Wireless and Multidisciplinary Research Group (WMRG)
To develop circuit techniques devoted to practical problems, to invent new concept-to-solution designs to underpin the development of wireless industry, and to develop advanced micro/hybrid systems that can be applicable to human beings, with research in biology and chemistry. Several key directions are highlighted:
- Ultra-low-power ZigBee and Bluetooth Low Energy (BLE) radios for low-power low-cost wireless connectivity such as Internet of Things.
- Wideband flexible receivers and transmitters for 5G communications.
- Micro-power analog circuits with enhanced performances, power and area efficiencies.
- Electronics-automated digital microfluidics with software-defined intelligence.
- Portable nuclear magnetic resonance (NMR) electronics for precision medicine.
- Ultra-low-power solar-powered CMOS/beyond-CMOS sensing chips.
This research line focuses on RF and mmWave ICs for a wide variety of applications, including but not limited to, 3G/4G/5G multi-standard cellular radios, ultra-low-cost ultra-low-power IoT radios, and tens-of-MHz radios for micro-nuclear magnetic resonance (μNMR) applications. The key research interests are:
- Sub-6GHz 2G/3G/4G wireless transceiver front-ends, and >28GHz 5G transceiver front-ends. SAW-less RF-flexible receivers and transmitters using our proposed gain-boosted N-path filter techniques are investigated.
- Ultra-low-power IoT transceiver front-ends from sub-GHz to 2.4GHz, conforming to Bluetooth Low Energy (BLE), ZigBee and NB-IoT. Ultra-low-cost and ultra-low-power RF and baseband (BB) techniques using our proposed function-reuse gain-boosted N-path receiver, RF-to-BB-current-reuse receiver, function-reuse VCO-PA, and ultra-low voltage receiver, transmitter and frequency synthesizer using a local micro-power manager are investigated.
- Analog baseband circuits such as micro-power amplifiers with high capacitive load drivability, continuous-time/discrete-time filters with a very compact chip area, energy harvesting units with high efficiency, sensor readout interfaces with low noise effective factor, and crystal oscillators with low startup energy are investigated.
- RF/mmWave circuits such as active-inductor-enhanced wideband amplifiers, multi harmonic-peaking wave-shaping VCOs, time-interleaved ring oscillators with a wide tuning range, and type-I phased-locked loops with ultra-low-voltage operation are investigated.
- Digital baseband correction techniques for I/Q mismatch, LO feedthrough and strong memory-effect distortion in wideband transmitters are investigated.
- Tens-of-MHz (e.g., 20MHz) transceivers with a sensing coil (on/off-chip spiral inductor) to allow electronic-automated biological and chemical assays in a small form factor.
The invented techniques are expected to advance the state-of-the-art knowledge in the fields, and should be potentially transferrable to the industry for practical applications.
Biomedical and Multidisciplinary IC
The research line focuses on advanced micro/hybrid systems that can be applicable to human beings, biological and chemistry researches. The key research interests are:
- Advanced electronics platform for small animal behavioral study. Miniaturized circuit/SoC for simultaneous extracellular electrophysiology recording and optogenetic neural manipulation is studied.
- Micro ultrasound transducer for biological imaging and measurement. New membrane structure CMUT is designed and fabricated based on MEMS technology to enhance the output ultrasonic pressure. Multi-frequency CMUT is investigated to extend the imaging capability of photoacoustic imaging.
- Intra-body Communication with study in physical layer and MAC layer and their IC implementation.
- Microprocessor with built-in multi-tasking ability for biomedical engineering applications. This can be used as a platform for ASIC development for related applications.
- Ultra-low-power energy harvesting CMOS biomedical implantable sensing chip. Single-chip energy harvesting solution with various ambient sources for low voltage operation, high efficiency and ultra-compact form factor are investigated.
- Ultra-low power biopotential interfacing circuit. Nanowatt analog signal processing and filtering is studied, focusing on nanowatt circuit design, subthreshold operation, linearity improvement and gain compensation.
- Digital microfluidic chips with software-defined intelligence. On-chip 3D structures for precise droplet splitting, fuzzy-logic and real-time feedback for precise droplet positioning, and non-DC driving voltage waveforms for higher droplet moving speed are investigated.
The invented techniques are expected to advance the state-of-the-art in terms of performances and understanding, and should be transferrable to the industry for practical applications.