A high video bandwidth radio frequency power device and a method of manufacturing the same

Abstract

The application discloses a high video bandwidth radio frequency power device, which comprises a carrier flange, at least one amplifier arranged on the carrier flange, wherein the amplifier comprises a power transistor, and the amplifier further comprises an inner matching circuit and a video bandwidth expansion circuit module arranged on the carrier flange; the inner matching circuit comprises an input matching capacitor arranged on an input end and an output matching capacitor arranged on an output end; the video bandwidth expansion circuit module comprises a carrier plate, and an expansion circuit is arranged on the carrier plate; and the comprehensive equivalent inductance from the output end of the power transistor to the grounding end in the video bandwidth expansion circuit module and the comprehensive equivalent capacitance of the source-drain parasitic capacitance of the power transistor and the output matching capacitor form a resonance loop. The video bandwidth of the radio frequency power device is improved, the assembly complexity is reduced, and the device cost is not substantially increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor devices, and particularly relates to a low-cost high-video-bandwidth radio frequency power device and a manufacturing method thereof. BACKGROUND

[0002] The radio frequency power device is a key element at the end of the transmitter in the communication base station system. It has a crucial influence on the overall performance of the communication system. With the advent of 5G, the wireless communication system needs increasingly high data speed and bandwidth. However, the expansion of the signal bandwidth brings greater challenges to the system digital pre-distortion technology. The most critical one is to require a higher video bandwidth. The bottleneck of the video bandwidth is the RF radio frequency power device. Therefore, it is increasingly important to improve the video bandwidth of the radio frequency power device.

[0003] At present, in order to improve the video bandwidth of the RF radio frequency power device, the existing scheme such as Figure 1 can set electronic elements in the internal structure of the power device to form a decoupling LC circuit between the electronic elements inside the power device, and the equivalent circuit diagram is as shown in Figure 2 However, in the existing mainstream high-power radio frequency power amplifier, the power device generally adopts a ceramic packaging structure, and the internal space of the ceramic packaging structure is limited and cannot be expanded outward. Therefore, the thickness of the electronic element 5 is often very thick due to the constraints of space and the size of the LC circuit (large capacitance and small inductance), and therefore a groove needs to be formed on the flange of the carrier, which is complicated in processing technology and high in cost. SUMMARY

[0004] In view of the above technical problems, the present application aims to provide a high-video-bandwidth radio frequency power device and a manufacturing method thereof, which can improve the video bandwidth of the radio frequency power device while reducing the assembly complexity and without substantially increasing the cost of the device.

[0005] In order to solve the problems in the prior art, the technical scheme provided by the present application is as follows:

[0006] A high video bandwidth radio frequency power device comprises a carrier flange, at least one amplifier arranged on the carrier flange, the amplifier comprising a power transistor, the amplifier further comprising an inner matching circuit and a video bandwidth expansion circuit module arranged on the carrier flange, the inner matching circuit comprising an input matching capacitor arranged at an input end and an output matching capacitor arranged at an output end, the video bandwidth expansion circuit module comprising a carrier plate, the carrier plate being arranged with an expansion circuit, one end of the input matching capacitor being connected to a device input end, the other end being connected to the power transistor, an output end of the power transistor being connected to a device output end, the output end of the power transistor being further connected to one end of the output matching capacitor; the output matching capacitor being connected to one end of the video bandwidth expansion circuit module, the other end of the video bandwidth expansion circuit module being grounded; and a comprehensive equivalent inductance from the output end of the power transistor to the ground end in the video bandwidth expansion circuit module and a comprehensive equivalent capacitance of a source-drain parasitic capacitance of the power transistor and the output matching capacitor forming a resonance circuit.

[0007] In the preferred technical solution, the expansion circuit comprises a series connection of a capacitor element and a resistor element, one end of the capacitor element being grounded, and one end of the resistor element being connected to the output matching capacitor through a bonding wire.

[0008] In the preferred technical solution, the capacitor element is a discrete element.

