A radio frequency microwave amplifier with extended modulation bandwidth

Abstract

The application provides a radio frequency microwave amplifier for expanding modulation bandwidth, and relates to the technical field of radio frequency microwave circuits.The amplifier comprises an active device current source end face parasitic capacitor, a first inductor, a first capacitor, a video bandwidth expansion circuit, an output circuit and a target load; the first end of the first inductor is connected with the first end of the active device current source end face parasitic capacitor and the first end of the output circuit respectively, and the second end of the first inductor is connected with the first end of the first capacitor and the first end of the video bandwidth expansion circuit respectively; the second end of the output circuit is connected with the target load; and the second end of the first capacitor is grounded.The application can effectively break through the limitation of traditional radio frequency microwave amplifiers in modulation bandwidth, so that the amplifier can process modulation signals in a wider frequency range, and meet the demand of modern communication systems for high-speed and large-capacity data transmission.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radio frequency microwave circuit, and particularly relates to a radio frequency microwave amplifier with extended modulation bandwidth. BACKGROUND

[0002] With the development of communication technology, various high-order modulation technologies are applied on a large scale, such as 256QAM and 512QAM, which significantly improve the data transmission rate and communication efficiency. However, high-order modulation also brings problems such as nonlinear interference and memory interference, which puts higher requirements on the indicators of solid-state power amplifiers, especially in maintaining high efficiency while meeting high linearity. In order to make up for the lack of linearity, analog pre-distortion and digital pre-distortion and other linearization technologies are often used, but these technologies have some shortcomings. The former has limited linearization capability and is affected by multiple factors such as operating point, bandwidth and temperature; the latter has good linearization compensation capability, but with the rapid development of satellite communication and 5G communication, it is difficult to meet the instantaneous wideband modulation (up to 160MHz) due to its speed, bandwidth and power consumption. How to expand the instantaneous wideband modulation capability of the power amplifier is a key bottleneck that needs to be broken through in the field of linear power amplifiers for communication.

[0003] The linearity of the solid-state power amplifier is not only affected by the impedance of the device at the fundamental and high harmonic frequencies, but also by the impedance of the baseband frequency (modulation signal). The modulation signal frequency, in a multi-carrier system, is represented as a difference frequency, and its impedance is mainly affected by the bias network, resulting in an increase or decrease in intermodulation level, causing the asymmetry of the upper and lower sideband intermodulation levels, which is due to the memory effect. The essence of the memory effect lies in that the instantaneous bandwidth of the power amplifier cannot completely cover the instantaneous bandwidth of the signal, thereby causing the amplitude and phase distortion to fluctuate with the modulation frequency, resulting in poor linearity. SUMMARY

[0004] The present application provides a radio frequency microwave amplifier with extended modulation bandwidth to solve the problem of poor linearity of the microwave amplifier under large modulation bandwidth in the prior art.

[0005] In a first aspect, the present application provides a radio frequency microwave amplifier with extended modulation bandwidth, which comprises an active device current source end face parasitic capacitance, and the radio frequency microwave amplifier with extended modulation bandwidth comprises a first inductor, a first capacitor, a video bandwidth expansion circuit, an output circuit and a target load.

[0006] The first end of the first inductor is connected with the first end of the active device current source end face parasitic capacitance and the first end of the output circuit respectively, and the second end of the first inductor is connected with the first end of the first capacitor and the first end of the video bandwidth expansion circuit respectively.

[0007] The second end of the output circuit is connected with the target load.

[0008] The second end of the first capacitor is grounded.

[0009] The application provides a radio frequency microwave amplifier with extended modulation bandwidth, which comprises an active device current source end face parasitic capacitor, a first inductor, a first capacitor, a video bandwidth expansion circuit, an output circuit and a target load; the first end of the first inductor is connected with the first end of the active device current source end face parasitic capacitor and the first end of the output circuit respectively, and the second end of the first inductor is connected with the first end of the first capacitor and the first end of the video bandwidth expansion circuit respectively; the second end of the output circuit is connected with the target load; and the second end of the first capacitor is grounded. By setting the video bandwidth expansion circuit and cooperating with the first inductor, the first capacitor and other elements, the application can effectively break through the limitation of the traditional radio frequency microwave amplifier in the modulation bandwidth, so that the amplifier can process modulation signals in a wider frequency range, and meet the demand of the modern communication system for high-speed and large-capacity data transmission; meanwhile, the reasonable circuit connection mode, especially the processing of the first inductor to the active device current source end face parasitic capacitor, helps to reduce the distortion and noise interference of the signal in the transmission process. The parasitic capacitor usually has an adverse effect on the signal, and the introduction of the first inductor can offset or improve this effect to some extent, so that the signal output to the target load is more pure and accurate, and the reliability and stability of the communication system are improved. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0011] Figure 1 is a circuit structure schematic diagram of the radio frequency microwave amplifier with extended modulation bandwidth provided by the embodiments of the application;

