A compact hexagonal Sierpinski fractal antenna for super wideband applications is presented. It consists of hexagonal radiation patch with two iterations of Sierpinski square slots and coplanar waveguide feeding. An impedance bandwidth of 3.4–37.4 GHz is achieved. The achieved bandwidth ratio is 11:1. Desirable radiation performance characteristics including relatively stable and omni-directional radiation patterns are obtained over this range. A good agreement is achieved between the simulated and experimental results. The designed antenna has advantages of wider bandwidth and miniaturised size over the previously reported structures.

CPW-fed hexagonal Sierpinski super wideband fractal antenna

Low-profile directional ultra-wideband (UWB) antennas are strongly demanded in many UWB applications. However, few such UWB antennas have been reported. To meet the demands, an original novel low-profile directional UWB antenna-the self-grounded Bow-Tie is developed and presented here. This new UWB antenna has a compact and simple geometry, and ultra-wideband performance, such as presented here over a frequency range of 2-15 GHz with about -10 dB reflection coefficient, stable radiation patterns, and good time-domain impulse response. Measurements of a prototype of the antenna have verified the design and the simulation. It can be foreseen that this new antenna will find many applications in the different areas in UWB technology.

https://publications.lib.chalmers.se/records/fulltext/local_155582.pdf

A Novel Low-Profile Compact Directional Ultra-Wideband Antenna: The Self-Grounded Bow-Tie Antenna

This review paper summarizes various approaches developed in the literature for antenna sensors with an emphasis on flexible solutions. The survey helps to recognize the limitations and advantages of this technology. Furthermore, it offers an overview of the main points for the development and design of flexible antenna sensors from the selection of the materials to the framing of the antenna including the different scenario applications. With regard to wearable antenna sensors deployment, a review of the textile materials that have been employed is also presented. Several examples related to human body applications of flexible antenna sensors such as the detection of NaCl and sugar solutions, blood and bodily variables such as temperature, strain, and finger postures are also presented. Future investigation directions and research challenges are proposed.

https://www.mdpi.com/1996-1944/13/17/3781/pdf

A Review of Flexible Wearable Antenna Sensors: Design, Fabrication Methods, and Applications

The technology of metallized foam offers a new approach to design wire-like, flat, and 3D antennas. Only the necessary metal skin depth (some microns in UHF band) is deposited over arbitrary shaped structures. Thanks to this technology, new antenna designs have been possible offering low weight, possible shaping, and innovative Corresponding author: J. Anguera (jaume.anguera@fractus.com). † Also with Electronics and Telecommunications Department, Universitat Ramon Llull, Barcelona, Spain. ‡ Also with Signal Theory and Communications Dept., Universitat Politecnica de Catalunya, Barcelona, Spain.

/pdf/metallized-foams-for-antenna-design-application-to-fractal-2lms2f1wr8.pdf

Metallized Foams for Antenna Design: Application to Fractal-Shaped Sierpinski-Carpet Monopole

A compact textile ultra-wideband (UWB) antenna with an electrical dimension of 0.24λo × 0.24λo × 0.009λo with microstrip line feed at lower edge and a frequency of operation of 2.96 GHz is proposed for UWB application. The analytical investigation using circuit theory concepts and the cavity model of the antenna is presented to validate the design. The main contribution of this paper is to propose a wearable antenna with wide impedance bandwidth of 118.68 % (2.96-11.6 GHz) applicable for UWB range of 3.1 to 10.6 GHz. The results present a maximum gain of 5.47 dBi at 7.3 GHz frequency. Moreover, this antenna exhibits Omni and quasi-Omni radiation patterns at various frequencies (4 GHz, 7 GHz and 10 GHz) for short-distance communication. The cutting notch and slot on the patch, and its effect on the antenna impedance to increase performance through current distribution is also presented. The time-domain characteristic of the proposed antenna is also discussed for the analysis of the pulse distortion phenomena. A constant group delay less than 1 ns is obtained over the entire operating impedance bandwidth (2.96-11.6 GHz) of the textile antenna in both situations, i.e., side by side and front to front. Linear phase consideration is also presented for both situations, as well as configurations of reception and transmission. An assessment of the effects of bending and humidity has been demonstrated by placing the antenna on the human body. The specific absorption rate (SAR) value was tested to show the radiation effect on the human body, and it was found that its impact on the human body SAR value is 1.68 W/kg, which indicates the safer limit to avoid radiation effects. Therefore, the proposed method is promising for telemedicine and mobile health systems.

