Performance and characterization of new micromachined high-frequency linear arrays.
A new approach for fabricating high frequency (> 20 MHz) linear array transducers, based on laser micromachining, has been developed. A 30 MHz, 64-element, 74-microm pitch, linear array design is presented. The performance of the device is demonstrated by comparing electrical and acoustic measurements with analytical, equivalent circuit, and finite-element analysis (FEA) simulations. All FEA results for array performance have been generated using one global set of material parameters. Each fabricated array has been integrated onto a flex circuit for ease of handling, and the flex has been integrated onto a custom printed circuit board test card for ease of testing. For a fully assembled array, with an acoustic lens, the center frequency was 28.7 MHz with a one-way -3 dB and -6 dB bandwidth of 59% and 83%, respectively, and a -20 dB pulse width of -99 ns. The per-element peak acoustic power, for a +/- 30 V single cycle pulse, measured at the 10 mm focal length of the lens was 590 kPa with a -6 dB directivity span of about 30 degrees. The worst-case total cross talk of the combined array and flex assembly is for nearest neighboring elements and was measured to have an average level -40 dB across the -6 dB bandwidth of the device. Any significant deviation from simulation can be explained through limitations in apparatus calibration and in device packaging.
Lukacs
Marc
M
Imaging Research, Sunnybrook and Women's College Health Science Centre, University of Toronto, Toronto, ON M4N 3M5, Canada. lukacs@sten.sunnybrook.utoronto.ca
Yin
Jianhua
J
Pang
Guofeng
G
Garcia
Richard C
RC
Cherin
Emmanuel
E
Williams
Ross
R
Mehi
Jim
J
Foster
F Stuart
FS
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D016014:Linear Models; D008904:Miniaturization; D011846:Radio Waves; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*