Power amplifier device with over-current and over-temperature protection

Abstract

The utility model discloses a power amplifier device with over-current and over-temperature protection, and relates to the technical field of electronic circuits. The device comprises a main control board, a multi-band radio frequency system and a detection module. The main control board integrates a main control unit, a DAC, an ADC and a memory. The multi-band radio frequency system comprises a signal conditioning module and a power amplification module. According to the signal conditioning module, an adjustable attenuator, a radio frequency switch and a filter group form a selectable filtering or straight-through path. The power amplification module comprises a final-stage power amplifier and an optional pre-driving amplifier; the detection module comprises a current detection unit connected in series in a power amplifier power supply loop and a temperature detection unit installed on the power amplification module, and the output ends of the current detection unit and the temperature detection unit are connected to the ADC. The main control unit controls the adjustable attenuator and the radio frequency switch through the DAC during over-current or over-temperature according to current and temperature data collected in real time, active protection such as rapid current limiting, power reduction or turn-off is achieved, the reliability of the power amplifier device is remarkably improved, and the service life of the power amplifier device is remarkably prolonged.

Description

Technical Field

[0001] This utility model relates to the technical field of radio frequency power amplifiers and their protection circuits, specifically a power amplifier device with overcurrent and overtemperature protection. Background Technology

[0002] Power amplifiers are widely used in wireless communication, broadcasting, and radio frequency identification, and their operational stability and reliability are of paramount importance. In practical applications, power amplifiers often suffer from overcurrent or overheating due to sudden load changes, impedance mismatch, or changes in ambient temperature, which can lead to permanent damage to the devices.

[0003] Existing power amplifier devices typically use simple fuses or thermistors for protection, but these protection mechanisms are slow to respond, have low accuracy, and cannot achieve real-time detection and intelligent control. In addition, with the development of multi-band communication requirements, power amplifier devices need to support multi-band signal processing, but traditional power amplifiers often lack flexible filtering and switching capabilities, making it difficult to maintain high efficiency under complex operating conditions.

[0004] Therefore, there is an urgent need for a power amplifier device that integrates overcurrent and overtemperature protection functions, capable of acquiring current and temperature data in real time through the main control unit, and combining it with a programmable RF link to achieve rapid protection and adaptive adjustment, thereby improving the reliability and service life of the device. Utility Model Content

[0005] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a power amplifier device with overcurrent and overtemperature protection, including: a main control board, wherein the main control board integrates a main control unit, a DAC, an ADC, and a memory, and the DAC, ADC, and memory are respectively connected to the main control unit. A multi-band radio frequency (RF) system includes an RF processing link, which comprises a signal conditioning module and a power amplification module. The signal conditioning module includes an adjustable attenuator, a first RF switch, a filter bank, and a second RF switch. The first RF switch has at least two output paths, one of which is connected to the second RF switch via the filter bank, and the other is connected to the second RF switch to form a direct path. The power amplification module includes a final-stage power amplifier, the input of which is connected to the output of the second RF switch. The adjustable attenuator, the first RF switch, and the second RF switch are connected to a DAC. A detection module includes a current detection unit and a temperature detection unit. The current detection unit is connected in series in the power supply circuit of the power amplification module, and its signal output is connected to the ADC. The temperature detection unit is mounted on the power amplification module, and its signal output is connected to the ADC.

[0006] Preferably, the signal conditioning module further includes a power divider and an input power detection unit; the input terminal of the power divider constitutes the signal input port of the RF processing link, its main output terminal is connected to the input terminal of the adjustable attenuator, and its detection output terminal is connected to the input terminal of the input power detection unit; the output terminal of the input power detection unit is connected to the ADC.

[0007] Preferably, the power amplification module further includes a preamplifier; the input terminal of the preamplifier is connected to the main output terminal of the power divider, its output terminal is connected to the input terminal of the adjustable attenuator, and its control terminal is connected to the DAC.

