Power amplifier, transformer and circuit module

Abstract

The utility model discloses a power amplifier, a transformer and a circuit module. The power amplifier comprises a differential cascode amplifier, a first neutralizing capacitor, a second neutralizing capacitor and a harmonic suppression unit. A common source electrode of the differential cascode amplifier is connected with a common grid electrode of the differential cascode amplifier to form a first node and a second node, and the first neutralizing capacitor and the second neutralizing capacitor are cross-coupled between a differential input end of the differential cascode amplifier and the first node and the second node. The harmonic suppression unit is connected among the first node, the second node and the ground voltage. According to the power amplifier, the transformer and the circuit module, by introducing the harmonic suppression unit, the fundamental frequency impedance and the second harmonic impedance of the power amplifier are adjusted, suppression of second harmonics is achieved, and the linearity of the power amplifier is improved. Meanwhile, the output impedance Q value of the amplifier is reduced, and compromise among linearity, efficiency and other performance indexes of an output matching network is optimized.

Description

Technical Field

[0001] The utility model belongs to the technical field of power amplification, and in particular relates to a power amplifier, a transformer and a circuit module. Background Art

[0002] The power amplifier and transformer are very important functional modules in the transmitter, which need to amplify the signal to a certain power and minimize the distortion of the signal. In order to obtain a better compromise between efficiency and linearity, the current power amplifier is generally biased in Class AB. At this time, the quadratic nonlinear term of the transistor is large, which will generate a large second harmonic component at the drain end, significantly reducing the linear range of the power amplifier.

[0003] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to a person skilled in the art. Utility Model Content

[0004] The utility model aims to provide a power amplifier, a transformer and a circuit module, which can suppress the second harmonic and improve the linearity of the power amplifier.

[0005] In order to achieve the above-mentioned purpose, a specific embodiment of the utility model provides a power amplifier, including a differential cascode amplifier, a first neutralization capacitor, a second neutralization capacitor and a harmonic suppression unit, the common source of the differential cascode amplifier is connected to the common gate of the differential cascode amplifier to form a first node and a second node, the first neutralization capacitor and the second neutralization capacitor are cross-coupled between the differential input terminal of the differential cascode amplifier and the first node and the second node, and the harmonic suppression unit is connected between the first node, the second node and the ground voltage.

[0006] In one or more embodiments of the present invention, the common source of the differential cascode amplifier includes a first input tube and a second input tube, the first end of the first input tube and the first end of the second input tube are connected to the ground voltage, the control end of the first input tube and the control end of the second input tube are used to form the differential input end of the differential cascode amplifier, the second end of the first input tube is connected to the common gate of the differential cascode amplifier and forms a first node, and the second end of the second input tube is connected to the common gate of the differential cascode amplifier and forms a second node.

[0007] In one or more embodiments of the present invention, the common gate of the differential cascode amplifier includes a first output tube and a second output tube, the second end of the first output tube is connected to the common source of the differential cascode amplifier and forms a first node, the second end of the second output tube is connected to the common source of the differential cascode amplifier and forms a second node, the control end of the first output tube and the control end of the second output tube are connected to a bias voltage, and the second end of the first output tube and the second end of the second output tube are used to generate a differential output signal.

[0008] In one or more embodiments of the present invention, the harmonic suppression unit includes a first inductor and a first capacitor, wherein a first end of the first inductor is connected to a first node, a second end of the first inductor is connected to a second node, a first end of the first capacitor is connected to a center tap of the first inductor, and a second end of the first capacitor is connected to a ground voltage.

[0009] In one or more embodiments of the present invention, the harmonic suppression unit includes a second capacitor, a third capacitor and a second inductor, the first end of the second capacitor is connected to the first node, the first end of the third capacitor is connected to the second node, the second end of the second capacitor and the second end of the third capacitor are connected to the first end of the second inductor, and the second end of the second inductor is connected to the ground voltage.

[0010] A specific embodiment of the utility model further provides a transformer, comprising the above-mentioned power amplifier, a primary winding and a secondary winding coupled to the primary winding, wherein the two ends of the primary winding are respectively connected to the differential output ends of the differential cascode amplifier.

[0011] In one or more embodiments of the present invention, the primary winding, the secondary winding and the first inductor are coupled to each other.

[0012] A specific embodiment of the utility model further provides a circuit module, including the above-mentioned power amplifier or transformer.

[0013] Compared with the prior art, the power amplifier, transformer and circuit module of the utility model adjust the fundamental frequency impedance and second harmonic impedance of the power amplifier by introducing a harmonic suppression unit, thereby achieving second harmonic suppression and improving the linearity of the power amplifier. At the same time, the output impedance Q value of the amplifier is reduced, the output matching network is optimized in terms of the compromise between linearity, efficiency and other performance indicators, and the flexibility and freedom of circuit design are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 This is a circuit schematic diagram of the power amplifier in the first embodiment of the utility model.

[0016] Figure 2 This is a circuit schematic diagram of the power amplifier in the second embodiment of the present utility model.

