Small-signal Detection System Based On Electric Field Sensor

Sensor has played a significant role in many fields of current society, especially in military reconnaissance, electro-magnetic compatibility and wireless communication. Traditional sensors of electric field have some disadvantages in applications,such as narrow measuring bandwidth, great bulk and so on. Thus, integrated optical waveguide electric field sensor using advance integrated optics technology can be adopted, which makes the whole measurement system super-small, steady and reliable, is characteristic of broad bandwidth, immunity to electromagnetics and tiny perturbation. They can be interconnected by optical fiber so that remote control and monitoring can be realized. At present, the electric field sensor is the one of research focus using integrated optics technology based on LiNbO3 substrate. Therefore, integrated optical waveguide electric field sensors are developed in this thesis, the feeble signal of wide band and low power detected by waveguide electric field sensors is processing.Because of the broadband and high cost, it is not feasible to realize the ideal digital receiving by directly placing the AD converter close to the antenna. Converting the broadband RFsignal to the IF signal which can be digital is the key to realize wide band digital receiving. In this thesis , for the wide band and low power RF signal detected by optical waveguide sensor. In this thesis, using the structure of digital IF receiving which is a wide band superheterodyne module, and combining with the actual components'level,a broadband RF front-end system is presented by ADS——a emulational soft for designing RF electrocircuit. The broadband, high sensitivity and large dynamic range are implemented in this RF front-end. According to the parameters of actual components given in this thesis, the feasibility of the RF front-end in hardware is validated by ADS. The technology of wide band digital receiving like this can be widely used in electronic reconnaissance , radar signal processing and wireless communication.The IF output of RF front-end is detected by a threshold. Before detecting , the probability distributing of signal and noise can be gained by modeling them., then different thresholds are adopted according to different SNR and accumulating numbers. The shortage and improvement of the arithmetic are discussed. The realization of arithmetic in hardware is analysed.