Ultra‐wideband antenna using Minkowski‐like fractal geometry

Abstract

In this letter, a Minkowski‐like fractal geometry‐based ultra‐wideband (UWB) monopole antenna is proposed and investigated. The radiator of the antenna is designed using similar segments of the Minkowski‐like structure. The multiple resonance phenomena of fractal geometry are utilized in the proposed structure to obtain the wideband operability by repetition of similar segments in the radiator structure of the antenna. The self‐similar nature of this geometry provides higher effective antenna length and wide operating bandwidth. The multiple slots are introduced in the ground plane to improve the reflection coefficient over the entire UWB frequency range. The proposed antenna has an optimized dimension of 23.5 × 26.5 mm2 and shows the operating bandwidth from 1.4 to 10.4 GHz. The proposed design is fabricated, and its measured result shows good agreement with the simulated one. The proposed antenna exhibits nearly omnidirectional radiation pattern, proper impedance matching over the entire UWB frequency range. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2273–2279, 2014

An Overview of Uwb Antennas for Microwave Imaging Systems for Cancer Detection Purposes

“…There are other prototypes with slightly better characteristics such as gains and bandwidths, but they use fractal techniques [23][24][25][26]. However, the dimensions are increased considerably compared to the one presented by Afifi et al (10 × 10 mm 2 ) [20], and the performance of this UWB antenna is dependent on the fractal patch, feeding, slots on the partial ground plane achieving approximately gains of 4 dB, and omnidirectional radiation patterns.…”

“…One of the main challenges in the design of these antennas is related to the physical size in order to allow a greater number of antennas to collect more information of the scattered signal for a successful image reconstruction, as well as to achieve a wider bandwidth to get a high-resolution image [20] and reduce the distortion in transmission of short-duration pulses [21]. Several antennas were proposed for cancer detection as monopole antennas [14,22], fractal antennas [23][24][25][26], antipodal Vivaldi antennas [27], slot antenna [28,29], and patch antenna [30], as will be described below.…”

“…The metamaterial unit cells are inserted on the Figure 17. UWB fractal antennas: (a) 4th iteration [23], (b) 4th iteration [24], (c) 3rd iteration [25], and (d) Minkowski-like geometry [26].…”

Microstrip line‐fed fractal antenna with a high fidelity factor for UWB imaging applications

“…Nowadays, there has been an expanding quantity of literature on fractal UWB antennas depending on self‐similarity and space filling property that contain many advantages such as multiband, broadband, and UWB properties, miniaturization of antenna dimension. In , a square shape fractal antenna of electrical dimension 0.47 λ × 0.47 λ at 2.355 GHz low frequency is proposed for wireless communications, medical imaging, and UWB applications.…”

“…In , a fractal antenna of electrical dimension 0.24 λ × 0.28 λ is proposed in an iterative fashion based on self‐similar structure. An UWB monopole antenna of 0.11 λ × 0.12 λ electrical dimension is presented using Minkowski‐like fractal . A trapezoid UWB antenna of 0.25 λ × 0.25 λ electrical dimension is narrated using Sierpinski sieve fractal .…”