In this article, the size of antenna Fresnel and Fraunhofer field regions are systematically derived starting from a general phase factor representation scalar diffraction theory. This is done by first expressing an arbitrary aperture in Taylor series terms small parameter then subsequently imposing appropriate conditions for regions.

A compact four‐element UWB MIMO antenna is proposed and its characteristics are investigated. The has a hexagon molecule‐shaped fractal structure as radiating element. elements placed orthogonally to each other in order yield good isolation, without any additional decoupling structure. band rejection WLAN attained by etching C‐shaped slot on size of 40 × 1.6 mm 3 exhibits stable omni‐directional radiation pattern. In addition, it shows an acceptable impedance bandwidth ( S 11 < −10 dB)...

This letter presents three wideband checkerboard metasurfaces (CMSs) for monostatic radar cross-section (RCS) reduction realized using low-cost FR4 material. The CMSs designed the target RCS of 10 dB conventional phase deviation condition 180 ± 37°, when simulated, exhibit an overshoot in lower frequency band and much higher reductions band. In order to maximize bandwidth considering these variations, a constriction 18° relaxation 48° are made condition. modifications offer over range...

In this study, a two-element multiple-input–multiple-output (MIMO) antenna with heptaband characteristics is proposed. The total size of the proposed 82 × 40 0.8 mm3. geometry radiating element derived from hybrid Quadric–Koch island fractal for miniaturisation. operates at bands 0.95–1.02 GHz (GSM 900), 1.73–1.79 1800), 2.68–2.85 (LTE-A), 3.66–3.7 [ultra-wideband (UWB)], 4.20–4.40 (UWB), 5.50–5.65 [worldwide interoperability microwave access/high-performance radio local area network] and...

Abstract In this communication, a 4 element ultra‐wide band (UWB) multiple‐input multiple‐output (MIMO) antenna is presented. The total size of the proposed 40 × mm 2 . A novel Sierpinski Knopp fractal geometry used in radiator design to accomplish miniaturization. elements are placed orthogonal each other. spacing between any pair 0.11 λ (λ being free space wavelength at 7.15 GHz). CSRR shape like slot etched on radiating achieve dual notch characteristics WiMax 3.5 GHz and WLAN 5.4...

A compact, shared-aperture antenna (SAA) configuration consisting of various planar antennas embedded into a single footprint is presented in this article. An L-probefed, suspended-plate, horizontally polarized operating an 900-MHz band; aperture-coupled, vertically polarized, microstrip at 4.2-GHz; 2 × patch array the X low-side-lobe level (SLL), corporate-fed, 8 4 for synthetic aperture radar (SAR) and printed, single-arm, circularly tilted-beam spiral C band are integrated simultaneous...

The displacement-current concept introduced by James Clerk Maxwell is generally acknowledged as one of the most innovative concepts ever in development physical science. It was through this that he led to discovery his electromagnetic theory light. While and its have received much admiration literature from viewpoints both scientific content philosophical methodology, there interestingly has been criticism, well. This article presents an overview these perspectives. With distinctive creative...

In this article, a compact 2 element UWB MIMO antenna is proposed. It has size of 40 mm × 20 (800 mm2). The utilizes hybrid Sierpinski Koch fractal shape as the radiating element. elements are placed parallel and close to each other. isolation between increased by employing modified stepped ground plane reflecting stub. use stub results in pattern diversity. A U- Shaped slot etched notch WLAN band that interferes with UWB. performance measured terms S-parameter, radiation diversity...

The efiect of shaping the ground plane on performance a square loop coplanar waveguide (CPW)-fed printed antenna is reported in this paper. Experimental results are presented re∞ection coe-cient and radiation pattern investigated antennas. Simulation current distribution, input impedance gain. It observed based that signiflcantly afiects coe-cients, impedances distributions.

A miniature two-element MIMO multiband planar patch antenna with potential applications in the ISM bands is presented. The elements of have been designed using a novel hybrid fractal geometry based on an altered Dragon Curve and Inverted Koch. Reduced dimensions are obtained acceptable performance even at lower frequency ranges. placed adjacent to each other very small spacing 0.004 λ0 (λ being free space wavelength 433 MHz), confining 51 × 50 mm2. resonates MHz (ISM), 2.4 GHz 3.9 GHZ (Fixed...

