scholarly journals Sensitive terahertz-wave detector responses originated by negative differential conductance of resonant-tunneling-diode oscillator

2020 ◽  
Vol 117 (2) ◽  
pp. 021107
Author(s):  
Yuma Takida ◽  
Safumi Suzuki ◽  
Masahiro Asada ◽  
Hiroaki Minamide
Keyword(s):  
Resonant Tunneling ◽  
Terahertz Wave ◽  
Resonant Tunneling Diode ◽  
Differential Conductance ◽  
Negative Differential Conductance ◽  
Wave Detector ◽  
Tunneling Diode ◽  
Diode Oscillator

scholarly journals Absolute and Precise Terahertz-Wave Radar Based on an Amplitude-Modulated Resonant-Tunneling-Diode Oscillator

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 52 ◽  
Author(s):  
Adrian Dobroiu ◽  
Ryotaka Wakasugi ◽  
Yusuke Shirakawa ◽  
Safumi Suzuki ◽  
Masahiro Asada
Keyword(s):  
Resonant Tunneling ◽  
Modulation Frequency ◽  
Propagation Distance ◽  
Sine Wave ◽  
Terahertz Wave ◽  
Resonant Tunneling Diode ◽  
Tunneling Diode ◽  
Wave Radar ◽  
Diode Oscillator ◽  
Modulation Signal

We present the principle of a terahertz-wave radar and its proof-of-concept experimental verification. The radar is based on a 522 GHz resonant-tunneling-diode oscillator, whose terahertz output power can be easily modulated by superimposing the modulation signal on its bias voltage. By using one modulation frequency and measuring the time delay of the returning signal, a relative measurement of the propagation distance is possible; adding a second modulation frequency removes the ambiguity stemming from the periodicity of the modulation sine wave and allows an absolute distance measurement. We verified this measurement method experimentally and obtained a submillimeter precision, as predicted by theory.

scholarly journals Subcarrier Frequency-Modulated Continuous-Wave Radar in the Terahertz Range Based on a Resonant-Tunneling-Diode Oscillator

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6848
Author(s):  
Adrian Dobroiu ◽  
Yusuke Shirakawa ◽  
Safumi Suzuki ◽  
Masahiro Asada ◽  
Hiroshi Ito
Keyword(s):  
Resonant Tunneling ◽  
Continuous Wave ◽  
Terahertz Wave ◽  
Resonant Tunneling Diode ◽  
Proof Of Concept ◽  
Fmcw Radar ◽  
Tunneling Diode ◽  
Wave Radar ◽  
Diode Oscillator ◽  
Wave Range

We introduce a new principle for distance measurement in the terahertz-wave range using a resonant-tunneling-diode (RTD) oscillator as a source at 511 GHz and relying on the frequency-modulated continuous-wave (FMCW) radar technique. Unlike the usual FMCW radar, where the sawtooth frequency modulation is applied to the carrier, we propose applying it to a subcarrier obtained by amplitude modulation; this is advantageous when the source cannot be controlled precisely in oscillation frequency, but can easily be modulated in amplitude, as is the case of the RTD oscillator. The detailed principle and a series of proof-of-concept experimental results are presented.

scholarly journals Discrete Fourier Transform Radar in the Terahertz-Wave Range Based on a Resonant-Tunneling-Diode Oscillator

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4367
Author(s):  
Hiroki Konno ◽  
Adrian Dobroiu ◽  
Safumi Suzuki ◽  
Masahiro Asada ◽  
Hiroshi Ito
Keyword(s):  
Resonant Tunneling ◽  
Measurement Range ◽  
Terahertz Wave ◽  
Resonant Tunneling Diode ◽  
Swept Source ◽  
Tunneling Diode ◽  
Wave Radar ◽  
Diode Oscillator ◽  
Modulation Signal ◽  
Wave Range

We used a resonant-tunneling-diode (RTD) oscillator as the source of a terahertz-wave radar based on the principle of the swept-source optical coherence tomography (SS-OCT). Unlike similar reports in the terahertz range, we apply the stepwise frequency modulation to a subcarrier obtained by amplitude modulation instead of tuning the terahertz carrier frequency. Additionally, we replace the usual optical interference with electrical mixing and, by using a quadrature mixer, we can discriminate between negative and positive optical path differences, which doubles the measurement range without increasing the measurement time. To measure the distance to multiple targets simultaneously, the terahertz wave is modulated in amplitude at a series of frequencies; the signal returning from the target is detected and homodyne mixed with the original modulation signal. A series of voltages is obtained; by Fourier transformation the distance to each target is retrieved. Experimental results on one and two targets are shown.

A quasioptical resonant-tunneling-diode oscillator operating above 200 GHz

1993 ◽  
Vol 41 (4) ◽  
pp. 720-722 ◽  
Author(s):  
E.R. Brown ◽  
C.D. Parker ◽  
A.R. Calawa ◽  
M.J. Manfra ◽  
K.M. Molvar
Keyword(s):  
Resonant Tunneling ◽  
Resonant Tunneling Diode ◽  
Tunneling Diode ◽  
Diode Oscillator
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