the overall performance of the rf front-end module.

In one embodiment, a second switch is disposed in the first chip 40; the second switch is connected in parallel with the first capacitor 20.

In this embodiment, a second switch is disposed in the first chip 40, the second switch is connected in parallel with the first capacitor 20, when the second switch is turned on, the first capacitor 20 is short-circuited and is not connected between the first primary coil section 311 and the second primary coil section 312, and when the second switch is turned off, the first capacitor 20 is connected between the first primary coil section 311 and the second primary coil section 312, so as to ensure impedance matching of the push-pull power amplification circuit in different operation modes. For example, when the rf front end module is in the first operation mode, and the second switch is turned on, the first capacitor 20 is short-circuited and is not connected between the first primary coil section 311 and the second primary coil section 312, and the first primary coil section 311 and the second primary coil section 312. When the rf front-end module is in the second working mode and the second switch is turned off, the first capacitor 20 is connected between the first primary coil segment 311 and the second primary coil segment 312, so as to switch the state of the second switch according to the working mode (for example, working frequency band) of the rf front-end module, thereby meeting the requirement of impedance matching.

In one embodiment, the first chip 40 further includes a second capacitor; the second capacitor is connected in series with the second change-over switch.

In one embodiment, a second switch is connected in parallel with the first capacitor 20, and a second capacitor is connected in series with the second switch. When the second switch is turned on, the capacitance between the first primary coil section 311 and the second primary coil section 312 is the capacitance corresponding to the parallel connection of the first capacitor 20 and the second capacitor, i.e. the first capacitance 20 value, and when the second switch is turned off, the capacitance between the first primary coil section 311 and the second primary coil section 312 is the capacitance corresponding to the first capacitor 20, i.e. the second capacitance value, and the first capacitance 20 value is greater than the second capacitance value.

In this embodiment, the first chip 40 further includes a second capacitor; the second switch is connected in parallel with the first capacitor 20, and the second capacitor is connected in series with the second switch, so as to switch capacitance values between the first primary coil section 311 and the second primary coil section 312, and ensure impedance matching of the push-pull power amplification circuit in different working modes, optionally, the working mode of the push-pull power amplification circuit is a working frequency band, when the working frequency band of the push-pull power amplification circuit is a first frequency band, the second switch is turned off, the capacitance value between the first primary coil section 311 and the second primary coil section 312 is a capacitance value corresponding to the first capacitor 20, when the working frequency band of the push-pull power amplification circuit is a second frequency band, and when the second switch is turned on, the capacitance value between the first primary coil section 311 and the second primary coil section 312 is a capacitance value corresponding to the first capacitor 20 and the second capacitor connected in parallel, the first frequency band is greater than the second frequency band, and the first frequency band and the second frequency band are any two of a high frequency band, a middle frequency band and a low frequency band. It should be noted that, because the target impedance Xc that needs to be adjusted is fixed, when the frequency f of the push-pull power amplifier circuit changes, the capacitance C of the first capacitor 20 needs to be adjusted, so that the suitable capacitive reactance Xc can be maintained at different frequencies f, so as to ensure impedance matching of the push-pull power amplifier circuit in different operating modes. Therefore, when the operating frequency band of the push-pull power amplifying circuit is increased, the capacitance value of the first capacitor 20 is decreased, and when the operating frequency band of the push-pull power amplifying circuit is smaller, the capacitance value of the first capacitor 20 is increased.

In one embodiment, the first primary coil section 311 is a different length than the second primary coil section 312.

In one embodiment, the first primary coil section 311 and the second primary coil section 312 are different lengths. In this embodiment, since the first primary coil section 311, the first capacitor 20 and the second primary coil section 312 form a loop, and only a capacitive element, such as the first capacitor 20, is included between the first primary coil section 311 and the second primary coil section 312, and no additional circuit, such as a ground terminal, affecting the virtual ground position between the first primary coil section 311 and the second primary coil section 312 is added, in an actual application process, although the lengths of the first primary coil section 311 and the second primary coil section 312 are different, the virtual ground position between the first primary coil section 311 and the second primary coil section 312 is not affected, and the balance of the push-pull power amplification circuit is not affected. Therefore, the position of the first capacitor 20 can be flexibly adjusted in this embodiment, and is not limited by the lengths of the first primary coil section 311 and the second primary coil section 312, and even if the lengths of the first primary coil section 311 and the second primary coil section 312 are different, the balance is not damaged, and the performance of the rf front-end circuit is not affected.

Optionally, the secondary winding 32 is located in the same metal layer as the primary winding 31, or the secondary winding 32 is located in a different metal layer from the primary winding 31.

Preferably, the secondary winding 32 and the primary winding 31 are located in the same metal layer, because when the secondary winding 32 and the primary winding 31 are located in different metal layers, that is, when the secondary winding 32 and the primary winding 31 are layered on top of each other, the position of the first capacitor 20 connected to the secondary winding 32 can be flexibly set and is not limited by the winding manner of the secondary winding 32.

Therefore, only when the secondary winding 32 and the primary winding 31 are located in the same metal layer, the location of the first capacitor 20 needs to be considered, in this application, the secondary winding 32 and the primary winding 31 of the first balun 30 are located in the same metal layer, the first end and the second end of the secondary winding 32 are located at the periphery of the first balun 30, and the first capacitor 20 is located close to the first end and the second end of the secondary winding 32, so that the metal layer of the substrate 10 is further reduced, the cost of the rf front-end module is reduced, and the integration level of the rf front-end module is improved;

in one embodiment, as shown in fig. 1, a first end of the first primary coil section 311 is connected to the first pad, and a second end of the first primary coil section 311 is a first input end of the first balun 30; a first end of the second primary coil section 312 is connected to the second pad, and a second end of the second primary coil section 312 is a second input end of the first balun 30; the first end of the first primary coil section 311 is used as a starting point, the wiring direction of the first primary coil section 311 is used as a first direction, the first end of the second primary coil section 312 is used as a starting point, and the wiring direction of the second primary coil section 312 is used as a second direction; the first direction is opposite to the second direction.

