In this paper, radio frequency (RF) stability performance of double gate junctionless transistor for different spacer material, the width of spacer, and bias conditions is reported. The impact of gate oxide thickness and gate work function on RF performance of double gate junctionless transistor is also presented. The analog and RF figure of merit, namely, intrinsic gain, unity gain cut-off frequency, stern's stability factor, critical frequency, maximum attainable gain, and maximum stable gain, are investigated with the help of numerical simulation. The result shows that the fringing fields of high k spacers have a major impact on the gate to source and gate to drain capacitance. The device design guideline along with bias and geometrical parameters are reported for the optimized structure. The optimized device structure exhibits better RF stability. © 2018 John Wiley & Sons, Ltd.