Compact coupled device structure and cascaded circuit structure of a radio frequency power amplifier-shunt switch

Abstract

The application discloses a kind of radio frequency power amplifier-shunt switch compact coupling device structures, comprising: radio frequency power amplifier structure and shunt switch structure based on active region coupling mode realizes integrated structure design;Wherein, radio frequency power amplifier structure includes the first source electrode of ground, as input end or output end first gate, as the second gate of first voltage source input end;Shunt switch structure includes the second source electrode of ground, as output end or input end drain, as the second gate of first voltage source input end, as the third gate of second voltage source input end;First voltage source input end, second voltage source input end respectively connect with large resistance.The application has ordinary radio frequency power amplifier signal amplification function, and has high isolation switch performance, solves the problem of circuit isolation deterioration under high frequency, solves the contradiction between low integration level and high frequency performance difficult to consider with minimum area cost.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, specifically relating to a compact coupling device structure and cascaded circuit structure for an RF power amplifier-shunt switch. Background Technology

[0002] In the era of high-speed 5G communication, the increase in operating frequency bands and the application of massive MIMO technology will lead to a surge in the number of RF front-end devices, making the design of RF front-end systems more complex. With the rapid evolution of wireless communication technology, the future development trend of RF front-ends will be high integration, small size, high performance, and low cost.

[0003] In wireless communication transceiver systems, RF power amplifiers and switches are crucial components. Switches control the system's transmission and reception of signals, while power amplifiers must meet high efficiency and high linearity requirements to achieve DC-to-RF conversion. Currently, the functional integration design of the RF front-end is primarily at the circuit level, while in the materials and device fields, mature components are selected based on the circuit performance requirements to complete the circuit design. Therefore, improvements in device performance and the integration of device functions will simplify circuit design and further enhance the system's integration level.

[0004] Traditional RF front-end circuits typically use a power amplifier and a switch connected in series, with impedance matching performed separately. This greatly increases the circuit area and complexity, and the microstrip matching process increases losses, affecting overall performance. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a compact coupling device structure for an RF power amplifier-shunt switch and a cascaded circuit structure. The technical problem to be solved by this invention is achieved through the following technical solution: In a first aspect, embodiments of the present invention provide a compact coupling device structure for a radio frequency power amplifier and a shunt switch. The compact coupling device structure includes a radio frequency power amplifier structure and a shunt switch structure, wherein the radio frequency power amplifier structure and the shunt switch structure are integrated into a single structure based on active region coupling. The radio frequency power amplifier structure includes a grounded first source, a first gate that serves as an input or output terminal, and a second gate that serves as the input terminal of a first voltage source. The shunt switch structure includes a grounded second source, a drain that serves as an output or input terminal, a second gate that serves as an input terminal of a first voltage source, and a third gate that serves as an input terminal of a second voltage source. Large resistors are connected to the first voltage source input terminal and the second voltage source input terminal, respectively.

[0006] In one embodiment of the present invention, the integrated structure of the RF power amplifier structure and the shunt switch structure, implemented based on active region coupling, includes: SiC substrate, with GaN buffer layer, AlGaN barrier layer and SiN passivation layer sequentially located on the SiC substrate; The first source and the second source are located at the two ends of the device, respectively, penetrating the SiN passivation layer and extending into the AlGaN barrier layer; wherein the first source and the second source are connected by an air bridge metal connection. The drain is located in the middle region of the device, penetrating the SiN passivation layer and extending into the AlGaN barrier layer. The first gate, the second gate, and the third gate are located between the first source and the drain, and between the drain and the second source. They all penetrate the SiN passivation layer to the upper surface of the AlGaN barrier layer and overlap the SiN passivation layer.

[0007] In one embodiment of the present invention, the large resistor is a resistor with a resistance value of not less than 1000 ohms.

[0008] In one embodiment of the present invention, the first gate and the second gate are fabricated by batch evaporation of gate metal, while the first gate and the third gate are fabricated by batch evaporation of gate metal.

[0009] In one embodiment of the present invention, from a top view, the gate widths of the first gate and the second gate are equal, and the gate width of the third gate is half the gate width of the first gate.

