Microwave imaging is an efficient technique that can be used for the early detection of breast cancer. Therefore the current research article presents the microwave imaging of two spherical tumors (radius 4 and 5 mm) in the breast phantom by using the monostatic radar-based technique. This is carried out by using an ultra-wideband (4.9–10.9 GHz), three-layered stacked aperture coupled microstrip antenna (SACMPA) with a defected ground structure to scan the breast phantom and make near field S parameter measurements from a breast phantom. The S parameter data from different locations and at different time intervals are noted and then used in a beam-forming algorithm; Delay and Sum to process it and form a 2D image of the tumor location in the breast phantom using MATLAB.
The proposed SACMPA is a three-layered structure with overall dimensions of 37 × 43 × 4.85 mm3 that shows an impedance bandwidth of 6 GHz (4.9–10.9 GHz) and a simulated peak gain of 6.32 dB at a frequency of 9.1 GHz. The validation of S parameters and gain results are done using a Vector Network Analyzer (VNA) and an anechoic chamber. The experimental validation of the proposed microwave imaging procedure is done by allowing the SACMPA to radiate parallel to the breast phantom made from polythene (skin), petroleum jelly (fat), and wheat flour (with water as tumor) and record the S parameters on the VNA. The proposed microwave method is safe for human exposure as the antenna also shows simulated specific absorption rates of 0.271 and 1.115 W/Kg (on the breast phantom) at frequencies of 5.7 and 6.5 GHz, respectively (for 1 g of body tissue).
This research article presents a proficient, convenient, and low-cost monostatic radar-based microwave imaging (RBMI) technique for the breast tumor detection. For this, a compact cubical dielectric resonator antenna (DRA) with impedance bandwidth of 8.3 GHz (ie, 4.3-12.6 GHz) has been simulated using CST V 0 17. In proposed monostatic RBMI technique, the designed DRA is placed parallel to the breast phantom and rotated around it at an interval of 10 in elevation plane (0-π) and azimuthal plane (0-2π), respectively; first, without and then with tumor inside the breast phantom. Total 1080 back-scattered signals are recorded for the entire impedance bandwidth, and processed for microwave imaging. For the validation of results, fabricated antenna is rotated around the artificial breast mimic. The artificial breast mimic is made up from gelatin (skin), petroleum jelly (fat), and wheat flour (tumor). The backscattered signals from the artificial breast phantom have been recorded on the vector network analyzer model no. E5063A for both the cases that is, with absence and presence of tumor at different position and time intervals. The recorded S-parameters have been processed in two beam-forming algorithms; delay and sum (DAS), delay multiply and sum (DMAS). These signals are then converted into digital data and processed in the MATLAB, to visualize the 2D image of the scanned area to detect the breast tumor. By comparing the reconstructed images, it is concluded that the DAS algorithm provides just a clue about the presence of the tumor, but DMAS provides the accurate position and size of the breast tumor.
Thulium-doped fiber amplifier is a very proficient broadband fiber amplifier in S-band. Silica-based TDFA is a popular choice due to some of its evident features such as non-toxic nature, easy splicing and simple assembling. In this work, we have simulated and optimized various TDFA’s physical and operational parameters in order to obtain required gain spectra at different channel spacings. Further, a comparative study has been carried out between single and dual-pumped TDFAs. By using dual pumping scheme (1040 nm and 1000 nm) as fundamental source of excitation, maximum gain of 23.31 dB has been achieved at 1468.8 nm in region spanning 1400 nm to 1470 nm wavelengths with noise figure of 3.72 dB.
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