High Frequency Annular Transducer Digital Beam Focus Technology

In the ultrasound diagnosis, in order to observing the smaller configuration andorganization, it demands rising the ultrasound frequency and realizing ultrasoundbeam focus. We adopt 10MHz high frequency annular transducer to achieve digitalbeam focusing. The transducer transmits synchronal pulse from the programminglogic chip EP1C12Q240C8. The trigger produces high voltage to inspirit thetransducer emitting ultrasound pulse. In the experiment, we use the nylon line as thedetected target. The ultrasound echo is changed to electric signal, then filtered andchanged the amplitude to 40dB gain by the chip AD8332. The chip AD9238 samplesthe ultrasound echo with the speed in 40MHz, and the five digital echoes enter theprogramming chip EP1C12Q240, which constructs five FIFO to storage the fivedigital ultrasound echoes. We control the digital ultrasound echo output according tothe delay time, the in-phase digital echoes added by the adder to achieve the fivedigital beam focused. Finally the focused digital echo is exported to the highfrequency D/A chip AD9772A to validate the result.The experiment result indicates that adopting the phased control technology,many focuses can be achieved in the beam axis, which reduces the 3dB width of theultrasound beam and improves the image resolving power.