The invention provides for a method of pipetting samples using a pipetting device including more than one pipetting unit. The analog IF signal includes a first carrier having a first frequency and a first bandwidth and a second carrier having a second frequency different from the first frequency and a second bandwidth. Ultrasonic waves reflected on an object are received by the acoustic matching member and converted into electrical signals in the piezoelectric element. A top connecting plate connects a top contact area of the second chip and a top contact area of the third chip to an outer pin of the first leadframe.