Three-dimensional super-wideband micro-antenna for high-resolution millimeter-wave medical imaging

This paper reports on a novel super-wideband micro-hemispherical antenna with application in millimeter-wave medical imaging. The antenna is composed of a hemispherical shell suspended above a substrate and can be fabricated using a fabrication technology originally developed for micron-scale electromechanical resonators. The antenna exhibits a wide fractional bandwidth of more than 80% (from 64 GHz to 150 GHz) and a high gain of 8.6 dBi at its center frequency. Radiation parameters of the antenna are characterized and the effect of its super-wideband behavior on pulsed millimeter-wave imaging is demonstrated. Finally, a preliminary array configuration composed of two antennas placed side-by-side in the vicinity of a skin-mimicking target is evaluated and the ability to fully detect the target has been demonstrated.