Dielectric Waveguide Technologies for High-Speed Interconnects

Dielectric waveguide interconnects harness insulating materials to confine and transmit electromagnetic signals with minimal loss and dispersion, offering a compelling alternative to traditional metallic and optical links for short-reach, high-bandwidth communication. By tailoring core and cladding geometries—ranging from solid polymers to hollow structures—researchers have achieved ultra-broadband performance across millimetre-wave and terahertz bands. Key advantages include low insertion loss, uniform group delay over wide frequency spans, immunity to electromagnetic interference and reduced fabrication cost compared with precision-machined metallic waveguides. Recent innovations address critical challenges such as impedance transitions at interfaces, bending-induced radiation and mode distortion, enabling flexible routing and compact form factors suited to board-to-board, chip-to-chip and data-centre interconnect fabrics. Continued progress promises to close the gap between device-level speeds and system-level data throughput, with direct implications for high-performance computing, 5G/6G backplanes and emerging quantum communication platforms.

Research from Nature Portfolio

Recent studies have demonstrated an all-electrical dielectric cable capable of nearly 25 GHz of continuous bandwidth at a 70 GHz carrier, exhibiting a frequency-independent insertion loss of around 5 dB m⁻¹ and stable group delay, and successfully transmitting 25 Gbps NRZ data over 3 m. Another investigation evaluated bending effects in commercially available solid and hollow PTFE waveguides at V-band (50–75 GHz), reporting bending losses near 1.46 dB for a 90° turn at a 25 mm radius, and quantifying the loss increase with tighter curvature and larger bending angles. Both works validated full-wave simulations against measurements, providing essential design guidelines for deploying waveguide interconnects in realistic architectures.

Dielectric Waveguide Technologies for High-Speed Interconnects publication trend

The graph below shows the total number of articles in dielectric waveguide technologies for high-speed interconnects across all publications each year (not limited to Nature Index journals).

Technical terms

Dielectric waveguide: A non-metallic structure guiding electromagnetic waves by confining them within regions of higher permittivity.
Insertion loss: The reduction in signal power, measured in decibels, caused by introducing a component into a transmission line.
Group delay: The time taken for the envelope of a modulated signal to travel through a device, indicative of dispersion.
Bending loss: Additional attenuation due to radiation of energy when a waveguide follows a curved path.
Subwavelength core: A guiding region whose dimensions are smaller than the operating wavelength, used to enhance field confinement and suppress higher-order modes.

References

1. E-TUBE: dielectric waveguide cable for high-speed communication. Scientific Reports (2020).
2. Experimental characterization of bending effects for solid and hollow dielectric waveguides at V-band. Scientific Reports (2021).
3. Signal distortions in circular dielectric waveguides at mm-wave frequencies. International Journal of Microwave and Wireless Technologies (2021).
4. Design of subwavelength optical fibre for low-loss Terahertz transmission. Journal of the European Optical Society-Rapid Publications (2013).