Wideband Array Signal Processing with Real-Time Adaptive Interference Mitigation.

Wideband beamforming and interference cancellation for phased array antennas requires advances in signal processing algorithms, software, and specialized hardware platforms. A high-throughput array receiver has been developed that enables communication in radio frequency interference-rich environments with field programmable gate array (FPGA)-based frequency channelization and packetization. In this study, a real-time interference mitigation algorithm was implemented on graphics processing units (GPUs) contained in the data pipeline.

Optical electric field sensor sensitivity direction rerouting and enhancement using a passive integrated dipole antenna.

This work introduces a passive dipole antenna integrated into the packaging of a slab-coupled optical sensor to enhance the directional sensitivity of electro-optic electric field measurements parallel to the fiber axis. Using the passive integrated dipole antenna described in this work, a sensor that can typically only sense fields transverse to the fiber direction is able to sense a 1.25 kV/m field along the fiber direction with a gain of 17.

Broadband RF impedance spectroscopy in micromachined microfluidic channels.

Impedance spectroscopy in the radio frequency range from 100 MHz to 20 GHz can reveal the dielectric relaxations of biological and chemical solutions. S-parameters for a coplanar waveguide are derived. To perform these measurements, a coplanar waveguide device was fabricated on a conventional FR-4 substrate for fluid interrogation.

Bilinear electric field gradient focusing.

Electric field gradient focusing (EFGF) uses an electric field gradient and a hydrodynamic counter flow to simultaneously separate and focus charged analytes in a channel. Previously, most EFGF devices were designed to form a linear field gradient in the channel. However, the peak capacity obtained using a linear gradient is not much better than what can be obtained using conventional CE.

Performance optimization in electric field gradient focusing.

Electric field gradient focusing (EFGF) is a technique used to simultaneously separate and concentrate biomacromolecules, such as proteins, based on the opposing forces of an electric field gradient and a hydrodynamic flow. Recently, we reported EFGF devices fabricated completely from copolymers functionalized with poly(ethylene glycol), which display excellent resistance to protein adsorption. However, the previous devices did not provide the predicted linear electric field gradient and stable current.

Programed elution and peak profiles in electric field gradient focusing.

Electric field gradient focusing (EFGF) methods have received increased attention in recent years, with potential applications demonstrated by several research groups. In order to move EFGF from the research stage to routine use in application areas, a more detailed understanding of practical aspects of device performance is required. Useful theoretical models for EFGF are available but have not been verified through systematic checks under a variety of conditions.

Poly(ethylene glycol)-functionalized devices for electric field gradient focusing.

Electric field gradient focusing (EFGF) is an equilibrium gradient focusing technique that depends on an electric field gradient and a hydrodynamic counterflow to focus, concentrate, and separate charged analytes. In this work, EFGF devices were fabricated from poly(ethylene glycol) (PEG)-functionalized acrylic plastic. The separation channel was formed in an ionically conductive and protein-resistant PEG-functionalized hydrogel, which was cast in a changing cross-sectional cavity in the plastic device.

Field gradient electrophoresis.

The class of equilibrium gradient methods utilizes the opposition of two forces, at least one of which changes in magnitude with position, to separate and concentrate analytes. The drawback of many methods of this type is that the production of two opposing forces requires in comparison to standard methods, such as capillary electrophoresis, a relatively complex apparatus. In addition, for techniques such as electric field gradient focusing, hydrodynamic flow leads to Taylor dispersion, which limits the attainable concentration factor.

Voltage-controlled separation of proteins by electromobility focusing in a dialysis hollow fiber.

Electromobility focusing (EMF) is a relatively new protein separation technique that utilizes an electric field gradient and a hydrodynamic flow. Proteins are focused in order of electrophoretic mobility at points where their electrophoretic migration velocities balance the hydrodynamic flow velocity. Steady state bands are formed along the separation channel when equilibrium is reached.