Modulated mm-wave radar signal generation using frequency multipliers

In this work, we present a method to generate modulated radar signals at mm-wave frequencies. The proposed method relies on the nonlinear behavior of frequency multipliers, and allows to convert a narrowband signal at moderate frequencies to a signal with larger bandwidth at a frequency around 76.5 GHz. Generating a simple narrowband signal at a relatively low frequency around 4.25 GHz can be realized with low complexity, which is an advantage compared to methods that use a stable mm-wave carrier with an additional modulation signal, or sweeping of a voltage controlled oscillator in a phase-locked-loop. The proposed signal generator is used to realize a radar system based on the sliding correlator principle. This radar system is used for ranging measurements, to demonstrate the applicability of the proposed approach. Furthermore, it can be shown that the realized signal generator offers the possibility of adjusting the bandwidth of the generated radar signal.