Analysis of chirp transducers using a circuit model approach

The authors present a method of calculating the electrostatic charge distribution on in-line and slant chirp transducers with apodization by using a circuit model approach. The charge distribution is used to find the conductance of the transducer along with the frequency response of the device. The results are compared with experimental data. The circuit model approach requires the chirp transducer to be transformed into a large number of small periodic electrodes, each representing a node of the circuit. The model assumes that capacitors are connected between nodes. The values of these capacitors vary according to the distance between the small electrodes. The voltage distribution is then computed, and, as a result, the charge distribution is easily obtained. Apodization is accounted for by dividing the transducer into tracks