Constant beamwidth beamformer for difference frequency in parametric array. - Khim Sia Tan; Woon S. Gan; Jun Yang 004; Meng Hwa Er (ICASSP (5), 2003)

An efficient digital beamsteering system for difference frequency in parametric array. - Khim Sia Tan; Woon-Seng Gan; Jun Yang 004; Meng Hwa Er (ICASSP (2), 2004)

A digital beamsteerer for difference frequency in a parametric array. - Woon-Seng Gan; Jun Yang 004; Khim Sia Tan; Meng Hwa Er (IEEE Trans. Speech Audio Process., 2006)