New Ultra-Wide Stopband Low-Pass Filter Using Transformed Radial Stubs

作者：Ma Kaixue^*; Yeo Kiat Seng

来源：IEEE Transactions on Microwave Theory and Techniques, 2011, 59(3): 604-611.

DOI：10.1109/TMTT.2010.2095031

• Hairpin resonator
• low-pass filter (LPF)
• microstrip
• physically based lumped element model
• radial stub
• transformed radial stub (TRS)
• ultra-wideband (UWB)

A new type of low-pass filter (LPF) with ultra-wide band rejection and compact size by using a proposed transformed radial stubs (TRSs) is introduced and investigated. The operating mechanism of the filter is investigated based on proposed equivalent- circuit model. The implemented LPF with 1-dB cutoff frequency f(c) of 3 GHz demonstrates stopband rejection up to i.e., 24 GHz. The skirt selectivity is achieved up to -144 dB per octave through multiple-zero generation using TRSs. The measured pass-band insertion loss is less than 1.5 dB. I/O loading cells are used to further extend the deep stopband to more than 13(fc) i.e., above 40 GHz. The size of the four-cell LPF is only 0.31 lambda g x 0.24 lambda g, (lambda g is the guide wavelength at center cutoff frequency) without using any lumped

• 出版日期2011-3
• 单位南阳理工学院