Observation of Quantum Capacitance of individual single walled carbon nanotubes

We report a measurement on quantum capacitance of individual semiconducting and small band gap SWNTs. The observed quantum capacitance is remarkably smaller than that originating from density of states and it implies a strong electron correlation in SWNTs

Gate-capacitance extraction from RF C-V measurements

In this work, a full two-port analysis of an RF C-V measurement set-up is given. This two-port analysis gives insight on the limitations of the commonly used gate capacitance extraction, based on the Y/sub 11/ parameter of the device. It is shown that the parasitics of the device can disturb the extracted gate capacitance and a new extraction scheme, based on the Z-matrix, is introduced that eliminates the effect of these parasitics. Measurement results prove the validity of this new extraction scheme, under different conditions

Fast RF-CV characterization through high-speed 1-port S-parameter measurements

We present a novel method to measure the capacitance-voltage relation of an electronic device. The approach is accurate, very fast, and cost-effective compared to the existing off-the-shelf solutions. Capacitances are determined using a single-frequency 1-port S-parameter setup constructed from discrete components. We introduce a new way to correct for non-linearities of the used components, which greatly increases the accuracy with which the phase and magnitude of the reflected signal is measured. The measurement technique is validated on an RF-MEMS capacitive switch and a BST tunable capacitor. Complete capacitance-voltage curves are measured in less than a millisecond, with a measurement accuracy well below 1%.\ud \u

On Machine Capacitance Dimensional and Surface Profile Measurement System

A program was awarded under the Air Force Machine Tool Sensor Improvements Program Research and Development Announcement to develop and demonstrate the use of a Capacitance Sensor System including Capacitive Non-Contact Analog Probe and a Capacitive Array Dimensional Measurement System to check the dimensions of complex shapes and contours on a machine tool or in an automated inspection cell. The manufacturing of complex shapes and contours and the subsequent verification of those manufactured shapes is fundamental and widespread throughout industry. The critical profile of a gear tooth; the overall shape of a graphite EDM electrode; the contour of a turbine blade in a jet engine; and countless other components in varied applications possess complex shapes that require detailed and complex inspection procedures. Current inspection methods for complex shapes and contours are expensive, time-consuming, and labor intensive

Resonant frequency measurements as an alternative to phase-selective A.C. polarography in tensammetry and pseudocapacitance determinations

A new method is proposed for the determination of the double-layer capacitance and pseudocapacitance of electrochemical cells. The method is based on the measurement of the resonant frequency of the circuit consisting of the electrochemical cell connected in series with a standard inductor. The performance of the method is demonstrated with double-layer capacitance measurements at the dropping mercury electrode in 1 M KCl and butanol-1/1 M KCl mixtures and with the determination of heterogeneous charge-transfer rate constants ranging from 10−2 to 10−5 m s−1