LTCC宽边耦合交指型超宽带滤波器设计

Design of an Ultra-Wideband LTCC filter based on broadside-coupled interdigital structure

提出用交指型结构实现超宽带(UWB)带通滤波器的小型化,并给出了设计方法。该结构通过宽边耦合实现超宽带滤波器需要的较大耦合系数,并通过加宽带状线谐振器的宽度减少不必要的交叉耦合,简化了滤波器的设计。最终设计了一个中心频率为f0,相对带宽为58%的六阶交指带通滤波器,滤波器尺寸仅为8 mm×11 mm。从仿真结果看,该滤波器保持了传统交指型滤波器阻带特性好,寄生通带远的优点。

To achieve miniaturization of Ultra-Wideband（UWB） bandpass filters,a novel interdigital filter and its design method are proposed.The filter realizes large coupling coefficient using broadsidecoupled structure,and unnecessary cross coupling is reduced by widening the width of stripline resonator.It simplifies the design method of the filter.A six-pole interdigital bandpass filter is designed using the proposed structure,which is centered at f0 GHz with a fractional bandwidth of 58%,and the size of the filter is 8 mm×11 mm.The simulation results show that the filter keeps the advantages of the traditional interdigital filter with good stopband characteristics and spurious response.