Figure - available from: International Journal of RF and Microwave Computer-Aided Engineering
This content is subject to copyright. Terms and conditions apply.
Source publication
This article concentrates on the design and analysis of a novel Minkowski fractal‐based antenna design with the aid of triangular dielectric resonator (TDR) elements for wideband wireless applications. mode is excited inside equilateral TDR antenna with the help of coaxial probe feed. Wide impedance bandwidth has been achieved by reducing the quali...
Similar publications
This article explains a novel approach for achieving wideband characteristics in case of dielectric resonator antenna (DRA). Wideband characteristic has been realized by uniting the concept of vastu purusha mandala (VPM)‐based fractal geometry with dielectric resonator antenna. VPM is Hindu religion‐based fractal geometry, which provides the advant...
Citations
... By increasing the volume-to-surface area ratio, fractal geometry minimises the frequency gaps between the higher-order modes. A wideband antenna inspired by the Minkowski fractal configuration, consisting of equilateral triangular dielectric resonator (TDR) elements, is explored [77]. The optimised fractal TDR antenna (ε r = 9.8) is excited by TM z 101 mode via a coaxial probe feeder. ...
... Minkowski fractal-based antenna configuration (a) Top view (b) Measurement results of co-polarisation and cross-polarization radiation patterns at 2.55 GHz[77]. ...
Dielectric resonator antennas (DRAs) use dielectric material as a resonator to accomplish high radiation efficiency and avoid severe conductor loss. The dielectric material that behaves as a resonator is plagued by a number of limitations, including strong cross-polarised (XP) radiation and difficulties integrating with any development platform. Yet, it also offers a lot of benefits, including compact size, lightweight, affordable price, and diversity in form, including cylindrical, rectangular, conical, and ring. A discussion of DRAs, covering DRA propagation modes, geometries, feeding mechanisms, and different bandwidth augmentation approaches, is presented. A stacked arrangement with two or more DRs has achieved the widest impedance bandwidth (BW). The perforated topology is a straightforward alternative for increasing the DRA's bandwidth while maintaining a small, discrete size.
... [13][14][15] Fractal structure is often used to obtain antennas and metamaterials which have excellent EM characteristics. 16,17 In previous works, we first designed a broadband omnidirectional antenna with TM 01 and TM 02 zero-order resonant modes 18 on the basis of the theory of composite rightand left-handed transmission lines. Then, epsilonnegative metamaterial and near-zero index metamaterial (NZIM) are loaded on the top of the antenna as covers to further improve the horizontal gain. ...
In this study, a novel low profile wideband omnidirectional antenna is proposed. Horizontal dimension is utilized by introducing annular patches and near‐zero‐index metamaterials, instead of enhancing horizontal gain through increasing the profile of antenna. Measured results illustrate that horizontal gain of this antenna is enhanced to more than 2.5 dBi with 9.81% relative bandwidth (4.97−5.49 GHz) and low profile (0.034λ). Compared with other works, this novel antenna has obvious advantages in electromagnetic characteristics and physical structure, which has great potential in vehicular communications.
... 10 Several research publications on fractal geometry-based dielectric resonators for wideband and ultrawideband applications are available in the open literatures. [11][12][13][14][15][16][17][18][19][20][21][22] By lowering the surface-to-volume ratio, fractal geometry is paired with DRAs to create broad impedance bandwidth. These articles 11,12 presented fascinating findings but they weren't validated. ...
... 18 The researcher designed a compact structure by removing a half portion of the fractal ring; however, the antenna has a large ground plane. Sur et al. introduced a triangular dielectric resonator antenna based on Minkowski fractals for the WiMAX application, 19 and the prototype is verified. The 32.65% tiny impedance bandwidth of the planned DRA is available. ...
... Table 2 provides a comparison of the results of different fractal-based wideband DRAs. [13][14][15][16][17][18][19][20][21][22][23][24][25][26] The comparative analysis demonstrates that the suggested DRA offers a significantly wider bandwidth while maintaining a compact construction, high peak gain, and good efficiency when compared with existing DRAs in different literatures. It should be noted that there are extremely few DRAs available that combines a fractal structure. ...
