Pointing error of transmitter and atmospheric turbulence cause signal fading for satellite-to-ground laser communication,and the anti-fading characteristics of distributed ground-based array receiver with optical preamplifiers are analyzed.

In order to improve the sensitivity measurement of the trace gas concentration, proposed one kind of advanced design of photo-electricity detection of preamplifier circuit applied to this monitoring system, that is, the programmable gain preamplifier circuit of photo-electricity detection.

The keystones and difficulties during the design and realization of NMR preamplifier for Oil Well Logging System were analyzed.

In this paper, problems and related technical measures about structure of acquisition system, preamplifier, power and earthing, which must be considered in designing foreside of high-speed data acquisition system, are discussed.

Based on the factors of PIN photodiode monitoring, we proposed a pre-amplifier circuit which can improve Signal-to-Noise and decrease the bandwith of noise, and pointed common prinples in designing low-noise, high-responsibility photodiode monitoring.

In this paper, a signal de-tection method and a pre-amplifier circuit design are elaborated according to the Lock-in amplifier (LIA) principle and OPA128 chip characteristic.