Title :
Analysis of worst-case phase quantization sidelobes in focused beamforming
Author :
Holm, Sverre ; Kristoffersen, Kjell
Author_Institution :
Vingmed Sound AS, Lysaker, Norway
Abstract :
The effect of phase quantization errors on the sidelobe level in a phased-array beamformer is considered. The theory of random and periodic phase errors is reviewed. Periodic phase errors occur for an unfocused array with uniform element distance and give rise to discrete sidelobes. The main result of the paper is an analysis of the periodic phase error in the case that the beamformer is focused. An estimate for the worst-case discrete sidelobe level as a function of focal depth is derived. The theory is illustrated and verified by simulations.<>
Keywords :
acoustic arrays; acoustic imaging; acoustic signal processing; error analysis; focal depth; periodic phase error theory; phase quantization errors; phased-array beamformer; random error theory; simulations; ultrasound imaging; unfocused array; worst case phase quantisation sidelobes analysis; Array signal processing; Biomedical imaging; Degradation; Delay effects; Focusing; Phased arrays; Quantization; Radar applications; Sonar applications; Ultrasonic imaging;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
