Design and simulation of a 600 GHz RTD oscillator using commercial harmonic balance software

We report on the design and optimisation of a 600 GHz double barrier resonant tunneling diode (RTD) oscillator. Using the simple Esaki equivalent circuit diode model and published DC experimental I-V data, a custom device model was developed and integrated within a commercial harmonic balance (HB) simulator. This technique utilizes a spline interpolation algorithm as part of the device model to determine instantaneous values of device voltage and current when called from within the main HB software. The maximum oscillation frequency for a 5 ohms load was 1.6 THz, whilst optimisation at 600 GHz was achieved with a 15 ohms load, with an output power of 420 micron W. The present technique should facilitate and simplify simulation of both existent and novel non-linear devices in other configurations, such as multipliers, mixers, self- oscillating mixers, etc.peer-reviewe

Dynamics of resonant tunneling diode optoelectronic oscillators

Tese de dout., Física, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2012The nonlinear dynamics of optoelectronic integrated circuit (OEIC) oscillators comprising semiconductor resonant tunneling diode (RTD) nanoelectronic quantum devices has been investigated. The RTD devices used in this study oscillate in the microwave band frequency due to the negative di erential conductance (NDC) of their nonlinear current voltage characteristics, which is preserved in the optoelectronic circuit. The aim was to study RTD circuits incorporating laser diodes and photo-detectors to obtain novel dynamical operation regimes in both electrical and optical domains taking advantage of RTD's NDC characteristic. Experimental implementation and characterization of RTD-OEICs was realized in parallel with the development of computational numerical models. The numerical models were based on ordinary and delay di erential equations consisting of a Li enard's RTD oscillator and laser diode single mode rate equations that allowed the analysis of the dynamics of RTD-OEICs. In this work, several regimes of operation are demonstrated, both experimentally and numerically, including generation of voltage controlled microwave oscillations and synchronization to optical and electrical external signals providing stable and low phase noise output signals, and generation of complex oscillations that are characteristic of high-dimensional chaos. Optoelectronic integrated circuits using RTD oscillators are interesting alternatives for more e cient synchronization, generation of stable and low phase noise microwave signals, electrical/optical conversion, and for new ways of optoelectronic chaos generation. This can lead to simpli cation of communication systems by boosting circuits speed while reducing the power and number of components. The applications of RTD-OEICs include operation as optoelectronic voltage controlled oscillators in clock recovery circuit systems, in wireless-photonics communication systems, or in secure communication systems using chaotic waveforms