## 1 Introduction  
Breast cancer is the most common type of cancer in women and is responsible for the second highest number of deaths worldwide [1]. In general, breast cancer accounts for 30 percent of cancers. Breast cancer causes 15 percent of cancer-related deaths [2]. The World Health Organization's goal is to prevent 2.5 million deaths worldwide between 2020 and 2040 by reducing the number of global breast cancer deaths by 2.5% per year. Thus, it is predicted that the number of deaths from breast cancer in women under the age of 70 will decrease by 25% by 2030 and by 40% by 2040. The most important aspect to achieve these goals is early diagnosis [3]. Early diagnosis of cancer is the main factor in reducing deaths caused by breast cancer [4; 5]. There are traditional imaging methods used in the early diagnosis of breast cancer. It is important to screen patients with these methods and detect cancer at an early stage [6]. Imaging methods such as ultrasound, positron emission tomography (PET), mammography, and magnetic resonance imaging (MRI) are important imaging tools in cancer detection [7; 8; 9; 10]. Besides the advantages of these imaging techniques, there are also various disadvantages. Mammography imaging is the most commonly used method (two screenings per year) and is good at detecting mammary gland calcification and is not suitable for people with high gland density. Screening is performed by compressing the breast and has a carcinogenic effect [11; 12]. Ultrasound, which is a painless imaging technique, does not have high resolution and is not suitable for small masses [13]. MRI imaging is expensive and time-consuming and has high resolution. It is also not suitable for those who are sensitive to contrast agents [14; 15]. Although PET imaging is good for detecting cancer stages, it is not suitable for screening because of its limited ability to detect tumors with low metabolic activity. In addition, radioactive tracers are used in the screening process [16; 17]. Microwave imaging has emerged as a promising alternative for breast tumor diagnosis to overcome the disadvantages of traditional imaging techniques [12]. Microwave imaging is an imaging technique that is cheap, painless, suitable for rapid screening, does not have the effect of ionizing radiation, and does not require contrast agents [11; 12; 16; 18; 19]. Microwave imaging detects differences in the dielectric properties of healthy and cancerous tissues in the breast [13; 20; 21; 22; 23]. It uses non-ionizing electromagnetic waves to examine tumor detection based on scattering. This has led to the development of microwave imaging techniques and has gained importance in recent years [24]. The dielectric properties of tumor tissues in the microwave spectrum significantly change their conductivity compared to normal tissue, and the tumor can be detected. The frequencies of biological tissues are not the same due to differences in water content [25; 26; 27]. Since there are frequency differences, benign and malignant tumors can be classified structurally. This can enable the detection of cancer in the initial stage (maximum tumor size of 20 mm) [28]. The structures of the tumor in stages can be listed as follows: tumor shape, edges, surface texture, and depth. Malignant tumors show features such as irregular and asymmetric shape, blurred borders, and rough and complex surface due to microlobules. Benign tumors show features such as spherical, oval, or regular shape, compactness, and smoother surface [29]. These features can help categorize the tumor in microwave imaging. The radar-based microwave breast cancer imaging (RMWBI) technique involves solving a nonlinear inverse scattering problem to reveal the electrical properties of tissues [30]. Extensive patient studies have been conducted with RMWBI since the 1990s [31; 32]. The purpose of RMWBI is to detect and localize tumors. In microwave hyperthermia tumor detection, dipole antennas focus energy on the tumor using electromagnetic waves.