This paper proposes fractal-inspired array antennae for wideband applications. The proposed antennae have a resonance frequency range of 20–40 GHz. The modified fractal antennae are fabricated with a height of 1.6 mm, substrate width, and length of 100, 50, 25, and 18.75 mm2, and a simulated result shows that the gain is increased to 11.04, 11.9, 8.4, and 6 dBi, and the designed antennae radiate power with directivity of 11.3, 13.4, 9.29, and 7.17 dBi concerning proposed designs A, B, C, and D, respectively. The proposed antennae with 5G New Radio (NR) bands have more radiation concerning resonate frequencies in the 20–40 GHz range with Φ = 0°, Φ = 90°, and θ = 90°. Moreover, the bandwidths for applications covered in the 5G NR and sub-6G are 1.92, 0.73, 0.7, 2.4, 1.3, 5.3, and 1.26 GHz, and 3.4, 3.7, 2.67, and 4.65 GHz, and 2, 3.5, and 1.57 GHz, and 2.5, 1.5, and 1.0 GHz with the maximum return loss of 37 dB, 32.8 dB, 31.2 dB, and 23 dB with corresponding resonate frequencies as 21.5, 27.6, 33, and 27.6 GHz concerning designs A, B, C, and D, respectively. The proposed antennae have been implemented and validated using Computer Simulation Technology (CST), Vector Network Analyzer (VNA), spectrum analyzer, and power sensor.

In this paper, the design and analysis of a complementary Sierpinski Knopp fractal antenna are presented. It is realized by applying the Sierpinski Knopp space-filling curve on the basic square monopole antenna. The performance metrics of the antenna such as S11 (reflection coefficient), voltage standing wave ratio, radiation pattern, gain and current distribution at resonant frequencies are analyzed by using ANSYS Electronic Desktop software package. FR4 dielectric material is used as a substrate in which the radiating element of an antenna is printed. Vector network analyzer and anechoic chamber are used for measuring the fabricated antenna in order to validate the simulated data. The proposed antenna resonates at three frequencies that are 2.08, 4.93, and 6.46 GHz with a reflection coefficient of −20.5, −23.1, and −24.3 dB, respectively. The suggested antenna covers the frequency bands for mobile satellite service, Public Protection and Disaster Relief communication devoted to the emergency management system and INSAT C band applications.

This paper presents a compact octagonal array of microstrip patch antennas for direct broadcast satellite (DBS) (12.2–12.7 GHz) services. The proposed single element of this array is a new fractal antenna, having considerably high gain and can heavily suppress cross polarization along the main beam direction. The single element is derived from a 2D spiral geometry. The corporate feed network of the array is designed in such a manner to make the structure very compact. The fabricated single element resonates at 12.51 GHz and gives a gain and bandwidth of 9.32 dBi and 280 MHz, respectively. The array resonates at 12.46 GHz and gives gain of 17.67 dBi and a bandwidth of 506 MHz, which ensures a 100% coverage of the entire DBS service band. The measured cross polarization of single element and array along the direction of main beam are −45.50 and −43.35 dB, respectively. Both the single element as well as the array maintains a reasonably good radiation efficiency of 86.70 and 82.20%, respectively.

An inscribed hexagonal fractal slotted patch antenna with some additional geometry and slots is proposed for the optimization in this paper. This research work is concerned with the optimization of this slotted fractal antenna with the help of the curve-fitting method in conjunction with the modified version of Lightning Attachment Procedure Optimization (MLAPO) technique. The data required for the curve-fitting technique and for the optimization technique have been obtained by varying some of the parameters of the proposed antenna. Different equations are developed to know the relations between these parameters of the proposed antenna. The MLAPO technique is applied thereafter to calculate the different optimized geometrical parameters to optimize the bandwidth for the proposed antenna. The optimized geometrical parameters are verified with the help of a parametric variation to justify the reliable optimization. The bandwidth obtained by the MLAPO technique has been found to be better than that obtained by PSO and normal LAPO algorithm. The prototype of the optimized antenna is fabricated and the experimental results are found to be compatible with the results obtained by simulation. The proposed optimized antenna may be utilized in various applications in C and X bands.

