TACS-RF: Streamlining RF and mmWave Module Design Process

Paper: TACS-RF: Tool-driven Agentic Circuit Synthesis of RF and mmWave Modules

Authors: Tristan Liang, Aravind Nagulu

Executive Summary

The research introduces TACS-RF, a new framework that leverages a large-language model (LLM) coding agent, specifically Claude Opus 4.8, to enhance the design process of radio frequency (RF) and millimeter-wave (mmWave) modules. This framework integrates with established electronic design automation (EDA) tools, such as Cadence Virtuoso/Spectre, Calibre, Cadence EMX, and Ansys HFSS, to facilitate a more efficient and potentially autonomous design process.

The practical application of this framework was validated through the semi-autonomous design of a sub-terahertz (sub-THz) transmitter operating in the 240-251 GHz range, using a 90 nm silicon-germanium (SiGe) BiCMOS technology. The design process included the development of critical components such as a 60 GHz push-push Colpitts voltage-controlled oscillator (VCO), multistage differential cascode power drivers, a frequency doubler, a differential bowtie antenna, and various interstage matching networks.

The resulting transmitter chain achieved significant performance metrics: it delivered output power levels ranging from +5.1 to +6.3 dBm across an 11 GHz tuning range that utilized only varactor components. Additionally, it maintained a phase noise performance of -80 to -88 dBc/Hz at a 1 MHz offset, while consuming a total DC power of 361 mW. These results were derived from simulations and benchmarks rather than real-world deployment, underscoring the framework's potential in a controlled environment.

The research outlines a novel design flow that illustrates how responsibilities can be divided between human engineers and the coding agent. This division of labor is pivotal as it demonstrates a significant step toward a "text-to-ASIC" (application-specific integrated circuit) approach for designing RF and mmWave hardware. This could streamline the development process, making it faster and potentially more cost-effective.

The implications of TACS-RF are noteworthy for companies in the telecommunications and electronics sectors, particularly those focused on developing high-frequency components. By automating parts of the design process, organizations may enhance their productivity and innovation capabilities. The framework could allow for more complex designs to be handled efficiently, reducing the time to market for new technologies.

In summary, TACS-RF represents a forward-looking approach to electronic design, where advanced AI tools could play a significant role in shaping the future of RF and mmWave hardware development.

Academic Abstract

We present the framework of TACS-RF - a Tool-driven Agentic Circuit Synthesis of RF and mmWave modules. In this framework, a large-language-model (LLM) coding agent (Claude Opus 4.8) directly drives industry-standard electronic-design-automation (EDA) tools such as Cadence Virtuoso/Spectre, Calibre, Cadence EMX, and Ansys HFSS to design RF and mmWave modules. We validate the framework through the agentic design of a 240-251 GHz sub-THz transmitter in a 90 nm SiGe BiCMOS process. The agent semi-autonomously designed the sub-blocks including a 60 GHz push-push Colpitts VCO with second-harmonic extraction, multistage differential cascode power drivers, a push-push frequency doubler, a differential bowtie antenna, and all the interstage matching networks. The transmitter chain with parasitic-extracted devices and EM-verified passives delivers +5.1 to +6.3 dBm across an 11 GHz varactor-only tuning range, phase noise of -80 to -88 dBc/Hz at 1 MHz offset while consuming a DC power of 361 mW. We describe the agent-driven design flow and the resulting division of labor between human and agent, taking a step toward a "text-to-ASIC" future for designing RF/mmWave hardware.