Microwave imaging via space-time beamforming is carried out by
transmitting microwave signals from multiple antenna locations into an
individual to be examined and receiving the backscattered microwave
signals at multiple antenna locations to provide received signals from
the antennas. The received signals are processed in a computer to remove
the skin interface reflection component of the signal at each antenna to
provide corrected signal data. The corrected signal data is provided to a
beamformer process that time shifts the received signals to align the
returns from a scatterer at a candidate location, and then passes the
time aligned signals through a bank of filters, the outputs of which are
summed, time-gated and the power therein calculated to produce the
beamformer output signal at a candidate location. The beamformer is then
scanned to a plurality of different locations in the individual by
changing the time shifts, filter weights and time-gating of the
beamformer process. The output power may be displayed as a function of
scan location, with regions of large output power corresponding to
significant microwave scatterers such as malignant lesions.