Millimeter-Wave and Terahertz Integrated Circuits and Systems
Millimeter-wave (mm-wave) and Terahertz (THz) frequency range is generally defined as the frequency spectrum between 30GHz to 3THz. With recent advancement in mm-wave/THz technologies, it has shown great promise to realize a wide range of emerging applications, such as high-speed wireless communication, non-invasive imaging, biomedical sensing, non-destructive quality control, and spectroscopy. One major technology roadblock for these emerging applications is the lack of cost-effective and compact implementations. Taking advantage of the rapid development of silicon technologies (CMOS and SiGe BiCMOS), we have been developing innovative circuit topologies and system architectures and pushing the fundamental limitations in fully integrated and self-contained electronic systems.
Conventionally, antennas and electronics are often treated as two distinct and separate domains: antenna designers handle the antennas; circuit designers deal with the electronics; and they only talk to each other over one single standard 50Ω interface. However, this partitioned approach may not lead to a globally optimal design if we artificially impose a boundary between antennas and electronics. It is noteworthy that the far-field antenna radiation characteristics are completely governed by its local current or voltage distributions, suggesting the possibility of actively synthesizing the desired antenna responses using multiple electronic feeds. Multi-feed antennas co-integrated with complex electronics now emerge as a very promising technology particularly for wireless communication and radar systems.
On-chip or on-package multi-feed antennas can support low-loss on-antenna power combining in one single antenna footprint, radically pushing the limit of output power and efficiency for wireless transmitters. The multi-feed antennas also enable on-antenna active load modulation, achieving high-efficiency on-antenna Doherty or Outphasing architectures with state-of-the-art energy efficiency. Furthermore, inherently wideband feed isolation can be explored in multi-feed antennas to realize millimeter-wave polarization-division-duplex wireless links with multi-Gbit/s complex modulated signals.
Biology-Electronics Hybrid Systems for Bio-Sensing and Drug Screening
Fully understanding the physiological behaviors of living cells is a prerequisite to further advance the frontiers in bioscience and biotechnologies, such as synthetic biology, stem cell manufacturing, and regenerative medicine. Cell-based assays are the key enablers in a plethora of high-impact applications, including characterizing the potency and toxicity of new drugs in pre-clinical pharmaceutical development, determining the patient-specific treatments in personalized medicine, fast pathogen screening for epidemic disease detections, and detecting biohazards and pollutants in environmental monitoring. We are interested in building biology-electronics hybrid systems with high resolution and high throughput for cell-based assays. These systems will serve as next-generation biomedical sensing and actuation platforms, which allow for holistic understanding of cellular physiology and enable large-scale high-content drug screening.