[0012] Figure 2 is a comparison schematic diagram of the impedance amplitude curves of the circuit with increased modulation bandwidth and the circuit without increased modulation bandwidth provided by the embodiments of the application;

[0013] Figure 3 is a comparison schematic diagram of the impedance amplitude curves of different drain line lengths when the first resistance is increased and not increased provided by the embodiments of the application. DETAILED DESCRIPTION

[0014] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, circuits, and

[0015] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be described with reference to the accompanying drawings and specific embodiments.

[0016] In order to solve the technical bottleneck of large modulation bandwidth and poor linearity, the embodiments of the present application start from the direct current bias path of the power amplifier, suppress or delay the resonance problem of the direct current bias, and realize high linearity under large modulation bandwidth.

[0017] Figure 1 The circuit structure schematic diagram of the radio frequency microwave amplifier with extended modulation bandwidth provided by the embodiments of the present application is shown in the figure. Figure 1 As shown in the figure, the radio frequency microwave amplifier with extended modulation bandwidth comprises an active device current source end surface parasitic capacitance , a first inductor , a first capacitor , a video bandwidth expansion circuit, an output circuit and a target load.

[0018] The first end of the first inductor is connected with the first end of the active device current source end surface parasitic capacitance and the first end of the output circuit respectively, and the second end of the first inductor is connected with the first end of the first capacitor and the first end of the video bandwidth expansion circuit respectively.

[0019] The second end of the output circuit is connected with the target load.

[0020] The second end of the first capacitor is grounded.

[0021] In the embodiments of the present application, referring to Figure 1 , the first inductor and the first capacitor compensating for the active device current source end surface parasitic capacitance This increases the output impedance of the active device to a real number, eliminating its frequency limitation. Simultaneously, the series video bandwidth extension circuit not only achieves drain choking but also adjusts the modulation signal bandwidth, significantly increasing the modulation bandwidth while suppressing the resonant peak of the video bandwidth extension circuit. Finally, the output matching impedance, including the active device with the drain bias path, is optimized, i.e., the first inductor. First capacitor The output matching impedance, combined with the video bandwidth expansion circuit, enables a low-loss, high-efficiency power amplifier.

[0022] In one possible implementation, the parasitic capacitance at the current source end face of the active device... Located on the gate path of the active device, in parallel with the current source, as referenced. Figure 1 As shown, the parasitic capacitance at the current source terminal of the active device. The first terminal is also connected to the first terminal of the current source, and the parasitic capacitance at the current source terminal of the active device... The second terminal is connected to the second terminal of the current source and then grounded.

[0023] In one possible implementation, refer to Figure 1 First Inductor and the first capacitor Located in the drain bias path of the active device.

[0024] In this embodiment, a compensation for the parasitic capacitance of the current source terminal of the active device is added to the drain bias path of the active device, i.e., from the current source terminal of the active device. First Inductor and the first capacitor This can increase the output impedance of active devices to a real number, thereby eliminating their frequency limitation.

[0025] In one possible implementation, the equivalent reactance of the first inductor and the first capacitor cancels out the capacitive reactance of the parasitic capacitance at the current source end face of the active device.

[0026] Optionally, if the parasitic capacitance at the current source terminal of the active device is a capacitive device, the first inductor is an inductive device, and the first capacitor is a capacitive device, then the equivalent reactance of the first inductor and the first capacitor includes both capacitive and inductive properties. In this case, the parasitic capacitance at the current source terminal of the active device can be canceled out, and only the real value is output.

