Enhanced InGaAs/AlAs RTD quantum device with frequency multiplier application

This study presents the development of advanced resonant tunneling diodes (RTD) based on InGaAs/AlAs that have an impressive 80% indium content in the quantum well. These cutting-edge diodes were meticulously grown in-house using the precise technique of molecular beam epitaxy. The proposed RTD showcased remarkable negative-differential resistance characteristics, achieving a 41 × 10³ cm^-2 peak current density (Jp) at 308 × 10⁻³ V, and a peak-to-valley current ratio of 8.5. A large-signal model of the fabricated RTD was developed in LTspice using experimental current-voltage (I-V) data, enabling the simulation of an RTD-based frequency multiplier circuit. A frequency multiplier with a multiplication factor of three (x3) was created and tested by arranging two RTDs in series to introduce non-linearity in the circuit. The experiment successfully demonstrated a threefold increase in frequency, converting an input signal of 166 MHz (3.07 mW) to an output frequency of 500 MHz (51.57 µW). The results highlighted the potential of InGaAs/AlAs RTDs for cost-effective ultra-high-frequency applications, particularly for communication systems, radar, and signal processing.