Frequency reconfigurable antenna for cognitive radios with sequential UWB mode of perception and multiband mode of operation

2018 ◽  
Vol 10 (9) ◽  
pp. 1096-1102 ◽  
Author(s):  
Ali Mansoul ◽  
Farid Ghanem
Keyword(s):  
Narrow Band ◽  
Cognitive Radios ◽  
Dual Band ◽  
Uwb Antenna ◽  
Switch Operation ◽  
Resonance Frequencies ◽  
Mode Of Operation ◽  
The Mean ◽  
Conductive Strip ◽  
Good Agreement

AbstractIn this work, an UWB/narrow band reconfigurable elliptical-shaped monopole antenna for cognitive radio applications with sequential perception and operation modes is presented. The proposed approach consists in integrating a reconfigurable filter, in an UWB antenna ground plan, by the mean of four horizontal slots and integrated switches that allow inserting/removing/varying zeros and poles in the frequency response. By acting on the slot lengths in order to alter their resonance frequencies, the different switch configurations allow the antenna to switch between an UWB mode that could be used for the perception (sensing) and different narrowband modes, mono-band and dual-band, that could be used for the operation at 2.4 or/and 3.5 GHz. To validate the concept, an experimental prototype has been fabricated and a good agreement between the simulated and the measured S-parameters has been obtained. While the presented work uses the presence/absence of a perfect conductive strip (PEC) to model real switch operation, it is believed that the obtained results conjugated with previous work using real switches on a very similar structure allows validating approach.

scholarly journals A Compact Novel Three-Port Integrated Wide and Narrow Band Antennas System for Cognitive Radio Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
N. Anvesh Kumar ◽  
A. S. Gandhi
Keyword(s):  
Cognitive Radio ◽  
Wireless Communication ◽  
Frequency Spectrum ◽  
Spectrum Sensing ◽  
Frequency Band ◽  
Return Loss ◽  
Narrow Band ◽  
Experimental Results ◽  
Uwb Antenna ◽  
Good Agreement

The design of a three-port radiating structure, integrating wide and narrow band antennas for cognitive radio applications, is presented. It consists of a UWB antenna for spectrum sensing and two narrow band antennas for wireless communication integrated on the same substrate. The UWB antenna covers the complete UWB spectrum (3.1 GHz to 10.6 GHz) approved by FCC. In the two narrow band antennas, each antenna presents dual bands. In particular, the first narrowband antenna resonates at 6.5 GHz, covering the frequency band between 6.36 GHz and 6.63 GHz, and at 9 GHz, covering the frequency band between 8.78 GHz and 9.23 GHz, presenting minimum return loss values of 28.3 dB at 6.5 GHz and 20.5 dB at 9 GHz, respectively. Similarly, the second one resonates at 7.5 GHz, covering the frequency band between 7.33 GHz and 7.7 GHz, and at 9.5 GHz, covering the frequency band between 9.23 GHz and 9.82 GHz, presenting minimum return loss values of 19.6 dB at 7.5 GHz and 28.8 dB at 9.5 GHz, respectively. Isolation among the three antennas is less than −20 dB over the UWB frequency spectrum. These antennas are realized on a FR4 substrate of dimensions 30 mm × 30 mm × 1.6 mm. Experimental results show a good agreement between the simulated and measured results.

scholarly journals A Compact CPW-Fed UWB Antenna with Dual Band-Notched Characteristics

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Aiting Wu ◽  
Boran Guan
Keyword(s):  
Simple Structure ◽  
Ground Plane ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Frequency Range ◽  
Uwb Antenna ◽  
Compact Size ◽  
Excellent Candidate ◽  
Uwb Applications ◽  
Good Agreement

A compact CPW-fed planar UWB antenna with dual band-notched property is presented. The dual band rejection is achieved by etching a C-shaped slot on the radiation patch and two L-shaped parasitic strips in the ground plane. The experimental and measured results show that the proposed antenna exhibits an impedance bandwidth over an ultrawideband frequency range from 2.4 to 12.5 GHz with VSWR less than 2, except for two stopbands at 3.3 to 3.75 GHz and 5.07 to 5.83 GHz for filtering the WiMAX and WLAN signals, respectively. It also demonstrates a nearly omnidirectional radiation pattern. The fabricated antenna has a tiny size, only 32 mm × 32 mm × 0.508 mm. The simulated results are compared with the measured performance and show good agreement. The simple structure, compact size, and good characteristics make the proposed antenna an excellent candidate for UWB applications.

