In order to minimize the influence of electrode polarization and noise in impedance measurements, especially in the low frequency region, current injection shows several advantages compared to voltage application. Although the existence of a great variety of current sources, they meet our requirements only partially. We developed a voltage controlled current source for active front ends for a w...

Conventional switch-mode dc-dc converters are operated at frequencies in the order of hundreds of kHz to single MHz. Switching frequencies in the order of tens of MHz would enable applications of RF converters in low power communications and computing integrated circuits with dynamic voltage scaling. Controllers for these converters would have to operate with a bandwidth in the GHz range. The m...

Fast and accurate frequency estimation of an unbalanced three-phase power system in the presence measurement offset is a challenging task. A simple to implement tune method proposed this work through delay-based linear-regression framework. Using two scenarios, we verify performance our procedure severe grid abnormalities, including voltage unbalance, harmonics, jump, dc offset. Comparative har...

A/D converters used in instrumentation and measurements often require high absolute accuracy, including high linearity and negligible DC offset. The incremental (or integrating) converter provides a solution for such measurement applications, as it has all the advantages of the ∆Σ (Delta-Sigma) converter, yet is capable of offset-free and accurate conversion. In this conference paper, theoretic...

A 900MHz balanced harmonic mixer for direct conversion receivers is fabricated in a 0.35 μm standard digital CMOS process. The self-mixing-induced DC offset is about 44dB lower than that of the conventional mixer. The inputreferred offset is reduced to the noise level. Specific techniques on flicker noise reduction are also discussed. At 3V power supply and -15.4dBm LO power, it achieves 13 dB ...