Abstract: A method for determining the set of focal laws of a plurality of focal points located in a test object includes the steps of providing a bidimensional array of transducer elements in a coupling medium and defining at least a scan line by a set of focal points. For each scan line, the method comprises performing the sub-steps of choosing a two preliminary focal points, calculating a first auxiliary time-of-flight corresponding to the time-of-flight of a wave emitted from the corresponding transducer element and received in the first preliminary focal point, and a second auxiliary time-of-flight corresponding to the time-of-flight of a wave emitted from the same transducer and received in the second preliminary focal point.

Abstract: The present patent application describes an approach to the protection of voltage sensitive instruments using a protection circuit that may be easily integrated in a three-terminal device, and which overcomes the drawbacks of previous approaches. The protection circuit of the invention performs very fast against overvoltages (in a few nanoseconds), automatically switching to a low impedance conduction state as soon as the overvoltage situation ends. It also minimizes insertion losses, shows a very low level of thermal noise and allows for obtaining broad bandwidths due to its low serial impedance in the conduction state. Furthermore, it does not require any power source or control signal.