A radar device (100) comprising transmit and receive parts, and a control unit (CU). The transmit part includes means (WG) for generating a signal within a certain band, and the receive part comprises a filter (AAF), an AD-converter (ADC) and a Fourier transform unit (FFT1). The transmit part generates a group of signals, each having a first bandwidth between a first and a second frequency, in such a way that a larger bandwidth (B1-B4) is covered by the group. The receive part is open over said larger bandwidth (B1-B4) during reception of each signal in said group, and the transmit part comprises means (PAD, FFT2) for creating FFT-copies of the received signals and means (CONJ) for creating conjugates of said copies. The receive and transmit parts comprise means (EXTR) for extracting data from the FFT from the first bandwidth covered by a received signal, and the radar device comprises means (DIFF) for correlating said extracted FFT-data.