TABLE II.

Performance comparisons for various beam-forming methods.

Methods		Lateral beam width	Main lobe width (×λzF)	Max side lobe height (dB)	eSNR (dB)
DRF	DRF-focus	$\frac{{\text{sin}}^2(\mathit{\text{kdN}}\prime x/2z)}{{\text{sin}}^2(\mathit{\text{kdx}}/2z)}$	$\frac{1}{N\prime d}$	−26	0
SA	SAF	$\frac{\text{sin}(\mathit{\text{kdN}}\prime x/z)}{\text{sin}(\mathit{\text{kdx}}/z)}$	$\frac{1}{2N\prime d}$	−13	-
	M-SPA	$\frac{{\text{sin}}^2(\mathit{\text{kdN}}\prime x/2z)}{{\text{sin}}^2(\mathit{\text{kdx}}/2z)}$	$\frac{1}{N\prime d}$	−26	-
	SMF-BF	$\frac{\text{sin}(\mathit{\text{kdN}}\prime x/z)}{\text{sin}(\mathit{\text{kdx}}/z)}$	$\frac{1}{2N\prime d}$	−13	13.35
	SMF	$\frac{{\text{sin}}^2(\mathit{\text{kdN}}\prime x/2z)}{{\text{sin}}^2(\mathit{\text{kdx}}/2z)}$	$\frac{1}{N\prime d}$	−26	20.63