Design Of 0.38-18GHz Solid State Power Amplifier Automatic Monitoring System

This design is a monitoring system for 0.38GHz-18 GHz ultra-wideband solid-state power amplifier.Because the power amplifier is applied to the transmitter part of the shipboard electronic countermeasure system,the fault protection of the solid-state power amplifier transmitter must be well protected in complex environments such as day-night temperature difference and humidity.At the same time,the solid-state power amplifier gain linearity and miniaturization are guaranteed to facilitate Under the premise of system integration,the use of power resources should be improved as much as possible.For this purpose,a solid-state power amplifier monitoring system in the 038GHz-18 GHz band was designed.The design goal of the monitoring system is to realize real-time detection of various states of the solid state power amplifier during operation,fault protection,improve the linearity of the whole machine gain,and improve the utilization of power resources.Because the power amplifier uses GaN synthesis technology,there are problems of high-end gain compression and poor overall linearity.In order to ensure linearity,it is difficult to achieve a relatively good index by the design of the RF link.The previous method used the output power at the expense of power resources and controlled the output power in the linear region after 3db of the saturation point.It wastes power resources seriously,and increases the synthesis volume and power synthesis difficulty.Due to the ultra-wide frequency band of 0.38-18 GHz,it is difficult to find such high-octave amplifier devices.Therefore,in order to reduce the octave of the design feasibility,a sub-channel design scheme was adopted.The whole machine is from 0.38-2GHz,2-6GHz,The 6-18 GHz consists of three independent channels,and its monitoring system must independently control the three channels and ensure that the channels do not affect each other.The monitoring system adopts the ARM chip of M4 core as the main controller,and realizes the interaction between man and machine with RS232,RS485 and Ethernet communication.In the fault detection and protection of solid-state power amplifiers,multiple sensors are used to collect various working parameters,such as the use of thermal temperature sensors to obtain temperature information,the power detector to obtain power information,and the TTL standard level generated by the monitoring system to match the power sequence circuit.To cut off the faulty channel,and at the same time display the fault location through the touch screen and the host computer.For the improvement of power amplifier linearity,gain flatness,power stability and power resource utilization,microwave power level control technology is adopted.The input and output power detector and ESC attenuator are combined with fuzzy parameter self-tuning PID algorithm to complete.Realize two working modes of constant power and constant gain,the output power is constant in constant power mode,and the input and output gains are constant in constant gain mode.Because power detection has a greater correlation with frequency and temperature,a frequency identification circuit and a temperature compensation circuit are added to the design of the power detection link.The high and low temperature tests show that the system performance is stable,and the real-time monitoring work state is good,which can achieve the purpose of monitoring and protection,and can accurately display the fault location,effectively reducing the difficulty of fault maintenance and improving the work efficiency of the amplifier.And security,the system has been delivered to the application.