E-band power amplifier and power amplification method

Abstract

The application relates to an E-band power amplifier and a power amplification method, and relates to the technical field of millimeter wave power amplification. The application is aimed at solving the problems of the existing millimeter wave high-end frequency band power amplifier, such as the mutual restriction of the synthesis efficiency and the synthesis number of GaN power amplifiers under a large bandwidth and high power, poor linearity, great difficulty in wideband linearization, high system power consumption and short device service life. In the application, the intermediate frequency input signal is digitally pre-distorted and compensated based on a radio frequency feedback signal; the analog intermediate frequency signal pre-distorted by digital pre-distortion is converted into an E-band radio frequency signal; the E-band radio frequency signal is pre-compensated for nonlinearity under a preset working temperature; the power of the analog pre-distorted E-band radio frequency signal is amplified by driving; based on the multi-mode scattering matrix theory and the amplitude and phase balance degree control principle, the E-band radio frequency signals amplified by multiple GaN power amplifier chips are combined in equal amplitude and in phase, so that the E-band power amplification result is obtained, and the E-band power amplification result is used as the radio frequency feedback signal.

Description

Technical Field

[0001] This application belongs to the field of millimeter-wave power amplification technology, and particularly relates to E-band high-gain, high-linearity, high-efficiency, and large-bandwidth power amplifiers. Background Technology

[0002] High-end millimeter-wave frequencies (such as the E-band, 71-76 GHz) have important applications in high-speed broadband communication systems. However, the following technical bottlenecks still exist in the field of E-band solid-state power amplifier technology:

[0003] First, the port isolation problem in radial power distribution / combining networks in the millimeter-wave high-frequency band has not yet been effectively solved. Power distribution / combining networks without isolation measures are prone to abrupt changes in the amplitude and phase frequency responses of amplifiers; during the combining process, amplitude-phase imbalance can easily excite interference modes, further reducing combining efficiency. Simply reducing the number of combining paths cannot meet the high-power output requirements of high-end communication systems. These problems limit the practical application of radial power combining technology in millimeter-wave communication.

[0004] Secondly, GaN power amplifiers inherently exhibit slow gain compression, resulting in poor linearity. While linearity can be improved through power combining and power back-off, simply increasing the number of combining channels leads to a surge in system power consumption, heat dissipation difficulties, and a bulky device size. Furthermore, without dynamic power control mechanisms, GaN chips operating at full load for extended periods generate excessively high junction temperatures, significantly shortening device lifespan. Simultaneously, existing systems lack power compensation mechanisms for temperature variations and chip aging, resulting in insufficient output power stability.

[0005] Third, most existing linearization techniques are suitable for narrowband scenarios. For broadband applications with bandwidths up to 5 GHz, simple analog predistortion compensation is insufficient, and existing solutions lack analog-digital coordinated linearization designs, making it difficult to meet the linearity requirements under high bandwidth. Therefore, when facing the high bandwidth requirements of high-speed broadband communication systems, traditional solutions struggle to achieve excellent in-band flatness and low error vector amplitude while ensuring high efficiency.

[0006] In summary, existing millimeter-wave high-end frequency band power amplifiers have the following prominent problems: the synthesis efficiency and number of synthesis channels of GaN power amplifiers under large bandwidth and high power are mutually constrained, the linearity is poor and broadband linearization is difficult, the system power consumption is high, and the device life is short, making it difficult to be directly applied to the next generation of high-speed broadband communication systems. Summary of the Invention

[0007] This application aims to address the problems of existing millimeter-wave high-end frequency band power amplifiers, such as the mutual constraint between the synthesis efficiency and the number of synthesis channels of GaN power amplifiers under large bandwidth and high power, poor linearity and difficulty in broadband linearization, high system power consumption and short device life. It provides an E-band power amplifier and power amplification method to achieve synergistic optimization of high efficiency, high linearity, low power consumption and high reliability of E-band power amplifiers, and meet the problems of E-band power amplifiers in high-speed broadband communication and air platform scenarios.

[0008] The first aspect of this application provides an E-band power amplifier, including: an E-band frequency conversion module, a linearization predistortion module, a drive amplification module, and a final stage power combining module;

[0009] The linearization predistortion module is used to perform digital predistortion compensation on the intermediate frequency input signal based on the radio frequency feedback signal, and send the digitally predistorted analog intermediate frequency signal to the E-band frequency conversion module.

[0010] The E-band frequency conversion module is used to convert the digital predistortion analog intermediate frequency signal to an E-band radio frequency signal and send it to the linearization predistortion module.

[0011] The linearization predistortion module is also used to perform nonlinear pre-compensation on the E-band radio frequency signal at a preset operating temperature, and send the simulated predistorted E-band radio frequency signal to the drive amplification module.

[0012] The drive amplification module is used to drive and amplify the power of the simulated pre-distorted E-band radio frequency signal and send it to the final stage power combining module.

[0013] The final stage power combining module is used to combine multiple E-band RF signals amplified by GaN power amplifier chips into equal-amplitude and in-phase power based on multimode scattering matrix theory and amplitude-phase balance control principle, to obtain the output result of the E-band power amplifier, and at the same time, the output result is fed back to the linearization predistortion module as an RF feedback signal.

