Harmonic distortion reduction technique of the power amplifier for very high frequency ultrasonic transducer applications

Power amplifiers are used to trigger the transducers in order to generate the acoustic waves into the desired target. The resolution of the ultrasound imaging systems is related with the sensitivity of the transducers so the high voltage output signals of the power amplifiers are required to be used to drive the transducers. Therefore, a linear power amplifier is more attractive choice because of its higher dynamic range of the output signals. The novel pre-distortion circuit using the passive resistor, capacitor and inductor components with a power MOSFET device was designed to enhance the dynamic range of the power amplifiers. The dynamic range of the power amplifiers is defined as the characteristic to amplify an input signal with less distortion. This characteristic can be improved by reducing the harmonic distortion components of the high voltage signals produced by the power amplifiers.