[0009] In the preferred technical solution, the output end of the power transistor is connected to the output matching capacitor through a fourth bonding wire, and an equivalent inductance of the fourth bonding wire and a drain-source parasitic capacitance of the power transistor form a resonance circuit.

[0010] In the preferred technical solution, the capacitance value of the capacitor element is greater than 10 nF.

[0011] In the preferred technical solution, the output matching capacitor is further connected to a pin through a bonding wire, and the other end of the pin is externally connected to a PCB.

[0012] The application further discloses a manufacturing method of the high video bandwidth radio frequency power device.

[0013] S01: at least one amplifier is attached to the carrier flange, the amplifier comprising a power transistor, an input matching capacitor and an output matching capacitor being attached to an input end and an output end of the power transistor respectively;

[0014] S02: a carrier plate of a video bandwidth expansion circuit module corresponding to the number of amplifiers is attached to the carrier flange, and an expansion circuit is arranged on the carrier plate;

[0015] S03: connecting the input matching capacitor with the device input terminal through a first bonding wire, connecting the input terminal of the power transistor with the input matching capacitor through a second bonding wire, connecting the output terminal of the power transistor with the device output terminal through a third bonding wire, and connecting the output terminal of the power transistor with the output matching capacitor through a fourth bonding wire;

[0016] S04: connecting the output matching capacitor with one end of the video bandwidth extension circuit module through a fifth bonding wire, and grounding the other end of the video bandwidth extension circuit module; the comprehensive equivalent inductance from the output terminal of the power transistor to the grounding end in the video bandwidth extension circuit module and the comprehensive equivalent capacitance of the source-drain parasitic capacitance of the power transistor and the output matching capacitor form a resonance circuit.

[0017] In the preferred technical solution, the extension circuit comprises a series connection of a capacitor element and a resistor element, the capacitor element is a discrete element, the resistor element is arranged between the first pad and the second pad, the capacitor element is attached on the second pad and the third pad of the carrier board by welding or bonding, one end of the first pad is connected with the output matching capacitor through the fifth bonding wire, and the third pad is grounded through a grounding via on the carrier board.

[0018] In the preferred technical solution, the equivalent inductance of the fourth bonding wire and the drain-source parasitic capacitance of the power transistor form a resonance circuit.

[0019] In the preferred technical solution, the output matching capacitor is connected with a bonding wire connecting pin, and the other end of the pin is externally connected with a PCB.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] Since the video bandwidth extension circuit module and the power transistor are arranged on the carrier flange and are close to each other, the comprehensive equivalent inductance Le is greatly reduced, so that the video bandwidth of the radio frequency power device is greatly improved, and the assembly is convenient and flexible. At the same time, the video bandwidth extension circuit module can use discrete capacitors, which greatly reduces the cost of the video bandwidth extension circuit module and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be further described below in combination with the drawings and embodiments:

[0023] Figure 1 is a top view of a high video bandwidth radio frequency power amplifier in a prior art implementation scheme;

[0024] Figure 2 is an equivalent circuit diagram of a high video bandwidth radio frequency power amplifier in a prior art implementation scheme;

[0025] Figure 3This is a connection diagram of the high video bandwidth radio frequency power device of the present invention;

[0026] Figure 4 This is another connection diagram of the high video bandwidth radio frequency power device of the present invention;

[0027] Figure 5 This is another connection diagram of the high video bandwidth radio frequency power device of the present invention;

[0028] Figure 6 This is a flowchart illustrating the fabrication method of the high video bandwidth radio frequency power device of the present invention. Detailed Implementation

[0029] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.

