Comprehensive design considerations for 2D matrix arrays

KLM and FEM (PZFLEX) models were used to compare piezoelectric materials in 2D matrix transducer designs, including PZT5H, high dielectric ceramics, single crystal, and multilayer PZT. The 5-layer PZT configuration demonstrated the best performance (10+dB more transmit sensitivity) for the impedance transformation effects. The PMN-PT single crystal array has higher bandwidth and consumes less dynamic power (power loss due to charging/discharging an element capacitor) and is more favorable than other PZT materials in a 2D matrix array. The disadvantages for the single crystal are low depoling voltage and low depoling temperature. The high dielectric ceramics had better transmit efficiency than PZT5H. The receive SNR for the three types of piezoelectric material and multilayer PZT were not much different in case of optimal preamp design available, i.e., when the preamp noise source impedance matches element impedance. The 2D FEM model demonstrated irregular angular response due to cross talk of a flex layer on top of the elements for a half lambda pitch 2D array. A 1.7 lambda pitch and 3.5 MHz 2D array was built and tested for pulse echo and angular response.