/pdf/wireless-body-area-networks-uwb-wearable-textile-antenna-for-2wq9q4psbj.pdf

Wireless Body Area Networks: UWB Wearable Textile Antenna for Telemedicine and Mobile Health Systems

In this article, we present a novel circular disc antenna for current and future ultrawideband (UWB) applications. The proposed antenna has a small size of 30 mm × 35 mm, a simple geometry, and the excitation is launched through a 50-Ω microstrip feed line. The impedance matching of the proposed antenna is improved by introducing a second microstrip line between the feed line and the circular patch. A prototype of the proposed antenna has been fabricated and its performances are measured. The obtained results show that the proposed antenna operates on UWB frequency range from 2.7 to 28.8 GHz. Measured radiation patterns and simulated gain and radiation efficiency of the proposed antenna are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1130–1133, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24261

A novel compact printed circular antenna for very ultrawideband applications

A 3-D fractal-tree monopole antenna was realized using electrochemical deposition technique Experimental results on the return loss over the band 1-20 GHz and radiation patterns at all resonating frequencies were presented The multiband electromagnetic behavior of the antenna was studied and compared to a previously reported 2-D fractal-tree antenna studied by C Puente It is shown that the impedance bandwidth of the 3-D structure were improved compared to the reported 2-D structure with less dense band distribution The resonating bands of the fractal structure are related to the length distribution over the fractal shape Results for the 3-D fractal-tree antenna structure show the expected self-similar behavior

Study of an Electrochemically-Deposited 3-D Random Fractal Tree-Monopole Antenna

This article provides an overview of Performance Analysis of Round Trip Time (RTT) in Narrowband RF Networks for remote wireless communications using narrow band radios modem &Routers ((RipEX unit) ,as a means of transmission to communicate between the loins broadcast sites TV/FM. RTT delay measurement is influenced by different parameters of Narrowband RF Networks. We illustrate, in this paper, how RTT varies (in remote wireless practical communications application) versus distance, modulation, baud rates, number of hops and throughput, between source and destination. Also, we will see how the Forward Error Correction (FEC) affect, in the same time, the RTT according the factors cited above.

/pdf/performance-analysis-of-round-trip-time-in-narrowband-rf-38ry4vekej.pdf

Performance Analysis of Round Trip Time in Narrowband RF Networks For Remote Wireless Communications

Low-cost and flexible radio frequency identification (RFID) tag for automatic identification, tracking, and monitoring of blood products is in great demand by the healthcare industry. A robust performance to meet security and traceability requirements in the different blood sample collection and analysis centers is also required. In this paper, a novel low-cost and flexible passive RFID tag is presented for blood sample collection tubes. The tag antenna is based on two compact symmetrical capacitive structures and works at the ultra-high frequency (UHF) European band (865 MHz–868 MHz). The tag antenna is designed considering the whole dielectric parameters such as the blood, substrate and tube. In this way, it operates efficiently in the presence of blood, which has high dielectric permittivity and loss. Measurement results of the proposed tag have confirmed simulation results. The measured performance of the tag shows good matching in the desired frequency band, leading to reading ranges up to 2.2 m, which is 4.4 times higher than typical commercial tags. The potential of this tag as a sensor to monitor the amount of blood contained in clinic tubes is also demonstrated. It is expected that the proposed tag can be useful and effective in future RFID systems to introduce security and traceability in different blood sample collection and analysis centers.

https://www.mdpi.com/1424-8220/19/22/4903/pdf

Flexible UHF RFID Tag for Blood Tubes Monitoring.

In this paper, we report a new design of a compact antenna based on the use of split ring resonator (SRR). The designed antenna consists of two SRRs, with the same geometrical parameters, printed symmetrically on both sides of the dielectric substrate. Excitation of the SRR element is performed by adequately placing the access microstrip lines with respect to the conflnement plane of the split rings. The resonance frequency of the antenna is essentially deflned by geometrical parameters of the SRR, which makes it suitable for a broad range of applications spanning from mobile terminals to WLAN and WPAN systems. The flnal result is low proflle, and can be easily integrated with other RF front-end circuits in a PCB.

/pdf/a-compact-split-ring-resonator-antenna-for-wireless-4cloezpdyv.pdf

Otman El Mrabet

Papers

A novel compact printed circular antenna for very ultrawideband applications

Study of an Electrochemically-Deposited 3-D Random Fractal Tree-Monopole Antenna

Performance Analysis of Round Trip Time in Narrowband RF Networks For Remote Wireless Communications

Flexible UHF RFID Tag for Blood Tubes Monitoring.

A compact split ring resonator antenna for wireless communication systems