Differential constant-beamwidth beamforming with cube arrays

Kronecker-Product Beamforming with Sparse Concentric Circular Arrays

“…For example, focusing on the endfire direction (ϕ 0 = 0 o with respect to the positive x-axis direction), we assume a wide potential range of DOA deviations on the x-y plane of all angles satisfying |ϕ| ≤ ϕ H . We note that unlike previous studies, which considered a relatively narrow deviation range (ϕ H ≈ 20 o − 30 o ) [33], [35], [36], in this study, we target more severe cases which require a broader range. To achieve this, we first take advantage of the microphone array topology optimization approach suggested in [35] with ULAs and in [36] with nonuniform rectangular arrays and optimize a K-sparse CCA structure out of a UCCA of M possible microphone locations (uniformly distributed and equally spaced on the N UCCA's rings, as elaborated in Section II).…”

“…Uniform circular arrays (UCAs) have been shown to allow a high level of control, compromising between the WNG, the DF, and a frequency-independent spatial response [21], [22]. Other studies have generalized UCAs by proposing uniform concentric circular array (UCCA) structures [23]- [25], which may also enable a constant mainlobe beamwidth concerning the azimuth angle, the elevation angle, or both [26]- [28]-a highly desirable property with broadband applications which has been extensively addressed in the literature [29]- [33]. In addition, it is known that UCCA structures can mitigate low-WNG issues and beampattern irregularities in case adjacent microphones are closely spaced on the circumference of the UCA [34].…”