AttoTude Achieves First-Pass 3 THz Silicon with Keysight ADS

AttoTude has expanded its use of Keysight Technologies’ Keysight ADS (Advanced Design System). The platform supports an end-to-end IC design flow from 100 GHz to 3 THz. This workflow has reduced development time by more than 50%. Teams can now move from concept to tape-out in under six weeks. They have also achieved first-pass silicon success across RF, sub-terahertz and terahertz IC development projects.

AttoTude’s THz Interconnect Solution for AI and Hyperscale Data Centers

AttoTude is developing a wired AttoTude THz interconnect platform for AI and hyperscale data centers. Its architecture combines ASIC-based signal generation hardware, called AttoEngine, with low-loss dielectric waveguides, branded AttoWire. The system aims to match the bandwidth density of optical links. It avoids power-hungry photonic components such as lasers and optical modulators. Target per-lane data rates are 200, 400 and 800 Gbit/s. These rates address the growing connectivity needs of large AI accelerator clusters.

Unique Challenges of 100 GHz to 3 THz Silicon Design

Silicon operating from 100 GHz to 3 THz presents major design challenges. Standard digital IC methods cannot fully address them. At these frequencies, on-chip conductors no longer behave like simple lumped connections. Interconnect length, geometry, substrate coupling, return-current paths and metal-stack properties all affect performance. These factors create distributed electromagnetic effects.

Parasitic inductance and capacitance can change circuit behavior. So can conductor loss, dielectric loss, dispersion, skin effect, impedance discontinuities and unintended radiation. At THz frequencies, even small effects can significantly reduce performance.

Need for Correlated Simulation and Physical Layout Modeling

Schematic-level transistor simulations must match electromagnetic models of the physical layout. A circuit may look stable in an ideal simulation but shift in frequency after layout extraction. It may also lose gain. Small geometric changes can affect phase, impedance and coupling. Errors that seem minor at microwave frequencies can become critical at THz wavelengths.

How Keysight ADS Solves These THz Design Challenges

Keysight ADS combines circuit design, layout, electromagnetic analysis and system-level verification in one environment. AttoTude’s engineers can model active devices with extracted passive structures. They can analyze frequency-domain and nonlinear behavior. They can also test architectural options before creating a mask set.

This integrated workflow reduces translation errors. It also limits model mismatches caused by moving design data between separate tools.

Built-in System-Level Scenario Planning Capabilities

ADS also supports system-level planning. Engineers can evaluate link budgets, modulation requirements, channel behavior and implementation trade-offs. They can do this before final transistor-level optimization.

The resulting system constraints flow directly into the IC design process. They help define bandwidth, output power, gain, linearity and noise targets. This reduces the risk of optimizing individual blocks that later fail at the system level.

Integrated Design Data Management for Full Traceability

AttoTude also uses Keysight’s design-data-management software for revision control. Traceability matters because electromagnetic models, schematics, layouts, process-design-kit components and verification results change together.

Engineers can track which model and layout revisions produced each result. They can reproduce earlier simulations and coordinate changes without losing configuration integrity.

Industry Impact of First-Pass 3 THz Silicon Success

The first-pass silicon results are technically significant. A silicon respin adds fabrication costs and can delay system testing by months. At THz frequencies, post-fabrication tuning is also very limited. Accurate predictive simulation is therefore essential for cost-effective development.

According to AttoTude ASIC architect Richard Chan, Keysight’s EDA software has helped the team work faster and with greater confidence. The team has repeatedly delivered functional silicon on its first manufacturing attempt.

The partnership also reflects a broader shift in data center connectivity. AI systems are pushing traditional electrical channels to their limits in reach, bandwidth and energy efficiency. Photonic solutions introduce their own cost and integration challenges.

AttoTude’s transistor-driven THz-over-dielectric approach addresses this gap. It uses extremely high carrier frequencies and scalable semiconductor technology to support electromagnetic transmission.

Final Takeaway

Keysight ADS combines circuit simulation, electromagnetic verification, system analysis and design-data management. This unified workflow takes AttoTude from concept to layout and tape-out.

First-pass silicon at frequencies up to 3 THz shows that terahertz IC development is becoming a repeatable engineering discipline. The technology could eventually support high-volume products for AI data center connectivity infrastructure.