In this paper designs of both planar ultra-wide band (UWB) antenna and UWB antenna with two rejected bands are given. The antenna consists of a rectangular patch etched on FR4-substrate with 50 Ω feed line. The rectangular patch has one round cut at each corner with one slot in the ground plane. The simulated bandwidth with return loss (RL) ⩾ 10 dB is 3.42–11.7 GHz. The rejected bands are the WLAN and X-bands, achieved by inserting slots in the patch and the feed. The simulated results of the proposed antenna indicate higher gain at the passbands while a sharp drop at the rejected bands is seen. The radiation pattern is of dipole shape in the E-plane and almost omnidirectional in the H-plane. The high frequency structure simulator (HFSS) is used to design and simulate the antennas behavior over the different frequency ranges. Measurements confirm the antenna characteristic as predicted in the simulation with a slight shift in frequencies.

/pdf/multislot-microstrip-antenna-for-ultra-wide-band-4g1n6qvn35.pdf

Multislot microstrip antenna for ultra-wide band applications

In this paper, an intensive study is proposed to recycle the organic materials use for microwave applications including RF-energy harvesting. Thus, the Iraqi Palme Tree Remnants (IPTR) is exemplified for this study to create dielectric substrates. The main texture of the fabricated substrates is IPTR mixed with Nickel Oxide Nanoparticles (NONP) hosted in Polyethylene (PE) to be called INP substrates. Nevertheless, a metamaterial (MTM) printed antenna on the proposed substrate is fabricated by material printer with Sliver Nanoparticles Conductive Ink (SNPCI). The antenna performance is tested numerically/experimentally in terms of S11 spectrum and radiation patterns. It is found excellent matching bandwidths at 2.45 GHz and 5.8 GHz frequencies with acceptable gains of 1.56 dBi and 2.48 dBi, respectively. The proposed antenna bandwidth is found to start from 2.4 GHz up to more than 10 GHz. The maximum achieved gain and efficiency are found about 3.456 dBi and 78% at 9 GHz. For this, the proposed antenna provides novel performance with ultimate antenna size reduction due to the introduction of the MTM based the proposed INP substrate. Finally, the harvested RF energy by the fabricated antenna is measured and found about 15 mV with a conversation efficiency of 85% at 2.45 GHz and 17.5 mV with a conversion efficiency of 91% at 5.8 GHz.

Novel UWB printed metamaterial microstrip antenna based organic substrates for RF-energy harvesting applications

This paper presents a novel breast model system based on a UWB antenna for locating a tumor cancer. The antenna with overall size of 35mm×20mm×1.6mm is characterized with an ultrawideband of 120% and frequency range of 3GHz–12 GHz for the FCC band. The proposed antenna exhibits good impedance matching, high gain and omnidirectional radiation patterns. The measurement results are presented to illustrate the performances of the proposed antenna. This antenna has been implemented in a designed system model with dielectric properties of a human breast capable to detect strange objects. The size and localization coordinates of the tumor are studied in detail for better tumor detection. The coordinates of the corresponding maximum value of SAR are identified in order to accurately detect different locations of tumor inside the breast. The results show that the localization of the tumor can be detected with high precision which demonstrates the performance of the proposed antenna and the entire system. The proposed breast model system was developed using the commercial CST Microwave studio simulator.

/pdf/breast-tumor-detection-system-based-on-a-compact-uwb-antenna-55bsydleqm.pdf

Breast Tumor Detection System Based on a Compact UWB Antenna Design

Fractal geometries are attractive for antenna designers seeking antennas with compact size and multiband resonant behavior. This paper presents the design of a new microstrip-fed printed slot antenna for use in dual-band wireless applications. The slot structure of the proposed antenna is in the form of Cantor square fractal geometry of the second iteration. The slot structure has been etched on the ground plane of a substrate with relative permittivity of 4.4 and 1.6 mm in thickness. A parametric study is conducted to explore the effects of some geometrical parameters on the antenna performance. Results show that the antenna possesses a dual-band behavior with a wide range of resonant frequency ratio. In addition to the ease of fabrication and simple design procedure, the antenna offers desirable radiation characteristics. A prototype of the proposed antenna has been simulated, fabricated, and measured. The measured 10 dB return loss bandwidths for the lower and the upper resonant bands are 42% (2.35–3.61 GHz) and 20% (5.15–6.25 GHz), respectively. This makes the proposed antenna suitable to cover a number of operating bands of wireless systems (2.4 GHz-Bluetooth, 2.4 GHz ISM, 2.4/5.8 GHz-WLAN, 3.5 GHz-WiMAX, and 5.8 GHz-ITS).

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1759078714001469

Cantor fractal-based printed slot antenna for dual-band wireless applications

In this paper, a simple microstrip antenna for the radio frequency identification (RFID) applications and wireless local area network (WLAN) is presented. The antenna has two operating bands at 2.45 and 5.8 GHz, which are reserved for RFID applications and WLAN applications. The studied antenna design, analysis and characterization have been performed using CST electromagnetic simulation software. The antenna was analyzed with FR4 substrate. Reflection coefficient, VSWR and directivity results were simulated, presented and discussed. The designed antenna was fabricated on ArlonAD320 dielectric with relative permittivity of 3.2. SMA female connector is used for feeding with characteristic impedance of 50 Ω. The measured reflection coefficient of the proposed antenna is compared with the simulated one, good agreement is observed. The proposed antenna is simple in design and compact in size, providing broadband impedance matching, consistent omnidirectional radiation patterns and appropriate gain characteristics (>1.5 dBi) in the RFID frequencies regions.

