A method for detecting an object using a transmitting antenna and an array
of receiving antennas. The method comprises the step of transmitting a
signal from the transmitting antenna. The magnitude and phase of a
respective received signal at each of the receiving antennas is then
measured. Next, the magnitude of a weighted sum of respective
phase-compensated signals related to each of the receiving antennas is
determined. The magnitude of the weighted sum is compared against a first
predetermined threshold value and, optionally, a second predetermined
threshold value. An object may be detected by considering a ratio of the
magnitude of the weighted sum to the first predetermined threshold value
and, optionally, to the second predetermined threshold value. In some
embodiments, a second array of receiving antennas may be provided to
facilitate the determination of the location of the object.