A device for determining the arrival time of a UWB signal comprising at least one pulse modulated at a carrier frequency, said device comprising: - at least one translation stage for translating to an intermediate frequency comprising a quadrature mixer comprising two I and Q mixing channels; - at least one integration stage connected to a translation stage, for integrating the signals delivered on the I and Q channels on a time window and providing integration results for each of the I and Q channels respectively; and - means for controlling said at least one translation and integration stage for: ∘ carrying out a first frequency translation of the UWB signal to a first intermediate frequency followed by an integration of the signal thus translated on a first time window to obtain first integration results r I 1, r Q 1; o carrying out a second frequency translation of the UWB signal to a second intermediate frequency, different from the first intermediate frequency, followed by an integration of the signal thus translated on a second time window to obtain second integration results r I 2, r Q 2; - calculating means (440, 450) for calculating a first phase value Θ 1 from the first integration results according to Θ 1 = Arc tan r Q 1 r I 1, a second phase value Θ 2 from the second integration results according to Θ 2 = Arc tan r Q 2 r I 2 and deducing therefrom a phase deviation ΔΘ = Θ 2 - Θ 1, said calculating means determining the arrival time of the UWB signal from the phase deviation thus obtained by means of a predetermined function. - at least one translation stage for translating to an intermediate frequency comprising a quadrature mixer comprising two I and Q mixing channels; - at least one integration stage connected to a translation stage, for integrating the signals delivered on the I and Q channels on a time window and providing integration results for each of the I and Q channels respectively; and - means for controlling said at least one translation and integration stage for: ∘ carrying out a first frequency translation of the UWB signal to a first intermediate frequency followed by an integration of the signal thus translated on a first time window to obtain first integration results r I 1, r Q 1; o carrying out a second frequency translation of the UWB signal to a second intermediate frequency, different from the first intermediate frequency, followed by an integration of the signal thus translated on a second time window to obtain second integration results r I 2, r Q 2; ∘ carrying out a first frequency translation of the UWB signal to a first intermediate frequency followed by an integration of the signal thus translated on a first time window to obtain first integration results r I 1, r Q 1; o carrying out a second frequency translation of the UWB signal to a second intermediate frequency, different from the first intermediate frequency, followed by an integration of the signal thus translated on a second time window to obtain second integration results r I 2, r Q 2; - calculating means (440, 450) for calculating a first phase value Θ 1 from the first integration results according to Θ 1 = Arc tan r Q 1 r I 1, a second phase value Θ 2 from the second integration results according to Θ 2 = Arc tan r Q 2 r I 2 and deducing therefrom a phase deviation ΔΘ = Θ 2 - Θ 1, said calculating means determining the arrival time of the UWB signal from the phase deviation thus obtained by means of a predetermined function.