In this paper, a circular slot antenna fed by an ofiset microstrip-fed line is proposed. The exhibits dual-band characteristics. two operating frequency bands are: 1.83{2.73GHz and 5.36{7.63GHz, which are of impedance bandwidth 39.5% 34.9% respectively. suitable for PCS, UMTS, IMT- 2000, ISM, Bluetooth, RFID WLAN applications. A parametric study has been carried out varying the location feedline to investigate its efiect on resonant frequency. Impedance, radiation gain characteristics...

This article reports the design and analysis of a wideband, single layer, dual-polarized microstrip reflectarray for Ku-band applications. The array element is constructed using crossed dipole enclosed by two cross loops. optimized to exhibit linear phase response wide reflection range. characteristic unit cell analyzed an infinite approach results are presented. A 324-element antenna size 20 × cm2 simulated, fabricated, experimentally evaluated. 2.9-dB gain-bandwidth aperture efficiency...

The horn synthesis problem is formulated in terms of a fourth degree polynomial. Explicit analytical formulas are subsequently derived for the accurate design standard gain pyramidal antennas. These do not need application iterative techniques, unlike existing methods, simpler to use, and restricted high-gain design.

A rigorous measurement effort on the gain estimation of a wideband double-ridge horn antenna in 2.0- to 4.8-GHz frequency range is presented. systematic uncertainty analysis carried out

The particle swarm optimization (PSO) is a powerful evolutionary computing technique used to optimize various continuous and discreet value problems. PSO have gained attention in electromagnetic community due its ability process complex multi-objective problems flexibility algorithm alteration. There has been growing research interest hybrid methods which combines two or more type of functions into single method. presented this paper one such method that genetic (GA). In paper, study...

A modified three-antenna gain measurement method is proposed to significantly simplify, and thereby reduce the costs of, uncertainty estimation.Unlike method, new employs a standard antenna whose gains limits have been established through absolute calibration.The measurements are carried out as in with reference also analysed presumed unknown.An overall figure for obtained only from resulting data conjunction on values.The proposal verified by using rigorous experimental study of three...

An exact solution is presented for the fourth-order polynomial representing general horn design problem. When available approximations are used gain reduction factors, this leads to closed-form expressions aperture, and hence other, dimensions of pyramidal any desired aperture phase error.

Much research is recently being made in improving the performance of smooth wall conical horns as an alternative to corrugated horns. This study investigates a metallic sphere-inserted horn Ku-band by using simulations and experiments. While proposed displays improved respect gain, aperture efficiency return loss, it also more compact comparison with disc(s)-inserted horn.

This article presents a comparative study based on measurements and simulations of Ku-band conical horn with an inserted metallic cone-sphere horns having integrated dielectric lens meta material loading. The results revealed that the performance was better than metamaterial-loaded horn. comparable to lens. In addition, offered advantages lower weight cost in comparison other under consideration.

This article reports an optimization procedure for further enhancing the wideband radar cross section (RCS) reduction bandwidth using a checkerboard metasurface (CMS). The improved fruitfly algorithm is used to determine unit cells dimensions that offer enhanced bandwidth. Two previously reported CMSs are chosen: (a) A square-circle pair designed on Rogers 5880 with thickness of 6.35 mm and (b) Jerusalem 3010 1.27 mm. First, cell optimized, resulting in improvement 7% from originally...

It is suggested that where possible fundamental concepts and theories be presented from a historical perspective in undergraduate engineering education. Apart being fairer to the contributions of several researchers whose works often significantly contribute later much-acclaimed theory, such an approach can also employed intellectually challenge young students, encourage them pursue life-long learning. Against this background, method presenting Maxwell's equations context presented.

In order to gain an understanding of what students feel about the incorporation substantial historical content into engineering teaching, a survey was recently conducted at University Nottingham Malaysia Campus. this article, results are presented and their possible meaning is discussed.

The use of Artiflcial Magnetic Conductor (AMC) as a re∞ector in printed antenna is known to improve the antenna's radiation characteristics. This work investigates implementation AMC on wideband planar monopole antenna. investigation conflned basic square unit cell with four possible variations. structures are constructed cells which have either similar or Perfect Electric (PEC) back plane. These same also fabricated vias. impedance bandwidth, gain and power pattern simulated measured over...