scholarly journals Reconfigured and Notched Tapered Slot UWB Antenna for Cognitive Radio Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Tamer Aboufoul ◽  
Akram Alomainy ◽  
Clive Parini
Keyword(s):  
Cognitive Radio ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Total Efficiency ◽  
Back Side ◽  
Radiation Patterns ◽  
Uwb Antenna ◽  
Design Concepts ◽  
Specific Frequency

A compact reconfigurable and notched ultra-wideband (UWB) tapered slot antenna (TSA) is presented. The antenna reconfiguration operation principle relies on 2 mechanisms: in the first mechanism a resonator parasitic microstrip line electrically coupled to the TSA is used to notch the TSA at a specific frequency and the second mechanism relies on changing the input impedance matching of the antenna by means of changing the length of a stub line extended from an additional tiny partial ground on the back side of the antenna. The reflection coefficient, radiation patterns, and gain simulations and measurements for the proposed antenna are presented to verify the design concepts featuring a very satisfactory performance. Total efficiency simulations and measurements are also presented to highlight the filtering performance of the reconfigured antenna. When the antenna was reconfigured from the UWB to work into multiple frequency bands, the radiation patterns were still the same and the total peak gain has slightly improved compared to the UWB case. In addition, when the antenna operated in the notched mode, the gain has significantly dropped at the notch frequency. The simplicity and flexibility of the proposed multimode antenna make it a good candidate for future cognitive radio front ends.

scholarly journals A CPW-fed Irregular Shaped Hexagonal Patch Antenna with Elliptical Substrate for UWB Applications

2019 ◽  
Vol 9 (2) ◽  
pp. 373-376
Keyword(s):  
Patch Antenna ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Total Efficiency ◽  
Uwb Antenna ◽  
Radiation Characteristics ◽  
Wide Range ◽  
Uwb Applications ◽  
Novel Design ◽  
Peak Gain

A novel design of Ultra-Wideband (UWB) antenna with irregularly shaped hexagonal patch built on the elliptical-shaped FR-4 laminate with εr = 4.3 and tanδ = 0.025 is presented. The feed mechanism utilized in the structure proposed is modified co-planar waveguide (CPW), the feeding microstrip is tapered near the connecting edge of the patch for better impedance matching. The proposed antenna is compared with the traditional rectangular substrate and found that the elliptical substrate enhances the radiation characteristics of the antenna and is capable of functioning effectively in the range of 3.1 GHz-11.7 GHz, accompanied by the total efficiency > 86% across the whole FCC allocated UWB operating band. The antenna can be used for wide range of UWB applications as it exhibits good omnidirectional characteristics with a realized peak gain of 4.178dB and an average realized gain of 3.063dB. The simulation work of the antenna is accomplished using CST Studio (v. 2014).

A CPW-fed stepped slot UWB antenna for MIMO/diversity applications

2015 ◽  
Vol 9 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Raj Kumar ◽  
Neha Pazare
Keyword(s):  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Uwb Antenna ◽  
Slot Antennas ◽  
Capacity Loss ◽  
Field Radiation

An ultra-wideband (UWB) slot antenna for diversity applications is introduced. The overall structure of the antenna consists of two similar coplanar waveguide (CPW)-fed stepped rectangular slots placed in an orthogonal position. The slots are asymmetric with respect to their placement in the ground plane. The CPW feeds are double stepped and terminated on hexagonal patches for better impedance matching. A wide impedance bandwidth (measured) from 3 to 12 GHz with an isolation better than 15 dB is obtained with this antenna. To improve the isolation, the design is modified and an I-shaped slot strip is introduced between the two slot antennas. With this, the isolation is brought about 25 dB of most of the band, while the impedance bandwidth remains the same (2.8–12 GHz for port 1, measured and 2.9–12 GHz for port 2, measured). The far-field radiation patterns are also measured and a peak gain of about 5 dBi is obtained. Finally, the diversity parameters such as envelope correlation coefficient and capacity loss are calculated and found to have low values. The antenna is expected to be useful for UWB diversity applications with good isolation.

Compact stepped slot antenna for ultra-wideband applications

2021 ◽  
pp. 1-7
Author(s):  
B. Hammache ◽  
A. Messai ◽  
I. Messaoudene ◽  
T. A. Denidni
Keyword(s):  
Radiation Pattern ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Back Side ◽  
Compact Size ◽  
Measurement Results ◽  
Operating Bandwidth ◽  
Uwb Applications

Abstract In this paper, a compact stepped slot antenna for ultra-wideband (UWB) applications is proposed. A very small size and UWB bandwidth operation are achieved by integrating a stepped slot in the back side of the antenna. This stepped slot is excited by using a 50 Ω-feed line in the top side of the antenna. The antenna is characterized by an impedance bandwidth between 3.05 GHz and more than 12 GHz. The dimensions of the antenna are 17 mm × 8 mm × 1.27 mm, which leads to the most compact size compared with other works in the literature. The integrated stepped slot is divided into additional elementary slots, where each elementary slot has a matching point. Adding these elementary slots allows to increase further the operating bandwidth. The radiation pattern of the compact stepped slot antenna is omnidirectional in the H-plane and bidirectional in the E-plane. The measurement results agree well with the simulated ones in terms of impedance matching and radiation pattern.

