In this paper, the radio-frequency (RF) performances and small-signal parameters of double-gate (DG) square-shaped extended source tunneling field-effect transistors (TFETs) are investigated and compared with those of single-gate (SG) square-shaped extended source TFETs in terms of their cut-off and maximum oscillation frequencies and small-signal parameters. By using of a nonquasi-static (NQS) radio-frequency model, the smallsignal parameters have been extracted. The results show that the DG square-shaped extended source TFET has higher transconductance, cut-off and maximum oscillation frequencies than single gate structure. The modeled Yparameters are in close agreement with the extracted parameters for high frequency range up to the cut-off frequency. Results suggest that the DG square-shaped extended source TFETs seem to be the most optimal ones to replace MOSFET for ultralow power applications and RF devices.