[0008] Preferably, the power amplification module further includes a driver amplifier, a power divider, a power combiner, and multiple final-stage power amplifiers; the input terminal of the driver amplifier is connected to the output terminal of the second RF switch, and the output terminal of the driver amplifier is connected to the input terminal of the power divider; the multiple output terminals of the power divider respectively drive multiple parallel final-stage power amplifiers, and the outputs of each final-stage power amplifier are then combined into the power combiner; the control terminals of the driver amplifier and each final-stage power amplifier are connected to the DAC.

[0009] Preferably, the detection module further includes an output detection unit; the output detection unit includes a coupler, a forward power detection chip, and a reverse power detection chip; the main input terminal of the coupler is connected to the output terminal of the power combiner, and its forward coupling terminal and reverse coupling terminal are respectively connected to the input terminals of the forward power detection chip and the reverse power detection chip; the output terminals of the forward power detection chip and the reverse power detection chip are connected to the ADC.

[0010] Preferably, the filter bank is a first filter bank, and the first RF switch and the second RF switch are single-pole multi-throw switches.

[0011] Preferably, the signal conditioning module further includes a third RF switch, a second filter bank, and a fourth RF switch; the output terminal of the final stage power amplifier is connected to the input terminal of the third RF switch, the multiple output terminals of the third RF switch are respectively connected to different filters in the second filter bank, the output terminal of the second filter bank is connected to the multiple input terminals of the fourth RF switch, and the third RF switch and the fourth RF switch are connected to the DAC.

[0012] Preferably, the power amplification module further includes a driver amplifier and an input amplifier. The driver amplifier is connected between the adjustable attenuator and the first RF switch. The input amplifier receives RF input and its output is connected to the power divider. The control terminals of the driver amplifier and the input amplifier are connected to the DAC.

[0013] Preferably, it further includes an output detection module, which includes a coupler, an output power detection chip, and an antenna port; the output terminal of the fourth RF switch is connected to the main input terminal of the coupler, the main output terminal of the coupler is connected to the antenna port, the coupling terminal of the coupler is connected to the input terminal of the output power detection chip, and the output terminal of the output power detection chip is connected to the ADC.

[0014] Preferably, the detection module further includes a voltage detection unit, the input terminal of which is connected to the power supply circuit of the power amplifier module for detecting its operating voltage; both the current detection unit and the voltage detection unit are configured to have an analog signal output terminal and a digital warning signal output terminal; the analog signal output terminal is connected to the ADC for providing the value of the detection parameter to the main control unit; the digital warning signal output terminal is connected to the main control unit for issuing a warning signal to the main control unit when the parameter exceeds the standard.

[0015] The beneficial effect of this utility model is that it achieves a precise and reliable active protection mechanism:

[0016] 1. By integrating current and temperature detection units and interacting with the main control unit in real time, it can quickly respond to overcurrent and overheating anomalies and take proactive measures such as current limiting, power reduction or shutdown, effectively preventing damage to power amplifier tubes and significantly improving the stability and service life of the equipment.

[0017] 2. Provides flexible multi-band signal processing capabilities: Through the reconfigurable signal conditioning module composed of RF switches and filter banks, it can intelligently select filtering or direct path according to the working frequency band, and can perform secondary filtering selection at the output end, which enhances the device's adaptability to complex multi-band application scenarios and signal quality.

[0018] 3. A comprehensive system performance testing and optimization system has been built: It integrates all-round power detection from input and driver stages to output stages, and combined with voltage detection, it provides complete system status data for the main control unit, thereby realizing real-time monitoring and dynamic adjustment of gain and matching status, ensuring that the power amplifier always works in the best performance state. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the main control board of a power amplifier device with overcurrent and overtemperature protection;

[0020] Figure 2 This is a schematic diagram of one implementation of a multi-band radio frequency system in a power amplifier device with overcurrent and overtemperature protection;

[0021] Figure 3This is a schematic diagram of another implementation of a multi-band radio frequency system in a power amplifier device with overcurrent and overtemperature protection.

