Abstract
Semiconductor radiation detector that we talk about in this research is using photodiode as a detector. Adding the preamplifier and shaping amplifier it forms a sensing system and provides the signal for counting and data processing. We combine photodiode and bipolar junction transistor (BJT) signal processing circuit (preamplifier and linear-amplifier) as a radiation detector. After analyzing the BJT circuit, we find the gain-bandwidth product requirement of the preamplifier is 2.88M and gain-bandwidth product requirement of the linear-amplifier is 3.88M. Therefore, If we find a Operational Amplifier satisfy the requirement, we can replace the BJT circuit by CMOS OP circuit.