This article examines a compact dielectric resonator antenna (DRA) for UWB applications. Here a composite feeding structure excites a dielectric resonator which in tern provides the resonant modes TE111, TE121, TE212, and TE222. The dielectric resonator (DR), built of alumina ceramic (εr, DR = 9.8), is mounted on a fractal triangular patch, inspired by Sierpinski Gasket. The suggested DRA is supported by a FR4 substrate (εr, sub = 4.4) and measures compactly 40 × 30 × 8.5 mm³. To confirm the results of its simulations, the proposed antenna's prototype is prepared and measured up to the second iteration. The measured outcome demonstrates that the suggested antenna has a frequency range of 3.38–10.71 GHz (104%) for S11 < −10 dB and provides a maximum gain of 7.23 dBi at 8 GHz along with highest possible simulated efficiency of 98%. The suggested DRA is appropriate for small‐range future 4G/5G UWB wireless multimedia applications due to its ultrawide bandwidth, excellent gain, reasonable efficiency, omnidirectional radiation features, and compact construction. This DRA is also suitable for repeaters of mobile and vehicular communications.
... 12 The combination of DRA and fractal geometry help overcome individual drawbacks. Fractal DRAs are also investigated by many researchers [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] but suffer from low bandwidth, [13][14][15][16][17][18][19][20][21] for example, 7.1-9.26, 13 2.3845-2.5083 ...
... 12 The combination of DRA and fractal geometry help overcome individual drawbacks. Fractal DRAs are also investigated by many researchers [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] but suffer from low bandwidth, [13][14][15][16][17][18][19][20][21] for example, 7.1-9.26, 13 2.3845-2.5083 ...
... 16 2.23-3.1, 17 2.25-2.60 and 3.10-4.10, 18 5.52-10.72, ...
This communication explains a novel approach for attaining wideband inverted Sierpinski Carpet fractal geometry with a rectangular shape dielectric resonator antenna (DRA). Dielectric Resonators (DRs) have advantages, like, high gain, efficiency, wide bandwidth, low conduction loss, and minimum surface waves. Rectangular shape DR (εrdr = 9.8, 14 × 12 × 8 mm³) made from alumina (Al2O3) is mounted on top of a primary square patch. Inverted Sierpinski fractal geometry provides the benefit to decrease the volume to the surface area without removing elements from the patch. The proposed fractal DRA is printed on an FR4 substrate (εr = 4.4), fed with a 50‐Ω microstrip feed line, and has a compact size of 38 × 38 × 9 mm³. At the backside of the antenna, an extended stub from the partial ground plane enhances impedance matching from 4 to 5 GHz. The prototype of the proposed DRA is fabricated and measured. The antenna functions with an impedance bandwidth of 98.84% for S11 < − 10 dB, covering 3.5–10.34 GHz of the ultrawideband range. The proposed DRA offers a stable omnidirectional radiation pattern, maximum measured gain of 7.01 dBi, and has an average efficiency above 97% over the region of operation. These features make the proposed DRA applicable for cellular communication repeaters, local area networks, and vehicular communication applications.
... At this point, the fractal miniaturization approach promises an effective way to reduce the antenna dimension while keeping the length of the effective EM wave current's route due to its self-similarity and space-filling characteristics. Various works have investigated the fractal antenna design, including the Koch-modified antenna [47], the Minkowski fractal antenna [48], the Fern-fractalshaped microstrip antenna [49], and the Peano-Gosper fractal antenna [50]. In Table 1, we have summarized several works on implantable fractal antennas. ...
Fractal structure is a unique geometry that can be seen in many objects in nature, such as clouds, coastlines, DNA, trees, and even pineapple. This structure has manifold geometries, self-similarities, and space-filling properties. Due to these properties, fractal geometries are preferred to miniaturize an antenna in wireless communications. There are many cases that require a small compact antenna, including in-body communications. In this article, we present a review of the recent trends and advancements in fractal antenna research, especially in the miniaturization of implantable antennas for in-body communications. The review is derived from articles that are gathered from online libraries such as IEEE, PubMed, Nature, MDPI, Elsevier, and Google Scholar. As a result, we have collected more than 60 articles related to fractal-implantable antenna and in-body communications. Indeed, many researchers have proposed an implantable compact antenna with fractal geometries in the last decades. Fractal geometry allows a longer electrical length to be routed in a smaller area of the antenna. However, several things remain challenging in designing a fractal antenna, including bandwidth, fabrication complexity, and intercell interference.
... Due to these properties effective length of the antenna increases without affecting the overall area and increase in current path length leads to generate additional resonating bands. Numerous fractal-based designs like modified Sierpinski gasket fractal [16], circular ring fractal [17], Sierpinski Knop fractal [18], Crinkle fractal [19], dual reverse arrow fractal [20], I-shaped fractal [21], Minkowski fractal [22] and Modified Koch fractal [23] have been applied to achieve multi resonance characteristics. Various hybrid fractal curve like Koch-Meander curve [3] and Koch-Sierpinski curve [10] loaded with partial ground plane have been implemented to design multiband antennas for wearable applications. ...
