Design Of Front-end Amplifier Circuit For Silicon Carbide Detector

With the continuous deepening of nuclear physics and high-energy particle physics,space environment detection has developed rapidly.The space environment is very complex,which is full of a large number of complex mixed particles.Traditional nuclear radiation detectors cannot meet the long-term detection in extreme environments.Silicon carbide(SiC)material,as a third-generation compound semiconductor material developed in recent years,has excellent performance such as large band gap,high thermal conductivity,strong thermal stability and large critical displacement energy,making it a radiation detector prepared It has the advantages of small size,low energy consumption,high temperature resistance and strong radiation resistance.In this paper,three types of amplifiers are designed for space particle radiation detection,time measurement system and energy spectrum measurement system based on silicon carbide detectors.1?A fast preamplifier is designed according to the requirements of the time measurement system of the silicon carbide detector.The fast preamplifier is composed of a two-stage cascaded RF amplifier chip and an LC low-pass filter circuit.In order to compare in practical applications,two types are used respectively.The RF amplifier chip has designed two kinds of fast preamplifiers.The ADS(Advanced Design System)simulation software is used to simulate and optimize the two fast preamplifiers.The two fast preamplifiers are debugged and measured by the vector network analyzer NA7682C.The measurement results show that the two fast preamplifiers are in Good matching within 1M-2GHz,flat gain,and wide linear dynamic range.Finally,the actual joint debugging was carried out with the JW-SCN5 Schottky silicon carbide detector,and the²⁴¹Am-Be neutron source was used for the irradiation test.The test results show that the output signal rise time of the two fast preamplifiers is less than 1ns.2?In addition,according to the requirements of the energy spectrum measurement system of the silicon carbide detector,a charge-sensitive preamplifier and main amplifier is designed.The charge-sensitive preamplifier is composed of an integrated operational amplifier.Through reasonable parameter design,smaller noise and larger noise are achieved.Charge conversion gain:According to the principle of optimal filter realization,the design of the main amplifier is completed by using a pole-zero cancellation circuit and a filter shaping circuit.Set up a test platform for charge-sensitive preamplifier and main amplifier.The actual test shows that the charge conversion gain of the charge-sensitive preamplifier and main amplifier system in the dynamic range of 4f C-4p C is about 1.25×10¹²V/C,and the equivalent noise charge of the system is 2.069×10^-15C,the actual joint adjustment is also carried out with the silicon carbide detector.The results show that the system has a good forming effect under the irradiation of the ²⁴¹Am-Be neutron source.