Circular UWB Research Articles

Design and Optimization of a Circular Ring-shaped UWB Fractal Antenna for Wireless Multi-band Applications Using Particle Swarm Optimization

Design and Optimization of a Circular Ring-shaped UWB Fractal Antenna for Wireless Multi-band Applications Using Particle Swarm Optimization

Defining Breast Tumor Location Using a Four-Element Wearable Circular UWB MIMO Antenna Array

The objective of this paper is to develop a wearable circular UWB MIMO antenna array, consisting of four elements, that is capable of detecting and locating tumor cells within a heterogeneous breast phantom. The antenna element operates within a bandwidth from 2.4 GHz to 10.6 GHz when FR4 is used as the substrate, and extends from 2.57 GHz to 12.6 GHz when a Dacron fabric is used instead. The antenna is fabricated and measured, yielding highly similar results to the simulated outcomes. In the suggested detection system, one antenna is used for transmission, while the other antennas receive the transmitted signal. The employed antenna demonstrates gains of 5.49 dBi, 9.87 dBi, 11.9 dBi, and 14.7 dBi at resonant frequencies of 2.84 GHz, 3.87 GHz, 5.83 GHz, and 8.24 GHz, respectively, when a Dacron fabric is used as the substrate. Moreover, the proposed antenna exhibits a flexible shape with minimal vertical and horizontal bending effects across the entire operating frequency band. The antenna has a compact size of 42.85 × 42.85 mm2 and is printed on an FR4 substrate with a dielectric constant of 4.5 and a thickness of 1.6 mm for testing purposes. The S-parameters of the suggested system can effectively identify and precisely locate small tumors. Furthermore, the SAR findings indicate that the amount of power absorbed by the breast phantom tissues complies with the IEEE standards, thus confirming the suitability of the recommended antenna for the early detection and localization of breast cancer.

Tuning of dual frequency resonance analysis of circular and rectangular patch UWB antenna used for wireless sensor networks

In our modern digital world, communication plays a most important role in research of new designs and novel findings. The proposed analysis is based on Ultra-wide band microstrip patch antenna with two methods of circular and rectangular patch. The design analysis and comparison of various antenna parameters are used for wireless sensor networks. The V-shaped slot is introduced on top of the circular patch and the horizontal T-shaped slot on rectangular patch using jeans substrate material, the design gives good resonance frequency of 9.5GHz and 7.7GHz for wireless communication networks. At resonance the receiver of UWB antenna has a frequency sensing element and the antenna parameters were analyzed using High Frequency Structural Simulator. From the analysis, gain of an antenna, VSWR, return loss as well as radiation pattern, Specific Absorption Rate SAR values are in the acceptable range. The VSWR value of both rectangular and circular patch is 1.05, return loss below -11dB determined in order to avoid surface wave propagation, the specific absorption rate SAR value should be below 2W and gain of each antenna consists of positive value. Hence the antenna meets the requirement suitable for wireless sensor network application.

Circular ring UWB antenna with reconfigurable notch band at WLAN/sub 6 GHz 5G mobile communication

Circular ring UWB antenna with reconfigurable notch band at WLAN/sub 6 GHz 5G mobile communication

Investigations on a circular UWB antenna with Archimedean spiral slot for WLAN/Wi-MAX and satellite X-band filtering feature

AbstractIn this article a compact circular monopole antenna is represented with dimensions of 38.87 × 24.00 × 1.60 mm3 applicable for WLAN/Wi-MAX and satellite band rejection characteristics. The impedance bandwidth is 9.42 GHz (3.12–12.54 GHz) for the final antenna with an equivalent fractional bandwidth of about 120.31%, producing triple notched bands centered at 3.95, 5.20 and 8.90 GHz with assistance of Archimedean spiral slot and incorporation of defected ground structure allowing WLAN (5.2 GHz), WiMAX (3.5 GHz) and higher satellite X-band (8.5 GHz) filtering abilities. Simulations of the antenna are performed to attain preferable return loss properties as well as gain and omni-directional radiation patterns. The suggested antenna yields a peak gain of about 7.46 dBi at 11.30 GHz and experimental values are in good obedience with simulated ones.

Linear and Circular UWB Millimeter-Wave and Terahertz Monostatic Near-Field Synthetic Aperture Imaging.

Millimeter-wave and terahertz frequencies offer unique characteristics to simultaneously obtain good spatial resolution and penetrability. In this paper, a robust near-field monostatic focusing technique is presented and successfully applied for the internal imaging of different penetrable geometries. These geometries and environments are related to the growing need to furnish new vehicles with radar-sensing devices that can visualize their surroundings in a clear and robust way. Sub-millimeter-wave radar sensing offers enhanced capabilities in providing information with a high level of accuracy and quality, even under adverse weather conditions. The aim of this paper was to research the capability of this radar system for imaging purposes from an analytical and experimental point of view. Two sets of measurements, using reference targets, were performed in the W band at 100 GHz (75 to 110 GHz) and terahertz band at 300 GHz (220 to 330 GHz). The results show spatial resolutions of millimeters in both the range (longitudinal) and the cross-range (transversal) dimensions for the two different imaging geometries in terms of the location of the transmitter and receiver (frontal or lateral views). The imaging quality in terms of spatial accuracy and target material parameter was investigated and optimized.

A Novel UWB Antenna with Reconfigurable Notch Bands

A UWB antenna with reconfigurable notch band characteristics is proposed in this paper. The tunable notches are created using modified E shaped resonators that can be reconfigured to modified C shape; etched on either side of the microstrip feed line of a circular patch UWB antenna. The single and dual band rejection characteristics are created by using C and E shaped structure respectively. Reconfigurability is achieved by using two RF switches. By varying the ON and OFF states of the RF switches, two different notch bands are created; single notch band from 4 to 6.2 GHz and an additional notch band from 7.6 to 10 GHz are achieved. These wide bandwidth rejection performance leads to notching of WLAN, WiMAX, C-band frequencies and X band Satellite communication systems.

