An Octagonal Ring-shaped Parasitic Resonator Based Compact Ultrawideband Antenna for Microwave Imaging Applications

Abstract

An Ultrawideband (UWB) octagonal ring-shaped parasitic resonator-based patch antenna for microwave imaging applications is presented in this study, which is constructed with a diamond-shaped radiating patch, three octagonal, rectangular slotted ring-shaped parasitic resonator elements, and partial slotting ground plane. The main goals of uses of parasitic ring-shaped elements are improving antenna performance. In the prototype, various kinds of slots on the ground plane were investigated, and especially rectangular slots and irregular zigzag slots are applied to enhance bandwidth, gain, efficiency, and radiation directivity. The optimized size of the antenna is 29 × 24 × 1.5 mm 3 by using the FR-4 substrate. The overall results illustrate that the antenna has a bandwidth of 8.7 GHz (2.80-11.50 GHz) for the reflection coefficient S 11 < −10 dB with directional radiation pattern. The maximum gain of the proposed prototype is more than 5.7 dBi, and the average efficiency over the radiating bandwidth is 75%. Different design modifications are performed to attain the most favorable outcome of the proposed antenna. However, the prototype of the proposed antenna is designed and simulated in the 3D simulator CST Microwave Studio 2018 and then effectively fabricated and measured. The investigation throughout the study of the numerical as well as experimental data explicit that the proposed antenna is appropriate for the Ultrawideband-based microwave-imaging fields.Sensors 2020, 20, 1354 2 of 20 technicians [6]. Therefore, it is indispensable to develop a novel imaging method to detect cancer, tumor, etc. in the human body without harmful. Last few decades, the alternative technique that is MWI has been recommended as safe to prevailing medical imaging techniques together with mammography, X-ray, ultrasound, and MRI [7]. MWI is an innovative technique, which fascinates enormous interest in medical diagnostic areas, for instance, breast tumor detection, brain tumor detection, early-stage heart failure recognition, health observing, etc. due to its low cost, low profile, portability, and non-ionizing effects. In this methodology, antenna plays a major role as well as acts as a transceiver, in which the transmitting antenna propagates the microwaves and then microwaves travel through the human body. After that, data are composed of the receiving antenna. When microwave signals scattered from dissimilar tissue of the human body, it is possible to distinguish by MWI antenna sensors. In this domain, the radiated and scattered energy is received by the antenna sensor(s) for further processing.The prime working procedure of MWI is to analyze the variance among the electrical characteristics of healthy tissue as well as malignant cells (e.g., breast tumor, brain tumor, etc.) of the human body. In a human body, the fluid of each organic tissue differs, which reasons diverse electrical characteristics. Additionally, the existence of ions, as well as free radicals in the malignant tissues, increases the dielectric loss gradually. Cons...

CPW-Fed Super-Wideband Antenna With Modified Vertical Bow-Tie-Shaped Patch for Wireless Sensor Networks

“…Using the U-shaped feedline, the reported design attained a working band ranging from 3.1-13.2 GHz. The antenna reported in [5] demonstrates better miniaturization with an overall footprint of 580 mm 2 when compared to the patch antenna with modified partial ground plane [7], a diamond-shaped radiating patch with partial multi-slotted ground plane [8], bird face-shaped patch with a single slotted limited ground plane [10], modified slotted U-shaped antenna [11], hibiscus petal-shaped radiator and small trapezoid ground plane [12], modified annular ring-shaped radiator with rectangular semi ground [13], corner truncated rectangular patch with single slotted ground plane [14], the circular patch with iterations of a hexagonal slot [16], annular ring-shaped radiator with small ground plane [18], circular radiator with hexagonal-square-shaped fractal geometry and partial ground plane [20], and semi-circular radiator with small trapezoid ground plane [23]. However, in microstrip line-fed antennas, the space available on both sides of the substrate is not entirely used resulting in elevated fabrication cost during mass production.…”

A Grounded Coplanar Waveguide-Based Slotted Inverted Delta-Shaped Wideband Antenna for Microwave Head Imaging

“…The elliptical slots on the ground distribute the current conduction pathway and enhance the electrical length. Besides, these slots also generating nearly directional radiation due to the extenuation of the surface current [11,42]. Nevertheless, the various modification structures have a significant effect on the gain, directivity, and efficiency.…”

“…This technology is used to head imaging for identifying the head abnormalities such as brain tumor, cancer, stroke, and intracranial hemorrhage [9,10]. Microwave-based technique has the advantage of being lightweight, low-cost, low profile, as well as non-ionizing, compared to other technologies [11]. The key technique of microwave medical imaging (MMI) and identification schemes is that there are dissimilarities in the dielectric characteristics among the healthy(i.e., without malignant tissues) and unhealthy(i.e., with malignant tissues) human head tissues [12].…”

Synthesis, Characterization and Development of Energy Harvesting Techniques Incorporated with Antennas: A Review Study

“…The polarization, frequency band number, antenna gain, and bandwidth are all determined by the shape of the radiator patch (rectangular [72][73][74], circular [75,76], square [77,78], and others [79][80][81]), as well as the feeding technique (position, type, and number of feeds). Plans of various types of techniques for the bandwidth improvement of microstrip topologies have been made: (I) patch modifications generating complex designs to mix various resonant frequency bands [73,75], (II) the addition of radiator patch slots [72,75,79], (III) the insertion to the radiator patch layer of parasitic components [72,79], and (IV) adjustments in the feeding technologies [72,82,83]. [75,76], square [77,78], and others [79][80][81]), as well as the feeding technique (position, type, and number of feeds).…”

“…It is essential to create an adjustable network between the receiving antenna and the antenna rectifier to suit the impedance between the two, which could also minimize the transmission loss and increase the voltage gain [83]. Figure 13 shows an illustration of an antenna and rectifier equivalent circuit.…”