Abstract
In this study, one method of using antennas based on fractals to cover few kinds of public protection and disaster relief (PPDR) communications was presented. Dedicated antenna forms, necessary for antenna design by 5G implementation, were enhanced to suit the requirements of specific applications. Employing fractal-shaped antennas have allowed us to accomplish all these actions, which request compact, conformal, and broadband high performance devices. Antennas derived from Koch’s curve fractals are studied. In order to implement PPDR communications in 5G technology, frequency bandwidths of importance have been carefully selected and properly included in the antenna developments under MATLAB environment. Important information necessary for antenna designers, such as 360 degrees directivity at various frequencies, the impedance (resistance and reactance) along the bandwidth of interest, as well as voltage standing wave ratio (VSWR) along the bandwidth of interest for dipole, one-iteration, and two-iteration Koch’s curves, respectively, have been obtained. The characteristic of directivity at selected frequencies is also highlighted. In order to maximize antenna parameters, this study has successfully proposed using fractal antennas, objects that use self-similarity property of fractals for optimum operation in several frequency ranges. For the studied antennas, we have obtained the following results regarding the maximum gains in dBi (which is the unit of the ratio between the gains of the antenna compared to the gain of an isotropic antenna). For the dipole antennas, the gains are 2.73 dBi and 4.76 dBi at 460 MHz and 770 MHz, respectively. The gains for one-iteration fractal Koch antenna are 6.91 dBi and 4.51 dBi at 460 MHz and 770 MHz, respectively, and finally, for two-iteration fractal Koch antenna, the gains are 4.91 dBi and 3.28 dBi at 460 MHz and 770 MHz, respectively. Moreover, the impedance along the bandwidth is approximately 360 Ohms for two-iteration fractal Koch antenna, 180 Ohms for one-iteration fractal Koch antenna, and 140 Ohms for dipole antenna, respectively.
Highlights
Today, the modern society needs more and more information
The results obtained using our developed MATLAB programs are presented, in specific frequency bandwidth carefully chosen in order to implement public protection and disaster relief (PPDR) communications in 5th generation (5G) technology. erefore, the reader is given an overview of important information necessary for antenna designers, such as 360 degrees directivity at various frequencies, the impedance along the bandwidth of interest, as well as voltage standing wave ratio (VSWR) along the bandwidth of interest for dipole, oneiteration, and two-iteration Koch’s curves, respectively. e characteristic of directivity at selected frequencies is highlighted. e study concludes in the sixth chapter
In order to implement PPDR communications in 5G technology, few bandwidths were suggested by ANCOM in Romania [14]: 452.5–457.5 MHz, 462.5–467.5 MHz, 753–758 MHz, and 788–791 MHz
Summary
The modern society needs more and more information. Apparently, individual customers, the government, have a fabulous appetite for information repositories. Whether we talk about access to entertainment information or to PPDR (public protection and disaster relief ) information, links to information sources are not allowed, from the customer’s point of view, to have delays or inability to access them At this moment, each of us has a smart communications terminal through which we access applications to facilitate our daily activities. Us, in order to optimize the production costs, in this document, it is proposed to design a fractal-shaped antenna that can be used for communications in different frequency bands. The results obtained using our developed MATLAB programs are presented, in specific frequency bandwidth carefully chosen in order to implement PPDR communications in 5G technology. The results obtained using our developed MATLAB programs are presented, in specific frequency bandwidth carefully chosen in order to implement PPDR communications in 5G technology. erefore, the reader is given an overview of important information necessary for antenna designers, such as 360 degrees directivity at various frequencies, the impedance along the bandwidth of interest, as well as voltage standing wave ratio (VSWR) along the bandwidth of interest for dipole, oneiteration, and two-iteration Koch’s curves, respectively. e characteristic of directivity at selected frequencies is highlighted. e study concludes in the sixth chapter
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