Chih-Ming Jack Wang

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We investigate a technique for counterfeit detection of high-frequency radio frequency identification (RFID) cards based on the electromagnetic characteristics of the cards rather than the digital information that they transmit. We describe a method of quantifying the electromagnetic signature of an RFID card and identify a small set of features that is(More)
Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment(More)
—We describe a stable method for calibrating digital waveforms and eye diagrams by use of the measurement system response function and its regularized inverse. The function describing the system response includes the response of the oscilloscope and any associated cables and test fixtures. We demonstrate the effectiveness of the method by performing a(More)
—We present a procedure for correcting the timebase distortion (TBD) and jitter of temporal waveforms of arbitrary lengths. This is achieved by estimating the TBD and jitter sequentially with overlapping measurements and using the information in the overlapping portion to adjust the results. We use eye diagrams to demonstrate the effectiveness of the(More)
We show that careful measurements of the unloaded resonance frequency and quality factor of RF identification proximity cards allow identification of different card models and, for the set of cards we studied, identification with minimal error of individual cards of the same model. Furthermore, we show that card identification performance is improved by(More)
Photonic components with adjustable parameters, such as variable-focal–length lenses or spectral filters, that can change functionality upon optical stimulation, could offer numerous useful applications. Tuning of such components is conventionally achieved by either micro-or nano-mechanical actuation of their constitutive parts, by stretching or heating.(More)
We present measurements demonstrating that electronic calibration units are stable enough to be used in place of mechanical vector-network-analyzer verification artifacts. This enables a new fully automated approach to verifying microwave vector-network-analyzer calibrations with a single computer-controlled electronic verification artifact. The new system(More)
In this work, the effects of plasma surface treatment, using oxygen gas, of Ba/sub 0.7/Sr/sub 0.3/Ti/sub 0.9/Zr/sub 0.1/O/sub 3/ (BSTZ) film on the electrical characteristic of a Al/BSTZ/Pt capacitor structure were investigated in detail. Experiment results showed that the leakage current density of the BSTZ thin film within oxygen plasma treatment was(More)
We provide techniques to generate and characterize precision wideband millimeter-wave modulated signals. We use predistortion to obtain a significant improvement in signal quality and an associated reduction in the error vector magnitude (EVM) of the signals generated by an arbitrary-waveform-generator-based source. We adapt a recently developed microwave(More)
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