10:20 AM - 10:35 AM
[13a-B508-6] Subcarrier frequency-modulated continuous-wave radar based on a terahertz-range resonant-tunneling-diode oscillator
Keywords:terahertz, radar, resonant-tunneling diode
We present a subcarrier frequency-modulated continuous-wave (FMCW) radar based on a resonant-tunneling-diode (RTD) oscillator emitting at 511 GHz. The output power of the RTD oscillator is modulated by adding a sinusoidal signal to the bias voltage and the frequency of this signal is swept linearly in the range from 3.5 to 10.5 GHz. The terahertz beam is allowed to propagate to the target and the reflected beam is detected. The detected signal is mixed with the original modulation signal, and the frequency of the resulting beat signal is proportional to the distance to the target. The beat signal is Fourier transformed to reveal the distances to the reflecting surfaces in the beam path. Our experiments show that the distance can be measured with an error around 1 mm and that the distances to at least two reflecting surfaces can be measured simultaneously.