3-D Wideband Antenna for Head-Imaging System with Performance Verification in Brain Tumor Detection

A 3-D slot-rotated antenna for a microwave head- imaging system is presented. The antenna is designed to have a wideband and unidirectional performance at the low microwave frequency band that are the requirements of the specified imaging system. Starting from a traditional wide-slot antenna, several conventional techniques are applied to enhance its bandwidth and directivity while miniaturizing its size. In that regard, four series of staircase-shaped slots are applied to lower the operating frequency, whereas a folding process is used to enhance the directivity and reduce the overall size. In addition, two parasitic patches are connected to the slot area to increase the operating bandwidth. The final design has the dimensions of 0.11 λ×0.23 λ×0.05 λ. ( λ is the wavelength of the lowest measured operating frequency.) It has a measured VSWR fractional bandwidth of 87% (1.41-3.57 GHz) and a peak front-to-back ratio of 9 dB. To verify the suitability of the antenna in head imaging, it is connected to a wideband microwave transceiver and used to circularly scan an artificial head phantom in 20^° angle steps in a monostatic mode. The collected backscattered data are then processed and used to generate an image that successfully shows brain tumors. The compact size, wide operating bandwidth, unidirectional radiation, and detection viability are merits of the presented antenna and the subsequent system.