ULTRASONIC DIAGNOSTIC EQUIPMENT AND TRANSMISSION SIGNAL GENERATION METHOD

摘要

PROBLEM TO BE SOLVED: To generate various transmission waveforms without storing various original waveforms in a waveform memory. SOLUTION: AωLUT (angular frequency LookUp Table) 44 stores an angular frequencyωcorresponding to each time value (t). An integrator 46 calculates the angular frequency and generates a phase angleθthereby. A sinLUT 52 equivalent to the waveform memory stores the original waveform composed of amplitude values in an example. If the phase angleθis applied thereto, the amplitude value corresponding to the phase angle is output. The frequency can be thus freely varied and modulated by appropriately setting angular frequency characteristics. The sinLUT 52 stores a sine wave for a single period alone so as to reduce a memory capacity. Weighting in the time axis direction can be performed by weighting. COPYRIGHT: (C)2005,JPO&NCIPI