[0022] Figure 4 This is a schematic diagram of the connection of the detection module of a power amplifier device with overcurrent and overtemperature protection. Detailed Implementation

[0023] The technical solution of this utility model is described in further detail below with reference to the accompanying drawings, but the scope of protection of this utility model is not limited to the following description.

[0024] The features and performance of this utility model will be further described in detail below with reference to embodiments.

[0025] like Figure 1 As shown, a power amplifier device with overcurrent and overtemperature protection is characterized by comprising: a main control board, wherein the main control board integrates a main control unit, a DAC, an ADC, and a memory, wherein the DAC, ADC, and memory are respectively connected to the main control unit; a multi-band radio frequency system, wherein the multi-band radio frequency system includes a radio frequency processing link, wherein the radio frequency processing link includes a signal conditioning module and a power amplification module, wherein the signal conditioning module includes an adjustable attenuator, a first radio frequency switch, a filter bank, and a second radio frequency switch, wherein the first radio frequency switch is configured with at least two output paths, one of which is connected to the second radio frequency switch through the filter bank, and the other output is connected to the second radio frequency switch to form a direct path; the power amplification module includes a final stage power amplifier, wherein the input terminal of the final stage power amplifier is connected to the output terminal of the second radio frequency switch, and the adjustable attenuator, the first radio frequency switch, and the second radio frequency switch are connected to the DAC; and a detection module, such as Figure 4 As shown, the detection module includes a current detection unit and a temperature detection unit; the current detection unit is connected in series in the power supply circuit of the power amplifier module, and its signal output terminal is connected to the ADC; the temperature detection unit is disposed on the power amplifier module, and its signal output terminal is connected to the ADC.

[0026] Example 1: As Figure 2 As shown, the signal conditioning module further includes a power divider and an input power detection unit; the input terminal of the power divider constitutes the signal input port of the RF processing link, its main output terminal is connected to the input terminal of the adjustable attenuator, and its detection output terminal is connected to the input terminal of the input power detection unit; the output terminal of the input power detection unit is connected to the ADC.

[0027] The power amplifier module also includes a preamplifier; the input of the preamplifier is connected to the main output of the power divider, its output is connected to the input of the adjustable attenuator, and its control is connected to the DAC.

[0028] The power amplification module further includes a driver amplifier, a power divider, a power combiner, and multiple final-stage power amplifiers; the input terminal of the driver amplifier is connected to the output terminal of the second RF switch, and the output terminal of the driver amplifier is connected to the input terminal of the power divider; the multiple output terminals of the power divider respectively drive multiple parallel final-stage power amplifiers, and the outputs of each final-stage power amplifier are then fed into the power combiner; the control terminals of the driver amplifier and each final-stage power amplifier are connected to the DAC.

[0029] The detection module further includes an output detection unit; the output detection unit includes a coupler, a forward power detection chip, and a reverse power detection chip; the main input terminal of the coupler is connected to the output terminal of the power combiner, and its forward coupling terminal and reverse coupling terminal are respectively connected to the input terminals of the forward power detection chip and the reverse power detection chip; the output terminals of the forward power detection chip and the reverse power detection chip are connected to the ADC, and the forward power detection chip and the reverse power detection chip can preferably be the ADL5904 chip.

[0030] Based on the hardware described in Example 1, its specific workflow, together with the FPGA main control board, forms a precise detection-control-protection closed-loop system. The MCU on the main control board dynamically configures and manages the entire RF link in real time by calling the pre-stored power amplifier gain curves, frequency band parameters, temperature thresholds, and attenuation code tables in the memory.

[0031] Upon power-on initialization or upon receiving a "system control signal" to switch frequency bands, the MCU controls the multi-channel D / A output module via the SPI1 bus to generate multiple analog voltage signals: one of which is output to an adjustable attenuator to set its initial attenuation value to match the gain requirements of the current frequency band; simultaneously, another route controls the selection channels of the first and second RF switches, thereby determining whether the RF signal is passed through a filter bank for out-of-band spurious suppression or through a "straight-through path" to meet wider bandwidth requirements.