[0030] Example:

[0031] like Figure 3 As shown, a high video bandwidth radio frequency power device includes a carrier flange F and at least one amplifier disposed on the carrier flange F. The amplifier includes a power transistor D1, an internal matching circuit disposed on the carrier flange F, and a video bandwidth extension circuit module VN. The internal matching circuit includes an input matching capacitor C1 disposed at the input terminal and an output matching capacitor C2 disposed at the output terminal. The video bandwidth extension circuit module VN includes a carrier board VC, on which an extension circuit is disposed. One end of the input matching capacitor C1 is connected to the device input terminal Lin through a first bonding wire B1, and the other end is connected to the power transistor through a second bonding wire B2. Transistor D1 is connected, and the output terminal of power transistor D1 is connected to the device output terminal Lout via the third bonding wire B3. The output terminal of power transistor D1 is also connected to one end of the output matching capacitor C2 via the fourth bonding wire B4. The output matching capacitor C2 is connected to one end of the video bandwidth extension circuit module VN via the fifth bonding wire B5, and the other end of the video bandwidth extension circuit module is grounded. The combined equivalent inductance Le from the output terminal of power transistor D1 to the ground terminal in the video bandwidth extension circuit module VN, together with the source-drain parasitic capacitance (Cds) of power transistor D1 and the combined equivalent capacitance Ce of output matching capacitor C2, form a resonant circuit. The resonant point is given by the formula... Calculations show that the frequency of this resonant point determines the range of the video bandwidth. Because the video bandwidth extension circuit module VN can be made relatively small, it is compatible with existing amplifiers of the same size.

[0032] It should be noted that the power transistor D1 here can be single or multiple. The input matching capacitor C1 and the output matching capacitor C2 are chip capacitors. The first, second, third, fourth and fifth bonding wires here are generally multiple bonding wires, which can form a bonding wire group, and the bonding wires are generally gold wires.

[0033] The carrier VC can be realized by a printed circuit board (PCB), a semiconductor substrate (such as silicon, gallium arsenide, etc.) or a ceramic substrate circuit. The carrier VC can be attached to the carrier flange F of the device by silver paste bonding or welding.

[0034] In a preferred embodiment, the expansion circuit includes a series connection of a capacitor element Cv and a resistor element R1, one end of the capacitor element Cv is grounded, and one end of the resistor element R1 is connected to the output matching capacitor C2 through the fifth bonding wire B5.

[0035] In a preferred embodiment, the capacitor element is a discrete element, i.e. a discrete capacitor, and the resistor element can be a discrete element or an integrated circuit (chip).

[0036] In a specific implementation, the carrier VC includes a first pad P1, a second pad P2 and a third pad P3, the resistor element R1 is arranged between the first pad P1 and the second pad P2, the capacitor element Cv is attached to the second pad P2 and the third pad P3 of the carrier VC by welding or bonding, one end of the first pad P1 is connected to the output matching capacitor C2 through the fifth bonding wire B5, and the third pad P3 is grounded through a ground via hole GVH on the carrier VC.

[0037] The resistor element R1 adopts the form of a discrete device and can be attached to the pad P1 and the pad P2 on the carrier VC by welding or bonding. The resistor element R1 adopts the form of a chip resistor, which can be realized by a semiconductor integrated passive device (IPD) or a ceramic thin film circuit and is directly integrated on the carrier VC.

[0038] In a preferred embodiment, the capacitance of the capacitor element Cv is greater than 10 nF.

[0039] In a preferred embodiment, the resistance of the resistor element R1 is between 1 ohm and 5 ohms.

[0040] In a preferred embodiment, the output end of the power transistor is connected to the output matching capacitor through a fourth bonding wire, and the equivalent inductance Li of the fourth bonding wire forms a resonance circuit with the drain-source parasitic capacitance (Cds) of the power transistor, and the resonance point is calculated by the formula The output impedance of the device can be improved within the radio frequency passband.

[0041] In another embodiment, when there are multiple amplifiers, such as in Doherty circuit applications, two or more video bandwidth extension circuit modules and two or more amplifiers can be placed in the same package F. As shown in Figure 4 , one amplifier and one video bandwidth extension circuit module VN1 are added to the basis of Figure 3 . The circuit connection structure of the two amplifiers is the same, and will not be repeated here.

[0042] In yet another example embodiment, as shown in Figure 5 , to further extend the video bandwidth and improve the linear performance of the wideband signal, the output matching capacitor (C2, C21) can be connected to the pin (VL, VL1) through the bonding wire (Bv, Bv1) on the basis of Figure 4 , and the other end of the pin (VL, VL1) is externally connected to the PCB. In a specific implementation, a package with a VBW pin can be used, and the output matching capacitor is connected to one end of the VBW pin through a bonding wire, and the other end of the VBW pin is externally connected to a ground capacitor on the PCB (not shown in the figure). Preferably, the capacitance value of the ground capacitor is preferably greater than 1uF.

