The unlicensed frequency band around 60 GHz (i.e., 57 to 66 GHz) is always the hot topic of researches due to its abundant spectrum resources. In addition to the high-data-rate wireless communications, current research efforts have also been focused on the short-range frequency-modulated continuous wave (FMCW) radar systems [1]–[3]. However, there are still some challenges to address. First, realizing a fully-integrated V-band FMCW radar transceiver (TRX) is nontrivial. Prior arts either exclude the integration of critical blocks (e.g. FMCW synthesizer, analog baseband (ABB)) or contain with limited chirp linearity and slope [1]–[3]. Second, due to the uncertain operating environment of radar systems, maintaining constant performance is required over a wide temperature range. Finally, it remains not easy to design the TRX that covers the entire band. In this paper, we present a 54-to-69-GHz fully-integrated wideband FMCW radar TRX with two transmitter and receiver channels (2T2R). To simplify the off-chip components, a cascaded-PLL topology is employed, achieving a maximum chirp bandwidth of 7.2 GHz with a fast slope up to $468.5\ \text{MHz}/\mu\mathrm{s}$. Thanks to the proposed proportional-to-absolute-temperature (PTAT)-enhanced temperature compensation (TC) technique, the average conversion gain (CG) varies less than 1.1 dB from −55 to 105°C.