Keysight ADS Enables First-Pass Silicon at 3 THz for AttoTude

AttoTude has expanded its use of Keysight Technologies’ Advanced Design System (ADS) to support an integrated-circuit design flow spanning signaling frequencies from 100 GHz to 3 THz. The company reports that the resulting workflow has reduced IC development cycles by more than 50%, enabling projects to move from concept to tape-out in less than six weeks while consistently achieving first-pass silicon success across RF, sub-terahertz and terahertz designs.

AttoTude is developing a wired THz interconnect platform for artificial-intelligence and hyperscale data centers. Its architecture combines ASIC-based signal generation—the AttoEngine—with low-loss dielectric waveguides called AttoWire. The objective is to provide the bandwidth density associated with optical links while avoiding lasers, optical modulators and other power-intensive photonic components. Target per-lane data rates include 200, 400 and 800 Gbit/s, addressing the scale-up connectivity requirements of increasingly large AI accelerator clusters.

Designing silicon across the 100-GHz-to-3-THz range introduces problems that conventional digital IC methodologies cannot adequately resolve. At these frequencies, an on-chip conductor is no longer a simple lumped connection. Interconnect length, geometry, substrate coupling, return-current paths and metal-stack properties produce distributed electromagnetic effects. Parasitic inductance and capacitance, conductor and dielectric loss, dispersion, skin effect, impedance discontinuities and unintended radiation can materially change circuit behavior.

Consequently, schematic-level transistor simulations must be correlated with electromagnetic models of the physical layout. A design that appears stable and properly matched in an ideal circuit simulation may shift in frequency or lose gain after extraction. Small geometric changes can alter phase, impedance and coupling, while model or layout errors that seem negligible at microwave frequencies become significant fractions of a wavelength in the THz regime.

Keysight ADS provides a common environment for circuit design, layout, electromagnetic analysis and system-level verification. AttoTude can model active devices together with extracted passive structures, evaluate frequency-domain and nonlinear behavior, and compare architectural alternatives before committing a mask set to fabrication. This unified workflow reduces the translation errors and model inconsistencies that can arise when design data moves manually between separate point tools.

System-level scenario planning is another important element. Engineers can assess link budgets, modulation requirements, channel characteristics and implementation trade-offs before transistor-level optimization is complete. Those system constraints then flow into the IC design, helping the team determine required bandwidth, output power, gain, linearity and noise performance. This approach reduces the risk of producing a circuit that meets an isolated block specification but fails when integrated into the complete interconnect.

AttoTude also uses Keysight design-data-management software to maintain revision control across its design environment. Traceability is particularly valuable when electromagnetic models, schematics, layouts, process-design-kit elements and verification results evolve concurrently. Engineers can identify which model and layout revisions produced a result, reproduce earlier simulations and coordinate changes without losing configuration integrity.

The reported first-pass results are technically significant because a silicon respin adds fabrication expense and can delay system evaluation by months. At THz frequencies, post-fabrication tuning options are limited, making predictive simulation fidelity central to development economics. According to AttoTude ASIC architect Richard Chan, the accuracy supplied by Keysight’s EDA software has enabled the engineering team to work faster and with greater confidence while repeatedly reaching functional silicon on the first attempt.

The collaboration also illustrates a broader change in data-center connectivity. AI systems are pushing electrical channels toward severe limits in reach, bandwidth and energy efficiency, while photonics introduces its own cost and integration challenges. AttoTude’s transistor-driven THz-over-dielectric approach occupies a different design space: electromagnetic transmission at exceptionally high carrier frequencies, implemented with scalable semiconductor technology.

Bottom line: By combining circuit simulation, physical electromagnetic verification, system analysis and controlled design-data management, ADS gives AttoTude a workflow capable of following an idea through layout and tape-out. Reaching first-pass silicon across designs extending to 3 THz suggests that THz IC development is moving from laboratory experimentation toward a repeatable engineering discipline—and potentially toward deployable, high-volume interconnect products for AI infrastructure.

Also Read:

Keysight Design Engineering Software at DAC 2026: Going Deep on Chiplets, RF and AI-Driven Design

PowerArtist RTL Power Estimation Folds into Keysight

On the high-speed digital design frontier with Keysight’s Hee-Soo Lee