A Fractal geometry based compact multiband wearable button antenna with wider bandwidth, less cross polarized radiation in both the orthogonal planes and low specific absorption rate (SAR) at all the resonating bands is presented in this article. The antenna comprises a slotted circular patch printed on the top of a circular piece of low-cost FR-4 substrate with radius 9.6 mm fed through coaxial feeding mechanism. Multiband behavior is achieved by the implementation of fractal based circular slots up to third iteration whereas the loading of two additional circular slots offers significant improvement in both bandwidth and gain. Radii of the circular slots are optimized properly in HFSS to attain the desired performance. On-cloth and on-body analyses of the proposed antenna are also carried out to investigate the effect of interaction with cloth and body materials on the antenna performance. The antenna offers multiband response covering the operating bands 4.1–4.64 GHz, 7.19–8.03 GHz and 8.85–9.67 GHz with very low SAR value ensuring less electromagnetic interaction with body tissues. The fabricated prototype shows comparable measured values with the simulated ones.
... Different slots along with fractal curve have been used in literature like circular slots [1], reverse C-shaped and L-shaped slot [2], plus shaped slots [8], triangular slots [12], fractal slots [13], [14] etc. to achieve multiband characteristics. Apart from slots different fractal shaped curves like crinkle fractal [5], I-shaped [6], circular ring fractal [7], [9], meander like fractal [10], dual reverse arrow fractal [11], modified Sierpinski gasket fractal [11], Minkowski fractal [15], Sierpinski fractal [16], [17], periwinkle flower shaped fractal [19] and hybrid fractal [20][21][22] also have been used to get multiband response. Alongside multiband response efforts have also been given to enhance bandwidth using several techniques like partial ground [3,20,23], crinkle fractal with partial ground [5], ring fractal with partial ground [8], circular slotted hexagonal shaped ring [10], elevated slotted triangular patch [11], fractal slot based DGS [13], [21] and Minkowski fractal with triangular dielectric resonator [15] in multiband antennas. ...
... Apart from slots different fractal shaped curves like crinkle fractal [5], I-shaped [6], circular ring fractal [7], [9], meander like fractal [10], dual reverse arrow fractal [11], modified Sierpinski gasket fractal [11], Minkowski fractal [15], Sierpinski fractal [16], [17], periwinkle flower shaped fractal [19] and hybrid fractal [20][21][22] also have been used to get multiband response. Alongside multiband response efforts have also been given to enhance bandwidth using several techniques like partial ground [3,20,23], crinkle fractal with partial ground [5], ring fractal with partial ground [8], circular slotted hexagonal shaped ring [10], elevated slotted triangular patch [11], fractal slot based DGS [13], [21] and Minkowski fractal with triangular dielectric resonator [15] in multiband antennas. CPW plates along with ground plane [3] are used to improve performance like gain and bandwidth over the operating frequency bands and CPW feeding has also been applied to achieve multiband response [19]. ...
... It has been observed that Koch fractal shaped slot provides more bandwidth in comparison to modified Sierpinski and Ψshaped slots. A triangular shaped dielectric resonator based Minkowski fractal antenna is designed to achieve wideband response [15]. Besides the Koch fractal, Sierpinski fractal has been also used for monopole antennas for wireless communications [16], [17]. ...
In this article, modified Koch fractal geometrybased patch antenna up to second iteration is implemented with partial ground configuration to achieve multiband response with wideband behavior at each of the resonating bands. The antenna is designed to operate over C and X bands that can be useful for Satellite, Radar and DBS TV applications. FR-4 epoxy substrate of maximum dimension 35 (formula-presented) 30 (formula-presented) 1.6 mm³(0.70(formula-presented)0 (formula-presented) 0.6(formula-presented)0 (formula-presented) 0.03 (formula-presented) 0) is used to simulate the antenna in HFSS 15 ( (formula-presented) 0 is the free space wavelength corresponding to the lowest resonance frequency). The design is started with a truncated star shape patch and ended up with five circular slots embedded Koch fractal through several design steps. In addition, coplanar waveguide (CPW) feeding is applied to achieve multiband response and wideband behavior over each operating band. The proposed antenna exhibits multiband response at 6.06 GHz, 9.76 GHz, 10.92 GHz, 11.68 GHz and 14.4 GHz with operating bands (5.8–6.31 GHz), (9.2–10.08 GHz), (10.78–12.36 GHz) and (13.64–15 GHz) respectively. A fabricated prototype of the proposed antenna is tested using Vector Network Analyzer (VNA). It has shown adequate amount of matching between the simulation and measured results.
