Homogenizing microwave illumination in thermoacoustic tomography by a linear-to-circular polarizer based on frequency selective surfaces

作者：He, Yu; Shen, Yuecheng; Feng, Xiaohua; Liu, Changjun^*; Wang, Lihong V.^*

来源：Applied Physics Letters, 2017, 111(6): 063703.

DOI：10.1063/1.4993942

• BREAST-CANCER
• FEASIBILITY
• SYSTEM

A circularly polarized antenna, providing more homogeneous illumination compared to a linearly polarized antenna, is more suitable for microwave induced thermoacoustic tomography (TAT). The conventional realization of a circular polarization is by using a helical antenna, but it suffers from low efficiency, low power capacity, and limited aperture in TAT systems. Here, we report an implementation of a circularly polarized illumination method in TAT by inserting a single-layer linear-to-circular polarizer based on frequency selective surfaces between a pyramidal horn antenna and an imaging object. The performance of the proposed method was validated by both simulations and experimental imaging of a breast tumor phantom. The results showed that a circular polarization was achieved, and the resultant thermoacoustic signal-to-noise was twice greater than that in the helical antenna case. The proposed method is more desirable in a waveguide-based TAT system than the conventional method. Published by AIP Publishing.

• 出版日期2017-8-7
• 单位四川大学