[0043] As shown in Figure 6 , the application also discloses a manufacturing method of a high video bandwidth radio frequency power device, comprising the following steps:

[0044] S01: mounting at least one amplifier on the carrier flange, the amplifier comprising a power transistor, an input matching capacitor and an output matching capacitor are mounted on the input end and the output end of the power transistor, respectively;

[0045] S02: mounting a carrier plate of a video bandwidth extension circuit module corresponding to the number of amplifiers on the carrier flange, and setting an extension circuit on the carrier plate;

[0046] S03: connecting the input matching capacitor to the device input end through a first bonding wire, connecting the input end of the power transistor to the input matching capacitor through a second bonding wire, connecting the output end of the power transistor to the device output end through a third bonding wire, and connecting the output end of the power transistor to the output matching capacitor through a fourth bonding wire;

[0047] S04: connecting the output matching capacitor to one end of the video bandwidth extension circuit module through a fifth bonding wire, and grounding the other end of the video bandwidth extension circuit module; the comprehensive equivalent inductance from the power transistor output end to the grounding end in the video bandwidth extension circuit module and the comprehensive equivalent capacitance of the source-drain parasitic capacitance of the power transistor and the output matching capacitor form a resonance circuit.

[0048] In step S02, the carrier board of the video bandwidth expansion circuit module is attached to a proper area on the carrier flange. For example, the carrier board of the video bandwidth expansion circuit module can be attached near (above or below) the output matching capacitor of each amplifier.

[0049] In a preferred embodiment, the expansion circuit includes a series connection of a capacitor Cv and a resistor R1. The capacitor Cv is a discrete component. The resistor R1 is arranged between the first pad P1 and the second pad P2. The capacitor Cv is attached to the second pad P2 and the third pad P3 of the carrier board VC by soldering or gluing. One end of the first pad P1 is connected to the output matching capacitor C2 by the fifth bonding wire B5. The third pad P3 is grounded through the ground via GVH on the carrier board VC.

[0050] The equivalent inductance Li of the fourth bonding wire B4 forms a resonance circuit with the drain-source parasitic capacitance (Cds) of the power transistor. The resonance point is calculated by the formula The output impedance of the device can be improved within the radio frequency passband.

[0051] Preferably, the capacitance of the capacitor Cv is greater than 10 nF. The resistance of the resistor R1 is between 1 ohm and 5 ohm.

[0052] In another embodiment, when there are multiple amplifiers, such as in a Doherty circuit application, two or more video bandwidth expansion circuit modules and two or more amplifiers can be placed in the same package F. As shown in Figure 4 , one amplifier and one video bandwidth expansion circuit module VN1 are added to Figure 3 . The circuit connection structure of the two amplifiers is the same, which will not be repeated here.

[0053] In yet another example embodiment, as shown in Figure 5 , to further expand the video bandwidth and improve the linear performance of the wideband signal, the output matching capacitor (C2, C21) can be connected to the pin (VL, VL1) through the bonding wire (Bv, Bv1) based on Figure 4 . In a specific implementation, a package with a VBW pin can be used, and the output matching capacitor is connected to one end of the VBW pin through the bonding wire. The other end of the VBW pin is connected to a ground capacitor (not shown in the figure) on the PCB. Preferably, the capacitance of the ground capacitor is greater than 1 uF. In addition, to protect the internal electronic components of the power device, a protective cover can also be provided outside the power device. The protective cover is fixed to the input and output pins and forms a closed cavity with the input and output pins. The protective cover covers all electronic components inside the power device to protect the power device from foreign matter entering the power device.

[0054] The assembling mode can be flexible and diverse, and can adopt traditional packaging forms such as ceramic, OMP, cavity plastic, etc. Of course, it can also be suitable for the power device PCB assembling mode form of non-packaging structure.

