Development of an ultra-wideband, stable and high-directive monopole disc antenna for radar-based microwave imaging of breast cancer

Abstract

ABSTRACTRadar-based ultra-wideband (UWB) microwave imaging (MI) system has recently attracted considerable attention for detection of breast cancer at early stage. A key component of the system is the sensor (antenna) that is used to radiate and receive the UWB pulses. In this study, a compact-size, UWB, directive, and microstrip-fed planar circular disc monopole antenna (PCDMA) with modified L-shaped ground plane for the radar-based UWB MI system is developed. Analysis and the performance optimization of the proposed antenna are performed by HFSS software. In the development process of the antenna design, some modifications such as adjusting feed point, adding parasitic element, slot, notches are made on the conventional PCDMA to improve the bandwidth, directivity and half-power beamwidth (HPBW) of the antenna. After obtaining the optimum parameters, the proposed antenna is fabricated and then tested by using Vector Network Analyser. Impedance bandwidth of the designed antenna covers the broad frequency range of 3–10 GHz (108%) for Return Loss < –10 dB. The good stability of the directional radiation patterns is obtained in the 3–10 GHz. The direction of the maximum radiation moves from 32° to 54° and HPBW decreases from 56° to 30° through the frequency band. The directivity changes between 6.2 and 9.4 dB in the 3–10 GHz. Results confirm that the proposed antenna is suitable for using in radar-based UWB MI of the breast cancer.