[0027] For example, to eliminate the frequency limitation imposed by active devices, when the parasitic capacitance at the current source terminal of the active device... for At that time, the first inductor and the first capacitor The equivalent reactance is At this time, the parasitic capacitance at the current source terminal of the active device is set as the first inductance. With the first inductor and the first capacitor The equivalent reactance can cancel out Only the real part R of the output is left.

[0028] The embodiments of this application address the parasitic capacitance at the current source terminal of the active device. At this point, the first inductor is connected in series. Then the first capacitor is connected in parallel. By adjusting the first inductor Or the first capacitor The value is used to ensure that, within the required operating frequency range, the equivalent reactance of both is equal to the parasitic capacitance at the current source terminal of the active device. The capacitive reactance cancels out, ensuring that the output impedance at the current source end face of the active device is shifted to the real axis of the Smith chart, thereby eliminating the frequency limitation imposed by parasitic capacitance.

[0029] In one possible implementation, the video bandwidth extension circuit is located on the drain bias path of the active device, with its first terminal connected to the second terminal of the first inductor and the first terminal of the first capacitor, respectively.

[0030] In one possible implementation, refer to Figure 1 The video bandwidth extension circuit may include a bias inductor. First resistor Second capacitor .

[0031] Bias Inductor The first terminal is connected to the first terminal of the video bandwidth expansion circuit, and the bias inductor is... The second end is respectively connected to the first resistor The first terminal is connected to the second terminal of the video bandwidth expansion circuit;

[0032] First resistor The second terminal and the second capacitor The first end is connected to the second capacitor. The second end is grounded.

[0033] Optionally, the video bandwidth extension circuit in this embodiment includes a bias inductor. First resistor Second capacitor Among them, the bias inductor Through the first inductor Parasitic capacitance at the current source terminal of active devices Series connection, then the first resistor Second capacitor After being connected in series, it is then connected in parallel to the bias inductor. the second capacitance is grounded. Wherein, the equivalent video impedance of the video bandwidth expansion circuit is:

[0034]

[0035] wherein, is the equivalent video impedance of the video bandwidth expansion circuit, is the first variable, is the first inductance, is the bias inductance, is the active device current source end surface parasitic capacitance, is the second variable, is the first capacitance, is the second capacitance, is the first resistance, is the angular frequency.

[0036] In the embodiment of the present application, the bias inductance and the second capacitance jointly play a role of reducing the video impedance of the video bandwidth expansion circuit and expanding the modulation bandwidth.

[0037] Meanwhile, the bias inductance also participates in the radio frequency impedance matching, and by optimizing the bias inductance , the drain choke function is realized.

[0038] In addition, the main purpose of the first resistance is to reduce the quality factor Q value of the resonance circuit, mainly to suppress the resonance point at low frequency, and at the same time to reduce the resonance peak value at high frequency. Referring to Figure 2 , the impedance amplitude curves of the modulation bandwidth circuit (i.e. the video bandwidth expansion circuit, Figure 2 is a thick solid line) and the circuit without increasing the modulation bandwidth (i.e. without increasing the video bandwidth expansion circuit, Figure 2 is a thin solid line) are compared, wherein the vertical coordinate of the curve represents the impedance amplitude, reflecting the size of the current impedance of the circuit at different frequencies; the horizontal coordinate represents the frequency, showing the change of the circuit impedance with the frequency. Through comparison, it can be directly seen that after using the modulation bandwidth circuit of the embodiment of the present application, the video impedance can be reduced in a larger range, thereby ensuring that the linearity of the power amplifier is not affected in a larger modulation bandwidth.

[0039] By optimizing the values of the bias inductance, the first resistance and the second capacitance, the embodiment of the present application can obtain low video impedance in a larger range and realize a wider modulation bandwidth.

[0040] The embodiment of the application can suppress or delay the resonance point of the drain DC bias, reduce the baseband video impedance, realize a high linearity power amplifier under a wide modulation bandwidth, meet the high peak-to-average ratio and large modulation bandwidth requirements in the communication field, and simplify the circuit structure. The bias inductance on the drain bias path has a choke function, and cooperates with the first resistor and the second capacitor to realize the expansion of the modulation bandwidth.

[0041] In a possible implementation, referring to Figure 1 , the radio frequency microwave amplifier for expanding the modulation bandwidth can further include a drain energizing circuit, a first end of the drain energizing circuit being connected with a second end of the video bandwidth expansion circuit, for eliminating power interference. The drain energizing circuit is also located on the drain bias path of the active device.