[0014] In one possible design, the linearization predistortion module includes: an analog predistortion circuit, a digital domain DPD predistortion module, an RF input port, and an RF output port;

[0015] The digital domain DPD predistortion module is used to extract the dynamic nonlinear characteristics of the power amplifier array based on the radio frequency feedback signal, and to perform digital predistortion compensation on the intermediate frequency input signal according to the dynamic nonlinear characteristics to generate a digitally predistorted analog intermediate frequency signal.

[0016] The E-band frequency converter module inputs the E-band radio frequency signal to the analog pre-distortion circuit through the radio frequency input port;

[0017] The analog pre-distortion circuit is used to perform nonlinear pre-compensation on the E-band radio frequency signal at a preset operating temperature.

[0018] The simulated pre-distorted E-band radio frequency signal is sent to the drive amplifier module through the radio frequency output port.

[0019] In one possible design, the digital domain DPD predistortion module includes: a conversion unit and a DPD algorithm processing unit;

[0020] The conversion unit is used to acquire the intermediate frequency input signal into the digital domain;

[0021] The DPD algorithm processing unit is used to extract the dynamic nonlinear characteristics of the power amplifier array based on the radio frequency feedback signal, and to perform digital predistortion compensation on the digital intermediate frequency signal according to the dynamic nonlinear characteristics.

[0022] The conversion unit is also used to convert the digital predistorted analog intermediate frequency signal into a predistorted analog intermediate frequency signal.

[0023] In one possible design, the analog predistortion circuit includes: FET devices and a temperature control voltage unit;

[0024] The FET device is used to fix its operating point in the pinch-off region by a gate bias voltage, and to perform nonlinear pre-compensation on the E-band radio frequency signal by utilizing the gain expansion and phase compression characteristics of the pinch-off region.

[0025] The temperature control voltage unit is used to update the gate bias voltage of the FET device once at fixed temperature intervals, so that the FET device can operate at a preset operating temperature.

[0026] In one possible design, the fixed temperature step is 10°C, and the preset operating temperature is -20°C to +60°C.

[0027] In one possible design, the E-band frequency conversion module includes: a fixed attenuator, a primary frequency conversion unit, a filter, a digitally controlled attenuator, and an RF amplifier unit;

[0028] The fixed attenuator is used to perform power back-off on the digitally predistorted analog intermediate frequency signal and send the attenuated analog intermediate frequency signal to the primary frequency conversion unit.

[0029] The primary frequency conversion unit is used to convert the attenuated analog intermediate frequency signal into an E-band radio frequency signal and send it to the filter.

[0030] The filter is used to suppress local oscillator leakage and send the suppressed E-band radio frequency signal to the digitally controlled attenuator.

[0031] The digitally controlled attenuator is used to adjust the power of the E-band radio frequency signal after local oscillator suppression to the target range and send it to the radio frequency amplification unit;

[0032] The radio frequency amplification unit is used to compensate for the frequency conversion loss of the E-band radio frequency signal after digital control attenuation, and to send the compensated E-band radio frequency signal to the linearization predistortion module.

[0033] In one possible design, the final stage power combining module includes a high-isolation radial power combining network, which includes a combining port and multiple branch arms. Each branch arm is equipped with multiple GaN power amplifier chips. The multiple branch arms are arranged in a ring array and are all electrically connected to the combining port.

[0034] The combining port will drive the amplified E-band radio frequency signal to distribute it to the multiple branch arms in equal amplitude and in phase through the coaxial TEM mode structure;

[0035] GaN power amplifier chips amplify the power of the radio frequency signals distributed to their respective branches;

[0036] The multiple radio frequency signals amplified by the GaN power amplifier chip are combined into equal-amplitude and in-phase power signals through the combiner port to obtain the output result of the E-band power amplifier.

[0037] In one possible design, the final stage power combining module further includes a water-cooling unit for water-cooling the GaN power amplifier chip.

[0038] In one possible design, the E-band power amplifier also includes a dynamic drain voltage control unit, the control signal output of which is electrically connected to the drain of multiple GaN power amplifier chips.

[0039] The dynamic leakage voltage control unit is used to adjust the leakage voltage of multiple GaN power amplifier chips.

[0040] The second aspect of this application provides an E-band power amplification method, including:

[0041] Digital predistortion compensation is performed on the intermediate frequency input signal based on the radio frequency feedback signal to obtain a digitally predistorted analog intermediate frequency signal;

[0042] The digitally predistorted analog intermediate frequency signal is converted to an E-band radio frequency signal;

[0043] The E-band radio frequency signal is nonlinearly pre-compensated at a preset operating temperature to obtain a simulated pre-distorted E-band radio frequency signal.

[0044] The power of the simulated pre-distorted E-band radio frequency signal is amplified by driving;

[0045] Based on the multimode scattering matrix theory and the amplitude-phase balance control principle, the E-band RF signals amplified by multiple GaN power amplifier chips are combined with equal amplitude and in phase to obtain the E-band power amplification result, and the E-band power amplification result is used as the RF feedback signal.