... Space filling property helps to reduce the size of antenna, that is, miniaturization of antenna by improving the effective permeability and permittivity of the substrate, 10,11 whereas, self-similarity is useful to attain the multiband/wideband characteristics. 12,13 The most common geometries which are used in designing of FAs are Sierpinski Gasket/Carpet, [14][15][16][17][18] Giuseppe Peano, [19][20][21][22][23] Minkowski, [24][25][26][27][28] Koch, [29][30][31][32][33] Hilbert, [34][35][36][37][38] Meander, [39][40][41][42][43] and so on. Apart from this, other fractal geometries are Amer and Sunflower fractal. ...
The comprehensive review of hybrid fractal antenna (HFA) has been presented in this article. Distinguished researchers have designed, analyzed, and investigated numerous types of HFA's as per the requirement of the market. Firstly, it gives introduction about the fractal antennas (FAs) along with the need of integration of the fractal geometries then research motivation. The extensive literature survey has been divided into three different parts as, fusion of same type of fractal geometries, amalgamation of two distinct fractal geometries and concoction of three different fractal geometries, further, the comparative analysis among these HFA's has been made on the basis of their size, geometries used for designing, number of resonant frequency bands, gain, bandwidth, radiation efficiency, circular polarization, and their applications. The juxtaposition among different HFA's has also been delineated in tabular form for more limpidity along with the findings of individual research article. The challenges faced by researchers while designing the antennas are also being portrayed in this article. This review may be supportive for the novices to carry out their research on HFA as such type of comparative analysis on HFA's is not existing in the open state of art literature as per best of authors knowledge.
... The triangular shaped dielectric resonator antennas (DRAs) of various forms are reported in the literature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] among which, the equilateral triangular dielectric resonator antennas (ETDRAs) are quite popular. ...
In this article, two configurations of dual‐band equilateral triangular dielectric resonator antennas (ETDRAs) for WLAN applications are proposed namely, configuration‐I and configuration‐II. The configuration‐I uses single ETDRA for dual‐band operation; whereas, configuration‐II includes two ETDRAs to operate as a dual‐band antenna. Both the antenna configurations, which uses 99.7% alumina material having a dielectric constant of εr = 9.9, are excited to operate in the bands of 2.4 to 2.5 GHz and 5.75 to 5.85 GHz. The antennas are excited using a conventional coaxial feed to have a simple feeding mechanism. Prototypes of both the antenna configurations are fabricated and measured. The radiation characteristics of the antennas are discussed. The circuit analysis for the proposed configurations of the dual‐band ETDRA is also performed and an appropriate equivalent circuit for each dual‐band ETDRA is presented. Further, the performance of the proposed configurations of the dual‐band antennas are also compared with other dual‐band DRAs reported in the literature.
... Spidron and Pixelated is also important fractal geometry for designing of wideband DRA [11,12]. Sur with her research group [13] proposed Minkowski fractal geometry, with the help of triangular DRA, which offers ∼32.64% fractional bandwidth. ...
... From Fig. 13, it can be observed that the impedance bandwidth is increasing after each condition. The reason for bandwidth enhancement is due to a decrease in the volume to the surface area of the antenna structure [13]. The calculated ratio of volume to the surface area in zeroth iteration, first iteration with single CDRA, first iteration with dual CDRA, second iteration with single CDRA, second iteration with dual CDRA, third iteration with single CDRA, and third iteration with dual CDRA is found to be 4.34, 4.12, 3.97, 3.78, 3.55, 3.23, 3.11, respectively. ...
This study explains a novel wideband curvilinear Sierpinski fractal geometry (CSFG) based cylindrical dielectric resonator antenna. CSFG provides wider bandwidth by the combination of two important concepts: (i) reduction in volume to the surface area of the complete radiating structure, which in turn reduces the Q-factor; (ii) generation of two radiating modes inside the radiating structure HEM 11δ and TM 01δ. The prototype of the proposed antenna is fabricated for verifying the simulated results. Measured reflection coefficient (|S 11 |) shows that the proposed antenna structure operates over the frequency range 2.2-3.5 GHz with the fractional bandwidth of 45.61%. Diversified radiation pattern, i.e. monopole (due to TM 01δ mode) and broadside (due to HEM 11δ mode) is also an important feature of the proposed antenna structure. The antenna design is relevant for WLAN (2.5 GHz) and WiMAX (3.3 GHz) applications.
