具有超宽带吸收特性的Ku波段带通滤波器设计  

Design of a Ku-Band Bandpass Filter with Ultra-wideband Reflectionless Behavior

作　　者：任乐 徐金平[1] REN Le;XU Jin-ping(State Key Laboratory of Millimeter Waves,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学毫米波国家重点实验室,南京210096

出　　处：《微波学报》2021年第6期15-20,共6页Journal of Microwaves

摘　　要：为解决Ku波段带通滤波器带外反射信号干扰系统性能的问题,研究了一种具有超宽带无反射特性的Ku波段吸收式带通滤波器(Absorptive Bandpass Filter,ABPF)。该滤波器基于超宽带多级威尔金森(Wilkinson)功分器/合成器和超宽带90°移相器,结合传统反射式带通滤波器,利用进入功分器/合成器的两个支路的反射波的等幅反相特性,使反射波功率被功分器/合成器内的隔离电阻吸收来实现ABPF阻带内的无反射特性。采用并联加载λ/4双短路枝节微带线和参考微带线实现超宽带范围内90°左右的移相特性。设计并制作了一款中心频率为15.2 GHz的Ku波段ABPF实验样品。实测结果表明,该滤波器的3 dB通带带宽为1.4 GHz,输入端与输出端的吸收带宽覆盖5~26.5 GHz,实现了优良的超宽带吸收特性。In order to solve the problem that the reflected signal within stopband of the Ku-band bandpass filter(BPF)may disturb the system performance,a Ku-band absorptive bandpass filter(ABPF)with ultra-wideband reflectionless behavior is studied in this paper.The filter consists of an ultra-wideband multi-stage Wilkinson-type power divider/combiner,wideband 90°phase shifters and conventional reflective microstrip BPFs.By utilizing the equal-amplitude and anti-phase characteristics of the reflected waves in the two branches of the power divider/combiner,the power of reflected waves is absorbed by the isolation resistors to realize the reflectionless behavior in stopband of the ABPF.The phase shifter adopts a microstrip line loaded with twoλ/4 short-ended stubs in parallel and a reference line to realize phase shifting around 90°over an ultra-wide bandwidth.A Ku-band ABPF with a center frequency of 15.2 GHz has been designed and fabricated.Tested results show that the proposed ABPF has a 3 dB bandwidth of 1.4 GHz and an absorption bandwidth of 5~26.5 GHz at both input and output ports.The ABPF features good ultra-wideband absorptive behavior.

关 键 词：吸收式滤波器 带通滤波器 移相器 功分器 宽带 

分 类 号：TN713.5[电子电信—电路与系统]