With the prevalence of breast cancer among women and the shortcomings of conventional techniques in detecting breast cancer at its early stages, microwave breast imaging has been an active area of research and has gained momentum over the past few years, mainly due to the advantages and improved detection rates it has to offer. To achieve this outcome, specifically designed antennas are needed to satisfy the needs of such systems where an antenna array is typically used. These antennas need to comply with several criteria to make them suitable for such applications, which most importantly include bandwidth, size, design complexity, and cost of manufacturing. Many works in the literature proposed antennas designed to meet these criteria, but no works have classified and evaluated these antennas for the use in microwave breast imaging. This paper presents a comprehensive study of the different array configurations proposed for microwave breast imaging, with a thorough investigation of the antenna elements proposed to be used with these systems, classified per antenna type, and per the improvements that concern the operational bandwidth, the size of the antenna, the radiation characteristics, and the techniques used to achieve the improvement. At the end of the investigation, a qualitative evaluation of the antenna designs is presented, providing a comparison between the investigated antennas, and determining whether a design is suitable or not to be used in antenna arrays for microwave breast imaging, based on the performance of each. An evaluation of the investigated arrays is also presented, where the advantages and limitations of each array configuration are discussed.

This paper presents a new approach for the design of a multi-wideband microstrip-patch antenna. The radiating elements in this antenna are composed of rectangular slots following a Chebyshev distribution of order 10 around a center rectangular slot, and an additional triangular slot. These slots are engraved in the rectangular and triangular patch, joined together in one structure, and fed by one probe feed. A sample antenna was analyzed, simulated, fabricated, and tested. There was good agreement between the computed and test results. The new antenna can be used for several applications, especially in the GSM domain, and for Wi-Fi, Bluetooth, and several other applications, as detailed in this paper.

This letter presents a new approach for the design of a multiresonant printed bowtie antenna. Several techniques were attempted to obtain one antenna which is operational in the 2, 3, and 5 GHz bands corresponding to many wireless applications. The idea of creating different slot configurations on different parts of a single antenna is the basic principle. A prototype of the final antenna design was fabricated tested and a good agreement was found between simulated and tested results.

This paper proposes a simple and novel design for breast cancer detection, sizing and localization. A miniature-sized antenna of volume 10 $ \times $ 10 $ \times $ 1.6 $\mathrm{m}{\mathrm{m}}^3$ is designed at an optimized frequency of 7.98 GHz with a positive gain using the fractal theory; it is based on two nested folds connected to each other using repeated lines, discs and circles. It exhibits a reflection coefficient of −39 dB over a simulated bandwidth of 340 MHz; it has a gain of 1.04 dB and an efficiency of around 70%. This prototype is fabricated and its S ₁₁ is measured to get an operational frequency of 8.08 GHz with same S ₁₁ and bandwidth values. The insertion of slots in the antenna design improved its performance to get a higher ${\mathrm{f}}_{\text{op}}$ of 8.21 GHz and an improved gain of 2.43 dB. The SAR value of the antenna is found to be around 1.4 W/Kg at a safe separation distance of 60 mm from the breast. As an array, it proved its ability to detect the presence of the tumor, its size and position. This is simply achieved by plotting the propagating E-field that is induced inside the breast. The main advantage of this system lies in the fact that it does not require any long-time complicated image processing. By observing E-field plots, it is seen that the $| {{\mathrm{E}}_{\mathrm{x}}} |$ decreased from 8.37 V/m to 1.91 V/m. As for the $| {{\mathrm{E}}_{\mathrm{y}}} |$ , it increased from 2.72 V/m to 4.12 V/m; both comparisons made between healthy and cancerous tissues, respectively. Simulations are conducted in HFSS; the antenna proved to be a good candidate for breast tumor detection, sizing and localization systems.