Vivaldi antenna for early cancer detection based on THz spectroscopy: Comparison between response of breast and skin cancer

Abstract

this paper suggests a Vivaldi antenna for the THz frequency range with a wide bandwidth (more than 120% bandwidth) for early cancer detection with dimensions of 1λ× 0.5λ× 0.034λ for 0.5 THz with special novel arrangement of photonic crystal and taper grating reflector. The photonic crystal walls are implemented on both sides of the antenna to make an electric shield to concentrate energy for increasing the gain and directivity of the antenna and reducing the side lobe. Front to back (F/B) ratio is another problem for this THz antenna where the grating parasitic elements are used as the reflector to reduce the back lobe of the basic antenna. This antenna covers 0.5–2 THz with a maximum gain of 8.8 dB in the broadside. The proposed antenna is used for detecting breast and skin cancers which are modeled by Debye’s second-order model. The reflection and transmission, pulse response, and phase variation for normal and tumor tissue are considered for the reorganization of cancers. The results show that reflection and transmission, pulse responses are not effective factors for breast cancer detection in comparison to skin cancer while the phase response is the best solution for this type of cancer.