Chip-Size Resonant-Tunneling-Diode Oscillator as a FMCW and OCT Source

We present a chip-size source for FMCW (frequency-modulated continues-wave) radar and frequency-domain OCT (optical coherence tomography) in the sub-THz range. As the source, we use resonant-tunneling-diode patch-antenna oscillators, creating a true chip-size source operating at 680 GHz with an output power of 23 mu W. A linearized frequency chirp with a bandwidth of 38 GHz (5.5 %) and 4 mm spatial resolution is demonstrated.