A method of microwave imaging via space-time (MIST) beamforming is proposed for
detecting early-stage breast cancer. An array of antennas is located near the surface of the
breast and an ultrawideband (UWB) signal is transmitted sequentially from each antenna.
The received backscattered signals are passed through a space-time beamformer that is
designed to image backscattered signal energy as a function of location. The beamformer
spatially focuses the backscattered signals to discriminate against clutter and noise while …

Microwave imaging via space-time beamforming has been proposed recently for early-stage
breast cancer detection. In this paper we present an efficient frequency-domain approach to
designing the beamformers. The low-power signal sequentially transmitted into the breast by
each antenna in an array may be either an ultrawideband pulse or a sequence of sinusoidal
signals with carrier frequencies corresponding to the discrete design frequencies.
Backscattered waveforms collected at each transmitting antenna are processed in the …