抑制WLAN信号干扰的超宽带滤波器设计

Design of Small Ultra-wideband(UWB) Bandpass Filter with Notched WLAN Band

介绍了一种具有抑制WLAN信号干扰功能的小型超宽带滤波器的结构设计.滤波器的通带频率范围为2.8～11.8GHz,相对带宽约为123%.设计中采用缺陷地结构(DGS)实现高频处的带外抑制,在12.3～30GHz的范围内带外抑制达到15dB以上.通过加入折叠耦合臂结构,在5.38GHz处产生阻带,实现滤波器的陷波功能,陷波阻带带宽为0.4GHz.该滤波器结构紧凑、性能优越,实际测量结果与仿真结果吻合良好.

A new structure of ultra-wideband（UWB） bandpass filter with notched band is proposed.The passband of the designed filter is 2.8—11.8GHz with a relative bandwidth of 123%.Three pairs of defected ground structures（DGS） are designed to suppress the spurious passband and to obtain a wide stopband bandwidth with 15dB attenuation up to 30GHz.A coupled-line section is extended and folded,aiming to create a notch band at the frequency of 5.38GHz by virtue of out-of-phase transmission cancellation.The designed BPF is very compact and shows great potential in the UWB wireless communications.