In order to determine the target range, the transmitted radar signal is modulated. There are many different modulation methods known for this purpose. The classic pulse modulation, in which short pulses are transmitted in the time domain, was used frequently in the past but is now rarely used in the millimeter wave range because this method cannot be implemented cost-effectively in modern radar circuits. Instead, analog modulation methods in which transmission and receiving are continuous, so-called continuous-wave methods, have become established. With these methods, the measurement of the radial target velocity is also taken into account: this is always achieved by evaluating the Doppler frequency shift between the transmitted and received signals. Since the mid-2010s, the use of digital modulation techniques for millimeter-wave radars has been widely discussed, at least in the research community. These radars offer enormous flexibility in the modulation design, but also require the processing of enormous amounts of data. Since it is becoming apparent that these radars are likely to replace analog-modulated radars at least in part in the medium run, they are presented in this chapter, as well.