%0 Journal Article
%T Radial Loaded Transformed Radial Stub for Lpf Stopband Extension
%A Kaixue Ma
%A Shouxian Mou
%A Keping Wang
%A Kiat Seng Yeo
%J PIER     Letters
%D 2012
%I EMW Publishing
%R 10.2528/PIERL12012009
%X A low pass filter with ultra-wide band rejection and compact size using a proposed radial loaded transformed radial stubs is introduced and investigated. The implemented unite cell low pass filter with 1-dB cutoff frequency of 3.2 GHz demonstrates stopband rejection up to 11.8 i.e. 38 GHz. The design is further extended to the high-order LPF through cell cascading. The implemented four-cell LPF with of 3.6 GHz demonstrated 35dB rejection from 4.8GHz to 39GHz, 50 dB rejection from 5.4 GHz to 26 GHz (7.2 ) and 20dB rejection from 4.4 GHz to 50 GHz (13.8 ). The measured passband insertion loss is less than 1.7 dB, and group delay is from 0.45~0.8 nS. The size of the four-cell low pass filter is only 0.33¦Ëg ¡Á 0.135¦Ëg, (¦Ëg is the guide wavelength at center cutoff frequency) without using any lumped elements.
%U http://www.jpier.org/pierl/pier.php?paper=12012009