Island THz on-chip slot-antenna resonant-tunneling-diode oscillators

Abstract

We demonstrate an “island” design of on-chip slot-antenna resonant-tunneling-diode (RTD) oscillators, where the contact n++ layer is removed everywhere except for a small island under the RTD. At frequencies around 2 THz, this design leads to a significant reduction (by a factor of ≈ 2) in the total Ohmic losses at the conducting surfaces of the slot antenna. With this design, we achieved the highest radiated power for RTD oscillators in the frequency range of 1.6–1.74 THz with around 2.2 μW at the fundamental frequency of 1.74 THz. Theoretical analysis of the oscillators indicates that with the utilized RTD design, the operating frequencies beyond 2 THz should be reached if the RTD contact resistance is reduced to 1–1.5 Ω  μm2.