A new Compact Ultra-Wideband Circularly Tapered Vivaldi Antenna with Director (CTVAD) for microwave-based breast tumour detection system is presented. By adding the slots on the back wall offset and introducing the directors at the centre of the radiating aperture facilitate focusing the E field distribution to the centre of the aperture which in turn helps to achieve narrow beam width and high gain. Compared with the other antennas, the proposed CTVAD is compact of size 48 mm × 45.7 mm and improves the impedance bandwidth with reduced sidelobe level. The measured results show that the return loss is significantly improved in the frequency band (3.1 GHz–10.6 GHz). A unidirectional radiation pattern, flat group delay, system fidelity factor greater than 90% and FBR value more than 9 dB are achieved. Furthermore, a 3-D breast model with a spherical tumour of size 5 mm is designed using the software CST microwave studio and it is illuminated by 2 × 10 proposed CTVAD antenna array and the backscattered signals are recorded. Then the image reconstruction algorithm is implemented with the help of MATLAB software to form the image of the backscattered energy. The imaging results suggest that CTVAD antenna is a suitable candidate to construct a device that can detect breast tumour.

提出了一种新的紧凑型超宽带环形锥形维瓦尔第带导向器天线（CTVAD），用于基于微波的乳腺肿瘤检测系统。通过在后壁偏移量上增加狭缝，并在辐射孔的中心引入引向器，有助于将电场分布聚焦到孔的中心，进而有助于实现较窄的光束宽度和高增益。与其他天线相比，拟议中的CTVAD尺寸紧凑，尺寸为48 mm×45.7 mm，并在减小旁瓣电平的情况下提高了阻抗带宽。测量结果表明，在3.1 GHz–10.6 GHz频带内，回波损耗得到了显着改善。实现了单向辐射方向图，平坦群延迟，系统保真度大于90％和FBR值大于9 dB。此外，使用CST微波工作室软件设计了一个球形肿瘤，大小为5 mm的3-D乳房模型，并使用2×10个建议的CTVAD天线阵列对其进行照明，并记录了反向散射信号。然后借助MATLAB软件实现图像重建算法，以形成反向散射能量的图像。成像结果表明，CTVAD天线是构建可以检测乳腺肿瘤的设备的合适候选者。