Abstract: A nested defected split-ring resonator(DSRR) dual-band filter based on synchronous parameter extraction technology is presented.Firstly,the coupling coefficients and external quality factors are obtained according to the filter specification,then making use of DSRRs as the double resonant units and E-shaped stubs as the common feed lines,the resonant frequency,coupled coefficients as well as external qualities of the nested double-rings are synchronous extracted and determined.Finally,a compact dual-band fi...