金属结构红外探测器振动噪声的研究

为使红外探测器在振动干扰的环境下仍具有足够高的探测率,必须降低其因振动而产生的噪声幅度.控制探测器振动噪声的主要手段之一是控制其机械振动幅度,尤其是共振振幅.采用锤击法,利用冲击激励的宽频特性,研究了金属结构红外探测器的共振特性及影响振动噪声的力学因素.通过改变探测器结构的动力学特性,探寻了减振降噪的几种途径.实验结果表明,探测器悬臂冷指的结构参数对探测器的振动特性起主要作用.在冷指自由端与壳体间填胶做支撑、或冷指固定端与壳体间用胶粘隔振的减振降噪效果最好,可使振动噪声降至原值的1/20.

Vibration noise of the metal structure IR detector

When an IR detector with high enough detectivity was needed,even under a condition with vibration interference,the amplitude of the noise introduced by vibration must be reduced.One of major means to control the amplitude of the vibration noise of a detector was to control the amplitude of mechanical vibration,especially the amplitude of resonance.Mechanical factors effecting on the vibration noise and resonance performance of IR detector were analyzed for the method of impact excitation using a hammer.The wide frequency range characteristic of impact excitation was used.And several ways to reduce the vibration noise were tried by structural dynamics modification of the detector.Experimental results showed that the structure parameters of the cantilever cold finger play a major role in the structure's dynamic behavior of a detector.Making a support between cold finger free end and housing of a detector with gum,or gluing the cold finger fixed end to housing for vibration insulation,had the best effect to reduce the vibration noise to 1/20 of the former value.