A high-performance, broad-band antenna that is small enough to be used in an array for biomedical imaging, yet has an aperture large enough to allow operations in the 1 GHz to 2.7 GHz frequency range. The present antenna advantageously uses a Vivaldi antenna with unique lobe designs to provide a small antenna that provides excellent near field imaging. The ends of each lobe have a tilted half-disc shape that increases the aperture of the antenna without increasing overall size. Other unique features of the lobes include exponential structures and an impedance matching design. Multiple units of the present antipodal Vivaldi antenna can be used in an array of antennas. Such an array, or stack or multiple arrays, can be used in many microwave applications for biomedical imaging.