[0010] In one embodiment of the present invention, when the compact coupling device structure is in the RF power amplifier operating mode, the signal is input through the first gate as the input terminal, the second gate as the first voltage source input terminal is not energized, the RF power amplifier is in operation, the third gate as the second voltage source input terminal is energized with a -28V DC gate voltage, the shunt switch is in a non-operating state, and the signal is amplified and output through the drain as the output terminal.

[0011] In one embodiment of the present invention, when the compact coupling device structure is in the shunt switch operating mode, the signal is input from the drain, which is the input terminal, and a -28V DC gate voltage is applied to the second gate, which is the input terminal of the first voltage source. The RF power amplifier is in a non-operating state. A 0V DC gate voltage is applied to the third gate, which is the input terminal of the second voltage source. The shunt switch is in an operating state, and the signal is output from the first gate, which is the output terminal, after being shunt.

[0012] In a second aspect, embodiments of the present invention provide a cascaded circuit structure of an RF power amplifier and a shunt switch, wherein the RF power amplifier and shunt switch cascaded circuit structure is designed based on the compact coupling device structure of the RF power amplifier and shunt switch described in any of the first aspects.

[0013] In one embodiment of the present invention, the cascaded circuit structure includes transistor M1, transistor M2, transistor M3, resistor R1, and resistor R2; wherein, The gate of transistor M1 serves as the first output terminal of the cascaded current structure, the source of transistor M1 is grounded, the drain of transistor M1 is connected to the source of transistor M2, the gate of transistor M2 is connected to the input terminal of the first voltage source through resistor R1, the drain of transistor M2 is connected to the drain of transistor M3 and serves as the second output terminal of the cascaded current structure, the gate of transistor M3 is connected to the input terminal of the second voltage source through resistor R2, and the source of transistor M3 is grounded. Among them, transistors M1 and M2 constitute an RF power amplifier, transistors M2 and M3 constitute a shunt switch, and the RF power amplifier and the shunt switch share transistor M2.

[0014] In one embodiment of the present invention, the resistance values ​​of resistors R1 and R2 are both not less than 1000 ohms.

[0015] The beneficial effects of this invention are: The compact coupling device structure of the RF power amplifier-shunt switch proposed in this invention has the signal amplification function of ordinary RF power amplifiers, while also possessing high isolation switching performance, solving the problem of circuit isolation degradation at high frequencies. Specifically, by adopting a compact coupling method in the active region, multiple functions are integrated in the same active region. This device achieves switching between different operating modes by controlling the opening and closing of the under-gate channels of the three gates. At the same time, the addition of shunt function makes it have higher isolation in shunt switch operating mode. It solves the contradiction between low integration density and difficulty in achieving high-frequency performance in discrete architectures with minimal area overhead, providing a new device path with high performance and high functional density for the next generation of highly integrated, wideband RF front-ends.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a compact coupling device structure and cascaded circuit structure for an RF power amplifier-shunt switch provided in an embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of the compact coupling device structure of the RF power amplifier-shunt switch provided in an embodiment of the present invention; Figure 3 This is a schematic planar layout of the compact coupling device structure of the RF power amplifier-shunt switch provided in an embodiment of the present invention; Figure 4 This is a partially enlarged schematic diagram of the compact coupling device structure of the RF power amplifier-shunt switch provided in an embodiment of the present invention; Figure 5This is a simulation comparison diagram of the isolation between the traditional power amplifier-switch dual-gate device structure and the RF power amplifier-shunt switch compact coupling device structure proposed in this invention.

[0018] Explanation of reference numerals in the attached figures: 1- SiC substrate; 2- GaN buffer layer; 3- AlGaN barrier layer; 4- SiN passivation layer; 5- First source; 6- First gate; 7- Second gate; 8- Drain; 9- Third gate; 10- Second source; 11- Air bridge metal. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0020] Firstly, this invention aims to address the problems of large size and difficulty in integration of RF front-ends. When integrating RF power amplifiers and shunt switching devices, it is necessary to ensure the performance of the RF power amplifier while further improving the isolation of the shunt switching devices to avoid signal crosstalk. For this purpose, please refer to... Figure 1 This invention provides a compact coupling device structure for an RF power amplifier and a shunt switch. This compact coupling device structure includes an RF power amplifier structure and a shunt switch structure, which are integrated into a single structure based on active region coupling. The RF power amplifier structure includes a first source 5 (grounded GND1), a first gate 6 (serving as an input or output terminal), and a first voltage source input terminal V. CTL1 The second gate 7; The shunt switch structure includes a second source 10 grounded to GND2, a drain 8 serving as an output or input terminal, a second gate 7 serving as an input terminal of a first voltage source, and a second voltage source input terminal V. CTL2 The third gate 9; V at the first voltage source input terminal CTL1 Second voltage source input terminal V CTL2 Large resistors are connected to each of them.

