Research On High Power Microwave Effects Of Low Noise Amplifiers

With the development of modern society,the electromagnetic environment is becoming more and more complex,the phenomenon of microwave interference and electromagnetic radiation is becoming more and more common,and the process technology of radio frequency and semiconductor devices is getting smaller and smaller,and the degree of integration is constantly improving.The more complex the composition,the more serious the consequences of electromagnetic interference.High-power microwave(HPM)has the characteristics of high frequency and high power,which is often more likely to cause interference or damage to electronic or communication systems.The receiver is the most important component of the front door coupling of the communication system,so the study of the HPM effect of the typical components inside the receiver can provide data reference for the electromagnetic protection of important communication equipment.In this paper,taking the typical device low noise amplifier(LNA)inside the receiver as the effect research target,under the action of HPM,LNA effect simulation simulation and injection experiment research are carried out.The specific research contents are as follows:According to the technical specifications and design steps of LNA,single-stage and two-stage LNA circuits were built in ADS,which met the design specifications.The designed single-stage and two-stage LNA circuits were nonlinearly analyzed by using the harmonic balance simulation tool.Effect simulation,through analysis and calculation results,it is concluded that when the input power of the LNA is small,the output power increases approximately linearly with the input power,that is,the gain is stable;when the input power exceeds a certain intensity,the LNA gradually reaches a saturated working state,showing In order to keep the output power basically unchanged,the gain gradually decreases;when the frequency of the input signal is different,the output power and gain of the LNA are basically the same as the change trend of the input power,that is,the correlation between the nonlinear effect of the LNA and the frequency of the input signal Weak;the designed single-stage and two-stage LNA circuits were simulated by using the transient response simulation tool to simulate the voltage of each pole.The analysis and calculation results show that when the HPM pulse signal is injected into the two-stage LNA,the transient voltage value of the gate of the first stage is the highest,and the increase trend is the most significant.,that is,the gate of the first-stage amplifier is the most sensitive and most susceptible to interference or damage;the value of the transient voltage has a weak correlation with the rising edge and pulse width of the injected pulse.The injection effect experiment was carried out on the LNA,and an experimental platform for the injection of the LNA was built.Through the experiment,the gain curve of the tested LNA in the frequency band 2.4?2.5 GHz was obtained when different powers were injected.The power threshold at which the damage effect occurs is 31 d Bm;the curve of the gain of the LNA with the injected power is obtained by analyzing the data.