[0032] During normal amplification, the MCU continuously reads multiple detection data from the A / D conversion module via the SPI2 bus: the signal from the input power detection unit is used to detect the input signal strength and prevent pre-amplifier overload; the signals from the forward and reverse power detection chips enable the MCU to calculate the output power and voltage standing wave ratio in real time, accurately controlling the power amplifier's operating status and antenna load. Simultaneously, the analog signals from the temperature and current detection units are also acquired by the ADC for real-time monitoring by the MCU.

[0033] When an abnormal situation occurs, the system's multi-layered protection mechanism takes effect immediately:

[0034] Analog soft protection: If the current, temperature or reflected power values ​​read by the MCU through the ADC exceed the software threshold set in the memory, but no hardware warning has been triggered, the MCU will take protective measures, such as rapidly increasing the attenuation of the adjustable attenuator through the DAC to reduce the gain, or directly canceling the power amplifier enable control signal to turn off the power amplifier.

[0035] Digital hardware protection: If the abnormality worsens rapidly, digital signals such as overcurrent warning and overtemperature warning will be directly set and sent to the MCU. The MCU responds quickly, executing the highest priority protection actions, including cutting off the power amplifier supply and immediately switching the system to receive mode via PTT transceiver control to ensure equipment safety.

[0036] Furthermore, the U / L switching control signal output by the MCU works in conjunction with the RF switch to switch the power amplifier's operating frequency band (such as U band or L band). Throughout the process, the MCU can send system status, alarm logs, and other data to the host computer via an external communication interface, enabling remote monitoring and diagnostics.

[0037] Example 2: This embodiment is an example Figure 3 As shown, the filter bank is a first filter bank, and the first RF switch and the second RF switch are single-pole multi-throw switches.

[0038] The signal conditioning module further includes a power divider and an input power detection unit; the input terminal of the power divider constitutes the signal input port of the RF processing link, its main output terminal is connected to the input terminal of the adjustable attenuator, and its detection output terminal is connected to the input terminal of the input power detection unit; the output terminal of the input power detection unit is connected to the ADC.

[0039] The power amplifier module also includes a preamplifier; the input of the preamplifier is connected to the main output of the power divider, and its output is connected to the input of the adjustable attenuator. The preamplifier is used to amplify the main signal after power division a second time.

[0040] The signal conditioning module further includes a third RF switch, a second filter bank, and a fourth RF switch; the output terminal of the final stage power amplifier is connected to the input terminal of the third RF switch, the multiple output terminals of the third RF switch are respectively connected to different filters in the second filter bank, the output terminal of the second filter bank is connected to the multiple input terminals of the fourth RF switch, and the third RF switch and the fourth RF switch are connected to the DAC.

[0041] The power amplifier module further includes a driver amplifier and an input amplifier. The driver amplifier is connected between the adjustable attenuator and the first RF switch. The input amplifier receives RF input and its output is connected to the power divider. The control terminals of the driver amplifier and the input amplifier are connected to the DAC. The input amplifier is used to perform primary amplification and driving of the input signal.

[0042] The detection module further includes an output detection module, which includes a coupler, an output power detection chip, and an antenna port; the output terminal of the fourth RF switch is connected to the main input terminal of the coupler, the main output terminal of the coupler is connected to the antenna port, and the coupling terminal of the coupler is connected to the input terminal of the output power detection chip; the output terminal of the output power detection chip is connected to the ADC.

[0043] The detection module further includes a voltage detection unit, the input of which is connected to the power supply circuit of the power amplifier module for detecting its operating voltage. Both the current detection unit and the voltage detection unit are configured to have an analog signal output terminal and a digital warning signal output terminal. The analog signal output terminal is connected to the ADC for providing the value of the detection parameter to the main control unit. The digital warning signal output terminal is connected to the main control unit for issuing a warning signal to the main control unit when the parameter exceeds the limit.

