原材料和制备工艺对硅酸锌陶瓷微波介电性能的影响

为了提高硅酸锌介质陶瓷的性能,研究了添加物、原材料和制备工艺对其微波介电性能的影响。采用固相法、并以去离子水代替乙醇作分散剂制备陶瓷粉料,闭腔法测量其无载Q值和频率温度系数。研究结果表明原材料的粒度、球磨工艺和烧结温度对Q.f值影响大,添加物TiO2不仅调节频率温度系数(τf),而且促进陶瓷烧结。当TiO2(wt%)12%,1240℃烧结时,获得优良的微波介电性能:介电常数(εr)为10.2,Q.f=91640GHz,τf=-5.78ppm/℃。并用该组成的材料制作了中心频率f0=5.4GHz,带宽Δf=96MHz,插损小于1.3dB的两级片式介质带通滤波器,可以用于通信系统。

EFFECT OF RAW MATERIALS AND PROCESSING ON MICROWAVE DIELECTRIC PROPERTIES OF ZINC SILICATE CERAMICS

In order to improve the properties of zinc silicate dielectric ceramic,the effects of additives,raw materials and processing on microwave dielectric properties of zinc silicate ceramic were developed.The ceramic powders were prepared using solid phase method,the dispersant is deionized water instead of ethyl alcohol.The unloaded Q value and temperature coefficient of frequency(τf) were measured with closed cavity method.The results indicate that the raw material sizes,ball milling process and sintering temperature have more effect on Q·f value.Titania not only adjustτf,but also enhance the sintering.With weight of Titania equal to 12 percent,at sintering temperature of 1240℃,the excellent microwave dielectric properties are obtained,which dielectric constant(εr) is 10.2,Q·f 91640GHz,τf negative 5.78ppm/℃.The SMT two poles dielectric bandpass filter,whose centre frequency is 5.49GHz,bandwidth 101MHz,insert loss below 1.2dB,was made of the ceramics,the filter can be used in communication system.