[0021] In this embodiment of the invention, the integrated structure of the RF power amplifier structure and the shunt switch structure is achieved based on active region coupling, as shown below. Figure 2As shown, the device includes: a SiC substrate 1, with a GaN buffer layer 2, an AlGaN barrier layer 3, and a SiN passivation layer 4 sequentially located on the SiC substrate 1; a first source 5 and a second source 10 located at opposite ends of the device, penetrating the SiN passivation layer 4 and extending into the AlGaN barrier layer 3; wherein the first source 5 and the second source 10 are connected by an air bridge metal 11; a drain 8 located in the middle region of the device, penetrating the SiN passivation layer 4 and extending into the AlGaN barrier layer 3; a first gate 6, a second gate 7, and a third gate 9, wherein the first gate 6 and the second gate 7 are located between the first source 5 and the drain 8, and the third gate 9 is located between the drain 8 and the second source 10, all penetrating the SiN passivation layer 4 and extending to the upper surface of the AlGaN barrier layer 3 and resting on the SiN passivation layer 4. The first source 5 and the second source 10 are connected by an air bridge metal 11.

[0022] In this embodiment of the invention, the second gate 7 is located between the first gate 6 and the drain 8. During the manufacturing process, considering that the first gate 6 and the second gate 7 are too close, the first gate 6 and the second gate 7 are prepared by evaporating the gate metal in batches. The first gate 6 and the third gate 9 are relatively far apart, and the first gate 6 and the third gate 9 are prepared by evaporating the gate metal in the same batch as usual.

[0023] In this embodiment of the invention, viewed from above, the gate widths of the first gate 6 and the second gate 7 are equal, and the gate width of the third gate 9 is half the gate width of the first gate 6. The large resistor is a resistor with a resistance value of not less than 1000 ohms. This is because the present invention uses active region coupling to combine the RF power amplifier and the shunt switch circuit into a single device. Only a single matching operation between the RF power amplifier and the shunt switch is required to complete the transmitter link function, reducing the difficulty of matching and the circuit area. Furthermore, by adjusting the width of the injection isolation region to change the gate width of the shunt switch, the gate widths of the RF power amplifier and the shunt switch can be designed independently. This satisfies the requirement of a large gate width for high-power RF power amplifiers, and the gate width of the shunt switch can be controlled by adjusting the width of the active region. Considering both the off-state capacitance and on-state resistance of the switching device, the gate width W1 of the shunt switch is ultimately determined to be half the gate width W2 of the RF power amplifier, that is, the gate width of the third gate 9 is half the gate width of the first gate 6. Meanwhile, to prevent signal leakage from the switch gate, the new device connects kiloohm high-voltage resistors to the second gate 7 and the third gate 9 of the shunt switch.

[0024] In this embodiment of the invention, when the compactly coupled device structure is in the RF power amplifier operating mode, the first gate 6 serves as the input terminal Port1, and the drain 8 serves as the output terminal Port2. The signal is input through the first gate 6 (Port1), the second gate 7 (VCTL1, the first voltage source input terminal) is not energized, the power amplifier region is turned on, and the RF power amplifier is in operation. A -28V DC gate voltage is applied to the third gate 9 (VCTL2, the second voltage source input terminal), the shunt region is turned off, the shunt switch is in a non-operating state, and the signal, after amplification, is output through the drain 8 (Port2).

[0025] In this embodiment of the invention, when the compact coupling device structure is in shunt switch mode, the first gate 6 serves as output port 1, and the drain 8 serves as input port 2. The signal is input through the drain 8 (port 2) and serves as the first voltage source input V. CTL1 When a -28V DC gate voltage is applied to the second gate 7, the power amplifier region is turned off and the RF power amplifier is in a non-operating state. When a 0V DC gate voltage is applied to the third gate 9, which serves as the input terminal of the second voltage source VCTL2, the shunt region is turned on and the shunt switch is in operation. Most of the signal is blocked by the second gate 7 and connected to ground through the shunt region, further improving the isolation of the device. Finally, the signal is output by the first gate 6, which serves as the output terminal Port1, after being shunt.

