Microstrip wideband bandstop filter with open stubs for UWB applications.

ABSTRACT This article describes the development of an optimized microstrip wideband bandstop filter (BSF) with open stubs for ultrawideband applications. Simulated results agree with the measured results, demonstrating in the experimental results a 10 dB bandwidth from 4.6 to 7.6 GHz, insertion loss (S21) of −33.9 dB, and minimum return loss (S11) of −0.40 dB at 6.1 GHz. Additionally, an equivalent circuit of the wideband BSF is built to estimate the electromagnetic simulation results for practical realization. The features of the design have a reduced size, wideband rejection, higher insertion loss, and tunable bandwidth, which can be performed by adjusting the L-shaped stubs (0.41λg and 0.29λg) toward the 50 Ω input and output ports. The designed BSF occupied the size of 0.35λg × 0.29λg. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1003-1006, 2015 [ABSTRACT FROM AUTHOR]