A novel compact fractal UWB antenna with triple reconfigurable notch reject bands applications

A compact, circular UWB fractal antenna with triple reconfigurable notch rejection bands is proposed. It rejects the crowded frequency bands WiMAX, WLAN and X band interferences produced in UWB communication systems. The proposed fractal structure consists of a basic circular patch with circular fractal iterations. By employing this new structure of fractals, the overall size of antenna is reduced 53% to 21 × 25 mm, in comparison with traditional circular monopole antenna. The implemented antenna operates at 3.1–10 GHz. Re-configurability is realized by designing slots and split ring resonators in desired frequencies with the attached PIN diodes. WLAN band rejection was realized by creating a pair of optimized L-shaped slots in the ground plane. By etching a split ring resonator and a U-shaped slot, X and WiMAX bands were also rejected. Furthermore, by attaching diodes to aforementioned slots and designating the diodes on/off, different bands can be included or rejected. In time domain, the antenna properties are evaluated by a figure of merit called fidelity factor. Finally, the antenna properties are measured in anechoic chamber and the results agrees with simulation findings.

A C-Band Planar Metamaterial-Inspired Antenna Employing a Hexagonal Cell Periodic Structure

In this paper, a metamaterial inspired antenna to operate in the C-band is designed, fabricated, and characterized. The structure is based on the metamaterial tripolar array, to obtain a better gain, bandwidth, and frequency resonance when compared to a conventional circular UWB antenna with same structural characteristics. Simulation and experimental results show an increase of about 32% on the bandwidth and 9% on the gain with a satisfactory radiation pattern.

Compact circular patch UWB antenna with WLAN band notch characteristics

ABSTRACTThe present study demonstrates the designing and characterization of a circular patch antenna having an impedance bandwidth of 2.4–13.8 GHz with band notch at WLAN operating region. The small size (30 × 40 mm2) and large bandwidth (140.7% fractional band width) makes it suitable for different UWB applications. Different size reduction and matching techniques are used in this model to achieve a better response. The Quarter wave transformer matching technique is used for broad band impedance matching between the radiating circular patch and the 50 ohm source impedance. The simple design and good agreement between the simulation and the experimental results makes the design a suitable candidate for practical applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1068–1073, 2016

Design of a Miniaturization Printed Circular-Slot UWB Antenna by the Half-Cutting Method

In this letter, the miniaturization design of a novel printed circular slot UWB antenna is presented and investigated. By the half-cutting method and adjusting VSWR, the size of the proposed antenna is reduced from 40 × 40 to 10 × 20 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Experimental results show that the proposed antenna meets the requirement of wide working bandwidth of 3.1-10.6 GHz with VSWR <; 2. Monopole-like radiation pattern is observed in both H-plane and E-plane. The study of transfer function (magnitude and phase of S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> ) and signal waveform indicate a good time-domain characteristic of the antenna. The proposed antenna has a compact size, good radiation characteristics, ultrawide bandwidth, and good time-domain behaviors to satisfy the requirement of the current wireless communication systems.

Implementation and investigation of circular slot UWB antenna with dual-band-notched characteristics

The design and analysis of an ultra wideband aperture antenna with dual-band-notched characteristics are presented. The proposed antenna consists of a circular ring exciting stub on the front side and a circular slot on the back ground plane. By utilizing a parasitic strip and a T-shaped stub on the antenna structure, two notched bands of 850 MHz (3.5-4.35 GHz) and 900 MHz (5.05-5.95 GHz) are achieved. The proposed antenna is fabricated and measured. Measured results show that this antenna operates from 2.3 GHz to upper 11 GHz for voltage standing wave ratio less than 2, except two frequency notched bands of 3.5-4.35 and 5.05-5.95 GHz. Moreover, the experimental results show that proposed antenna has stable radiation patterns and constant gain. A conceptual circuit model, which is based on the measured impedance of the proposed antenna, is also shown to investigate the dual-band-notched characteristics.

A CIRCULAR WIDE-SLOT ANTENNA WITH DUAL BAND-NOTCHED CHARACTERISTICS FOR UWB APPLICATIONS

A circular wide-slot UWB antenna with dual band- notched characteristics is proposed in this paper. The microstrip- fed antenna consists of a calabash-shaped feeding patch and a metal ground with a circular slot etched. Dual band-notched characteristics are achieved by introducing arc-shaped parasitic strip and slot etched on the ground plane. According to the measured results, the proposed antenna can operate at the range of 2.91{11.45GHz with VSWR < 2 for UWB applications, except the notched bands of 3.38{3.71GHz and 5.39{6.27GHz for the 3.5GHz WiMAX and 5.8GHz WLAN, respectively.

NOVEL CIRCULAR SLOT UWB ANTENNA WITH DUAL BAND-NOTCHED CHARACTERISTIC

In this paper, a novel circular slot UWB antenna with dual notched frequency band is presented and investigated. A C-shaped slot is inserted into the fed element, and a parasitic strip is printed in the circular slot, so that the proposed antenna achieves dual band- notched characteristics, respectively. The measured and simulated results show that the proposed antenna meets the requirement of wide working bandwidth of 3.1{10.6GHz with VSWR < 2, while avoiding the interference with the 3.5GHz WiMAX and 5.5GHz WLAN band. Study of transfer function (amplitude of S21/group delay) and time domain characteristic (radiated pulses/power spectrum density (PSD)) correspond well with the VSWR, which indicate the dual band notched characteristic of the antenna.