Publications
Four-tap RF canceller evaluation for indoor in-band full-duplex wireless operation
Summary
Summary
Analog self-interference mitigation techniques are currently being investigated in a variety of operational settings for In-Band Full-Duplex (IBFD) systems. The significant multipath effects of realistic environments, such as inside buildings, can severely limit performance. The influence of different transceiver parameters on the effectiveness of a four-tap RF canceller using a...
Covariance estimation in terms of Stokes parameters with application to vector sensor imaging
Summary
Summary
Vector sensor imaging presents a challenging problem in covariance estimation when allowing arbitrarily polarized sources. We propose a Stokes parameter representation of the source covariance matrix which is both qualitatively and computationally convenient. Using this formulation, we adapt the proximal gradient and expectation maximization (EM) algorithms and apply them in...
Nonlinear equalization of microwave photonic links
Summary
Summary
High dynamic range is a key requirement in advanced microwave photonic systems. We demonstrate compensation of nonlinearities occurring in microwave photonic links using a novel digital nonlinear equalization technique and demonstrate suppression of distortion products by 33 dB with a small number of equalizer coefficients.
3D printed conformal array antenna: simulations and measurements
Summary
Summary
A conformal array antenna has been investigated using a combination of 3D printer and copper plating techniques. Circular patch antenna elements were copper plated onto a 3D printed dielectric substrate made of ABS-M30 material. Measured and simulated element reflection coefficient, element gain patterns, and array scanned beam radiation patterns at...
Aperture PCB assemblies: transition to production ready designs
Summary
Summary
MACOM designed the initial radar panels for the next generation surveillance radar with limited funds, with the philosophy that the initial design would be kept as simple as possible and that incremental improvements would be made as the program progressed, with the intent of having a tile assembly that is...
Design and analysis of an axisymmetric phased array fed Gregorian reflector system for limited scanning
Summary
Summary
An axisymmetric phased array fed confocal parabolic Gregorian reflector system is explored. The antenna utilizes a planar phased array located near the vertex of the primary reflector. Numerical electromagnetic simulations based on the multilevel fast multipole method (MLFMM) were used to analyze and optimize the antenna parameters for limited scanning...
Development of a high-throughput microwave imaging system for concealed weapons detection
Summary
Summary
A video-rate microwave imaging aperture for concealed threat detection can serve as a useful tool in securing crowded, high foot traffic environments. Realization of such a system presents two major technical challenges: 1) implementation of an electrically large antenna array for capture of a moving subject, and 2) fast image...
Simultaneous transmit and receive with digital phased arrays
Summary
Summary
A new architecture is proposed for achieving Simultaneous Transmit and Receive (STAR) with a digital phased array. We demonstrate how digital beamforming and cancellation enables adjacent transmitting and receiving sub-arrays to operate simultaneously in the same frequency band without a significant reduction in performance. Our approach uses only digital signal...
Scalable prototyping testbed for MMW imager system
Summary
Summary
A prototyping testbed for an experimental millimeter-wave multiple-imput multiple-output (MIMO) radar system for security applications in high foot-traffic areas will be presented. The system is designed for flexible operation at a 10 Hz video rate, enabled by high-speed electronic scanning and real-time signal processing. Overall imaging system costs are reduced...
HF vector sensor for radio astronomy: ground testing results
Summary
Summary
The radio sky below ~10 MHz is largely unexplored due to the inability of ground-based telescopes to observe near or below the ionospheric plasma frequency, or cut-off frequency. A space-based interferometric array is required to probe the portion of the electromagnetic (E-M) spectrum below 10 MHz with sufficient angular resolution...