One THz harmonic oscillation of resonant tunneling diodes

Abstract
One THz harmonic oscillation was observed in a sub-THz oscillating Ga In As ∕ Al As resonant tunneling diode integrated with a slot antenna. The fundamental and third-harmonic frequencies were 342 GHz and 1.02 THz , respectively, for a 50 μ m long antenna. The maximum output power of the fundamental mode was around 23 μ W , and that of the third-harmonic component was 2.6% of the fundamental. Theoretical analysis with the van der Pole equation qualitatively explained the measured results.