Increased frame rate for linear array imaging using novel frequency modulation scheme

The search for an increase in medical imaging frame rate has been on-going for decades. A number of coding techniques may be applied based on simultaneous transmission from multiple sub-apertures. Linear frequency modulated (LFM) signals or chirps is a coding technique with the ability to enhance the SNR but the coding diversity is limited, for example up chirp and down chirp. In this paper the cross-correlation properties are explored for the LFM and a closely related variant employing a sinusoidal frequency modulation (SFM). As well as offering a novel type of excitation, that behaves similarly to a standard chirp, the SFM also yields similar cross-correlation to chirps of opposite rate.