[0044] Example 2 provides an implementation scheme for a power amplifier system with input detection, output spectrum cleanup, and multiple fast protection features. Its core lies in achieving end-to-end signal management from input to output through a main control board.

[0045] During system startup or frequency band switching, the main control unit (MCU) reads parameters for the corresponding frequency band from memory based on system control signals or preset strategies. These parameters include the expected range of input power, the bias point of the final stage power amplifier, the selection of the output filter, and the gain compensation value of the drive amplifier. Subsequently, the MCU sends commands to the multiplexed D / A output module via the SPI1 bus.

[0046] One DAC output controls the first RF switch and the second RF switch (single-pole multi-throw switch) to select the input filter that matches the target frequency band from the first filter bank.

[0047] The other key output simultaneously controls the third and fourth RF switches, selecting the corresponding output filter from the second filter bank. This filtering network, located after the final power amplifier stage, is crucial for ensuring the purity of the final output signal spectrum and suppressing spurious signals and harmonics.

[0048] During signal amplification and detection, the RF signal is first amplified and driven by the preamplifier, and then sent to the power divider. The power divider separates the signal into two paths: the main path signal is sequentially regulated by the adjustable attenuator, amplified again by the driver amplifier, then selected and filtered by the input switch filter link composed of the first RF switch and the first filter bank, and finally amplified by the final stage power amplifier; the coupled path signal is directly sent to the input power detection unit for real-time detection of the input signal strength. The signal output from the final stage power amplifier enters the output switch filter link composed of the third RF switch, the second filter bank, and the fourth RF switch for final frequency band selection and spectrum purification. The purified signal passes through the coupler, with its main path energy radiated to the antenna port, and its coupled path energy sent to the output power detection chip for accurate detection of the final output power. At this time, the A / D conversion module provides the MCU with comprehensive system status information, including input, output, and power status, via the SPI2 bus: the input power detection unit provides input signal strength data, and the output power detection chip provides purified final output power data. The voltage and current sensing units provide real-time operating data of the power supply circuit. The MCU utilizes this data to precisely control the output power level and monitor the overall system efficiency.

[0049] The multiple fast protection mechanisms in Example 2 are an inherent feature:

[0050] Analog detection and software protection: The MCU continuously analyzes the input power, voltage, current, temperature, and output power data from the ADC. If any parameter becomes abnormal, the MCU can dynamically adjust the driver amplifier bias or control the adjustable attenuator via the DAC to perform power back-off.

[0051] Digital warnings and hardware-level rapid protection: The hardware comparison circuits built into the voltage and current detection units operate in parallel. Once a momentary overvoltage or overcurrent is detected, a digital warning signal is sent directly to the MCU's interrupt pin. The MCU responds within microseconds, unconditionally executing the most urgent protection actions, such as immediately canceling the power amplifier enable control, thereby achieving rapid hardware-level power-off.

[0052] Through the above design, Example 2 constructs a power amplifier system suitable for multi-band operation, high spectral purity requirements, and demanding operating environments. This system ensures high reliability under high-performance operation through its inherent end-to-end detection and dual-path protection mechanisms.

[0053] The above description is merely a preferred embodiment of this utility model. It should be understood that this utility model is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this utility model should be protected within the scope of the appended claims.

Claims

1. A power amplifier device with overcurrent and overtemperature protection, characterized in that, The application relates to a multi-band radio frequency system. The main control board is integrated with a main control unit, a DAC, an ADC and a memory, and the DAC, the ADC and the memory are connected with the main control unit. The signal conditioning module comprises an adjustable attenuator, a first radio frequency switch, a filter group and a second radio frequency switch.

2. The power amplifier device with over-current and over-temperature protection according to claim 1, wherein, The first radio frequency switch is provided with at least two output channels, one of which is connected with the second radio frequency switch through the filter group, and the other is connected with the second radio frequency switch to form a straight-through channel.

