B. G. Colpitts

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The design and operation along with verifying measurements of a harmonic radar transceiver, or tag, developed for insect tracking are presented. A short length of wire formed the antenna while a beam lead Schottky diode across a resonant loop formed the frequency doubler circuit yielding a total tag mass of less than 3 mg. Simulators using the(More)
Brillouin scattering-based distributed fiber-optic sensing is a powerful measurement tool that uses the inelastic scattering of incident light by an acoustic wave (phonon) to determine strain and/or temperature conditions of the fiber. Since the original Brillouin-time-domain-analysis (BOTDA) technique was proposed, several other analysis methods have been(More)
A novel dark-pulse-based technique has been used for the first time in a Brillouin scattering-based distributed fiber sensor. Experimentally obtained Brillouin spectra demonstrate that the dark-pulse configuration is as capable of strain and temperature measurement as conventional pulse-based systems but at much higher spatial resolution. A spatial(More)
A novel Brillouin-based distributed sensing technique is presented that can obtain the strain profile of the entire sensing fiber with a single optical pulse. Experimentally obtained spectra show that this comb excited pump signal is capable of strain and temperature measurement in a dynamic system. The results show the expected sinusoidal strain profile(More)
Design considerations and simulations are presented for an identification tag to be used in tracking insects through the use of harmonic radar. Radar is used instead of a radio transmitter in order to minimize the loading of the insect which for the Colorado potato beetle under study will require a tag of less than 5 mg mass. Frequency selection, antenna(More)
Diffraction techniques are used to predict the propagation path loss between a radio transmitter site and receiver sites located in the shadow of mountainous and hilly terrain. These predictions are used to determine the effective coverage range for a radio paging service and, in the reverse problem, are used to determine the required transmitter power and(More)
This paper presents the performance of a dielectric barrier discharge (DBD) device, when powered by a single phase, voltage source, 4-pulse, PWM inverter. The main focus of this paper is to investigate the applicability of switch-mode inverters in supplying DBD devices to generate plasma body forces. Also, this paper aims to establish relationships between(More)
Using a finite integration (FI) electromagnetic model of a simulation software, a three dimensional section of aluminum honeycomb is analyzed. It is shown that, at 8 MHz, this structure behaves as a flux guide, preventing the attenuation of a penetrating magnetic field. The flux guiding effect was confirmed through MRI measurement of water inside an(More)
We present a method for designing single-sided magnets suitable for unilateral magnetic resonance (UMR) measurements. The method uses metal pole pieces to shape the field from permanent magnets in a target region. The pole pieces are shaped according to solutions to Laplace's equation, and can be designed using a combination of analytical methods and(More)
Input impedance of truncated coaxial cable is of considerable importance both from the calibration standard and non-destructive testing points of view. Significant effort has been expended in their analysis [1-3] in order to understand and exploit the fringing field effects. For a calibration standard knowledge of the fringing fields is essential to(More)