Abstract: The intensity profile of an ultrasound beam in an ultrasound imaging system is adjusted by driving the individual piezoelectric crystals with drive signals having adjustable pulse durations. The duration of the drive pulse determines the frequency spectrum of the pulse and therefore determines the amplitude of the emitted ultrasound wave. The pulse durations may be selected such as to compose a desired profile of the ultrasound beam.

Abstract: A switch matrix for a transceiver of ultrasonic waves containing a configuration of electroacoustic transducer elements in which in succession proceeding over the arrangement a group of transducer elements can be activated, contains a number of inputs (K1, K2, K3, K4), the number corresponding to the number of transducer elements of a group which are each connected to one of the activated transducer elements, an equal number of outputs (R1, R2, R3, R4) connected to delay elements and a large number of switches T11, T12, . . . , T44) to establish each of the connections required for electronic focusing between the inputs and the outputs. Each input line (K1) is connected to a number of switches (T11, T12, T13, T14), this number corresponding to the number of transducer elements of a group. The switches of the switch matrix are activated through a control circuit (50) over a number of control lines (L1, L2, L3, L4), this number corresponding to the number of transducer elements of a group.