Integrated SFCW Transceivers for UWB Breast Cancer Imaging: Architectures and Circuit Constraints

We present a behavioral analysis of two different transceiver architectures for UWB breast cancer imaging employing a SFCW radar system. A mathematical model of the direct conversion and super heterodyne architectures together with a numerical breast phantom are developed. FDTD simulations data are used on the behavioral model to investigate the limits of both architectures from a circuit-level point of view. Insight is given into I/Q phase inaccuracies and their impact on the quality of the final reconstructed images. The result is that the simplicity of the direct conversion makes the receiver more robust towards the critical circuit impairments for this application, that is the random phase mismatches between the TX and RX local oscillators.