一种极小尺寸的分立式压电石英晶体滤波器研制

Study and Preparation of a Kind of Extreme Smaller Size of Separation Form Piezoelectric Quartz Crystal Filter

采用了4只AT切、基频为43.5 MHz、UM-1(5)微型金属壳封装的石英晶体和两节差接桥型电路设计,成功研制出一种外形尺寸仅为25 mm×11 mm×28 mm(L×W×H)的小体积分立式带通石英晶体滤波器。在带宽≥±6.5 kHz的范围内通带波动≤1 dB,在阻带宽度≤±25 kHz范围内衰减≥60 dB;较好地实现了器件所要求的各项技术参数。高基频晶体振子的设计及小尺寸器件的制作体现了该项目的两大特点。

A new type of disctete band-pass piezoelectric quartz crystal filter with small size of 25 mm× 11 mm× 28 mm（L × W × H） has been developed. The device is designed by composing of four pieces of AT-cut quartz crystals with fundamental frequency of 43. 5 MHz and metal micro-package of UM-1（5） and two section differential bridge-model circuits. The pass-band ripple is equal to or less than 1 dB in the bandwidth of equal to or greater than ±6.5 kHz and the attenuation is equal to or greater than 60 dB in the stopband width of equal to or less than ±25 kHz. All the thchnical parameters have been achieved according to the requirements to the device. This work is characterized by the design of high fundamental frquency crystal resonator and the fabrication of small device.