基于反馈电容的LTCC带通滤波器设计和优化

The Methodology and Optimization for LTCC Bandpass Filter Based on Feedback Capacitor

该文利用LTCC技术设计微型多层带通滤波器。为了在带外获得陡峭的衰减,通过并联反馈电容,引入了传输零点。然后利用毕奥-萨法尔定律来计算带通滤波器相应的多层结构的各微带线尺寸。结合HFSS电磁仿真,利用MIM电容尺寸与值的关系来优化滤波器的尺寸。最后设计了一个中心频率为2.45GHz,插入损耗小于2dB,阻带衰减大于30dB,尺寸为2.0mm×1.2mm×0.9mm的带通滤波器。

This paper outlines the design of a miniaturized bandpass filter realized in low-temperature co-fired ceramic（LTCC） substrate.To get steep attenuation in outbands,by using parallel capacitor,it may introduce transmission zero for the purpose.After that,take advantage of the Biot-Savart law to calculate the stripline size of a corresponding multilayer bandpass filter.Combine with EM simulation,the configuration be optimized by using the relationship between the value and its size of MIM capacitors.Eventually,this paper is aimed at designing a bandpass filter with central frequency about 2.45GHz,insertion loss in passband less than 2dB,attenuation in stopband more than 30dB,and the size smaller than 2.0mm×1.2mm×0.9mm.