The embodiments of the probe include a preprocessing unit that is directly connected to a first predetermined number of the receiving elements for preprocessing the channel signals to generate preprocessed channel signals as well as a switch unit that is connected to the preprocessing unit for connecting the preprocessed channel signals into a predetermined number of output channel signals. In the above embodiments, the second predetermined number is smaller than the first predetermined number. In addition, the embodiments of the probe also include an analog-to-digital converter connected to the switch unit for converting the output channel signals into digital signals, and a dynamic range of the analog-to-digital converter is related to a ratio between the second predetermined number and the first predetermined number.
