Novel UWB BPF with a controllable notched band using hybrid structure

In this letter, an ultra-wideband (UWB) bandpass filter (BPF) based on CPW-to-microstrip transition structure is proposed. To improve its selectivity, an interdigital coupled-line and split ring resonator (SRR) are used to generate two extra transmission zeros located at the lower and upper edge of the passband separately. The measured results show that the proposed filter possesses satisfactory performance such as compact size, sharp roll-off, and wide fractional bandwidth of 133 % (2.35-11.75 GHz). Moreover, a notched band with deep attenuation introduced by coupling T-shaped short stub (CTSSS) is achieved to block the ITU8.0 band with centre frequency of 8.2 GHz. And the notched band is controllable. This filter can be a good candidate for ultra-wideband applications.

[1]  Srikanta Pal,et al.  A miniaturized microstrip-to-CPW transition based UWB-BPF with sharp roll-off and minimum insertion loss , 2016 .

[2]  Tao Yang,et al.  Compact high selectivity UWB filter using composite CPW-microstrip structure , 2016, IEICE Electron. Express.

[3]  Chung-I G. Hsu,et al.  Band-notched ultra-wideband bandpass filter design using combined modified quarter-wavelength tri-section stepped-impedance resonator , 2009 .

[4]  Q. Chu,et al.  Ultra-Wideband Bandpass Filter With a Notch-Band Using Stub-Loaded Ring Resonator , 2013, IEEE Microwave and Wireless Components Letters.

[5]  S Pirani,et al.  Band-Notched UWB BPF Design Using Parasitic Coupled Line , 2010, IEEE Microwave and Wireless Components Letters.

[6]  Sai-Wai Wong,et al.  A compact UWB CPW bandpass filter with short-ended H-shaped resonator and controllable notched band , 2013 .

[7]  Xiao-wei Shi,et al.  Compact UWB BPF with notch band based on SW-HMSIW , 2015 .

[8]  G. Karimi,et al.  Compact UWB BPF using slotted resonator with an independently controllable notched band , 2014, International Journal of Microwave and Wireless Technologies.

[9]  Ching-Her Lee,et al.  Band-Notched Balanced UWB BPF With Stepped-Impedance Slotline Multi-Mode Resonator , 2012, IEEE Microwave and Wireless Components Letters.

[10]  Xianhong Chen,et al.  UWB bandpass filter with sharp rejection and narrow notched band , 2014 .

[11]  Tao Yang,et al.  A novel ultra-wideband bandpass filter using defected microstrip structures , 2016, IEICE Electron. Express.