[0046] The beneficial effects of this application are:

[0047] 1. High-isolation radial power combining, using a multi-mode scattering matrix design and a multi-path circular symmetrical branch layout, achieves a combining efficiency of ≥80%, E-band ≥30W, 5G bandwidth high-power RF signal output, and when a few GaN chips fail, the output power does not deteriorate significantly, and the system reliability is significantly improved.

[0048] 2. Analog-digital joint linearization further reduces the nonlinear distortion of the power amplifier through the coordinated work of analog predistortion and digital DPD, making the in-band flatness ≤3dB to meet the stringent requirements of high-speed broadband communication;

[0049] 3. Dynamic drain voltage control and low power consumption design: By dynamically adjusting the drain voltage, the junction temperature of the GaN chip is controlled at around 165℃, and the device life can be extended to 15 years. The power consumption of the whole machine's RF BUC section is ≤250W, which balances high reliability and low power consumption.

[0050] This application is applicable to scenarios such as high-speed broadband communication and aerial platforms. Attached Figure Description

[0051] Figure 1 This is a block diagram illustrating the principle of the E-band high-gain, high-linearity, high-efficiency, and large-bandwidth power amplifier described in the embodiment.

[0052] Figure 2 This is a schematic diagram of an E-band frequency converter module;

[0053] Figure 3 A schematic diagram of the linearization predistortion module;

[0054] Figure 4 This is a schematic diagram of the final stage power combining module. Detailed Implementation

[0055] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0056] Specific implementation method one: The E-band power amplifier described in this implementation method includes: an E-band frequency conversion module 2, a linearization predistortion module 3, a drive amplification module 4, and a final stage power combining module 5;

[0057] The linearization predistortion module 3 is used to perform digital predistortion compensation on the intermediate frequency input signal based on the radio frequency feedback signal, and send the digitally predistorted analog intermediate frequency signal to the E-band frequency converter module 2.

[0058] The E-band frequency conversion module 2 is used to convert the digital predistortion analog intermediate frequency signal to an E-band radio frequency signal and send it to the linearization predistortion module 3.

[0059] The linearization predistortion module 3 is also used to perform nonlinear pre-compensation on the E-band radio frequency signal at a preset operating temperature, and send the simulated predistorted E-band radio frequency signal to the drive amplification module 4;

[0060] The drive amplification module 4 is used to drive and amplify the power of the simulated pre-distortion E-band radio frequency signal and send it to the final stage power combining module 5.

[0061] The final stage power combining module 5 is used to combine the E-band RF signals amplified by the GaN power amplifier chip into equal amplitude and in phase power based on the multimode scattering matrix theory and the amplitude and phase balance control principle, to obtain the output result of the E-band power amplifier, and at the same time, the output result is fed back to the linearization predistortion module 3 as an RF feedback signal.

[0062] In one embodiment, the linearization predistortion module 3 includes: an analog predistortion circuit 3-1, a digital domain DPD predistortion module 3-2, an RF input port 3-3, and an RF output port 3-4;

[0063] The digital domain DPD predistortion module 3-2 is used to extract the dynamic nonlinear characteristics of the power amplifier array based on the radio frequency feedback signal, and to perform digital predistortion compensation on the intermediate frequency input signal according to the dynamic nonlinear characteristics to generate a digitally predistorted analog intermediate frequency signal.

[0064] The E-band frequency converter module 2 inputs the E-band radio frequency signal to the analog pre-distortion circuit 3-1 through the radio frequency input port 3-3;

[0065] The analog pre-distortion circuit 3-1 is used to perform nonlinear pre-compensation on the E-band radio frequency signal at a preset operating temperature.

[0066] The simulated pre-distorted E-band radio frequency signal is sent to the drive amplifier module 4 through the radio frequency output port 3-4.

[0067] In one embodiment, the digital domain DPD predistortion module 3-2 includes: a conversion unit 3-2-1 and a DPD algorithm processing unit 3-2-2;

[0068] The conversion unit 3-2-1 is used to acquire the intermediate frequency input signal into the digital domain;

[0069] The DPD algorithm processing unit 3-2-2 is used to extract the dynamic nonlinear characteristics of the power amplifier array based on the radio frequency feedback signal, and to perform digital predistortion compensation on the digital intermediate frequency signal according to the dynamic nonlinear characteristics.

[0070] The conversion unit 3-2-1 is also used to convert the digital predistorted analog intermediate frequency signal into a predistorted analog intermediate frequency signal.

[0071] In one embodiment, the analog predistortion circuit 3-1 includes: a FET device 3-1-1 and a temperature control voltage unit 3-1-2;

[0072] The FET device 3-1-1 is used to fix its operating point in the pinch-off region by the gate bias voltage, and to perform nonlinear pre-compensation on the E-band radio frequency signal by utilizing the gain expansion and phase compression characteristics of the pinch-off region.

[0073] The temperature control voltage unit 3-1-2 is used to update the gate bias voltage of the FET device 3-1-1 once every fixed temperature step, so that the FET device 3-1-1 can operate at a preset operating temperature.

[0074] In one embodiment, the fixed temperature step is 10°C, and the preset operating temperature is -20°C to +60°C.