[0017] Figure 3 This is a circuit diagram of the transformer in Embodiment 3 of the present utility model.

[0018] Figure 4 This is a circuit diagram of the transformer in the fourth embodiment of the present utility model. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] The term "coupled" or "connected" or "connected" in the specification includes both direct connection and indirect connection. Indirect connection is a connection through an intermediate medium, such as a connection through an electrically conductive medium, which may have parasitic inductance or parasitic capacitance; indirect connection may also include connection through other active or passive devices on the basis of achieving the same or similar functional purpose, such as connection through circuits or components such as switches and follower circuits. In addition, in the present utility model, words such as "first" and "second" are mainly used to distinguish one technical feature from another technical feature, and do not necessarily require or imply that there is a certain actual relationship, quantity or order between these technical features.

[0021] Embodiment 1

[0022] like Figure 1 As shown, the power amplifier in one embodiment of the utility model includes a differential cascode amplifier, a first neutralization capacitor C1, a second neutralization capacitor C2 and a harmonic suppression unit.

[0023] Among them, the common source of the differential cascode amplifier is connected to the common gate of the differential cascode amplifier to form a first node D1 and a second node D2, the first neutralization capacitor C1 and the second neutralization capacitor C2 are cross-coupled between the differential input terminal of the differential cascode amplifier and the first node D1 and the second node D2, and the harmonic suppression unit is connected between the first node D1, the second node D2 and the ground voltage.

[0024] Specifically, the common source of the differential cascode amplifier includes a first input tube M1 and a second input tube M2. The first end of the first input tube M1 and the first end of the second input tube M2 are connected to the ground voltage, the control end of the first input tube M1 is used to form the first differential input end of the differential cascode amplifier, and the control end of the second input tube M2 is used to form the second differential input end of the differential cascode amplifier. The control end of the first input tube M1 is connected to the first end of the first neutralization capacitor C1, and the second end of the first neutralization capacitor C1 is connected to the second end of the second input tube M2. The control end of the second input tube M2 is connected to the first end of the second neutralization capacitor C2, and the second end of the second neutralization capacitor C2 is connected to the second end of the first input tube M1. The second end of the first input tube M1 is connected to the common gate of the differential cascode amplifier and forms a first node D1, and the second end of the second input tube M2 is connected to the common gate of the differential cascode amplifier and forms a second node D2.

[0025] The common gate of the differential cascode amplifier includes a first output tube M3 and a second output tube M4. The second end of the first output tube M3 is connected to the second end of the first input tube M1 and forms a first node D1, the second end of the second output tube M4 is connected to the second end of the second input tube M2 and forms a second node D2, the control end of the first output tube M3 and the control end of the second output tube M4 are connected to the bias voltage, the second end of the first output tube M3 is used to form the first differential output end of the differential cascode amplifier, and the second end of the second output tube M4 is used to form the second differential output end of the differential cascode amplifier.

[0026] In one embodiment, the first input tube M1, the second input tube M2, the first output tube M3 and the second output tube M4 are all NPN MOS tubes, whose first end is the source, the second end is the drain, and the control end is the gate. In other embodiments, the first input tube M1, the second input tube M2, the first output tube M3 and the second output tube M4 can also be PNP MOS tubes or other types of devices, and their connection methods are all adaptively adjusted.

[0027] The first input tube M1, the second input tube M2, the first output tube M3 and the second output tube M4 form a common-source common-gate amplifier. The cross-coupled first neutralization capacitor C1 and the second neutralization capacitor can provide positive feedback, reduce the influence of the gate-drain parasitic capacitance of the first input tube M1 and the second input tube M2, and improve the stability and gain of the circuit.

[0028] like Figure 1 As shown, the harmonic suppression unit includes a first inductor L1 and a first capacitor C3. The first end of the first inductor L1 is connected to the second end of the first input tube M1, the second end of the first inductor L1 is connected to the second end of the second input tube M2, the first end of the first capacitor C3 is connected to the center tap of the first inductor L1, and the second end of the first capacitor C3 is connected to the ground voltage.

[0029] The first inductor L1 and the first capacitor C3 form an LC resonant network. The inductance of the first inductor L1 can change the load impedance of the first input tube M1 and the second input tube M2 at the fundamental frequency. At the same time, the LC resonant network can also adjust the load impedance of the first input tube M1 and the second input tube M2 at the second harmonic, thereby achieving harmonic suppression and improving the linearity of the power amplifier.

[0030] At the same time, the first inductor L1 can reduce the output impedance Q value of the power amplifier, optimize the trade-off between linearity, efficiency and other performance indicators of the output matching network, and improve the flexibility and freedom of circuit design.

[0031] This embodiment also provides a circuit module, including the above-mentioned power amplifier.

