Frequency scanning probe for microwave imaging

In order to easily introduce a scanning probe for data acquisition in microwave imaging systems, a frequency steering microstrip antenna array operating from 15 to 18 GHz has been proposed. Aperture coupled microstrip antennas have been used as individual radiators in order to avoid the detrimental influence of the spurious radiation produced by the feeding network. The behaviour of the antenna has been evaluated through measurements in the anechoic chamber, obtaining a scanning range Aθ = 30°, with a 3 dB beamwidth under 8°. The secondary lobes are below -7 dB throughout all the range.