鉴频中周失谐对鉴频特性的影响

分析了集成峰值鉴频器的工作原理，得出鉴频中周失谐的原因是内置的配谐瓷管电容容量的衰减。衰减机理是该电容内外表面的银涂覆层受空气中硫化氢的侵蚀，局部或大面积生成硫化银而变黑，电极的有效面积减小，导致电容量减小。改进配谐瓷管电容生产工艺，在内外层圆柱型银的表面加保护层可有效防止中周失谐。

Influence of the Disharmony of Discriminator on its Properties of Frequency Discrimination

Through the analyses on the principle of integrated peak discriminator,it is found that the reason of disharmony of discriminator is due to the decrease of the capacity of oscillator.The decay mechanism is that the silver coating on the inner or outside surfaces of the capacitor partly or largely reacts with H_2S in air to produce Ag_2S,which causes the effective area of electrode to reduces so that reduces its capacity.Improving the production technologies of capacitors and adding a protection layer outside the capacitor can effectively avoid the disharmony of discriminator.