Amplitude-modulated radar in the terahertz band based on a resonant-tunneling-diode oscillator

摘要

We report on a terahertz-wave radar based on a resonant-tunneling-diode (RTD) oscillator. By modulating the output power of the RTD at two frequencies and measuring the corresponding phase delays after the terahertz wave propagates from the source to the detector, we were able to measure the absolute propagation distance between them with an error of about 6 mm. We then combined this absolute distance with the phase delay measured at one frequency to further reduce the error of the distance measurement to about 0.4 mm. When a radar configuration is employed, the error increases due to additional losses to 8 mm before the error reduction step, and to 0.6 mm afterwards.