Study Of Quick-Response And High-power Limiting Technology

With the development of information technology,the number of frequency equipment is increasing,the power of radiation source is increasing,and the technology of strong electromagnetic weapon is developing rapidly.Electronic information system is facing unprecedented strong electromagnetic threat.High speed and high power limiting technology is one of the most effective means of RF front-end protection.This paper focuses on the high-speed and high-power limiting technology applied to transmission lines and antennas.Firstly,a broadband high-speed high-power integrated limiter is designed.By comparing and analyzing the advantages and limitations of various limiting circuits,a highspeed and high-power limiter is designed,which is composed of three kinds of semiconductor devices in series.The designed limiter can work at 10 MHz SIM4GHz,with small insertion loss,fast response speed and high withstand power in the whole frequency band.The limiter can be encapsulated in a 10 mm times10 mm times1.5 mm shell,which has a strong practicability.Then,a new waveguide energy selective filter protection device is designed,which is characterized by band stop filter for high power signal.The relationship between the size of the filter element and the frequency response characteristics is analyzed.The equivalent circuit of the element structure and the array structure is studied.The principle of the energy selective filter is described by numerical simulation.In order to expand the frequency band and improve the withstand power,the design of cell cascade array is completed.Finally,the structure of one cell and nine cell array are fabricated.The test results show that the insertion loss in the frequency range of the waveguide is small,and the signal injected with high power has strong reflection,which can obtain good protective effect.Finally,a new design method of integration of limiting and antenna is put forward.The limiting technology is directly integrated in the antenna end,and the adaptive protection of antenna to strong electromagnetic signal is realized by simulation.Taking Ka band antenna as an example,a high gain low profile antenna is designed in this paper.Then,the diode is loaded at the place where the electric field is most concentrated on the antenna surface.Through simulation,it can be seen that the main lobe gain of the antenna decreases with the increase of the incident power,which can provide a maximum protection effect of 11 d B,so as to achieve the strong electromagnetic protection effect in the direction of the main lobe.