TITLE:
Compact Metamaterial Microstrip Low-Pass Filter
AUTHORS:
Sudhakar Sahu, Rabindra Kishore Mishra, Dipak Ranjan Poddar
KEYWORDS:
Hex-Omega Structure, Microstrip Low-Pass Filter, Metamaterial, Sharp Cut-Off
JOURNAL NAME:
Journal of Electromagnetic Analysis and Applications,
Vol.3 No.10,
October
24,
2011
ABSTRACT: Complimentary hexagonal-omega structures are used to design compact, low insertion loss (IL), low pass filter with sharp cut-off. It has been designed for improvement of roll-off performance based on both μ and ε negative property of the complimentary hex-omega structure while maintaining the filter pass-band performance. By properly designing and loading the hexagonal-omega structure in the ground of microstrip line not only improve the roll-off of the low pass filter, but also reduced the filter size. The simulated results indicate that the proposed filter achieves a flat pass band with no ripples as well as selectivity of 19.68 dB/GHz, corresponding to 5-unit cells hex-omega structures. This significantly exceeds the 5.6 dB/GHz selectivity of the conventional low pass filter design, due to sub-lambda dimensions of the hex-omega structure. A prototype filter implementing area is: 0.712λg x 0.263λg, λg being the guided wavelength at 3-dB cut-off frequency (fc). The proposed filter has a size smaller by 36.2%.