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This work investigates through numerical simulations a novel device that improvesdynamic range and linearity. The standard DC SQUID can increase in linearity by adding athird junction, changing to a device known as the bi-SQUID. It is known that the dynamicrange can increase by connecting SQUIDs in series, and it has been shown that nonuniformityin the loops sizes in arrays of SQUIDs can produce a unique 'anti'-peak at thezero magnetic flux (device know as a SQIF). Thus, combining these ideas we can improvethe dynamic range and design a highly linear device with a unique 'anti'-peak. Hence, this device can be referred to as a bi-SQIF or non-uniform bi-SQUID array. Results have shown that the maximum voltage swing increase proportional to N, where N is the number of loops connected in series. The spur free dynamic range also improves as N increases, which is directly related to the linearity of the device. Therefore, we have designed a device which can lead to improvements which can be applicable to low noise amplifier (LNA), and provide a platform for creating "electrically" small antennas.

The complex behaviours of gyroscope systems have been scientifically researched and thoroughly studied for decades. Most of scientific research involving gyroscopes specifically concentrates on studying the designs and fabrications at the circuitry level. Although gaining a recent popularity with the low cost of MEMS device that offers an attractive approach for gyroscope fabrications, its performance is far from meeting the requirements for an inertial grade guidance system. To improve the performance, our current research is theoretically focusing upon investigating the dynamics of vibratory gyroscopes coupled in a ring configuration. Particularly, a certain topology of arrangements among coupled gyroscopes can be designed and studied to enhance robustness. The main operation depends mostly on an external source for a stable oscillation in the drive axis, while an oscillatory motion in the sense axis, which is used to detect an angular rate of rotation, is enabled through the transfers of energy from th...

In this work we numerical model series and parallel non‐uniform superconducting quantum interference device (SQUID) array. Previous work has shown that series SQUID array constructed with a random distribution of loop sizes, (i.e. different areas for each SQUID loop) there exists a unique ‘anti‐peak’ at the zero magnetic field for the voltage versus applied magnetic field (V‐B). Similar results extend to a parallel SQUID array where the difference lies in the arrangement of the Josephson junctions. Other system parameter such as bias current, the number of loops, and mutual inductances are varied to demonstrate the change in dynamic range and linearity of the V‐B response. Application of the SQUID array as a low noise amplifier (LNA) would increase link margins and affect the entire communication system. For unmanned aerial vehicles (UAVs), size, weight and power are limited, the SQUID array would allow use of practical ‘electrically small’ antennas that provide acceptable gain.

We present theoretical and experimental investigations of the fundamental idea that coupling‐induced oscillations can enhance the sensitivity of an array of magnetic sensors. In particular, we consider arrays made up of fluxgate magnetometers inductively coupled through electronic circuits. The underlying dynamics of the coupled system is more complicated as it shows new spatio‐temporal features that are not observed in a single fluxgate. Among these new features, self‐induced oscillations in the form of a traveling wave pattern are of particular interest because they can lead to higher sensitivity levels at reduced costs. Details of the experiments, a new signal detection mechanism, and results from numerical bifurcation analyzes are described in this work.

The heartbeat of the medicinal leech consists of two intricate patterns of oscillatory behavior, which are driven by two lateral arrays of motorneurons. On one side of the animal the motorneurons oscillate synchronously, while on the other side they produce a peristaltic wave of oscillations. Then every 20 heartbeats, approximately, the two sides alternate their activity. These two rhythms, including the transitions between them, are known to be initiated by a Central Pattern Generator (CPG) network of neurons. The translation mechanism from CPG dynamics to motorneuron activity, however, is not well understood. In this work, we use symmetric systems of differential equations, accompanied with computational simulations, to investigate such mechanism.

Numerical simulations of two symmetrically coupled arrays of N Van Der Pol oscillators are conducted. Under certain conditions on the type of connectivity, ie., which oscillators communicate with each other, and strength of coupling, it is shown that symmetry can force one array to oscillate in a synchronous mode (same waveform and same phase) while the second array exhibits a traveling wave mode, in which the oscillations have the same waveform but they are out‐of‐phase by a constant amount. More importantly, it is shown that the synchronous mode is forced to oscillate at N times the frequency of the traveling wave mode.

Numerical simulations of transport phenomena in fluidized beds are carried out to investigate the complex interaction between gas and solid particles, and to explore the validity of a reduced order model based on the Proper Orthogonal Decomposition. The transport phenomena in the fluidized bed are modeled by conservation of mass, momentum, energy and species equations. In order to get insight, we conduct simulations of gas‐solid interactions in a two‐dimensional bed filled with sand particles and with a central nozzle to inject the gas. Aided by the Proper Orthogonal Decomposition, spatial dominant features are identified and separated from the spatio‐temporal dynamics of the simulations. The numerical results indicate that a significant portion of the gas‐solid interaction is confined to a central channel structure. The flow within this structure is successfully captured by a few POD eigenfunctions. This result supports the validity of a reduced order model for fluidized beds, which can then be construct...