Using dispersive delay lines and time reversal for low contrast tumour detection

On the basis of the technique of time reversal (TR), through adding dispersive delay lines to each element of a TR mirror, a method for low contrast tumour detection is proposed. When compared with a conventional detection method, the proposed method improves refocusing onto a low dielectric contrast tumour. The method does not require an accurate estimate of the position of the tumour. The theoretical basis for the approach is given and numerical simulated results demonstrate the capability of the proposed method.