Theoretical Investigation of Large-Signal Noise in Nanometric Schottky-Barrier Diodes Operating in External Resonant Circuits

Abstract

We report Monte Carlo simulations of electronic noise in heavily doped nanometric GaAs Schottky-barrier diodes operating in series with a parallel resonant circuit when a high-frequency large-signal voltage is applied to the whole system. Significant modifications of the noise spectrum with respect to the unloaded diode are found to occur in the THz-region.

High-frequency voltage noise of nanometric Schottky-barrier diodes and heterostructure barrier varactor in cyclostationary conditions

“…3) The voltage spectrum noise: Here the diodes (HBV or SBD) embedded into a particular parallel resonant circuit characterized by an inductance L, by a capacitance C l and by a noiseless resistance R when a microwave voltage U (t)=U 0 +U 1 sin(ω 0 t) is applied to the whole circuit [3]. The corresponding equivalent scheme is presented in Fig.…”

“…The first order approximation of the spectral density of voltage fluctuations S 1 U d U d (ω) is given by [3]:…”

“…The nonlinear characteristics are used to generate a large number of high-order harmonics when an input harmonic signal of large amplitude is applied to the diode. More recently, the Heterostructure Barrier Varactor (HBV) diodes have emerged as interesting competitors of SBD as frequency multipliers due to their symmetric capacity-voltage and antisymmetric currentvoltage characteristics [2], which lead to produce only odd harmonics compared to the SBD [3].…”

“…An extra noise appearing by the up-down conversion of voltage drop between the diode terminals is originated by a periodic modulation of the varactor capacitance [3]. Moreover, under large-signal conditions, the intrinsic current noise which is described by the spectrum of current fluctuations constitutes a critical limit for the extraction of the high-order harmonics at the basis of terahertz generation.…”