[0075] In one embodiment, the E-band frequency conversion module 2 includes: a fixed attenuator 2-2, a primary frequency conversion unit 2-3, a filter 2-4, a digitally controlled attenuator 2-5, and an RF amplification unit 2-6;

[0076] The fixed attenuator 2-2 is used to perform power back-off on the digitally predistorted analog intermediate frequency signal and send the attenuated analog intermediate frequency signal to the primary frequency conversion unit 2-3;

[0077] The primary frequency conversion unit 2-3 is used to convert the attenuated analog intermediate frequency signal into an E-band radio frequency signal and send it to the filter 2-4;

[0078] The filter 2-4 is used to suppress local oscillator leakage and send the suppressed E-band radio frequency signal to the digitally controlled attenuator 2-5;

[0079] The digitally controlled attenuator 2-5 is used to adjust the power of the E-band radio frequency signal after local oscillator suppression to the target range and send it to the radio frequency amplification unit 2-6;

[0080] The radio frequency amplification units 2-6 are used to compensate for the frequency conversion loss of the E-band radio frequency signal after digital control attenuation, and send the compensated E-band radio frequency signal to the linearization predistortion module 3.

[0081] In one embodiment, the final stage power combining module 5 includes a high-isolation radial power combining network 5-1. The high-isolation radial power combining network 5-1 includes a combining port 5-1-1 and multiple branch arms 5-1-2. Each branch arm 5-1-2 is provided with multiple GaN power amplifier chips 5-2. The multiple branch arms 5-1-2 are arranged in a ring array and are all electrically connected to the combining port 5-1-1.

[0082] The combining port 5-1-1 distributes the amplified E-band radio frequency signal to the multiple branch arms 5-1-2 in equal amplitude and in phase through the coaxial TEM mode structure.

[0083] GaN power amplifier chip 5-2 amplifies the power of the RF signal distributed to its branch;

[0084] The multiple radio frequency signals amplified by the GaN power amplifier chip 5-2 are combined into equal-amplitude and in-phase power signals through the combiner port 5-1-1 to obtain the output result of the E-band power amplifier.

[0085] In one embodiment, the final stage power combining module 5 further includes a water-cooling unit, which is used to perform water-cooling heat dissipation on the GaN power amplifier chip 5-2.

[0086] In one embodiment, the E-band power amplifier further includes a dynamic leakage voltage control unit 7, wherein the control signal output terminal of the dynamic leakage voltage control unit 7 is electrically connected to the drain of a plurality of GaN power amplifier chips 5-2 respectively.

[0087] The dynamic leakage voltage control unit 7 is used to adjust the leakage voltage of multiple GaN power amplifier chips 5-2.

[0088] To further illustrate the implementation scheme of this application, Figure 1 We offer E-band high-gain, high-linearity, high-efficiency, and wide-bandwidth power amplifiers. Each unit is described in detail below:

[0089] like Figure 1 As shown, the E-band high-gain, high-linearity, high-efficiency, and wide-bandwidth power amplifier described in this embodiment consists of a main signal flow region and a control and power supply region.

[0090] The main signal flow area includes: input interface unit 1, E-band frequency conversion module 2, linearization predistortion module 3, drive amplification module 4, final stage power combining module 5, and output interface unit 6.

[0091] The E-band frequency converter module 2 includes: intermediate frequency input port 2-1, fixed attenuator 2-2, primary frequency conversion unit 2-3, filter 2-4, digitally controlled attenuator 2-5, RF amplifier unit 2-6, and E-band RF output port 2-7.

[0092] The linearization predistortion module 3 includes: an analog predistortion circuit 3-1, a digital domain DPD predistortion module 3-2, an RF input port 3-3, and an RF output port 3-4. The analog predistortion circuit 3-1 includes: a FET device 3-1-1 and a temperature control voltage unit 3-1-2. The digital domain DPD predistortion module 3-2 includes: a conversion unit 3-2-1 and a DPD algorithm processing unit 3-2-2. The digital domain DPD predistortion module 3-2 and the analog predistortion circuit 3-1 form a joint analog-digital linearization architecture. Through the digital predistortion algorithm, it compensates for the insufficient linearization capability of the analog domain RF, further reducing the nonlinear distortion of the power amplifier, making the power amplifier system's EVM ≤ 10% and in-band spurious ≤ -60dBc.

[0093] The final stage power combining module 5 includes a high-isolation radial power combining network 5-1 and a GaN power amplifier chip 5-2. The final stage power combining module 5 is equipped with a water-cooling unit for water-cooling the GaN power amplifier chip 5-2. The high-isolation radial power combining network 5-1 includes a combining port 5-1-1, a branch arm 5-1-2, and port isolation 5-1-3.

[0094] The control and power supply area includes: dynamic leakage control unit 7, protection and monitoring unit 8, and power supply module 9.

[0095] In this embodiment, the intermediate frequency input bandwidth is 0.6GHz~5.6GHz, the intermediate frequency input power is 0dBm±2dB, and the system ultimately achieves the core indicators of a working frequency of 71 GHz~76GHz, instantaneous RF bandwidth of 5GHz, saturated output power ≥30W, synthesis efficiency ≥80%, and in-band power flatness ≤3.0dB, which is suitable for high-speed broadband communication, air platform and other scenarios.