[0055] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation on the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. A high video bandwidth radio frequency power device, comprising a carrier flange, at least one amplifier disposed on the carrier flange, the amplifier comprising a power transistor, characterized in that, The amplifier further includes an internal matching circuit and a video bandwidth expansion circuit module disposed on the carrier flange. The internal matching circuit includes an input matching capacitor disposed at the input end and an output matching capacitor disposed at the output end. The video bandwidth expansion circuit module includes a carrier board on which expansion circuit is disposed. One end of the input matching capacitor is connected to the input end of the device, and the other end is connected to the power transistor. The output end of the power transistor is connected to the output end of the device and is also connected to one end of the output matching capacitor. The output matching capacitor is connected to one end of the video bandwidth expansion circuit module, and the other end of the video bandwidth expansion circuit module is grounded. The combined equivalent inductance from the output end of the power transistor to the ground end in the video bandwidth expansion circuit module, together with the source-drain parasitic capacitance of the power transistor and the combined equivalent capacitance of the output matching capacitor, forms a resonant circuit.

2. The high video bandwidth radio frequency power device according to claim 1, characterized in that, The expansion circuit includes a capacitor and a resistor connected in series. One end of the capacitor is grounded, and one end of the resistor is connected to the output matching capacitor via a bonding wire.

3. The high video bandwidth radio frequency power device according to claim 2, characterized in that, The capacitor element is a discrete component.

4. The high video bandwidth radio frequency power device according to claim 1, characterized in that, The output terminal of the power transistor is connected to the output matching capacitor through a fourth bonding wire, and the equivalent inductance of the fourth bonding wire and the drain-source parasitic capacitance of the power transistor form a resonant circuit.

5. The high video bandwidth radio frequency power device according to claim 2, characterized in that, The capacitance value of the capacitor element is greater than 10nF.

6. The high video bandwidth radio frequency power device according to claim 1 or 2, characterized in that, The output matching capacitor is also connected to a pin via a bonding wire, and the other end of the pin is connected to an external PCB.

7. A method for fabricating a high video bandwidth radio frequency power device, characterized in that, Includes the following steps: S01: At least one amplifier is mounted on the carrier flange, the amplifier including a power transistor, and an input matching capacitor and an output matching capacitor are mounted on the input and output terminals of the power transistor, respectively. S02: A carrier board with a corresponding number of video bandwidth expansion circuit modules for the amplifiers is mounted on the carrier flange, and expansion circuits are set on the carrier board. S03: Connect the input matching capacitor to the device input terminal through the first bonding wire, connect the input terminal of the power transistor to the input matching capacitor through the second bonding wire, connect the output terminal of the power transistor to the device output terminal through the third bonding wire, and connect the output terminal of the power transistor to the output matching capacitor through the fourth bonding wire. S04: Connect the output matching capacitor to one end of the video bandwidth expansion circuit module through the fifth bonding wire, and ground the other end of the video bandwidth expansion circuit module; the combined equivalent inductance from the power transistor output terminal to the ground terminal in the video bandwidth expansion circuit module, together with the combined equivalent capacitance of the power transistor source-drain parasitic capacitance and the output matching capacitor, form a resonant circuit.

8. The method for fabricating a high video bandwidth radio frequency power device according to claim 7, characterized in that, The expansion circuit includes a capacitor and a resistor connected in series. The capacitor is a discrete component. The resistor is placed between the first pad and the second pad. The capacitor is mounted on the second and third pads of the carrier board by soldering or bonding. One end of the first pad is connected to the output matching capacitor through the fifth bonding wire. The third pad is grounded through a grounding via on the carrier board.

9. The method for fabricating a high video bandwidth radio frequency power device according to claim 7, characterized in that, The equivalent inductance of the fourth bonding wire and the drain-source parasitic capacitance of the power transistor form a resonant circuit.

10. The method for fabricating a high video bandwidth radio frequency power device according to claim 7 or 8, characterized in that, Connect the output matching capacitor to the pin via a bonding wire, and connect the other end of the pin to the PCB.

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