[0026] Figure 3 The diagram illustrates a planar layout of the device structure proposed in this invention. To more clearly see the arrangement of the three gates in the planar layout, a partial enlarged view of the area where the three gates are located is further provided, as shown below. Figure 4 As shown.

[0027] As can be seen, this invention seamlessly embeds a shunt switch structure into a dual-gate device, achieving monolithic integration of RF power amplifier and shunt switch functions. In shunt switch mode, the device effectively bypasses leakage signals using a parallel low-impedance path, further improving isolation compared to conventional dual-gate switches and maintaining excellent isolation performance over a wide frequency band, overcoming the technical bottleneck of the sharp decline in high-frequency isolation in traditional switches. Simultaneously, in RF power amplifier mode, the shunt branch is turned off, maintaining high output power and high efficiency, ensuring that the transmit link performance is unaffected. Through a compact coupling design of the active region, a new device structure design approach is provided for improving device performance and expanding device functions, achieving high integration of the RF front-end while further improving switch isolation performance. Figure 5 Simulation results of the isolation of the traditional power amplifier-switching dual-gate device structure and the RF power amplifier-shunt switch compact coupling device structure proposed in this invention are presented. Figure 5 The horizontal axis represents the operating frequency in GHz, and the vertical axis represents the isolation in dB. Figure 5The blue line represents the isolation simulation results of the traditional power amplifier-switching dual-gate device structure, while the orange line represents the isolation simulation results of the RF power amplifier-shunt switch compact coupling device structure proposed in this invention. Figure 5 It can be seen that the device structure proposed in this invention has higher isolation.

[0028] In summary, the compact coupling device structure of the RF power amplifier-shunt switch proposed in this invention has the signal amplification function of a general RF power amplifier, while also possessing high isolation switching performance, thus solving the problem of circuit isolation degradation at high frequencies. Specifically, by adopting a compact coupling method in the active region, multiple functions are integrated into the same active region. This device achieves switching between different operating modes by controlling the opening and closing of the under-gate channels of the three gates. At the same time, the addition of the shunt function enables it to have higher isolation in the shunt switch operating mode. It solves the contradiction between low integration density and difficulty in achieving high-frequency performance in discrete architectures with minimal area overhead, providing a new device path with high performance and high functional density for the next generation of highly integrated, wideband RF front-ends.

[0029] Secondly, continue as Figure 1 As shown, an embodiment of the present invention provides a cascaded circuit structure of an RF power amplifier and a shunt switch, wherein the RF power amplifier and shunt switch cascaded circuit structure is designed according to the compact coupling device structure of the RF power amplifier and shunt switch described in any of the first aspects.

[0030] In this embodiment of the invention, the cascaded circuit structure includes transistor M1, transistor M2, transistor M3, resistor R1, and resistor R2; wherein, The gate of transistor M1 serves as the first output terminal of the cascaded current structure, the source of transistor M1 is grounded, the drain 8 of transistor M1 is connected to the source of transistor M2, the gate of transistor M2 is connected to the input terminal of the first voltage source through resistor R1, the drain 8 of transistor M2 is connected to the drain 8 of transistor M3 and serves as the second output terminal of the cascaded current structure, the gate of transistor M3 is connected to the input terminal of the second voltage source through resistor R2, and the source of transistor M3 is grounded; wherein, transistors M1 and M2 constitute an RF power amplifier, transistors M2 and M3 constitute a shunt switch, and the RF power amplifier and the shunt switch share transistor M2.

[0031] In this embodiment of the invention, the resistance values ​​of resistors R1 and R2 are both not less than 1000 ohms.

[0032] As for the cascaded circuit structure embodiment of the second aspect, since it is basically similar to the compactly coupled device structure embodiment of the first aspect, the description is relatively simple. For relevant details, please refer to the description of the compactly coupled device structure embodiment of the first aspect.

[0033] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the specification and accompanying drawings, will understand and implement other variations of the disclosed embodiments in carrying out the claimed invention. In the specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. While certain measures are described in different embodiments, this does not mean that these measures cannot be combined to produce good results.

