Coded excitation waveform engineering for high frame rate synthetic aperture ultrasound imaging.

Coded excitation was initially introduced to ultrasound imaging as a method for enhancing the signal-to-noise ratio (SNR). However, this method was also shown to be helpful in conjunction with synthetic aperture transmission for high frame rate imaging. Recently, we introduced two families of mismatched coded excitations based on frequency modulation chirp and combined frequency modulation and Golay code. Here "mismatched" indicates that the coded excitations generate very small cross-correlations among themselves while each has a very strong autocorrelation. Employing weakly correlated coded excitations enables performing simultaneous insonifications from several elements of the ultrasonic transducer and receiving distinguishable responses to each code. In this work, we propose and experimentally demonstrate another set of mismatched correlated coded excitations based on Golay codes. The generated phase codes share identical duration and center frequency which results in similar SNR and image resolution.