In one embodiment, as shown in fig. 1, the second end of the first primary coil segment 311 is a first input end of the first balun 30; a second end of the second primary coil section 312 is a second input of the first balun 30. In the present embodiment, the arrangement of the secondary winding 32 and the primary winding 31 in the first metal layer can be achieved by setting the wiring direction of the first primary coil section 311 to the first direction with the first end of the first primary coil section 311 as a starting point, and setting the wiring direction of the second primary coil section 312 to the second direction with the first end of the second primary coil section 312 as a starting point, and making the first direction opposite to the second direction.

Optionally, the first direction is a clockwise direction, and the second direction is a counterclockwise direction; or the first direction is counterclockwise and the second direction is clockwise.

In one embodiment, as shown in fig. 1, the secondary winding 32 is located in the same metal layer as the primary winding 31; the secondary winding 32 includes a first secondary coil section 321 and a second secondary coil section 322; a first end of the first secondary coil section 321 is a first output end of the first balun 30, a second end of the first secondary coil section 321 is connected with a first end of the second secondary coil end, and a second end of the second secondary coil section 322 is a second output end of the first balun 30; the first end of the first secondary coil section 321 is taken as a starting point, the wiring direction of the first secondary coil section 321 is taken as a first direction, the second end of the second secondary coil section 322 is taken as a starting point, and the wiring direction of the second secondary coil section 322 is taken as a second direction; the first direction is opposite to the second direction.

In an embodiment, the first end of the first secondary coil section 321 is a first output end of the first balun 30, the second end of the first secondary coil section 321 is connected to the first end of the second secondary coil section, and the second end of the second secondary coil section 322 is a second output end of the first balun 30. Optionally, the second end of the first secondary coil section 321 is connected to the first end of the second secondary coil section through a bridge line. In the present embodiment, by setting the wiring direction of the first secondary coil section 321 as the first direction and the wiring direction of the second secondary coil section 322 as the second direction with the first end of the first secondary coil section 321 as the starting point, the secondary winding 32 and the primary winding 31 can be disposed in the first metal layer, and the first end of the first secondary coil section 321 and the second end of the second secondary coil section 322 are disposed at the periphery of the first balun 30, so that the first capacitor 20 is disposed close to the first end of the first secondary coil section 321 (the first end of the secondary winding 32) and the second end of the second secondary coil section 322 (the second end of the secondary winding 32).

The above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims (10)

1. A radio frequency front end module is characterized by comprising a substrate, a first capacitor and a first balun arranged on the substrate, wherein the first balun comprises a primary winding and a secondary winding, and the primary winding comprises a first primary coil section and a second primary coil section; a second end of the first primary coil segment is connected to a first end of the first capacitor, and a second end of the first capacitor is connected to a first end of the second primary coil segment; the first end and the second end of the secondary winding are arranged on the periphery of the first balun, and the first capacitor is arranged close to the first end and the second end of the secondary winding.

2. The rf front-end module of claim 1, further comprising a first chip, wherein a first end of the secondary winding is connected to the first chip and a second end of the secondary winding is connected to ground.

3. The rf front-end module of claim 2, wherein the first chip has a first switch disposed therein, a first terminal of the first switch is connected to a first terminal of the secondary winding, and a second terminal of the first switch is coupled to a signal output terminal.

4. The radio frequency front end module of claim 1, wherein the first capacitor is disposed on the substrate in a region between the first end and the second end of the secondary winding.

5. The rf front-end module of claim 2, wherein the first capacitor is disposed within the first chip; the first end of the first capacitor is connected with the second end of the first primary coil section through a first bridging line, and the second end of the first capacitor is connected with the first end of the second primary coil section through a second bridging line.

6. The RF front-end module of claim 5, wherein the first chip further includes a second switch; the second change-over switch is connected in parallel with the first capacitor.

7. The radio frequency front end module of claim 6, wherein the first chip further comprises a second capacitor, the second capacitor being connected in series with the second switch.

8. The radio frequency front end module of claim 1, wherein the first primary coil segment is a different length than the second primary coil segment.

9. The radio frequency front end module of claim 1, wherein the secondary winding and the primary winding are located in a same metal layer of the substrate.

10. The radio frequency front end module of claim 9, wherein the first end of the first primary coil segment is a first input of the first balun and the second end of the second primary coil segment is a second input of the first balun; the first end of the first primary coil section is taken as a starting point, the wiring direction of the first primary coil section is taken as a first direction, the first end of the second primary coil section is taken as a starting point, and the wiring direction of the second primary coil section is taken as a second direction; the first direction is opposite to the second direction;

the secondary winding comprises a first secondary coil section and a second secondary coil section; the first end of the first secondary coil section is a first output end of the first balun, the second end of the first secondary coil section is connected with the first end of the second secondary coil section, and the second end of the second secondary coil section is a second output end of the first balun; taking a first end of the first secondary coil section as a starting point, a wiring direction of the first secondary coil section as a first direction, and taking a second end of the second secondary coil section as a starting point, the wiring direction of the second secondary coil section as a second direction; the first direction is opposite to the second direction;

wherein the first direction is clockwise and the second direction is counterclockwise; or the first direction is a counterclockwise direction, and the second direction is a clockwise direction.

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