[0035] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A compact coupling device structure for an RF power amplifier-shunt switch, characterized in that, The compact coupling device structure includes an RF power amplifier structure and a shunt switch structure, which are integrated into a single structure based on active region coupling. The radio frequency power amplifier structure includes a grounded first source, a first gate that serves as an input or output terminal, and a second gate that serves as the input terminal of a first voltage source. The shunt switch structure includes a grounded second source, a drain that serves as an output or input terminal, a second gate that serves as an input terminal of a first voltage source, and a third gate that serves as an input terminal of a second voltage source. Large resistors are connected to the first voltage source input terminal and the second voltage source input terminal, respectively.

2. The compact coupling device structure of the RF power amplifier-shunt switch according to claim 1, characterized in that, The integrated structure of RF power amplifier and shunt switch based on active region coupling includes: SiC substrate, with GaN buffer layer, AlGaN barrier layer and SiN passivation layer sequentially located on the SiC substrate; The first source and the second source are located at the two ends of the device, respectively, penetrating the SiN passivation layer and extending into the AlGaN barrier layer; wherein the first source and the second source are connected by an air bridge metal connection. The drain is located in the middle region of the device, penetrating the SiN passivation layer and extending into the AlGaN barrier layer. The first gate, the second gate, and the third gate are located between the first source and the drain, and between the drain and the second source. They all penetrate the SiN passivation layer to the upper surface of the AlGaN barrier layer and overlap the SiN passivation layer.

3. The compact coupling device structure of the RF power amplifier-shunt switch according to claim 1, characterized in that, A large resistor is a resistor with a resistance value of not less than 1000 ohms.

4. The compact coupling device structure of the RF power amplifier-shunt switch according to claim 1, characterized in that, The first gate and the second gate are fabricated by evaporating gate metal in batches, while the first gate and the third gate are fabricated by evaporating gate metal in the same batch.

5. The compact coupling device structure of the RF power amplifier-shunt switch according to claim 1, characterized in that, Viewed from above, the first and second gates have the same gate width, while the third gate has half the gate width of the first gate.

6. The compact coupling device structure of the RF power amplifier-shunt switch according to claim 1, characterized in that, When the compact coupling device structure is in the RF power amplifier operating mode, the signal is input through the first gate, which is the input terminal, and no voltage is applied to the second gate, which is the input terminal of the first voltage source. The RF power amplifier is in operation. A -28V DC gate voltage is applied to the third gate, which is the input terminal of the second voltage source. The shunt switch is in a non-operating state. The signal is amplified and output through the drain, which is the output terminal.

7. The compact coupling device structure of the RF power amplifier-shunt switch according to claim 1, characterized in that, When the compact coupling device structure is in shunt switch operating mode, the signal is input through the drain, which is the input terminal. A -28V DC gate voltage is applied to the second gate, which is the input terminal of the first voltage source, and the RF power amplifier is in a non-operating state. A 0V DC gate voltage is applied to the third gate, which is the input terminal of the second voltage source, and the shunt switch is in an operating state. The signal is shunted and output through the first gate, which is the output terminal.

8. A cascaded circuit structure of an RF power amplifier and a shunt switch, characterized in that, The RF power amplifier-shunt switch cascade circuit structure is designed according to any one of claims 1 to 7 as a compact coupled device structure of RF power amplifier-shunt switch.

9. The RF power amplifier-shunt switch cascaded circuit structure according to claim 8, characterized in that, The cascaded circuit structure includes transistor M1, transistor M2, transistor M3, resistor R1, and resistor R2; wherein, The gate of transistor M1 serves as the first output terminal of the cascaded current structure, the source of transistor M1 is grounded, the drain of transistor M1 is connected to the source of transistor M2, the gate of transistor M2 is connected to the input terminal of the first voltage source through resistor R1, the drain of transistor M2 is connected to the drain of transistor M3 and serves as the second output terminal of the cascaded current structure, the gate of transistor M3 is connected to the input terminal of the second voltage source through resistor R2, and the source of transistor M3 is grounded. Among them, transistors M1 and M2 constitute an RF power amplifier, transistors M2 and M3 constitute a shunt switch, and the RF power amplifier and the shunt switch share transistor M2.

10. The RF power amplifier-shunt switch cascaded circuit structure according to claim 9, characterized in that, The resistance values ​​of resistors R1 and R2 are both not less than 1000 ohms.

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