High-Frequency Si/SiGe Integrated Circuits and Systems

Ahmet Cagri Ulusoy | ulusoy@egr.msu.edu | www.egr.msu.edu/~ulusoy/


The continuously growing demand for higher data rates and ubiquitous mobile connectivity in every aspect of life necessitates transformative technologies for future wireless network architectures. The need for ever increasing network capacity, and widespread use of sensor technologies in various applications have been identified as crucial future technological trends. One of the key enabler elements for these emerging fields will be the integrated circuits (IC) operational at higher frequencies being able to access wider bandwidth, at the same time providing a higher degree of integration and multi-functionality. This encompasses usage of state-of-the art IC processes such as nanometer scale CMOS and high-performance silicon germanium (SiGe) BiCMOS, but also inclusion of unique approaches in terms of packaging and technological advancements going beyond the Moore’s Law. These unique approaches can be in a technological scale, introducing non-traditional integration approaches, such as radio frequency micro-electromechanical systems (RF-MEMS) or optical technologies monolithically, but also in the application domain realizing unique functions making use of the capabilities of the IC technology tailored towards the emerging applications. Multi-channel ICs for electronic beam steering and analog signal processing for wideband applications are two examples. The higher degree of integration makes it possible to develop systems that are size, weight and cost favorable that can be deployed in large quantities for future millimeter-wave and sub-millimeter-wave systems. The IC includes four complete transceivers, including amplitude and phase control for electronic beamforming and steering, as well as an on-chip frequency synthesizer. By combining such ICs with novel packaging approaches and compact on-chip components, such as on-chip antennas, highly miniaturized, yet highly functional high-frequency components can be realized that will impact many applications in the near future. Some research areas are listed in the following.

Large-Scale Multiple-Input Multiple-Output Systems

Millimeter-wave systems for radar, sensing and for communication applications show a tendency to require operation with multiple independent receive/transmit antenna units. ICs integrated with antennas and complete transceivers in a small footprint, with various control functions and digital capabilities are essential components for such systems. The research needs are providing MIMO capability, integrated solutions for array synchronization and pattern synthesis, solutions to reduce latency, and capability to support multi-band operation.

Analog Enhanced Ultra-Wide Bandwidth Systems

For emerging communication and radar systems, the tendency is to enable access to much larger bandwidth than what is available today. This potentially comes with a paradigm shift in terms of signal processing, due to foreseeable end of the Moore’s law, and the cost of digital signal processing for extreme bandwidth. The research needs are to identify functions that can be performed in analog domain in an energy efficient manner, and develop novel methods to integrate these to traditionally digital-dominated architectures. Examples include synchronization, equalization and true-time delay enabled signal processing.

Electrical/Optical Merger Technologies

A critical area will be to pursue approaches that bring optical and electrical domains together, for instance connecting optical fiber backbone with wireless technologies. Potential areas exist not only limited to communication but also for sensing. Research needs are miniaturized and low-cost implementation of electro/optical interfaces, and achieving desired bandwidth for receiver and transmitter assemblies.