Minimum-Norm Solution for Robust Differential Arrays - Study and Design of Differential Microphone Arrays - page 125

90 ◦ 90 ◦

0 dB
−10 dB
−20 dB
−30 dB
−40 dB

0 dB
−10 dB
−20 dB
−30 dB
−40 dB

120 ◦ 60 ◦ 120 ◦ 60 ◦

150 ◦ 30 ◦ 150 ◦ 30 ◦

180 ◦ 0 ◦ 180 ◦ 0 ◦

210 ◦ 330 ◦ 210 ◦ 330 ◦

240 ◦ 300 ◦ 240 ◦ 300 ◦

270 ◦ 270 ◦

(a) (b)

90 ◦ 90 ◦

0 dB
−10 dB
−20 dB
−30 dB
−40 dB

0 dB
−10 dB
−20 dB
−30 dB
−40 dB

120 ◦ 60 ◦ 120 ◦ 60 ◦

150 ◦ 30 ◦

150 ◦ 30 ◦

180 ◦ 0 ◦

180 ◦ 0 ◦

210 ◦ 330 ◦

210 ◦

330 ◦

240 ◦ 300 ◦ 240 ◦ 300 ◦

270 ◦ 270 ◦

(c) (d)

90 ◦ 90 ◦

0 dB
−10 dB
−20 dB
−30 dB
−40 dB

0 dB
−10 dB
−20 dB
−30 dB
−40 dB

120 ◦ 60 ◦

120 ◦ 60 ◦

150 ◦ 30 ◦ 150 ◦ 30 ◦

180 ◦ 0 ◦ 180 ◦ 0 ◦

210 ◦ 330 ◦ 210 ◦ 330 ◦

240 ◦ 300 ◦

240 ◦ 300 ◦

270 ◦ 270 ◦

(e) (f)

FIG. 6.8 Patterns of the second-order cardioid with 8 microphones for several frequencies:
(a) F =0 . 5 kHz, (b) F =1 . 0 kHz, (c) F =2 . 0 kHz, (d) F =3 . 0 kHz, (e) F =4 . 0 kHz, and
(f) F =5 . 0 kHz.