Jordi Soler

Bio: Jordi Soler is an academic researcher from Polytechnic University of Catalonia. The author has contributed to research in topics: Microstrip antenna & Patch antenna. The author has an hindex of 17, co-authored 30 publications receiving 1145 citations.

Fractal Shaped Antennas: A Review

Abstract: The combination of fractal geometry with electromagnetic theory opens an interesting window for research to find new antenna designs and applications Fractal technology applications can be divided into six main groups: (1) multifrequency antenna elements, frequency-selective surfaces, and arrays; (2) electrically small antennas; (3) high-directivity radiating elements; (4) low-sidelobe arrays; (5) undersampled arrays; and (6) fast computational methods This article reviews most of the work done in the fractal technology field covering the last six fields Keywords: fractal; antennas; multifrequency; arrays; small antennas; arrays; microstrip antennas; broadband; high-directivity

Broad-band dual-frequency microstrip patch antenna with modified Sierpinski fractal geometry

Abstract: A dual-frequency antenna based on the Sierpinski fractal with two parasitic patches to enhance the impedance bandwidth is presented. An electrical circuit model formed by RLC resonators is proposed to learn about the antenna physical behavior and to achieve the dual band operation minimizing a trial-and-error numerical/measurement proofs. The antenna has been designed using a method of moment commercial code and has been experimentally tested, obtaining two bands with a broad bandwidth and similar radiation patterns.

Stacked H-shaped microstrip patch antenna

Abstract: A small H-shaped microstrip patch antenna (MPA) with enhanced bandwidth is presented. The H-shaped antenna is first studied by a transmission line model and then is fully analyzed with a MoM code. A stacked patch configuration is proposed to increase the narrow bandwidth, radiation efficiency and directivity. The stacked H-shaped MPA is studied using Chu's fundamental limit for electrically small antennas.

Small and high-directivity bow-tie patch antenna based on the Sierpinski fractal

Abstract: The unique geometrical properties of fractals have been proven to be useful to design advanced antennas. Enhanced performance in terms of size, gain, or multifrequency behavior is observed in fractal-shaped antennas. Here, a small and high-directivity antenna based on the Sierpinski fractal is presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 239–241, 2001.

Multifrequency microstrip patch antenna using multiple stacked elements

Abstract: A multifrequency microstrip patch antenna comprised of a driven patch and a plurality of parasitic elements placed underneath a driven patch is proposed. The antenna features a multifrequency behavior (five operating band) with similar gain.

An overview of fractal antenna engineering research

Abstract: Recent efforts by several researchers around the world to combine fractal geometry with electromagnetic theory have led to a plethora of new and innovative antenna designs. In this report, we provide a comprehensive overview of recent developments in the rapidly growing field of fractal antenna engineering. Fractal antenna engineering research has been primarily focused in two areas: the first deals with the analysis and design of fractal antenna elements, and the second concerns the application of fractal concepts to the design of antenna arrays. Fractals have no characteristic size, and are generally composed of many copies of themselves at different scales. These unique properties of fractals have been exploited in order to develop a new class of antenna-element designs that are multi-band and/or compact in size. On the other hand, fractal arrays are a subset of thinned arrays, and have been shown to possess several highly desirable properties, including multi-band performance, low sidelobe levels, and the ability to develop rapid beamforming algorithms based on the recursive nature of fractals. Fractal elements and arrays are also ideal candidates for use in reconfigurable systems. Finally, we provide a brief summary of recent work in the related area of fractal frequency-selective surfaces.

Microstrip Patch Antennas

Abstract: Introduction Review of Some Background Materials General Formulation of the Cavity Model Characteristics of the Rectangular Patch Characteristics of the Circular Patch The Annular-Ring and the Equilaterial Triangular Patch Introduction to Full Wave Analysis of Microstrip Antennas Some Methods of Tuning the Resonant Frequencies of Patch Antennas Broadbanding Techniques Size Reduction Techniques Dual and Multi-Band Designs Dual Polarized Patch Antenna Designs Circular Polarization Microstrip Arrays

Experimental Validation of Performance Limits and Design Guidelines for Small Antennas

Abstract: The theoretical limit for small antenna performance that was derived decades ago by Wheeler and Chu governs design tradeoffs for size, bandwidth, and efficiency. Theoretical guidelines have also been derived for other details of small antenna design such as permittivity, aspect ratio, and even the nature of the internal structure of the antenna. In this paper, we extract and analyze experimental performance data from a large body of published designs to establish several facts that have not previously been demonstrated: (1) The theoretical performance limit for size, bandwidth, and efficiency are validated by all available experimental evidence. (2) Although derived for electrically small antennas, the same theoretical limit is also generally a good design rule for antennas that are not electrically small. (3) The theoretical predictions for the performance due to design factors such as permittivity, aspect ratio, and the internal structure of the antenna are also supported by the experimental evidence. The designs that have the highest performance are those that involve the lowest permittivity, have an aspect ratio close to unity, and for which the fields fill the minimum size enclosing sphere with the greatest uniformity. This work thus validates the established theoretical design guidelines.

Hybrid Fractal Shape Planar Monopole Antenna Covering Multiband Wireless Communications With MIMO Implementation for Handheld Mobile Devices

Abstract: A hybrid fractal shape planar monopole antenna covering multiple wireless communication bands is presented for multiple-input-multiple-output (MIMO) implementation for handheld mobile devices. The proposed structure is the combination of Minkowski island curve and Koch curve fractals. It is placed with edge to edge separation of 0.16λ0 at 1.75 GHz. The T-shape strip is inserted and rectangular slot is etched at top side of ground plane, respectively to improve the impedance matching and isolation between the antennas. A measured impedance matching fractional bandwidths ( S11 ≤ -10 dB) are 14% from 1.65 GHz to 1.9 GHz for the band 1 and 80% from 2.68 GHz to 6.25 GHz for the band 2. Acceptable agreement is obtained between the simulated and measured antenna performance parameters. These characteristics demonstrate that the proposed antenna is an attractive candidate for handheld mobile devices.

Multiband Handset Antenna Combining a PIFA, Slots, and Ground Plane Modes

Abstract: A multiband handset antenna combining a PIFA and multiple slots on a ground plane is presented. It is shown by means of simulations that the slots on the ground plane have a double function: to tune the ground plane resonance at low frequencies (f ? 900 MHz) and to act as parasitic radiators at high frequencies (f ? 1800 MHz). A prototype is designed and built featuring a behavior suitable for low frequencies (GSM850 and GSM900) and for high frequencies spanning from DCS1800 to Bluetooth, and including, for instance, PCS1900, UMTS2000, and other possible systems. Reflection coefficient, efficiency, and radiation patterns are measured and compared with a design without slots to prove the advantages of the slotted ground plane. The component effect is investigated to determine critical areas where the placement is not recommended. Besides, the effect of the slot of the ground plane on SAR is investigated, by discussing the effect of the ground plane and slot modes for two phone positions. The total antenna volume of the proposed design is 40 × 15 × 6 mm3.