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Full-Text Articles in Engineering
Effects Of Channel Mismatches On Beamforming And Signal Detection, Christopher I. Allen
Effects Of Channel Mismatches On Beamforming And Signal Detection, Christopher I. Allen
Theses and Dissertations
Tuner gain measurements of a multichannel receiver are reported. A linear regression model is used to characterize the gain, as a function of channel number, tuner set-on frequency, and intermediate frequency. Residual errors of this model are characterized by a t distribution. Very strong autocorrelation of tuner gain at various frequencies is noted. Tuner performance from one channel to the next is diverse; several defects at specific frequencies are noted. The Wilcoxon signed rank test is used to test normality of tuner gain among devices; normality is rejected. Antenna directivity and phase pattern measurements are also reported. An antenna element …
Delta-Sigma Subarray Beamforming For Ultrasound Imaging, Hasan Şaki̇r Bi̇lge
Delta-Sigma Subarray Beamforming For Ultrasound Imaging, Hasan Şaki̇r Bi̇lge
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, an ultrasonic digital beamformer based on subarray processing of 1-bit delta-sigma (\Delta \Sigma ) oversampled echo signals is presented. The single-bit oversampling \Delta \Sigma conversion simplifies the coherent processing in beamforming with improved timing accuracy. Subarray processing also aims to simplify the beamforming complexity, where the partial-beam sums (low-resolution beams) are acquired from small subarrays, and then these partial beams are coherently processed for producing high-resolution beams. In the \Delta \Sigma subarray beamforming, the \Delta \Sigma coded echo signals are summed over the subarray channels, and then these partial beam-sums are first \Delta \Sigma demodulated, then processed …