UWB Active Antenna for Microwave Breast Imaging Sensing Arrays

An ultrawideband (UWB) active slot antenna for tissue sensing arrays is developed and measured to operate from 3 to 8 GHz. The sensing element reported here is to be used in the imaging of the breast. It integrates a low-noise amplifier (LNA) with a printed-slot antenna to achieve gain enhancement of about 20 dB. The first prototype integrates the biasing of the LNA on the same board as the antenna. The second prototype uses an external bias tee providing dc power to the LNA through the coaxial connector of the active antenna. Both prototypes achieve the expected gain enhancement in comparison with the passive antenna element.