Design of a Novel Zig-Zag 192+192 Row Column Addressed Array Transducer: A Simulation Study

Abstract

Super resolution imaging (SRI) can benefit greatly from full 3D imaging to compensate for vessel structures moving out of the image plane. Row Column Addressed (RCA) arrays can provide such 3D imaging with low-complexity probe design. A RCA probe is being designed for a rat kidney with 192 + 192 elements to ensure low sidelobes and an imaging volume of 15×15×15 mm3The design space of such a transducer is investigated with this in mind. Capacitive micromachined ultrasonic transducer (CMUT) technology allows for new geometric shapes, including a near kerf-less zig-zag interwoven structure, which provides flexibility in the design process of new RCA. This work compares the image quality of a straight element RCA array with an RCA array with an interwoven zig-zag structure by simulations, to assess the image quality of a zigzag structured RCA. The Point Spread Function (PSF) showed symmetry in both the azimuth and elevation direction. Both the straight and interwoven design had a lateral Full Width Half Maximum (FWHM) of approximately 0.6 A, close to the ideal FWHM without apodization. The interwoven design showed a slight contrast loss over the straight desig, which was quantified with the Cystic Resolution (CR). The CR at 20 dB for the straight design was 1.3 A, compared to 1.4 $A$ of the interwoven design. The two designs had comparable PSF metrics. The interwoven zig-zag structure is therefore a viable solution to meet the requirements of the rodent experiments and provides a new level of design flexibility for manufacturing RCA transducer arrays.