[0096] In the main signal flow region, the intermediate frequency signal enters the input interface unit 1. The input interface unit 1 adopts the unified N-type interface of the whole machine and has a built-in coaxial 50Ω impedance matching circuit to ensure that the VSWR of the intermediate frequency interface is ≤1.5:1.

[0097] like Figure 3 As shown, the intermediate frequency (IF) signal from 0.6 GHz to 5.6 GHz is fed into the digital domain DPD predistortion module 3-2. The conversion unit 3-2-1 within the DPD predistortion module 3-2 acquires the analog IF signal into the digital domain. Based on the RF feedback signal coupled from the final-stage power combining module 5 and after down-conversion processing, the DPD algorithm processing unit 3-2-2 extracts the dynamic nonlinear characteristics of the GaN power amplifier array in real time, adaptively updates and applies digital predistortion compensation. Subsequently, the predistorted digital signal is converted into an analog IF signal by the conversion unit 3-2-1 and sent to the E-band conversion module 2 for up-conversion.

[0098] E-band frequency converter module 2 is connected to linearization predistortion module 3, employing a single-conversion structure. E-band frequency converter module 2 receives analog intermediate frequency signals from 0.6GHz to 5.6GHz and directly converts them to E-band radio frequency signals from 71GHz to 76GHz. The specific signal flow is as follows:

[0099] like Figure 2As shown, the analog intermediate frequency (IF) signal is fed into a fixed attenuator 2-2 through the IF input port 2-1. The fixed attenuator 2-2 suppresses high-order spurious emissions generated during the frequency conversion process by performing power back-off on the analog IF signal, achieving a coherent spurious emission of ≤-50dBc and an incoherent spurious emission of ≤-50dBm. The attenuated analog IF signal is then fed into a primary frequency conversion unit 2-3. The primary frequency conversion unit 2-3 performs a mixing operation between the local oscillator signal and the up-conversion of the analog IF signal, directly converting the analog IF signal into an E-band radio frequency (RF) signal. The local oscillator signal frequency is set to 70.4GHz (with phase noise satisfying ≤-65dBc / Hz@100Hz and ≤-110dBc / Hz@1MHz), achieving direct frequency conversion from the analog IF signal to the E-band RF signal. The E-band RF signal is then fed into a filter 2-4, which is specifically used to suppress 70.4GHz local oscillator leakage. After local oscillator suppression, the E-band RF signal is fed into the digitally controlled attenuator 2-5, enabling adjustable E-band RF power with a power adjustment range ≥30dB and a step accuracy of 1dB. The digitally attenuated E-band RF signal is then fed into the RF amplifier unit 2-6, providing gain for the frequency conversion channel and compensating for signal loss during the frequency conversion process, resulting in an output power ≥10dBm for the module. The gain-compensated E-band RF signal is then output to the linearization predistortion module 3 through the RF output port 2-7.

[0100] The E-band radio frequency signal is input to the linearization predistortion module 3, and the specific signal flow is as follows:

[0101] like Figure 3 As shown, the E-band RF signal is fed into the analog pre-distortion circuit 3-1 through the RF input port 3-3. The FET device 3-1-1 has its operating point fixed in the pinch-off region by a gate bias voltage. Utilizing the unique gain expansion (6dB~7dB) and phase compression (40°~45°) characteristics of this pinch-off region, nonlinear pre-compensation is performed on the E-band RF signal to counteract the gain compression and phase distortion of the subsequent GaN power amplifier, ensuring insertion loss of less than 20dB, in-band flatness ≤1dB, and return loss greater than 10dB. The temperature control voltage unit 3-1-2 updates the control voltage every 10°C to ensure a wide operating temperature range of -20~+60°C.

[0102] Through the analog-digital joint linearization architecture of the linearization predistortion module 3, the analog predistortion circuit 3-1 is responsible for large-scale, static nonlinear compensation in the 70GHz band; the digital domain DPD predistortion module 3-2 performs precise closed-loop calibration of residual fine nonlinearity and memory effect in the mid-frequency domain, ultimately enabling the entire system to meet the specifications of EVM≤10% and in-band clutter≤-60dBc.

[0103] The RF signal, after analog-digital joint linearization and predistortion, is sent to the drive amplifier module 4 through the RF output port 3-4. The drive amplifier module 4 amplifies the power of the predistorted RF signal to the input power required by the final stage power combining network, ensuring the consistency of the amplitude and phase of each branch signal to meet the input signal requirements of the final stage power combining module 5.

[0104] In the final stage power combining module 5, such as Figure 4 As shown, the high-isolation radial power combining network 5-1 operates in coaxial TEM mode and is designed based on multimode scattering matrix theory and amplitude-phase balance control principle, with an operating bandwidth greater than 10%. Sixteen branch arms 5-1-2 are uniformly arranged in a ring array, and the amplified RF signal is fed into each branch arm 5-1-2. The length of each branch arm 5-1-2 is designed to ensure that each branch port satisfies the equal amplitude and in-phase relationship. Amplitude and phase balance are important indicators of the power combining network, determining the combining efficiency. In radial combining with higher-order or degenerate modes, amplitude-phase balance determines the presence and suppression of interfering modes.

