Abstract: Stationary devices employing quadrature phase analysis light scattering are provided, to aid in the determination of the magnitude and polarity of electrophoretic mobility and zeta potential of particles in colloids. The devices use an optical quadrature interferometer with an electrophoresis sample chamber containing sample particles undergoing electrophoresis, the optical quadrature interferometer being configured to generate a quadrature signal. The phase of the quadrature signal may be analyzed at the frequency of the sample chamber electric field to estimate displacements and directions of the particles. The estimates can be used to determine a central value of the magnitude of the electrophoretic mobility, as well as its polarity. Particles having low electrophoretic mobility, or that may be adversely affected by high electric fields, can be analyzed, and constraints on vibration and light source coherence length may be relaxed. A phase modulator or frequency shifter is not required.

Abstract: Stationary devices employing quadrature phase analysis light scattering are provided, to aid in the determination of the magnitude and polarity of electrophoretic mobility and zeta potential of particles in colloids. The devices use an optical quadrature interferometer with an electrophoresis sample chamber containing sample particles undergoing electrophoresis, the optical quadrature interferometer being configured to generate a quadrature signal. The phase of the quadrature signal may be analyzed at the frequency of the sample chamber electric field to estimate displacements and directions of the particles. The estimates can be used to determine a central value of the magnitude of the electrophoretic mobility, as well as its polarity. Particles having low electrophoretic mobility, or that may be adversely affected by high electric fields, can be analyzed, and constraints on vibration and light source coherence length may be relaxed. A phase modulator or frequency shifter is not required.

Abstract: Devices and methods are provided for determining frequency spectra, as well as the polarity of frequency, of energy in quadrature signals. In Doppler detection systems, found in sonar, radar, lidar, optical velocimeters using interferometers, and ultrasonics applications, for example, this information can be used to determine target speed and direction. Embodiments obtain a quadrature signal and determine a sine transform of a cross correlation between the I and Q components of the quadrature signal, and can provide an output comprising a signed frequency spectrum. A sign of a sample of the signed frequency spectrum can correspond to a polarity of frequency. The signed frequency spectrum can be rapidly determined over a unipolar frequency span that may be only approximately half the baseband sampling frequency. The signed frequency spectrum may be impervious to imaging under severe conditions of uncorrected quadrature amplitude imbalance.

Abstract: Devices and methods employing stationary homodyne interferometry to aid in the determination of the magnitude and polarity of electrophoretic mobility and zeta potential of particles are provided. The devices use an optical quadrature interferometer having a sample holder loadable with an electrophoresis sample chamber that may contain sample particles undergoing electrophoresis, the optical quadrature interferometer being configured to perform optical velocimetry on the particles and to generate a quadrature signal comprising characteristics related to the speeds and directions of the particles. The quadrature signal may be used to determine the speeds and directions of particles. The speeds and directions of particles may be used, together with other information, for the determination of the magnitudes and polarities of the electrophoretic mobility and zeta potential of the particles. Constraints on vibration, light source coherence length, and measurement resolution may be relaxed.

Abstract: Devices and methods for estimation of quadrature signal imbalance are provided. A quadrature signal is coupled to a computing system. The computing system determines several points on a symmetry function of corrected quadrature signals, and identifies a symmetry point that may satisfy a threshold level. An imbalance corresponding to the identified symmetry point may be used as an imbalance estimate. The imbalance estimate can be used for imbalance correction. Multiple imbalance estimates can be combined to reduce random errors caused by noise. Triangulation can be used to identify a value of symmetry that satisfies a threshold level. Triangulation allows the determination of the location of a symmetry trough by calculating as few as four symmetry points, thereby permitting embodiments to track rapidly changing imbalance. The disclosed embodiments may be employed in optical velocimetry systems, detection and ranging systems such as radar, sonar, and lidar, ultrasonics, and communications systems.

Abstract: A reconfigurable secure keyboard console receives an encryption key and at least one transformation instruction. The reconfigurable secure keyboard console stores the encryption key in a reconfigurable first memory. The reconfigurable secure keyboard console stores the at least one transformation instruction in a reconfigurable second memory. A keyboard processor utilizes the at least one transformation instruction to create a plurality of transformed codes. The plurality of transformed codes along with a plurality of values corresponding to each of the plurality of potential keyboard inputs are both stored in a transformed lookup table. The keyboard processor receives an actual keyboard input. The keyboard processor matches the actual keyboard input with one of the plurality of the potential keyboard inputs to create a matching value. The keyboard processor outputs a transformed code from the transformed lookup table corresponding to the matching value.

Abstract: A reconfigurable secure input device (RSID) receives an encryption key and at least one transformation instruction. The RSID stores the encryption key in a memory section. The RSID stores the at least one transformation instruction in a second memory section. A RSID processor utilizes the at least one transformation instruction to create a plurality of transformed codes. The plurality of transformed codes along with a plurality of values corresponding to each of the plurality of potential actual input device inputs are both stored in a transformed lookup table. The RSID processor receives an actual input device input. The RSID processor matches the actual input device input with one of the plurality of the potential keyboard inputs to create a matching value. The RSID processor outputs a matching transformed code from the transformed lookup table corresponding to the matching value.