[0042] Referring to Figure 1 , the drain energizing circuit includes a metal bonding wire Wire, a decoupling capacitor and a power supply VDD.

[0043] A first end of the metal bonding wire Wire is connected with a first end of the drain energizing circuit, and a second end of the metal bonding wire Wire is connected with a first end of the decoupling capacitor and a first end of the power supply VDD respectively.

[0044] A second end of the decoupling capacitor is grounded, and a second end of the power supply VDD is grounded.

[0045] Optionally, the embodiment of the application uses the metal bonding wire Wire to be led out to the power supply VDD after the modulation bandwidth, and realizes energizing and removing power interference in combination with the decoupling capacitor. Referring to Figure 1 , the metal bonding wire Wire, the decoupling capacitor and the power supply VDD are connected in sequence.

[0046] In addition, referring to Figure 1 , the decoupling capacitor can include a first sub-decoupling capacitor and a second sub-decoupling capacitor connected in parallel.

[0047] A first end of the first sub-decoupling capacitor is connected with a first end of the decoupling capacitor and a first end of the second sub-decoupling capacitor respectively, and a second end of the first sub-decoupling capacitor is connected with a second end of the decoupling capacitor;

[0048] A second end of the second sub-decoupling capacitor is connected with the second end of the decoupling capacitor.

[0049] The first sub-decoupling capacitor and the second sub-decoupling capacitor The magnitude is set according to a preset ratio, which is 1:10. For example, the first sub-decoupling capacitor... The magnitude is set to 1 At this time, the second sub-decoupling capacitor The magnitude is set to 10 .

[0050] For example, the diameter of the metal bonding wire can be set to 0.05 mm, the length can be set to 1 mm, and the resistance value can be set to 1 ohm.

[0051] At the same time, refer to Figure 3 This demonstrates the impedance difference in the video bandwidth extension circuit between having a first resistor and not having one (i.e., high impedance at low frequencies). It also shows the change in the length of the metal bonding wire and the impact of adding or removing the first resistor on the circuit impedance amplitude, ensuring that the influence of the metal bonding wire length on impedance is negligible. The first resistor primarily serves to reduce the Q value of this circuit path and suppress its resonant peak. Figure 3 The vertical axis represents the impedance amplitude, reflecting the magnitude of the circuit impedance. The vertical axis values ​​corresponding to different frequency points of the curve under different metal bond wire lengths and whether or not a first resistor is added reflect the impedance amplitude at that frequency under the corresponding conditions. The horizontal axis represents the frequency, showing how the circuit impedance amplitude changes with different metal bond wire lengths and whether or not a first resistor is added.

[0052] The impedance differs at low frequencies when the first resistor is added versus when it is not. Without the resistor, the impedance at low frequencies is high. Adding the resistor can suppress the resonance point at low frequencies and reduce the resonance peak at high frequencies. This effect can be clearly seen from the changes in values ​​corresponding to different frequency points on the curve.

[0053] In one possible implementation, refer to Figure 1 The output circuit may include a third inductor. and the third capacitor .

[0054] Third Inductor The first terminal is connected to the first terminal of the output circuit, and the third inductor The second terminal is connected to the second terminal of the output circuit and the third capacitor, respectively. The first end is connected;

[0055] Third capacitor The second terminal is grounded.

[0056] In one possible implementation, the target load could be 50 ohms, 80 ohms, or 100 ohms, depending on the specific requirements.

[0057] The application provides a radio frequency microwave amplifier for expanding modulation bandwidth, comprising an active device current source end face parasitic capacitor, a first inductor, a first capacitor, a video bandwidth expansion circuit, an output circuit and a target load; a first end of the first inductor is connected with a first end of the active device current source end face parasitic capacitor and a first end of the output circuit respectively, a second end of the first inductor is connected with a first end of the first capacitor and a first end of the video bandwidth expansion circuit respectively; a second end of the output circuit is connected with the target load; and a second end of the first capacitor is grounded. The video bandwidth expansion circuit is arranged and cooperates with the first inductor, the first capacitor and other elements to effectively break through the limitation of the traditional radio frequency microwave amplifier in modulation bandwidth, so that the amplifier can process modulation signals in a wider frequency range, and meet the demand of the modern communication system for high-speed and large-capacity data transmission; meanwhile, the reasonable circuit connection mode, especially the processing of the first inductor on the active device current source end face parasitic capacitor, helps to reduce the distortion and noise interference of the signal in the transmission process. The parasitic capacitor usually has an adverse effect on the signal, and the introduction of the first inductor can offset or improve this effect to some extent, so that the signal output to the target load is more pure and accurate, and the reliability and stability of the communication system are improved.

