Fractal geometry has been proven to be useful in several disciplines. In the field of antenna engineering, fractal geometry is useful to design small and multiband antenna and arrays, and high-directive elements. A historic overview of the most significant fractal mathematic pioneers is presented, at the same time showing how the fractal patterns inspired engineers to design antennas.

Fractal antennas: An historical perspective

This paper premeditates an optimal design of fractal antenna with modified ground structure for wideband applications. The proposed antenna has been designed by taking numerous iterations started from 0th to 3rd. To attain the wideband characteristics, the partial ground plane has been introduced in the 3rd iteration, and the length of the ground plane has been varied to enhance the bandwidth. The maximum value of bandwidth has been adorned in the final iteration as 1.88 and 0.20 GHz. Further, this bandwidth has been improved and embellished as 2.48 GHz within the frequency range of 3–6 GHz by employing horizontal and vertical extensions in the partial ground plane. Antenna is simulated by using HFSS and performance parameters of antenna like return loss (S11 ≤ − 10 dB), gain and radiation efficiency are in the acceptable limits. The maximum value of gain is reported as 5.1 dB and radiation pattern is also omnidirectional. The proposed antenna is useful for the wireless applications as WiMAX (3.4–3.69 GHz) and WLAN (5.15–5.35 and 5.72–5.82 GHz) Simulated and experimental results are also juxtaposed and found in good agreement with each other.

An Optimal Design of Fractal Antenna with Modified Ground Structure for Wideband Applications

This paper describes a novel design of Minkowski and Meander curves based hybrid fractal antenna for mobile devices used for communication in delay tolerant networks, wireless sensor networks and mobile adhoc networks. Meander curve improves the impedance bandwidth. Minkowski fractal curve gives its contribution to make antenna multiband. The proposed antenna resonates at five frequencies 1.98, 5.94, 10.61, 12.73, 14.85 GHz. Prior to fabrication, better performance parameters such as return loss, radiation pattern, gain, current distribution, impedance, VSWR are achieved. The maximum bandwidth 2.83 GHz and gain 9.0 dB at 2.4 GHz are achieved. The proposed antenna can be used for various applications like Bluetooth, Wi-Fi, Wi-Max, Wi-Bro, AWS, GPS, S-DMB, WLAN 802.11b/g and DTH services etc. Simulated and measured results are compared and are found in agreement with each other.

Hybrid Fractal Antenna Using Meander and Minkowski Curves for Wireless Applications

Today’s world, multiband antenna has immensely beneficial for fulfill the requirements of wireless communication. In this paper, Hybrid Fractal Antenna (HFA) is designed using three popular fractal curves koch, minkowski and moore. The generator curve is created by adding minkowski curve and invert of koch curve. This hybrid generator curve is then superimposed on moore curve to get proposed HFA. FR4 material is used for the design of proposed HFA. The effect of defected ground and dielectric constant of different materials on the performance of antenna is studied. Proposed antenna is fabricated and S11 in dB is measured using Vector Network Analyzer. A comparison between simulated and measured return loss is done. It is found that simulated and measured results are agreement with each other. The antenna parameters such as return loss, VSWR, radiation pattern, gain are described in this article. A gain of 20.1 dB is obtained at frequency 1.70 GHz. The maximum bandwidth of proposed HFA is 2870 MHz and VSWR range varies between 1.887MAX and 1.008MIN. The dimensions of proposed HFA is 41.5 × 37 mm2 which is small as compared to existing hybrid geometries in literature. This proposed HFA can be used for Bluetooth (2.4 GHz), Wi-Fi (IEEE 802.11b and 802.11g) Wireless LAN (5.5 GHz), Wireless computer networking (2.4 GHz and 5.5 GHz), Wi-MAX (5.20 GHz–5.8 GHz), Satellite communication uplink (5.90 GHz), Military satellite downlink (7.25–7.30 GHz) applications.

Moore, Minkowski and Koch Curves Based Hybrid Fractal Antenna for Multiband Applications

Modified minkowski fractal multiband antenna with circular-shaped split-ring resonator for wireless applications

The sudden growth in wireless communication area has increased the requirements of compact integrated antennas. This paper describes the design of Modified Sierpinski Carpet Fractal Antenna which resonates at six frequencies 4.825, 5.455, 6.265 GHz and 6.805, 8.02 and 9.145 GHz. Different performance parameters like radiation pattern, gain, Voltage Standing Wave Ratio, return losses are observed at all the frequencies. The FR4 glass epoxy with relative permittivity 4.4 and height 1.6 mm is used as substrate material. Antenna is fed by coaxial probe feed and simulated using ANSYS/ANSOFT HFSS V13 software. Proposed antenna has simple structure. Investigation is done between 1 and 10 GHz frequencies. The proposed antenna is fabricated and tested on the Vector Network Analyzer. The measured and simulated results of proposed antenna are compared and are found to be good agreement with each other.

A Modified Sierpinski Carpet Fractal Antenna for Multiband Applications

Lantern Logo Shaped Novel Monopole Antenna with Semi-Circular Notch Loaded Partial Ground Plane for Ultra-Wideband Wireless Applications

The Circular Split Ring Microstrip Patch Antenna (CSRMPA) is designed in this paper. FR4 glass epoxy substrate material with thickness 1.6mm and relative permittivity 4.4 is used to design the proposed antenna. The proposed antenna has a compact size of 40.01mm × 33.01 mm × 1.6 mm. The antenna is proposed with the complementary circular ring patch with width 0.5mm that radiate at different frequencies. It works on six frequencies 3.63GHz, 3.81GHz, 7.36GHz, 8.09GHz, 9.27GHz and 9.81GHz with S11 values -15.31dB, -13.56dB, -12.23dB, -12.57dB, -28.46dB and -10.88dB respectively. Microstrip line feed techniques have been used for feeding the antenna. Simulated results of the proposed CSRMPA are calculated using High-Frequency Structure Simulator (HFSS) software. The proposed antenna can be used for various applications like S-band (2 to 4 GHz) used in weather radar system, ship radars, and cordless phones, C-band (4 to 8 GHz) used in wide range of the applications such as satellite communication and X-band (8 to 12 GHz) allow for space communications, military system and air traffic control.

Amandeep Kaur Sarao

Papers

A Modified Sierpinski Carpet Fractal Antenna for Multiband Applications

Lantern Logo Shaped Novel Monopole Antenna with Semi-Circular Notch Loaded Partial Ground Plane for Ultra-Wideband Wireless Applications

Design of Circular Split Ring Microstrip Patch Antenna for Multiband Applications