A Novel Corner Etched Rectangular shaped Ultrawideband Antenna Loaded with Truncated Ground Plane for Microwave Imaging
Authors: Kumar Om Prakash , Ali Tanweer , Kumar Pramod 
Published: June 2022

Abstract
Microwave imaging has become a popular research issue in recent decades as a result of its several benefits over traditional imaging technologies. To analyse biological tissues in depth, a microwave imaging instrument is employed.The test determines the presence and location of morphological alterations in specific biological tissues. Ultrawideband (UWB) microwave imaging is a new technique that produces improved results while avoiding the use of ionizing radiation. Antennas play a critical part in these systems, and as a result, antenna optimization has become a hot topic due to the device's proximity to the human body. Recent research has revealed a number of initiatives to improve the electromagnetic sensors employed in these systems, whether as single or array components. In this article, the development of a compact ultrawideband (UWB) antenna functioning in the frequency range of 3.25-14.63GHz is proposed. The reported antenna comprises of a rectangular patch and a modified ground plane “etched on a FR4” substrate excited by a 50Ω feed line. The overall dimension of antenna is \(0.44 {\lambda }_{0}\times 0.38 {\lambda }_{0}\times 0.02{\lambda }_{0}\). The proposed antenna has been fabricated on FR-4 substrate. Measused and simulated results are in good agreement. The proposed antenna is compact and displays good radiation characteristics along with good gain. 1. INTRODUCTION In recent years, UWB technology has gained significant interest from researchers throughout the globe. In February 2002, the Federal Communication Commission (FCC) released the frequencies of 3.1GHz to 10.6GHz for commercial applications [1]. The design of a UWB antenna requires the antenna to be small and compact, it should have wide bandwidth performance, the radiation pattern has to be Omni-directional and the antenna should be easy to fabricate [2–3]. The benefits of an ultra-wideband antenna are its low complexity and it is inexpensive to manufacture. UWB patch antenna can be designed with various geometries such as circular, triangular, square, or rectangular. UWB technology is applied in several fields such as microwave imaging and radar systems. Microwave imaging utilizes EM waves to see through the inner structure of a tissue. It recognizes tumors based on dielectric properties, which are different compared to normal tissue [4–5]. X-rays, ultrasound, and MRI scans are used in the early detection of cancerous cells [6]. However, these methods pose some disadvantages. X-ray mammography is agonizing for patients, and long exposure to X-ray may cause healthy cells to become cancerous [7]. Another technique used to detect cancerous cells is ultrasound, but this technology is unable to detect deeply buried tumors and it is comparatively expensive [8]. To overcome these limitations, microwave imaging employs low ionizing radiation and is cost-effective compared to other methods [9]. Microwave imaging incorporates the use of UWB pulses which range from “low to high” frequencies in order to generate images of human tissues [10]. The higher frequency band is used to create high-resolution images of the tissue, whereas the lower frequency band is used to detect deeply buried tumors [11]. A microwave imaging system has two parts, a “front end,” which requires the antenna to be inexpensive, compact and it should operate efficiently, whereas the second part requires analyzing the performance of the antenna to detect the tumor and generate the image using the various processing techniques. The need for the antenna to be is compact is because it is to be incorporated into portable microwave imaging systems. This paper overviews the design and optimization of a novel microwave antenna which must serve as an element in a sensor array for early detection. The proposed microstrip patch antenna in this work displays good UWB characteristics and also displays good gain characteristics. The antenna consists of a modified square patch and a ground plane built on a FR4 substrate. Parametric analysis is done on the proposed antenna to observe the effect of various design parameters on the antenna performance, further, the simulations of the current density, gain and radiation pattern are also reported in this paper.