scholarly journals A Planar UWB Antenna with Dual Band Rejection Capability Using Double Rotated ESRRs

2018 ◽  
Vol 7 (1) ◽  
pp. 19-24 ◽  
Author(s):  
A. S. Elkorany ◽  
G. T. Ahmed ◽  
D. A. Saleeb
Keyword(s):  
Return Loss ◽  
Group Delay ◽  
Ultra Wideband ◽  
Ring Resonators ◽  
Dual Band ◽  
Uwb Antenna ◽  
Split Ring ◽  
Wireless Applications ◽  
Different Dimensions ◽  
Good Agreement

In this paper, CPW-Fed ultra wideband (UWB) planar monopole antenna (PMA) loaded by double elliptical split ring resonators (ESRRs) for double band-notch characteristics is introduced and examined. Two different ESRRs with different dimensions are printed in the antenna backside to notch two different frequencies. The ESRRs are also rotated and the corresponding return loss effect is examined.  Different notch frequencies can be obtained by varying the ESRRs, dimensions. Two single SRRs are used to notch two frequencies instead of using dual SRR pairs. Two notch frequencies at 5.2 GHz and 6.9 GHz has been obtained to notch WLAN and C-band wireless applications, respectively. A directive radiation pattern in E-plane and omnidirectional radiation patterns in the H-plane could be observed. Also the gain is suppressed in the notch frequencies. The group delay is nearly stable in the UWB frequency range, except at the notch frequencies, which is distorted sharply. So, the proposed antenna is a good candidate for the modern UWB systems. Finite element method FEM and finite integration technique FIT are used to simulate the proposed structures through the usage of Ansys HFSS and CST MWS. Very good agreement between both results has been obtained.

scholarly journals Dual Band-Notched UWB Antenna based on Electromagnetic Band Gap Structures

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Son Trinh-Van ◽  
Chien Dao-Ngoc
Keyword(s):  
Band Gap ◽  
Frequency Band ◽  
Stop Band ◽  
Ultra Wideband ◽  
Dual Band ◽  
Uwb Antenna ◽  
Directional Characteristic ◽  
Electromagnetic Band Gap ◽  
Final Design ◽  
Good Agreement

A printed ultra-wideband (UWB) antenna with dual band-notched characteristics based on electromagnetic band-gap (EBG) structure is presented. To produce dual-band rejection, the microstrip feed line is placed between two pairs of EBG cells which are designed to act as stop-band filters. The final design of the antenna satisfies the voltage standing wave ratio (VSWR) requirement of less than 2.0 in a bandwidth spreading from 2.275 GHz to 10.835 GHz, which entirely covers UWB frequency band allocated from 3.1 to 10.6 GHz. The antenna also shows dual band-notched performance at the frequency bands of 3.375 − 3.875 GHz for WiMAX and 5.325 − 6.150 GHz for WLAN, while possessing omni-directional characteristic in the whole operating frequency band. The results show good agreement between simulation and measurement.

Photo-electric Hβ and uvby photometry

1966 ◽  
Vol 24 ◽  
pp. 170-180
Author(s):  
D. L. Crawford
Keyword(s):  
Narrow Band ◽  
Line Strength ◽  
Interference Filter ◽  
B Stars ◽  
Relative Line ◽  
The Mean ◽  
F Stars ◽  
Two Parameters ◽  
Filter Photometry ◽  
The Continuum

Early in the 1950's Strömgren (1, 2, 3, 4, 5) introduced medium to narrow-band interference filter photometry at the McDonald Observatory. He used six interference filters to obtain two parameters of astrophysical interest. These parameters he calledlandc, for line and continuum hydrogen absorption. The first measured empirically the absorption line strength of Hβby means of a filter of half width 35Å centered on Hβand compared to the mean of two filters situated in the continuum near Hβ. The second index measured empirically the Balmer discontinuity by means of a filter situated below the Balmer discontinuity and two above it. He showed that these two indices could accurately predict the spectral type and luminosity of both B stars and A and F stars. He later derived (6) an indexmfrom the same filters. This index was a measure of the relative line blanketing near 4100Å compared to two filters above 4500Å. These three indices confirmed earlier work by many people, including Lindblad and Becker. References to this earlier work and to the systems discussed today can be found in Strömgren's article inBasic Astronomical Data(7).

