Pulser for arbitrary width and position square pulse trains generation

Abstract

Special kind of Spread Spectrum excitation is analyzed: trains of arbitrary position and width pulses (APWP). Such signals are easy to generate and to handle in digital domain. They offer an advantage over a single pulse: spectral response has no dips and posses higher that single pulse energy, yet being capable of short duration after matched filer compression. Pulser design for such signals generation is described. In order to have the electrical power consumption economy, both high and low - pulling elements are active. Such decision would allow to save the energy when pulser is loaded with capacitive (piezoceramic transducers, capacitive micromachined ultrasonic transducers, CMUT) or inductive load (electromagnetic acoustic transducer, EMAT). In order to evaluate the amount of energy consumed theoretically and real generator performance, energy per pulse was suggested as comparison parameter. Reasoning for output topology, element parameters is given. Pulser structure is described. Investigation of prototype performance is given. Output signal waveforms, energy per pulse performance is presented.