基于薄膜工艺的C频段交指滤波器小型化设计  

Design of miniaturized C-band interdigitalfilter based on thin film process

作　　者：唐陆瑶 江肖力[1] 刘巍巍 Tang Luyao;Jiang Xiaoli;Liu Weiwei(The 54th Research Institute of CETC,Shijiazhuang 050081,China)

机构地区：[1]中国电子科技集团公司第五十四研究所,石家庄050081

出　　处：《电子测量技术》2021年第16期86-90,共5页Electronic Measurement Technology

摘　　要：为满足卫星通信某滤波器小型化需求,基于薄膜工艺设计了一款陶瓷基板的C频段交指滤波器。该滤波器由5阶平行耦合的谐振单元构成,输入输出形式采用抽头结构,相比于平行耦合输入输出更有利于实现滤波器的小型化。为了满足高抑制度的指标,该滤波器采用交叉耦合与并联1/4波长开路线的方式引入传输零点,有效地提高了滤波器的带外抑制度。同时采用了阻抗补偿的方式对滤波器驻波进行调节。测试结果显示,滤波器中心频率为3.7 GHz,相对带宽为27%,通带插损为-1 dB,在2.7 GHz与4.8 GHz处阻带抑制>30 dB,在2.5 GHz与5 GHz处阻带抑制>40 dB。滤波器尺寸为9.25 mm×6.72 mm。In order to meet the miniaturization requirements of a certain filter in satellite communications,a C-band interdigital filter with a ceramic substrate was designed based on thin film technology.The filter is composed of a 5-order parallel coupled resonant unit,and the input and output form adopted a tap structure,which is more conducive to the miniaturization of the filter than the parallel coupling input and output.In order to meet the high rejection index,the filter adopted cross-coupling and parallel 1/4 wavelength open route to introduce transmission zero points,which effectively improved the filter’s out-of-band rejection.Besides,the standing wave of the filter was adjusted by means of impedance compensation.The test results showed that the center frequency of the filter is 3.7 GHz,the relative bandwidth is 27%,the center insertion loss is-1 dB,the stopband rejection is 30 dB at 2.7 GHz and 4.8 GHz,and the stopband rejection is 40 dB at 2.5 GHz and 5 GHz.The filter size is 9.25 mm×6.72 mm.

关 键 词：带通滤波器 薄膜工艺 小型化 交指滤波器 传输零点 

分 类 号：TN713.5[电子电信—电路与系统]