Half-Elliptical UWB Planar Monopole with Reconfigurable Slot Antenna for Cognitive Radio Front-End

2018 ◽  
Vol 27 (13) ◽  
pp. 1850213 ◽  
Author(s):  
Santasri Koley ◽  
Himanshu Pant ◽  
Lakhindar Murmu
Keyword(s):  
Cognitive Radio ◽  
Wide Frequency Range ◽  
Good Choice ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Back Side ◽  
Transmission Line Model ◽  
Rectangular Slot ◽  
Lumped Elements ◽  
Integrated Antenna

In this paper, a half-elliptical disc ultra-wideband (UWB) monopole antenna integrated with a reconfigurable rectangular slot antenna is presented. It consists of a half-elliptical disc radiator to operate in the UWB mode whereas the etched rectangular slot on the half-elliptical patch is designed to operate as a reconfigurable narrowband slot antenna which is fed through a microstrip line from the back side of the patch. Both the antennas are placed in such a way that they are isolated to each other. Frequency reconfigurability has been achieved by inserting three lumped elements (two PIN diodes and a varactor diode) in the slot. An approximate transmission line model of the proposed slot antenna is derived to calculate the proper positioning of the diodes, and the design has been verified through numerical simulations. The simple compact proposed antenna covers a wide frequency range from 0.75 to 12[Formula: see text]GHz. Additionally, a wide tuning range from 0.8 to 2.9[Formula: see text]GHz (with the frequency ratio of 3.625:1) has been achieved. This compact integrated antenna is a good choice to be implemented in Cognitive Radio (CR) devices.

A Dual Polarized Ultra-Wideband Slot Antenna Using Stepped Microstrip Feed Structure

Frequenz ◽  
2015 ◽  
Vol 69 (11-12) ◽  
Author(s):  
R. V. S. Ram Krishna ◽  
Raj Kumar
Keyword(s):  
Impedance Matching ◽  
Correlation Coefficients ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Radiation Patterns ◽  
Dual Polarization ◽  
Printed Circuit ◽  
Peak Gain ◽  
Microstrip Feed

AbstractIn this paper, a printed slot antenna for ultra-wideband dual polarization is proposed and experimentally demonstrated. The slot is L-shape and its two arms are individually microstrip fed for producing the orthogonal polarizations. The slot arms and the microstrip feed lines are step sectioned for wideband impedance matching. For isolation purpose, a slant narrow metallic stub is inserted at the junction of the slot arms. The antenna has an impedance bandwidth of 118% (3.1–12 GHz) and isolation of around 20 dB over most of the band. The radiation patterns are nearly omnidirectional with a peak gain varying from 3 to 6 dBi. For assessing the diversity performance of the antenna, the envelope correlation coefficients are computed from the simulated and measured S-parameters and found to be within acceptable limits. With a compact, single substrate design, the antenna is expected to be useful for printed circuit ultra wideband applications requiring dual polarization features.

Selectivity and in-band impedance enhancement of a compact slot antenna with defected ground structures

2019 ◽  
Vol 11 (10) ◽  
pp. 1010-1016
Author(s):  
Hailong Yang ◽  
Xiaoli Xi ◽  
Lili Wang ◽  
Yuchen Zhao ◽  
Xiaomin Shi
Keyword(s):  
Reflection Coefficient ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Band Edge ◽  
Slot Antenna ◽  
Defected Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Uwb Antennas ◽  
Low Pass

AbstractIn this study, a new ultra-wideband (UWB) band-edge selectivity antenna with a modified radiation slot using defected ground structure (DGS) is presented to obtain bandpass filtering reflection coefficient and gain performance. The well-designed DGS is designed on backside metallic of the substrate and can be seen as a low-pass filter that provides a good roll-off at a higher frequency. By connecting the DGS and the stepped slot and making them merge with each other, good cut-off property in the upper passband and better in-band impedance characteristics are obtained. Measured results show that the proposed design not only shows good band-edge selectivity in reflection coefficient and gain performance but also has a good impedance matching of −13.5 dB reflection coefficients and a good radiation efficiency of 90% in the operating frequencies. The measured bandwidth defined with the reflection coefficient less than −10 dB is from 3.1–11.2 GHz. Furthermore, the size of the filtering UWB antenna is 22 mm × 12 mm, which is smaller than many individual UWB antennas and UWB filters.

scholarly journals A Compact Four-Port Coplanar Antenna Based on an Excitation Switching Reconfigurable Mechanism for Cognitive Radio Applications

2019 ◽  
Vol 9 (15) ◽  
pp. 3157 ◽  
Author(s):  
O ◽  
Jin ◽  
Choi
Keyword(s):  
Cognitive Radio ◽  
High Frequency ◽  
Coplanar Waveguide ◽  
Low Frequency ◽  
Loop Antenna ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Uwb Antenna ◽  
High Isolation ◽  
Loop Antennas

