Enhancing Conversion Gain in HEB Mixers using Negative Differential Resistance

@misc{karasik2026enhancing,
  title = {{Enhancing Conversion Gain in HEB Mixers using Negative Differential Resistance}},
  author = {Boris S. Karasik and Changyun Yoo},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.32112},
  eprint = {2609.32112},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.32112},
  note = {CC BY-NC-SA 4.0},
}

TY  - UNPB
TI  - Enhancing Conversion Gain in HEB Mixers using Negative Differential Resistance
AU  - Boris S. Karasik
AU  - Changyun Yoo
PY  - 2026
DA  - 2026/09/26
PB  - arXiv
DO  - 10.48550/arxiv.2609.32112
UR  - https://arxiv.org/abs/2609.32112
AB  - This work investigates how negative differential resistance (NDR) can be utilized to enhance conversion gain in superconducting niobium nitride (NbN) hot-electron bolometer (HEB) mixers. Conventional HEB operation avoids NDR regions due to parasitic oscillations caused by interactions between thermal inertia and bias-line reactance. Recent experimental results show that reducing the bias-T inductance suppresses these oscillations and enables stable biasing within the NDR regime, thereby increasing the mixer conversion gain beyond levels achievable under positive differential resistance (PDR) bias. Using a lumped thermal-electrical model, we interpret these experimental findings, derive stability conditions for NDR-biased operation, and predict the future performance limits achievable through optimized bias circuit designs. Our results indicate that further reductions in bias inductance, combined with appropriate load-line conditions, could yield several decibels of additional gain while maintaining practical IF bandwidths.
ER  -