Acoustic transmitter

An acoustic transmitter which comprises

• a. an acoustic transmission line having a plurality of ports disposed at spaced positions along said line,
• b. means included in each line and external thereto for providing substantially equal values of acoustic driving pressure at each of said ports when acoustic pressure of the same value as each of said substantially equal values is applied to one end of said line,
• c. a source of acoustic energy for providing acoustic input pressure at one end of said line of the same value as each of said equal values.

An acoustic transmitter which comprises

• a. a source of acoustic energy,
• b. an acoustic transmission line having a plurality of ports disposed at spaced positions along said line for extracting acoustic energy from said line at each of said ports, successive sections of said line being disposed on opposite sides of successive ones of said ports, the first section of said line being disposed at one end of said line and being coupled to said source, and
• c. means provided in each of said successive sections of said line for presenting to the preceding section of said line an acoustic impedance which together with the acoustic impedance of the port therebetween equals the characteristic acoustic impedance of the preceding section of said line.