3. The power amplifier device with over-current and over-temperature protection according to claim 2, characterized in that, The power amplifier module comprises a final-stage power amplifier, and the input end of the final-stage power amplifier is connected with the output end of the second radio frequency switch.

4. The power amplifier device with over-current and over-temperature protection according to claim 1, wherein, The adjustable attenuator, the first radio frequency switch and the second radio frequency switch are connected with the DAC.

5. The power amplifier device with over-current and over-temperature protection according to claim 4, wherein, The detection module comprises a current detection unit and a temperature detection unit.

6. The power amplifier device with over-current and over-temperature protection according to claim 1, wherein, The current detection unit is connected with the ADC through the signal output end. The temperature detection unit is arranged on the power amplifier module, and the signal output end is connected with the ADC. The signal conditioning module further comprises a power divider and an input power detection unit. The input end of the power divider forms the signal input port of the radio frequency processing link. The output end of the input power detection unit is connected with the ADC. The power amplifier module further comprises a pre-stage power amplifier. The input end of the pre-stage power amplifier is connected with the main road output end of the power divider. The output end of the pre-stage power amplifier is connected with the input end of the adjustable attenuator. The control end of the pre-stage power amplifier is connected with the DAC. The power amplifier module further comprises a driving amplifier, a power distributor, a power synthesizer and a plurality of final-stage power amplifiers. The input end of the driving amplifier is connected with the output end of the second radio frequency switch. The output end of the driving amplifier is connected with the input end of the power distributor. The plurality of output ends of the power distributor drive a plurality of parallel final-stage power amplifiers. The control ends of the driving amplifier and the final-stage power amplifiers are connected with the DAC. The power synthesizer has a plurality of input ends and an output end. The output detection unit comprises a coupler, a forward power detection chip and a reverse power detection chip. The main road input end of the coupler is connected with the output end of the power synthesizer. The forward coupling end and the reverse coupling end of the coupler are respectively connected with the input ends of the forward power detection chip and the reverse power detection chip. The output ends of the forward power detection chip and the reverse power detection chip are connected with the ADC. The filter group is a first filter group. The first radio frequency switch and the second radio frequency switch are single-pole multi-throw switches.

7. The power amplifier device with over-current and over-temperature protection according to claim 1, wherein, The signal conditioning module further comprises a third radio frequency switch, a second filter set and a fourth radio frequency switch; an output end of the final-stage power amplifier is connected with an input end of the third radio frequency switch, multiple output ends of the third radio frequency switch are respectively connected to different filters in the second filter set, an output end of the second filter set is connected with multiple input ends of the fourth radio frequency switch, and the third radio frequency switch and the fourth radio frequency switch are connected with the DAC.

8. The power amplifier device with over-current and over-temperature protection according to claim 1, wherein, The power amplification module further comprises a driving amplifier and an input amplifier, the driving amplifier is connected between the adjustable attenuator and the first radio frequency switch, the input amplifier receives a radio frequency input, and an output end is connected with the power divider, and control ends of the driving amplifier and the input amplifier are connected with the DAC.

9. The power amplifier device with over-current and over-temperature protection according to claim 7, wherein, Further comprising an output detection module, the output detection module comprises a coupler, an output power detection chip and an antenna port; an output end of the fourth radio frequency switch is connected with a main path input end of the coupler, a main path output end of the coupler is connected with the antenna port, and a coupling end of the coupler is connected with an input end of the output power detection chip; an output end of the output power detection chip is connected with the ADC.

10. The power amplifier device with over-current and over-temperature protection according to claim 1, wherein, The detection module further comprises a voltage detection unit, an input end of the voltage detection unit is connected with a power supply circuit of the power amplification module, and is used for detecting a working voltage; the current detection unit and the voltage detection unit are both configured to have an analog signal output end and a digital warning signal output end; the analog signal output end is connected with the ADC, and is used for providing a numerical value of a detection parameter to the host control unit; and the digital warning signal output end is connected with the host control unit, and is used for sending a warning signal to the host control unit when a parameter exceeds a standard.

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