[0058] It should be understood that the size of the serial number of each step in the above-mentioned embodiments does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the application.

[0059] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A radio frequency microwave amplifier with extended modulation bandwidth comprising an active device current source face parasitic capacitance, characterized in that, The extended modulation bandwidth radio frequency microwave amplifier comprises a first inductor, a first capacitor, a video bandwidth extension circuit, an output circuit and a target load; a first end of the first inductor is connected with a first end of the active device current source end face parasitic capacitor and a first end of the output circuit respectively, and a second end of the first inductor is connected with a first end of the first capacitor and a first end of the video bandwidth extension circuit respectively; a second end of the output circuit is connected with the target load; a second end of the first capacitor is grounded; The video bandwidth extension circuit comprises a bias inductor, a first resistor and a second capacitor. a first end of the bias inductor is connected with a first end of the video bandwidth extension circuit, and a second end of the bias inductor is connected with a first end of the first resistor and a second end of the video bandwidth extension circuit respectively; a second end of the first resistor is connected with a first end of the second capacitor, and a second end of the second capacitor is grounded; The equivalent video impedance of the video bandwidth extension circuit is: wherein, is an equivalent video impedance for the video bandwidth extension circuit, is a first variable, is the first inductance, is the bias inductance, is the active device current source terminal parasitic capacitance, is a second variable, is the first capacitance, is the second capacitance, is the first resistance, is an angular frequency.

2. The extended modulated bandwidth radio frequency microwave amplifier of claim 1, wherein, The equivalent reactance of the first inductor and the first capacitor is opposite to the capacitive reactance of the active device current source end face parasitic capacitor.

3. The extended modulated bandwidth radio frequency microwave amplifier of claim 1, wherein, The extended modulation bandwidth radio frequency microwave amplifier further comprises a drain energizing circuit, a first end of the drain energizing circuit is connected with a second end of the video bandwidth extension circuit, and is used for eliminating power supply interference.

4. The extended-modulation-bandwidth radio-frequency microwave amplifier of claim 3, wherein, The drain energizing circuit comprises a metal bonding wire, a decoupling capacitor and a power supply; a first end of the metal bonding wire is connected with a first end of the drain energizing circuit, and a second end of the metal bonding wire is connected with a first end of the decoupling capacitor and a first end of the power supply respectively; a second end of the decoupling capacitor is grounded, and a second end of the power supply is grounded.

5. The extended modulated bandwidth radio frequency microwave amplifier of claim 4, wherein, The decoupling capacitor comprises a first sub-decoupling capacitor and a second sub-decoupling capacitor in parallel; a first end of the first sub-decoupling capacitor is connected with a first end of the decoupling capacitor and a first end of the second sub-decoupling capacitor respectively, and a second end of the first sub-decoupling capacitor is connected with a second end of the decoupling capacitor; a second end of the second sub-decoupling capacitor is connected with a second end of the decoupling capacitor.

6. The extended-modulation-bandwidth radio-frequency microwave amplifier according to claim 5, characterized in that, The order of magnitude of the first sub-decoupling capacitor and the second sub-decoupling capacitor is set according to a preset ratio, and the preset ratio is 1:

10.

7. The extended-modulation-bandwidth radio-frequency microwave amplifier of claim 1, wherein, The output circuit comprises a third inductor and a third capacitor; a first end of the third inductor is connected with a first end of the output circuit, and a second end of the third inductor is connected with a second end of the output circuit and a first end of the third capacitor respectively; a second end of the third capacitor is grounded.

8. The extended-modulation-bandwidth radio-frequency microwave amplifier of claim 3, wherein, The first inductor, the first capacitor, the video bandwidth extension circuit and the drain energizing circuit are located in a drain bias path of the active device.

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