A compact UWB antenna with triple band notch reconfigurability

2020 ◽  
pp. 1-7
Author(s):  
Lei Li ◽  
Jingchang Nan ◽  
Jing Liu ◽  
Chengjian Tao
Keyword(s):  
Coplanar Waveguide ◽  
Ring Resonators ◽  
Uwb Antenna ◽  
Split Ring ◽  
X Band ◽  
Compact Size ◽  
Nested Structure ◽  
P Type ◽  
Good Agreement ◽  
Triple Band

Abstract A compact ultrawideband (UWB) antenna with reconfigurable triple band notch characteristics is proposed in this paper. The antenna consists of a coplanar waveguide-fed top-cut circular-shaped radiator with two etched C-shaped slots, a pair of split-ring resonators (SRRs) on the backside and four p-type intrinsic n-type (PIN) diodes integrated in the slots and SRRs. By controlling the current distribution in the slots and SRRs, the antenna can realize eight band notch states with independent switch ability, which allows UWB to coexist with 5G (3.3–4.4 GHz)/WiMAX (3.3–3.6 GHz), WLAN (5.15–5.825 GHz), and X-band (7.9–8.4 GHz) bands without interference. By utilizing a nested structure of C-shaped slots and SRRs on the backside, a compact size of 18 × 19.5 mm2 is achieved along with multimode triple band notch reconfigurability. The antenna covers a bandwidth of 3.1–10.6 GHz. A prototype is fabricated and tested. The simulated and experimental results are in good agreement.

scholarly journals Realizing UWB Antenna Array with Dual and Wide Rejection Bands Using Metamaterial and Electromagnetic Bandgaps Techniques

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 269
Author(s):  
Ayman A. Althuwayb ◽  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Pancham Shukla ◽  
Ernesto Limiti
Keyword(s):  
Antenna Array ◽  
Ground Plane ◽  
Ultra Wideband ◽  
Dual Band ◽  
Area Network ◽  
Electromagnetic Bandgap ◽  
Uwb Antenna ◽  
Average Gain ◽  
Left Handed ◽  
Notched Band

This research article describes a technique for realizing wideband dual notched functionality in an ultra-wideband (UWB) antenna array based on metamaterial and electromagnetic bandgap (EBG) techniques. For comparison purposes, a reference antenna array was initially designed comprising hexagonal patches that are interconnected to each other. The array was fabricated on standard FR-4 substrate with thickness of 0.8 mm. The reference antenna exhibited an average gain of 1.5 dBi across 5.25–10.1 GHz. To improve the array’s impedance bandwidth for application in UWB systems metamaterial (MTM) characteristics were applied it. This involved embedding hexagonal slots in patch and shorting the patch to the ground-plane with metallic via. This essentially transformed the antenna to a composite right/left-handed structure that behaved like series left-handed capacitance and shunt left-handed inductance. The proposed MTM antenna array now operated over a much wider frequency range (2–12 GHz) with average gain of 5 dBi. Notched band functionality was incorporated in the proposed array to eliminate unwanted interference signals from other wireless communications systems that coexist inside the UWB spectrum. This was achieved by introducing electromagnetic bandgap in the array by etching circular slots on the ground-plane that are aligned underneath each patch and interconnecting microstrip-line in the array. The proposed techniques had no effect on the dimensions of the antenna array (20 mm × 20 mm × 0.87 mm). The results presented confirm dual-band rejection at the wireless local area network (WLAN) band (5.15–5.825 GHz) and X-band satellite downlink communication band (7.10–7.76 GHz). Compared to other dual notched band designs previously published the footprint of the proposed technique is smaller and its rejection notches completely cover the bandwidth of interfering signals.

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