WMA: All-Digital RF Transceivers: Architectures, Technologies and Applications for the Future of Wireless Systems

Presentation Abstract
The transition to all-digital RF transceivers marks a transformative shift in wireless system design, promising unprecedented levels of flexibility, scalability, and integration. This workshop brings together leading researchers and practitioners from academia and industry to explore the current state, challenges, and future directions of all-digital transceivers, covering a broad spectrum of topics from foundational architectures to application-driven innovations. All-digital transceivers replace traditional analog-intensive RF front-ends with fully digital architectures, where signal generation, modulation, transmission, and reception are primarily handled in the digital domain. This approach leverages high-speed digital-to-analog and analog-to-digital converters (DACs/ADCs), direct digital synthesis, and reconfigurable digital logic to create highly adaptable, software-defined systems that support multi-standard and multi-band operation. The workshop will begin with an overview of the architectural principles of all-digital transceivers, highlighting key building blocks, including pulsed modulators, up/down conversion architectures, filters, amplifiers and other fundamental building blocks. A comprehensive exploration of cutting-edge advances in digital and RF front-end technologies for next-generation wireless systems is presented. The first sessions focus on Delta-Sigma Modulation (DSM) for high-performance All-Digital RF Transmitters (ADTs). After revisiting key principles, advanced techniques for high-speed operation, out-of-band noise management, and hybrid DSM architectures are discussed, alongside emerging concepts such as spatial DSM for massive MIMO. Building on this, the relevance of ADTs as digital replacements for conventional RF chains is examined, highlighting their advantages in frequency agility, scalability, and integration with programmable platforms. Subsequent talks review progress in agile and scalable ADT architectures, including FPGA-based implementations and single-bit transmitters for direct antenna array driving. The benefits and trade-offs of wideband, multi-band, and multi-element operation are analyzed, providing participants with a clear perspective on the opportunities and limitations compared to analog-intensive designs. Extending the all-digital paradigm to the complete transmission–reception chain, another session introduces a Pulse-Width Modulation (PWM) approach for receivers, demonstrating how the combination of DSM-based transmitters and PWM receivers supports low-power, high-performance wireless architectures. The workshop also addresses digital transmitters for 5G and 6G, focusing on GaN-based amplifiers up to 6GHz, their role in boosting efficiency, and prospects for scaling digital architectures beyond 100GHz. This is complemented by advances in RF/microwave filter design, where new approaches achieve quasi-flat group-delay responses beyond the 3dB transmission band, thereby improving signal integrity without sacrificing selectivity. Emerging system-level concepts are also presented. A Distributed MIMO (D-MIMO) testbed based on all-digital radio-over-fiber is showcased, demonstrating practical solutions for sub-6GHz and mm-wave implementations and addressing synchronization challenges inherent to distributed architectures. Finally, the role of LEO satellite communications in the Q/V band is explored through digital beamforming and compact RF front-ends leveraging high-order Nyquist zones, enabling flexible beam generation for next-generation constellations. This workshop provides a unique platform for attendees to engage in in-depth technical discussions, exchange ideas, and foster collaborations that advance the frontier of all-digital RF systems. Together, these seven talks provide an integrated perspective on the transition to fully digital RF front-ends, offering insights into architectures, components, and system-level innovations that will shape future 5G, 6G, and non-terrestrial networks.