6. Antennas and track formation (DI term)

6.1 Examples of antennas

A passive antenna is made up of a set of piezoelectric sensors which convert pressure variations in the water into an electric current transmitted to a receiver responsible for processing, the main one being panoramic channel formation (VF). In practice, this general definition conceals a very wide variety of equipment.

First of all, many materials are piezoelectric, such as bone. Hydrophones can be made from sections of chicken bone, which is certainly economical, but the sensitivity may not be there. It's better to use more expensive ceramics or appropriate polymers. Recall that the sensitivity of a hydrophone (Sh) is 20 log V/p with V the output voltage of the ceramic in volts and p an effective pressure of 1 μPa. A hydrophone of...