Research On Electromagnetic Protection Components For Radio Frequency Terminals

With the popularization and development of electromagnetic technology,especially the breakthroughs in the military field,an increasing number of advanced and highly destructive strong electromagnetic interference technologies have emerged.At the same time,the deteriorating environment poses significant challenges and tests to the safety and stability of future communication systems.In response,research on electromagnetic protection technology has become increasingly important.This thesis focuses on existing front-door electromagnetic protection technologies,ranging from the low-frequency bands of tens of MHz to the high-frequency bands of 7 GHz.According to the different protection targets,application scenarios,and the various component loading positions in the radio frequency front-end,a total of 6 electromagnetic protection components have been designed.Among them,four low-frequency components loaded with Gas Discharge Tubes and Transient Voltage Suppressors are primarily aimed at protecting against strong electromagnetic pulses,while high-frequency components loaded with PIN diodes are mainly targeted at high-power microwaves.This design starts with the main targets of electromagnetic protection,namely strong electromagnetic pulses and high-power microwaves,and first analyzes their characteristics and coupling mechanisms.Subsequently,the integrated design principles of filtering and protection are summarized based on these characteristics and mechanisms,and the main design ideas are derived.Following the integrated design approach,the application background,protection approach,and design ideas of each protection component are described in detail,from low to high frequency and from strong electromagnetic pulse protection to high-power microwave protection,in combination with the inherent characteristics of the devices.Three coaxial protection components based on GDT have been designed,with different interfaces and frequency bands according to the application scenarios,mainly targeting strong electromagnetic pulses.Only one TVS protection component has been designed for low-frequency application scenarios,with an LC circuit chosen for the implementation of the filtering network in the integrated design,also targeting strong electromagnetic pulses.Two PIN diode protection components have been designed,mainly aimed at protecting the commonly used C-band frequency in satellite and radar communication.These further validate the two integrated design ideas proposed in the second chapter.One of the PIN diode components is based on the LC filtering circuit,further verifying the effectiveness,correctness,and advantages of the integrated design idea compared to conventional protection circuits after the first two chapters’ groundwork.The other component is based on a microstrip filtering circuit,addressing the limitations of LC filtering networks in higher frequency applications and verifying the feasibility of the integrated design idea from a different perspective.The main protection target for these components is highpower microwaves.All the electromagnetic protection components involved in this design have undergone simulation and fabrication testing,and the test results have been compared with the simulation results.Both results are basically consistent,and the design ideas and principles proposed in the theoretical stage have been verified and are in line with expectations,meeting the design requirements.