[0105] The excitation signal containing amplitude error is represented as: This can be seen as an ideal incentive signal. and error excitation signal Therefore, the voltage vector of the non-ideal synthesized mode is expressed as:

[0106] (1),

[0107] In the formula, The synthesized terminal voltage vector includes error components. For the transmission matrix, For a normalized ideal amplitude signal, yes The error components are:

[0108] (2),

[0109] In the formula, This is the gain matrix.

[0110] Since mode interference is an error excitation signal Synthesized error components Caused by, existing In the case of one interference mode, the interference component It can be written as:

[0111] (3),

[0112] In the formula, This indicates the number of interfering modes. For the first The transfer gain matrix of each interference mode. The equivalent voltage vector for each interference mode, For the first The excitation efficiency of each interference mode (depends on the excitation method and the degree of matching between each interference mode).

[0113] For the TE11 combined mode, the error component The direction of rotation and Conversely, there were no other interference modes. Therefore, It is still the vector transfer matrix of the radial synthesizer:

[0114] (4),

[0115] In the formula, For amplitude imbalance, For phase imbalance, For phase error, This represents the total number of branch ports.

[0116] Substituting equation (4) into equation (2), we get:

[0117] (5),

[0118] (6),

[0119] For phase.

[0120] Therefore, the synthesized terminal voltage vector containing the error component can be calculated. This takes into account the random correlation of the error component. Suppression degree of interference mode It can be represented as:

[0121] (7),

[0122] In the formula, The error signal power corresponding to the interference mode. The signal power of the main mode.

[0123] It is evident that, provided the maximum phase error can be guaranteed, the more synthesis paths there are, the better the model purity.

[0124] The fundamental reason why traditional N+1 networks cannot achieve full matching is that their scattering matrix is ​​constrained by the network symmetry in a specific dimension, thus mathematically it cannot guarantee that the reflection coefficients of all ports are zero. This embodiment proposes a multimode scattering matrix theory to study the characteristics of high-order mode radial synthesis networks, and to understand the mechanism of non-full matching in radial networks containing interfering modes. The research methods and approaches are as follows:

[0125] The order of the multimode scattering matrix is , For the number of branch ports, This represents the number of interference modes in the radial portion. Substituting the parameters of this embodiment, , get The radial network containing interfering modes has a total of 19 physical ports, including 1 combining port, 16 physical branch ports, and 2 virtual ports for interfering modes. Defining the interfering modes as ports 18 and 19, the multimode scattering matrix of the network can be obtained. As shown in equation (8):

[0126] (8),

[0127] (9),

[0128] , , (10)

[0129] Indicates the main model, and These represent two different interference modes.

[0130] The presence of interference modes makes the number of electrical ports in the network greater than the number of physical ports, which is equivalent to increasing the number of ports. All combined ports are orthogonal modes, and ports 1, 18 and 19 cannot excite each other, as shown in equation (9). Branch ports are reciprocal, as shown in equation (10).

[0131] Due to the presence of multiple modes, the calculation of the coupling coefficients between modes is complex. However, it can be predicted that when the branch port is subjected to non-ideal excitation or mismatch, it will excite the interfering mode, and the branch reflection coefficient will be less than [a certain value]. In the current instance, The branch reflection coefficient is less than Based on this conclusion, it can be seen that the best way to solve the problem of radial network isolation is to increase the number of network ports. Therefore, compared with the main mode synthesis network, the high-order mode synthesis network proposed in this embodiment can reduce the traction effect of branches to a certain extent under non-ideal excitation, thereby achieving port isolation 5-1-3.

[0132] The RF signal input to branch arm 5-1-2 passes through GaN power amplifier chips 5-2 on 16 branches. GaN power amplifier chips 5-2 are 4-watt chips with a saturated output power of 71GHz~76GHz. The chip's operating leakage voltage is finely adjusted by the dynamic leakage voltage control unit 7. The water-cooling unit dissipates the heat generated by the chip's operation through circulating cooling water, keeping the chip junction temperature around 165℃ and the carrier temperature around 65℃, extending the device lifespan to 15 years. Simultaneously, it ensures stable chip operating parameters. The saturated output power decreases from 4W to 2.5W, at which point the single-chip power-added efficiency is ≥15%, the single-chip power consumption is ≤16.7W, the total power consumption of the final stage at saturated operation is ≤267W, and the actual rated power consumption is ≤200W. Finally, the 16 RF signals amplified by the GaN power amplifier chips 5-2 converge at the combiner port 5-1-1, and are matched and connected to the subsequent output interface unit 6, achieving the aggregated output of the 16 signals. The combined output E-band RF signal is no less than 30W, 71~76GHz, with a combining efficiency of ≥80% and in-band flatness of ≤3dB, thus achieving high-gain, high-linearity, high-efficiency, and large-bandwidth power amplification in the E-band.

