제민규 교수

Wireless power transfer provides a safe and robust way for powering biomedical implants, where high efficiency is of great importance. A new wireless power transfer technique using optimal resonant load transformation is presented with significantly improved efficiency at the cost of only one additional chip inductor component. The optimal resonant load condition for the maximized power transfer efficiency is explained. The proposed technique is implemented using printed spiral coils with discre

An integrated CMOS ultrawideband wireless telemetry transceiver for wearable and implantable medical sensor applications is reported in this letter. This high duty cycled, noncoherent transceiver supports scalable data rate up to 10 Mb/s with energy efficiency of 0.35 nJ/bit and 6.2 nJ/bit for transmitter and receiver, respectively. A prototype wireless capsule endoscopy using the proposed transceiver demonstrated in vivo image transmission of 640 × 480 resolution at a frame rate of 2.5 frames/s

The design of a novel differentially fed dual-band implantable antenna operating at 402-405 MHz Medical Implant Communication Services (MICS) band and 2.4-2.5 GHz Industrial, Scientific, and Medical (ISM) band is introduced. The proposed implanted antennas are for both planar and flexible implantation scenarios. Biocompatible material parylene-C is adopted to cover the implanted antenna. The size of the proposed antennas including the encapsulation for planar and flexible case is 179.0 mm <sup x

After reviewing the basic concept and general strategies, we have examined a variety of examples of modeling and parameter extraction methods for RF MOSFET's. Modeling and parameter extraction techniques popular in III-V FET modeling were reviewed and recent efforts to model the RF MOSFET and extract the model parameters were examined in light of the differences between the MOSFET and the III-V FET. A very simple and accurate parameter extraction method studied in our laboratory for three-termin

This paper presents an error-tolerant and power-efficient impedance measurement scheme for bioimpedance acquisition. The proposed architecture measures the magnitude and the real part of the target complex impedance, unlike other impedance measurement architectures measuring either the real/imaginary components or the magnitude and phase. The phase information of the target impedance is obtained by using the ratio between the magnitude and the real components. This can allow for avoiding direct

Analytical expressions for the Y-parameters of RF MOSFETs including the substrate signal coupling effect were systematically derived. The expressions are physically correct and simple enough to be intuitive. With the expressions, how signal coupling occurs through the substrate network of parasitics could be clearly explained in physical terms, for the first time. In particular, we focused on how substrate signal coupling makes an influence on the output admittance of an RF MOSFET as the gate bi

A small-signal equivalent circuit of an RF MOSFET not only fully compatible with 4 terminal large-signal quasi-static I-V and Q-V models but suitable for 3 terminal two-port s-parameter measurement, is proposed along with very simple and accurate parameter extraction method. This model includes the intrinsic and extrinsic elements important for AC simulation at RF. The validity and accuracy of our approach is verified from 0.18 /spl mu/m RF NMOS results.

Simultaneous monitoring of critical parameters (e.g., pressure, shear, and temperature) at bony prominences is essential for the prevention of pressure injuries in a systematic manner. However, the development of wireless sensor array for accurate mapping of risk factors has been limited due to the challenges in the convergence of wireless technologies and wearable sensor arrays with a thin and small form factor. Herein, a battery-free, wireless, miniaturized multi-modal sensor array is introduc

A four-terminal RF MOSFET model to accurately describe the three-port network characteristics is presented. It has been found that the short-channel effect in the source-to-drain capacitance plays a critical role in predicting behavior of the MOSFET in the common-gate/body configuration. Performance of the developed model was verified with the device simulation results.

Mobile society is opening the way to “Always-On” future where we are constantly connected to everything we care about, which allows us to do “Anything”, “Anytime”, from “Anywhere”. This future mobile society will come true only when major technology advances are successfully made to overcome challenges in mobile devices, connectivity, and cloud computing infrastructure. While incessant technology push dictated by Moore's Law is certainly relevant, there are still so much more to innovate, to add