Matthew R. Harper

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Instruments for measuring high-speed waveforms typically require calibration to obtain accurate results. The national metrology institutes of the United States of America, the United Kingdom, and Germany offer measurement services based on electro-optic sampling that can be used to establish a traceable calibration chain between high-speed waveform(More)
We have developed a calibration technique for Vector Signal Analyzers (VSA) that provides traceability to primary standards. This technique has been implemented using standard commercial equipment. A multisine signal generator provides detailed magnitude and phase stimulus over the instrument bandwidth and a Digital Sampling Oscilloscope (DSO) measures the(More)
A jitter-free vector frequency-domain measurement technique to characterize optical reference receivers is presented. The system is based on a Mach-Zehnder integrated-optic modulator (IOM). Results from this new technique and those obtained by optical impulse and heterodyne methods are compared up to 76 GHz. An IOM down-conversion scheme was used to measure(More)
The paper presents the results of the first intercomparison of the rise-time calibration of a 50-GHz sampling oscilloscope between Physikalisch-Technische Bundesanstalt, Germany, and National Physical Laboratory, U.K. (EUROMET project 641). Rise-times between 6.0 and 6.6 ps were obtained using optoelectronic techniques. Detailed uncertainty budgets are(More)
The definition, measurement, and traceability of aberrations in pulse waveform metrology is discussed. The use of reference waveforms and masks allows the definition of aberrations within specific regions relative to the transition point of a pulse generator, as desired by manufacturers and users. Of particular importance is the definition of aberrations(More)
Measurement of two phase-standard designs based on different technologies, over a range of drive frequencies shows differences in behavior. The step-recovery based design is nonlinear with both power and frequency but the time-domain pulse response of the newer phase standard shows little variation with drive frequency. Source-match of the phase standard is(More)
10:00 B07.6 DIFFRACTION COEFFICIENTS FOR DIELECTRIC WEDGES AND CORNERS WITH APPLICATION TO MONOSTATIC BUILDING IMAGING P. C. Chang, R. J. Burkholder, R. J. Marhefka, J. L. Volakis, The Ohio State University, United States 10:20 B07.7 PHASE SENSITIVE DETECTION AND CLASSIFICATION OF DEFECTS IN CONCRETE STRUCTURES BY ULTRASONIC AND ELECTROMAGNETIC IMAGING(More)
A high power pulsed laser system has been installed on the high magnetic field muon spectrometer (HiFi) at the International Science Information Service pulsed neutron and muon source, situated at the STFC Rutherford Appleton Laboratory in the UK. The upgrade enables one to perform light-pump muon-probe experiments under a high magnetic field, which opens(More)
Primary power standards are required to provide traceability for measurements. NPL has recently built a new primary power standard for use in the 75 GHz to 110 GHz band. Compared to NPL's older standard (which has been used for several decades) the new system has a reduced thermal mass and improved thermal isolation. This gives slightly reduced overall(More)
An automated reaction mechanism generator is used to develop a predictive, comprehensive reaction mechanism for the high-temperature oxidation chemistry of n-butanol. This new kinetic model is an advancement of an earlier model, which had been extensively tested against earlier experimental data (Harper et al., Combust. Flame, 2011, 158, 16-41). In this(More)
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