In this paper, a new reconfigurable microstrip fractal ultra-wideband antenna with a capability of variable rejection frequency bands is presented. The main patch of this antenna has two modified C-shaped gaps. Also, on these c-shaped gaps, 10 ideal MEMS switches are used to produce band-notch frequencies at six different frequencies of: 5.4 GHz (5.2–5.5), 5.8 GHz (5.7–5.9), 6.1 GHz (5.9–6.3), 7 GHz (6.9–7.2), 7.9 GHz (7.7–8.1), and 8.4 GHz (8.2–8.6). This antenna is fed by a 50 Ω microstrip line and works in a wide bandwidth of 2.9–11 GHz. The antenna is designed and fabricated on an inexpensive substrate of FR4. Dimensions of the antenna are 31.2 × 38.4 mm. Measurement and simulation results are in good agreement.

In this paper, a solid co-planar waveguide-fed fractal metamaterial antenna is offered. The proposed design consists of Sierpinski gasket iterations and a complementary triangular split ring resonator (CTSRR) loaded underneath the substrate, which is accountable for pull off multiband uniqueness and resolve good impedance identical. In sketch to hassle multiresonant frequency band facet, these CTSRR are entrenched reverse side of the substrate. The anticipated antenna with a dense dimension of 12 × 14 × 1.6 mm3 is fabricated and tested. The testing result designates that the projected design has −10 dB of 5.72, 14.3, and 16.06 GHz, respectively, and covers 5.72 GHz wireless local area network, 14.3 GHz fixed satellite, and 16.06 GHz International Telecommunication Union (ITU) band. It has fine emission uniqueness for jointly E-plane and H-plane in all the preferred occurrence bands and produce superior performance compared with the offered antenna intend in the prose. The loaded CTSRR construction recital is validated all the way during negative permeability pulling out and assorted parametric study.

Fractals have unique properties such as self-similarity and space-filling. The use of fractal geometry in antenna design provides a good method for achieving the desired miniaturization, multi-band, and wideband properties. In this communication, novel fractal geometry is proposed based on which a multiband antenna is designed. The proposed antenna has fractal patches which are shaped as different iterations of an eight-pointed star. The multiband behavior is in the frequency range from 4.50 to 17.00 GHz. The proposed antenna is designed on a dielectric substrate Roggers RO4003 lossy with a dielectric constant of εr = 3.55. The antenna has applications in commercial and military communication system.

This paper of lettering reveals about a modified Koch snowflake fractal multiband antenna for cognitive radio applications. Multiband antennas can be employed for spectrum sensing in cognitive radio. This new microstrip-modified Koch fractal antenna exhibits multiple actions in four dissimilar resonant frequencies at 3.2, 5.2, 6, and 9.5 GHz correspondingly that covers the frequency bands such as S, C, and X bands. Its multiband behavior was analyzed by designing and simulating in ADS EMDS software. Three iterations were carried out to study the performance of modified Koch snowflake fractal antenna. The outer ring and a small rectangular slot in the center of the antenna are used for 50 Ω impedance matching and to increase the number of resonant frequencies. The fractal antenna parameters such as gain, directivity, and its radiation pattern are also analyzed in this paper. The measured results show good agreement with the simulated results.

A dual wideband design of Sierpinski carpet fractal-shaped planar monopole antenna with a coplanar waveguide (CPW) feed is proposed in this letter. Wide impedance bandwidth of 22% at lower resonance from 4.88 to 6.08 GHz and 41.7% at higher one, which ranges from 9.5 to 14.5 GHz, is obtained. Measured realized antenna gain is around 5 dBi at the lower band centered around 5.5 GHz and are around 4.5 dBi at the higher band. A fabricated prototype is developed with good agreement between simulation and measurement.