This paper is devoted to describe a kind of select-frequency amplifier of special use,analyse about its electronic phenomenons such as the multi-frequency peak value, amplitude disturbance, resonance disturbance, and provide a functional designs and data.

A new method is proposed for null steering using amplitude perturbations,by which Genetic Algorithm is used for optimization in the course of amplitude perturbation SO as to form the null steering with given depth in a given direction.

Experimental research for γ-ray interference threshold effect of high electromagnetic pulse sensor;

Coupling paths, interference threshold, the relation of the threshold with rising time and duration time of the field were studied by changing the peak value, duration time and rising time of the simulated pulsed magnetic field.