Barker coded excitation using pseudo chirp carrier with pulse compression filter for ultrasound imaging

Inhalt:
A novel Barker coded excitation using pseudo chirp carrier (called Pchirp-Barker) is proposed for improving ultrasound imaging quality in terms of axial resolution and signal-to-noise ratio (SNR). In this study, a pseudo chirp pulse with proper (<5.5) time-bandwidth (TB) product is considered as the carrier. Pulse compression filter is also developed that is formed by the pseudo chirp matched filter convoluted with the Barker code mismatched filter. In the simulation, the pulse compression filter is well performed to suppress sidelobes below -40 dB roughly. Simulation results show that in comparison with conventional Barker coded excitation using sinusoid carrier (called Sinusoid-Barker), the axial resolution of Pchirp-Barker coded excitation is doubly improved with the SNR loss of less than 1 dB. And the SNR can be improved by about 4 dB with the same axial resolution. Simulation of B-mode images with the Field II program is carried out to demonstrate that the axial resolution is improved from 0.7 mm to 0.4 mm. In addition, the Pchirp-Barker coded excitation has the advantages of binary-coded waveform and simple pulser.