arXiv subjects

Nguyen H. Ngo

Publications and source records attributed to Nguyen H. Ngo.

3 recordsLinked to original sources

arXiv2026

Terahertz Communications Using Effective-Medium-Slot Waveguides

All-dielectric effective-medium-clad waveguides have been widely exploited in terahertz communications owing to their extremely low loss, low dispersion, and broad bandwidth. In this work, we propose a substrateless effective-medium-slot waveguide. Additionally, we introduce a taper-free interface that allows terahertz waves to directly couple from a metallic hollow waveguide without requiring dielectric insertion. By engineering slot couplers with an effectivemedium channel for impedance and modal matching, the waveguide achieves a fractional 3-dB bandwidth of 40% with a maximum coupling efficiency of 90% in the WR-2.2 band (330-500 GHz). By employing a broadband uni-traveling-carrier photodiode transmitter and sub-harmonic mixer receivers, we achieve an aggregated data rate of 0.8 Tbit/s with quadrature amplitude modulation schemes across 14 channels from 330-600 GHz. The effective-medium-slot waveguide platform yields robust broadband coupling with enhanced mechanical protection, offering reliable interconnects for ultra-high-speed terahertz integrated systems.

physics.optics↗

arXiv2026

Resonant tunneling diode-integrated terahertz transceiver module for wireless communications

Terahertz bands enable ultra-broadband wireless communications but require compact, low-cost, and efficient transceiver modules. Conventional implementations based on metallic waveguides or silicon lenses suffer from high loss, bulkiness, and fabrication complexity. Here, we present a compact terahertz transceiver module enabled by a resonant tunneling diode (RTD) integrated with a photonic-electronic antenna chain. The RTD on InP is coupled to a modified Vivaldi antenna and an all-silicon effective-medium-clad waveguide, terminating in a rod antenna interfaced with a 3D-printed cyclic olefin copolymer lens. This architecture enables broadband directive radiation without matching networks or anti-reflection coatings. Packaged in a low-cost 3D-printed PLA enclosure, the module achieves realized gains of 28-33 dBi (E11x) and 30-33 dBi (E11y) across 220-330 GHz. As a receiver, it exhibits a noise voltage density of 5.6 x 10^-9 V/sqrt(Hz), a minimum noise equivalent power of 1.8 pW/sqrt(Hz), and an average responsivity of 6.8 kV/W. It supports error-free transmission up to 30 Gbit/s (OOK) and 80 Gbit/s (16-QAM) over 10 cm, and enables real-time uncompressed high-definition video streaming over 1 m. As a transmitter, it achieves error-free OOK transmission up to 12 Gbit/s at 332 GHz. These results demonstrate a promising terahertz transceiver architecture for 6G systems.

physics.optics↗

arXiv2026

Advances in All-Silicon Waveguides for Terahertz Integration

In chip-to-chip communication, terahertz waves provide a promising approach to achieve high data capacity with improved energy efficiency, effectively bridging the gap between electrical and optical domains. By realizing this potential, all-dielectric waveguides have emerged as high-speed interconnects, offering broad bandwidth and low-loss characteristics while being compatible with planar integration. This paper reviews different types of terahertz all-dielectric waveguides, including photonic-crystal and effective-medium-clad structures, and highlights recent progress in implementing these platforms to develop various passive functional devices, paving the way for high-speed operation and large-scale integration in terahertz systems.

physics.app-ph↗