[0133] The E-band RF signal output by the final stage power combining module 5 is down-converted to form a signal, which is then output to the digital domain DPD predistortion module 3-2 for use by the digital predistortion algorithm, ultimately completing the entire link feedback.

[0134] In the control and power supply area, the dynamic leakage voltage control unit 7 is electrically connected to the drain of each GaN power amplifier chip 5-2. This allows for fine-tuning of the leakage voltage to reduce the saturated output power of the GaN chip from 4W to 2.5W, keeping the chip junction temperature around 165℃ and the carrier temperature around 65℃. This reduces power amplifier power consumption while maintaining a relatively constant power-added efficiency, extending device lifespan. While ensuring a total system output power ≥30W, this reduces overall power consumption and allows for real-time reception of output power data transmitted by the protection and monitoring unit 8. When power attenuation due to temperature changes or aging effects is detected, the leakage voltage is automatically fine-tuned to compensate for power loss, ensuring the stability of the power amplifier system's output power.

[0135] The protection and monitoring unit 8 has overcurrent, overheat, and excessive VSWR protection functions, fault location indication function, and functions for uploading the output power, reflected power, DC operating current, and temperature of the whole machine.

[0136] Power supply module 9 provides 22V~30V power to the modules and functional units.

[0137] In summary, in this embodiment, the linearization predistortion module integrates an analog predistortion circuit and a digital domain DPD predistortion module, forming a joint analog-digital linearization architecture. Analog predistortion utilizes the gain expansion and phase compression characteristics of FET devices biased in the pinch-off region for initial compensation, while the digital domain DPD compensates for the insufficient RF linearization capability of the analog domain. The final-stage power combining module employs a high-isolation radial power combining network, designed based on multimode scattering matrix theory. This network achieves branch port isolation by increasing the number of electrical ports, reducing branch pulling effects under non-ideal excitation. The dynamic drain voltage control unit fine-tunes the operating drain voltage of the final-stage GaN power amplifier chip, reducing the chip's saturated output power to control the junction temperature and compensating for output power attenuation caused by temperature changes and aging effects. Radial power combining achieves a balance between combining efficiency and the number of paths, analog domain drain voltage control achieves initial linearization and reduces power consumption, and digital domain DPD predistortion compensates for the insufficient RF capability of the analog domain.

[0138] Specific Implementation Method Two: The E-band power amplification method described in this implementation method includes:

[0139] Digital predistortion compensation is performed on the intermediate frequency input signal based on the radio frequency feedback signal to obtain a digitally predistorted analog intermediate frequency signal;

[0140] The digitally predistorted analog intermediate frequency signal is converted to an E-band radio frequency signal;

[0141] The E-band radio frequency signal is nonlinearly pre-compensated at a preset operating temperature to obtain a simulated pre-distorted E-band radio frequency signal.

[0142] The power of the simulated pre-distorted E-band radio frequency signal is amplified by driving;

[0143] Based on the multimode scattering matrix theory and the amplitude-phase balance control principle, the E-band RF signals amplified by multiple GaN power amplifier chips are combined with equal amplitude and in phase to obtain the E-band power amplification result, and the E-band power amplification result is used as the RF feedback signal.

[0144] While specific embodiments of this application have been described herein with reference to them, it should be understood that these embodiments are merely examples of the principles and applications of this application. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of this application as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. An E-band power amplifier, characterized in that, include: E-band frequency conversion module (2), linearization predistortion module (3), drive amplification module (4) and final stage power synthesis module (5); The linearization predistortion module (3) is used to perform digital predistortion compensation on the intermediate frequency input signal based on the radio frequency feedback signal, and send the digitally predistorted analog intermediate frequency signal to the E-band frequency converter module (2). The E-band frequency conversion module (2) is used to convert the analog intermediate frequency signal of the digital predistortion to the E-band radio frequency signal and send it to the linearization predistortion module (3). The linearization predistortion module (3) is also used to perform nonlinear pre-compensation on the E-band radio frequency signal at a preset operating temperature, and send the simulated predistorted E-band radio frequency signal to the drive amplification module (4). The drive amplification module (4) is used to drive and amplify the power of the simulated pre-distorted E-band radio frequency signal and send it to the final stage power synthesis module (5). The final stage power combining module (5) is used to combine the E-band RF signals amplified by the GaN power amplifier chip into equal amplitude and in phase power based on the multimode scattering matrix theory and the amplitude and phase balance control principle, so as to obtain the output result of the E-band power amplifier. At the same time, the output result is fed back to the linearization predistortion module (3) as an RF feedback signal.

2. The E-band power amplifier according to claim 1, characterized in that, The linearization predistortion module (3) includes: an analog predistortion circuit (3-1), a digital domain DPD predistortion module (3-2), an RF input port (3-3), and an RF output port (3-4). The digital domain DPD predistortion module (3-2) is used to extract the dynamic nonlinear characteristics of the power amplifier array based on the radio frequency feedback signal, and to perform digital predistortion compensation on the intermediate frequency input signal according to the dynamic nonlinear characteristics to generate a digitally predistorted analog intermediate frequency signal. The E-band frequency converter module (2) inputs the E-band radio frequency signal to the analog pre-distortion circuit (3-1) through the radio frequency input port (3-3). The analog pre-distortion circuit (3-1) is used to perform nonlinear pre-compensation on the E-band radio frequency signal at a preset operating temperature. The simulated pre-distorted E-band radio frequency signal is sent to the drive amplifier module (4) through the radio frequency output port (3-4).