[0032] Embodiment 2

[0033] like Figure 2 As shown, the power amplifier in this embodiment is different from the power amplifier in the first embodiment only in the specific structure of the harmonic suppression unit, and the connection method of the first input tube M1, the second input tube M2, the first output tube M3, the second output tube M4, the first neutralization capacitor C1, the second neutralization capacitor C2 and the harmonic suppression unit is the same as that in the first embodiment.

[0034] Specifically, the harmonic suppression unit includes a second capacitor C4, a third capacitor C5 and a second inductor L2. A first end of the second capacitor C4 is connected to a second end of the first input tube M1, a first end of the third capacitor C5 is connected to a second end of the second input tube M2, a second end of the second capacitor C4 and a second end of the third capacitor C5 are connected to a first end of the second inductor L2, and a second end of the second inductor L2 is connected to a ground voltage.

[0035] This embodiment also provides a circuit module, including the above-mentioned power amplifier.

[0036] Embodiment 3

[0037] like Figure 3 As shown, the third embodiment of the present invention further provides a transformer, including the power amplifier, the primary winding L3 and the secondary winding L4 in the first embodiment.

[0038] The first end of the primary winding L3 is connected to the second end of the first output tube M3, and the second end of the primary winding L3 is connected to the second end of the second output tube M4. The first inductor L1, the primary winding L3 and the secondary winding L4 are coupled to each other, and the secondary winding L4 is connected to the rear-end load circuit to supply power to the rear-end load circuit.

[0039] By incorporating the first inductor L1 into the output matching network to form a three-coil network with the primary winding L3 and the secondary winding L4, the output power of the transformer can be increased while achieving harmonic suppression and improving output linearity.

[0040] This embodiment also provides a circuit module, including the above-mentioned transformer.

[0041] Embodiment 4

[0042] like Figure 4 As shown, the fourth embodiment of the present invention further provides a transformer, including the power amplifier, the primary winding L3 and the secondary winding L4 in the second embodiment.

[0043] The first end of the primary winding L3 is connected to the second end of the first output tube M3, and the second end of the primary winding L3 is connected to the second end of the second output tube M4. The primary winding L3 and the secondary winding L4 are coupled to each other, and the secondary winding L4 is connected to the rear-end load circuit to supply power to the rear-end load circuit.

[0044] The transformer in this embodiment adopts a power amplifier with a harmonic suppression function, which can achieve harmonic suppression and improve output linearity.

[0045] This embodiment also provides a circuit module, including the above-mentioned transformer.

[0046] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0047] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A power amplifier, characterized in that: The invention comprises a differential cascode amplifier, a first neutralization capacitor, a second neutralization capacitor and a harmonic suppression unit, wherein the common source of the differential cascode amplifier is connected to the common gate of the differential cascode amplifier to form a first node and a second node, the first neutralization capacitor and the second neutralization capacitor are cross-coupled between the differential input terminal of the differential cascode amplifier and the first node and the second node, and the harmonic suppression unit is connected between the first node, the second node and the ground voltage.

2. The power amplifier according to claim 1, characterized in that: The common source of the differential cascode amplifier includes a first input tube and a second input tube, the first end of the first input tube and the first end of the second input tube are connected to the ground voltage, the control end of the first input tube and the control end of the second input tube are used to form the differential input end of the differential cascode amplifier, the second end of the first input tube is connected to the common gate of the differential cascode amplifier and forms a first node, and the second end of the second input tube is connected to the common gate of the differential cascode amplifier and forms a second node.

3. The power amplifier according to claim 1, characterized in that: The common gate of the differential cascode amplifier includes a first output tube and a second output tube, the second end of the first output tube is connected to the common source of the differential cascode amplifier to form a first node, the second end of the second output tube is connected to the common source of the differential cascode amplifier to form a second node, the control end of the first output tube and the control end of the second output tube are connected to a bias voltage, and the second end of the first output tube and the second end of the second output tube are used to generate a differential output signal.

4. The power amplifier according to claim 1, characterized in that: The harmonic suppression unit includes a first inductor and a first capacitor, wherein a first end of the first inductor is connected to a first node, a second end of the first inductor is connected to a second node, a first end of the first capacitor is connected to a center tap of the first inductor, and a second end of the first capacitor is connected to a ground voltage.

5. The power amplifier according to claim 1, characterized in that: The harmonic suppression unit includes a second capacitor, a third capacitor and a second inductor, the first end of the second capacitor is connected to the first node, the first end of the third capacitor is connected to the second node, the second end of the second capacitor and the second end of the third capacitor are connected to the first end of the second inductor, and the second end of the second inductor is connected to the ground voltage.

6. A transformer, characterized in that: The invention comprises a power amplifier as claimed in any one of claims 1 to 5, a primary winding and a secondary winding coupled to the primary winding, wherein two ends of the primary winding are respectively connected to the differential output ends of the differential cascode amplifier.

7. The transformer according to claim 6, characterized in that: The primary winding, the secondary winding and the first inductor are coupled to each other.

8. A circuit module, characterized in that: The method comprises a power amplifier as claimed in any one of claims 1 to 5 or a transformer as claimed in any one of claims 6 to 7.

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