Rectangular Patch Antenna for Dual-Band RFID and WLAN Applications

Difierent slot structures have been widely used in numerous designs to produce antennas with enhanced bandwidths. In this paper, a printed slot antenna has been introduced as a candidate for use in the multi-band wireless communication applications. The antenna slot structure has a rectangular shape with its width, from the side of feed, has been modifled in the form of Koch fractal curve of the second iteration. The antenna has been fed with 50Ohm mi- crostrip transmission line etched on the reverse side of the substrate. Modeling and performance evaluation of the proposed antenna design have been carried out using a method of moments based EM simulator, IE3D. Simulation results show that the resulting antenna exhibits a multi- resonant behavior making it suitable for a wide variety of multi-band wireless communication applications. The flrst resonant band, centered at 2.58GHz, extends from 2.40 to 2.89GHz. This band covers the 2.4GHz WLAN band (frequency range 2.4{2.483GHz) and the 2.5GHz mobile WiMAX operating band (frequency range 2.5{2.7GHz). The second resonant band, centered at 4.03GHz, extends from 3.40 to 4.50GHz. This band covers the 3.5GHz mobile WiMAX oper- ating band (frequency range 3.4{3.6GHz). While the third resonant band centered at 5.74GHz, extends from 5.42 to 6.18GHz. This band covers the U-NII mid-band (frequency range 5.47{ 5.725GHz) and U-NII high-band (frequency range 5.725{5.875GHz). Parametric study has been carried out to explore the efiect of varying the antenna feed line length on its performance.

A Printed Fractal Based Slot Antenna for Multi-band Wireless Communication Applications

This paper presents the design of a new Co-Planar Waveguide (CPW) fed dual band printed slot antenna with enhanced bandwidths for use in wireless applications. The fractal based slot structure of the proposed antenna is in the form of Peano fractal curve of the second iteration as being applied to the two sides of a rectangular slot. The proposed antenna is to be etched using a substrate with relative permittivity of 4.4 and thickness of 1.6 mm. The resulting antenna has overall dimensions of 36 mm × 45 mm which is suitable for mobile terminal applications. Modeling and performance evaluation of the proposed antenna have been carried out using the CST Microwave Studio. Simulation results shows that the proposed antenna offers dual -10 dB impedance bandwidths of more than 1.2 GHz and 1.4 GHz for the lower and the upper bands respectively with corresponding average gains of about 2.5 dBi and 4 dBi throughout these bands. The first resonant band, centered at 2.50 GHz, extends from 1.91 to 3.11 GHz. This band covers the 2.4 GHz WLAN band (2.4-2.483 GHz) and the 2.5 GHz mobile WiMAX operating band (2.5-2.7 GHz), while the second resonant band, centered at 5.20 GHz; extends from 4.51 to 5.91 GHz. This band covers the U-NII mid-band (5.47-5.725 GHz) and U-NII high-band (5.725-5.875 GHz). Besides the compact size, the antenna offers reasonable radiation characteristics with omnidirectional radiation patterns in the two bands.

A compact Peano-type fractal based printed slot antenna for dual-band wireless applications

The design of a fractal based slot antenna, to serve the dual-band communication applications, is proposed in this paper. The structure of the proposed antenna is based on the Koch snowflake fractal geometry of the third iteration as applied to the outer and inner perimeters of an annular ring slot configuration. The antenna slot structure has been etched on one side of a substrate representing its ground plane, and a microstrip line feed is printed on the other side. The realized results proved that the proposed antenna could excite three resonant modes. The first one was assigned for the lower resonating band from (2.24–2.93) GHz, while the second and third modes have been merged forcibly to generate the upper resonating band from (4.48–5.54) GHz. In terms of the guided wavelength, λg, the resulting antenna has a compact size of 0.57λg × 0.57λg. The results reveal that the antenna yields two resonant bands with a significant extent of the frequency ratio. To improve the antenna performance at the two resonant bands, investigation of current density distributed on the surface of the antenna is conducted at selected frequencies within the swept range. With the aid of this study, it has been found that when applying a defected ground structure (DGS) on the antenna ground plane, it can be considered as a tuning means of the two resonant bands. Measured results carried out on two fabricated prototypes confirm those theoretically predicted.

A Dual-Band Printed Antenna Design Based on Annular Koch Snowflake Slot Structure

In this paper, a printed monopole antenna with reduced ground plane has been presented as a candidate for use in ultra-wideband applications. The monopole antenna structure is a nearly square shaped with m-slot embedded in it. A 50› microstrip line is used to feed the proposed antenna. The proposed antenna has been supposed to be etched using a substrate with relative permittivity of 4.6 and thickness of 1.6mm. Modeling and performance evaluation of the proposed antenna have been carried out using a method of moments based EM simulator, IE3D. Results show that the proposed antenna has a compact size of 20mm £ 25mm. The resulting antenna has been found to possess an impedance bandwidth, for voltage standing- wave ratio less than 2, covering the required impedance bandwidth for UWB applications with 5/6GHz band notch characteristics. Simulation results show that the lower frequency is primarily determined by the monopole radiating element perimeter, while the slot has an efiective role to allocate the position of the band notch. A parametric study has been conducted to provide more understanding of the efiects of antenna parameters on its performance. Besides the reasonable performance, the simple structure of the proposed antenna will make it an attractive choice for the antenna designers.

Mahmood T. Yassen

Papers

Cantor fractal-based printed slot antenna for dual-band wireless applications

A Printed Fractal Based Slot Antenna for Multi-band Wireless Communication Applications

A compact Peano-type fractal based printed slot antenna for dual-band wireless applications

A Dual-Band Printed Antenna Design Based on Annular Koch Snowflake Slot Structure

A New Compact Ultra Wideband Printed Monopole Antenna with Reduced Ground Plane and Band Notch Characterization