A novel type of millimeter/submillimeter wave sampler based on resonant tunneling diodes (RTDs) was proposed, and its operation was confirmed by circuit simulation. It consists of an RTD pulse generator and an RTD detector. Owing to the fuse-like nonlinear I-V curve, highly sensitive sampling can be obtained. We also found that the effects of non-ideality in the I-V curve of the RTD can be corrected by sweeping the DC bias for the RTD detector.

The oscillators based on an active transmission line periodically loaded with RTD pairs are studied using circuit simulation with special attention to the behavior of harmonics. Generation of strong high order harmonic (9th) was observed. This is caused by the frequency locking in the high frequency passband. The harmonic oscillators based on this phenomenon are promising for high performance THz sources.

Super regenerative detectors using a resonant tunneling diode (RTD) were fabricated and investigated for ultra-high frequency detectors. A key point is to use the RTD super regenerative detector for detecting much higher frequencies than the free-running oscillation frequency of the detector. This is possible owing to the superior high frequency characteristics of the RTDs. This has various advantages, such as circuit simplicity, easy design, and low power consumption. Clear detection of 50,GHz signal was demonstrated with a super regenerative detector which has 1.5,GHz free-running frequency. Moreover, detailed experiments revealed that the frequency dependence of the detection efficiency is smooth, and the harmonic frequencies have no effect. This is advantageous for high frequency detection.