Principle of a Subcarrier Frequency-modulated Continuous-wave Radar in the Terahertz Band Using a Resonant-tunneling-diode Oscillator

We introduce a new principle for distance measurement using terahertz waves. The method relies on the frequency-modulated continuous-wave radar technique, in which a sawtooth frequency modulation is applied to a subcarrier of the terahertz-wave. We used a resonant-tunneling-diode oscillator as the terahertz-wave source. Our first experimental results in verifying the measurement principle are presented.