In this paper, we propose a compact four-port coplanar antenna for cognitive radio applications. The proposed antenna consists of a coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna and three inner rectangular loop antennas. The dimensions of the proposed antenna are 42 mm × 50 mm × 0.8 mm. The UWB antenna is used for spectrum sensing and fully covers the UWB spectrum of 3.1–10.6 GHz. The three loop antennas cover the UWB frequency band partially for communication purposes. The first loop antenna for the low frequency range operates from 2.96 GHz to 5.38 GHz. The second loop antenna is in charge of the mid band from 5.31 GHz to 8.62 GHz. The third antenna operates from 8.48 GHz to 11.02 GHz, which is the high-frequency range. A high isolation level (greater than 17.3 dB) is realized among the UWB antenna and three loop antennas without applying any additional decoupling structures. The realized gains of the UWB antenna and three loop antennas are greater than 2.7 dBi and 1.38 dBi, respectively.

scholarly journals A Novel Compact Microstrip UWB Rectangular Stair Slot Antenna for the Analysis of Return Losses

2019 ◽  
Vol 8 (10) ◽  
pp. 4597-4603 ◽  
Keyword(s):  
Return Loss ◽  
Wide Band ◽  
Directional Pattern ◽  
Slot Antenna ◽  
Ultra Wide Band ◽  
Radiation Patterns ◽  
Uwb Antenna ◽  
Antenna Performance ◽  
Ansoft Hfss ◽  
Radiation Behavior

This article deals with the various designs of a novel compact microstrip fed UWB antenna to investigate the corresponding return losses of different structures. The dimension of the designed antenna is 33 x 19 x 1.9 mm3 with FR4 substrate and it can be operated from 2.846 - 11.7458 GHz. The effects of varying the structure of antenna are to exhibit the investigation of corresponding return losses. Different structures of antenna are simulated in Ansoft HFSS simulator. The results of return losses and radiation patterns are explored with the ultra wide band (UWB) rectangular Stair slot antenna. The modified structure of antenna shows the minimized return loss with an enhanced bandwidth that satisfies good UWB characteristics. Antenna performance can also be explored from the radiation behavior of the antenna which is relatively omni-directional pattern for rectangular Stair slot antenna

Miniaturized Implantable Ultra-Wideband Antenna with Bio-Compatible Substrate Material

2016 ◽  
Vol 850 ◽  
pp. 71-76
Author(s):  
Maisarah Abu ◽  
Nurul Hafiza Izahar ◽  
Najimiah Radiah Mohamad ◽  
Adib Othman ◽  
N.A.M. Aris ◽  
...  
Keyword(s):  
Return Loss ◽  
Circular Ring ◽  
Substrate Material ◽  
Ultra Wideband ◽  
Center Frequency ◽  
Total Efficiency ◽  
Uwb Antenna ◽  
Band Frequency ◽  
Materials Used ◽  
The One

Ultra-wideband (UWB) technology was nowadays increased in interest for various applications due to its distinctive characteristics where it able to carry signals passes through obstacles unlikely narrow-band frequency that tends to reflect the signal. Through this paper, a design of miniaturized implantable UWB antenna utilizing various bio-compatible materials is studied. These materials are to be compared and determined the best material to be used for the design in terms of its return loss, center frequency, bandwidth, antenna gain and total efficiency. The antenna is designed in a structure of circular-ring with slit patch antenna using CPW profile with dimension of 10×10 mm2. As for the materials used in this study are Silicon, PDMS and Teflon PTFE. Each of this substrate has a thickness of 0.5 mm, 2.5 mm, and 1.5 mm correspondingly. After comparing these three materials, the one that gives the best result is Teflon PTFE with return loss at 11.91 GHz and 5.58 GHz bandwidth that covers from 9.16 GHz to 17.74 GHz frequency range. The antenna gives out total gain and efficiency of 2.54 dB and 86.5% respectively.

scholarly journals Design of Ultra Wideband Antenna

2020 ◽  
Vol 8 (5) ◽  
pp. 3988-3990
Keyword(s):  
Return Loss ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Dielectric Substrate ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Uwb Antenna ◽  
Rectangular Patch ◽  
Microstrip Feed

In this paper, A coplanar waveguide (CPW) ultra-wideband(UWB) antenna is designed, analyzed and simulated by computer simulation technology(CST). The proposed antenna is fabricated on FR-4 dielectric substrate. A microstrip feed line is used to excite the antenna.The ground plane is slotted to improve the impedance bandwidth (BW). Here, a rectangular patch is used as radiator and two corners out of four are truncated to improve impedance matching and UWB characterization.This antenna satisfies UWB characteristics like VSWR<2, Return loss(S11)<-10 dB,Gain<5dB and the antenna is operating within the frequency range of 1.59 to 11.87 GHz range which covers whole ultra wideband i.e. 3.1 to 10.6 GHz range.

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