IMEC Offers Licensing for ‘Beyond-5G’ ADCs

The latest advancements in analog-to-digital converter (ADC) technology were unveiled at the IEEE Symposium on VLSI Technology & Circuits, showcasing two innovative ADCs optimized for different applications. One ADC is tailored for basestations, while the other is designed for smartphones.

The basestation ADC is specifically engineered to support RF sampling and can operate across multiple frequency bands up to 5GHz. It boasts a unique combination of high resolution, high linearity, and low power consumption. In contrast, the single-channel handset ADC for smartphones focuses on achieving power efficiency through multi-bit pipelined stages and background calibration.

One of the key advantages of the basestation ADC is its ability to eliminate the need for multiple transceivers per frequency band to achieve multiband operation. By enabling gigahertz sampling speeds, this ADC streamlines the design of basestation systems, particularly those utilizing large antenna arrays for multiple-input multiple-output (MIMO) configurations.

The CMOS-based 10GS/s hierarchical time-interleaved ADC developed by IMEC for RF-sampling applications delivers impressive performance metrics, including 9/8.2 effective number of bits (ENOB) at low/Nyquist frequencies and a spurious-free dynamic range exceeding 60dB within a power budget of 350mW.

Joris Van Driessche, program manager at IMEC, highlighted the innovative features of the ADCs, stating, "To help basestation radios combat interference from other wireless signals, our ADC incorporates built-in wideband-linear signal buffering to enhance ENOB without the need for digital nonlinear distortion correction engines. The hierarchical interleaver architecture further boosts linearity and speed."

For mobile handset applications, IMEC has developed a single-channel ADC leveraging multi-bit pipelined stages based on ring amplification. This handset ADC achieves an impressive 10.91 ENOB and 81dB spurious-free dynamic range at 1GS/s while consuming only 17.8mW.

Looking ahead, Van Driessche emphasized IMEC's commitment to advancing ADC technology for beyond-5G communications. The institute aims to develop basestation ADCs supporting FR3 frequencies (6 to 20GHz) while maintaining high linearity and low power consumption using cutting-edge sub-5nm CMOS nodes.