Tunnel field effect transistor (TFET) is being considered as an alternative to the conventional MOSFETs for low power system on chip applications. In this Letter, gate-drain underlap (UL) feature of double gate TFET for analogue/RF characteristic is discussed. Here, it is found that parasitic resistance induced by gate drain UL is not significant as compared with DG tunnel field effect transistor (DG-FET). Thus, the behaviour of RF figure of merit is different from DG-FET. © 2016 The Institution of Engineering and Technology.