Tied-array beam flatfielding

Characterization of Beam-Squint and Beam-Split Effects in RIS-Assisted Multi-Frequency Networks

Multi-frequency operation in beyond-5G and 6G systems renders the beam directions of large-aperture arrays inherently frequency-dependent, giving rise to beam misalignment effects that are particularly critical for reconfigurable intelligent surfaces (RISs). When an RIS phase profile is configured at one frequency but...

RF Chain Count to Mitigate Beam Split in Wideband Hybrid Arrays: From Far-Field to Near-Field

Deploying large antenna arrays transitions wireless communication into the radiative near-field (NF), where spherical wavefronts enable beamfocusing in the joint angle-distance domain. However, wideband beamforming with large antenna arrays suffers from beam split across both spatial dimensions. Although fully digital...

An L-Shaped Sparse Array with Reduced Sensitivity to Parametric Mutual Coupling for 2D DOA Estimation

Mutual coupling among array receiving antennas in passive detection systems can introduce amplitude and phase inconsistencies between antenna elements. The resulting amplitude and phase errors across receiving channels not only affect the spectral peak values in subsequent MUSIC-based direction finding, but also cause...

Array Gain for Digital Beamforming Effects of Distributed Targets and Quantization

Fully digital phased-array radars (PARs) have several advantages over conventional architectures, including flexible multibeam steering, adaptive beamforming, and signal-to-noise ratio (SNR) improvement in array gain due to the independence of receiver noise across array elements. However, the resulting data volume pos...

On-sky demonstration of dual-field interferometry at the CHARA Array

Dual-field interferometry uses a bright reference star for real-time fringe tracking, allowing a second beam combiner to record long coherent integrations on a fainter off-axis science target. At the Center for High Angular Resolution Astronomy (CHARA) Array, we implement this mode using the six-telescope MIRC-X and MY...

Kaiser, Jr. SCANNABLE BEAM FORMING INTERFEROMETER ANTENNA ARRAY SYSTEM