3. The E-band power amplifier according to claim 2, characterized in that, The digital domain DPD predistortion module (3-2) includes: a conversion unit (3-2-1) and a DPD algorithm processing unit (3-2-2). The conversion unit (3-2-1) is used to acquire the intermediate frequency input signal into the digital domain; The DPD algorithm processing unit (3-2-2) is used to extract the dynamic nonlinear characteristics of the power amplifier array based on the radio frequency feedback signal, and to perform digital predistortion compensation on the digital intermediate frequency signal according to the dynamic nonlinear characteristics. The conversion unit (3-2-1) is also used to convert the digital predistorted analog intermediate frequency signal into a predistorted analog intermediate frequency signal.

4. The E-band power amplifier according to claim 2 or 3, characterized in that, The analog predistortion circuit (3-1) includes: a FET device (3-1-1) and a temperature control voltage unit (3-1-2). The FET device (3-1-1) is used to fix its operating point in the pinch-off region by the gate bias voltage, and to perform nonlinear pre-compensation on the E-band radio frequency signal by utilizing the gain expansion and phase compression characteristics of the pinch-off region. The temperature control voltage unit (3-1-2) is used to update the gate bias voltage of the FET device (3-1-1) once every fixed temperature step, so that the FET device (3-1-1) can operate at a preset operating temperature.

5. The E-band power amplifier according to claim 4, characterized in that, The fixed temperature step size is 10℃, and the preset operating temperature is -20℃ to +60℃.

6. The E-band power amplifier according to claim 1, characterized in that, The E-band frequency conversion module (2) includes: a fixed attenuator (2-2), a primary frequency conversion unit (2-3), a filter (2-4), a digitally controlled attenuator (2-5), and an RF amplification unit (2-6). The fixed attenuator (2-2) is used to perform power back-off on the digitally predistorted analog intermediate frequency signal and send the attenuated analog intermediate frequency signal to the primary frequency conversion unit (2-3). The primary frequency conversion unit (2-3) is used to convert the attenuated analog intermediate frequency signal into an E-band radio frequency signal and send it to the filter (2-4). The filter (2-4) is used to suppress local oscillator leakage and send the suppressed E-band radio frequency signal to the digitally controlled attenuator (2-5). The digitally controlled attenuator (2-5) is used to adjust the power of the E-band radio frequency signal after local oscillator suppression to the target range and send it to the radio frequency amplification unit (2-6). The radio frequency amplification unit (2-6) is used to compensate for the frequency conversion loss of the E-band radio frequency signal after digital control attenuation, and to send the compensated E-band radio frequency signal to the linearization predistortion module (3).

7. The E-band power amplifier according to claim 1, characterized in that, The final stage power combining module (5) includes a high-isolation radial power combining network (5-1). The high-isolation radial power combining network (5-1) includes a combining port (5-1-1) and multiple branch arms (5-1-2). Each branch arm (5-1-2) is provided with multiple GaN power amplifier chips (5-2). The multiple branch arms (5-1-2) are arranged in a ring array and are all electrically connected to the combining port (5-1-1). The combining port (5-1-1) distributes the amplified E-band radio frequency signal to the multiple branch arms (5-1-2) with equal amplitude and in phase through the coaxial TEM mode structure. The GaN power amplifier chip (5-2) amplifies the power of the RF signal distributed to its branch; The multiple radio frequency signals amplified by the GaN power amplifier chip (5-2) are combined into equal-amplitude and in-phase power through the combiner port (5-1-1) to obtain the output result of the E-band power amplifier.

8. The E-band power amplifier according to claim 7, characterized in that, The final stage power combining module (5) also includes a water-cooling unit, which is used to cool the GaN power amplifier chip (5-2) with water.

9. The E-band power amplifier according to claim 7, characterized in that, It also includes a dynamic leakage control unit (7), whose control signal output terminal is electrically connected to the drain of multiple GaN power amplifier chips (5-2); The dynamic leakage voltage control unit (7) is used to adjust the leakage voltage of multiple GaN power amplifier chips (5-2).

10. E-band power amplification method, characterized in that, include: Digital predistortion compensation is performed on the intermediate frequency input signal based on the radio frequency feedback signal to obtain a digitally predistorted analog intermediate frequency signal; The digitally predistorted analog intermediate frequency signal is converted to an E-band radio frequency signal; The E-band radio frequency signal is nonlinearly pre-compensated at a preset operating temperature to obtain a simulated pre-distorted E-band radio frequency signal. The power of the simulated pre-distorted E-band radio frequency signal is amplified by driving; Based on the multimode scattering matrix theory and the amplitude-phase balance control principle, the E-band RF signals amplified by multiple GaN power amplifier chips are combined with equal amplitude and in phase to obtain the E-band power amplification result, and the E-band power amplification result is used as the RF feedback signal.

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