Band-notched Characteristics Research Articles

CPW-fed star shaped UWB antenna with and without band-notch characteristics

A CPW-fed star shaped slot like monopole antenna with and without ITU-8 band notch characteristics for ultra wideband communication are proposed. They comprise a stage 1 Koch fractal star shaped radiating patch, modified feedline and slot loaded CPW ground plane. The band notch characteristic is achieved by loading the radiating patch with half wavelength long meander line slot. An impedance bandwidth of 3.1-17.6 GHz with band rejection for 8-9 GHz band (ITU-8 band) (S11 ≤ -10 dB) is achieved. The band notch characteristic is modeled by an equivalent RLC resonant circuit. The equivalent circuit is validated with simulated input impedance and VSWR results. The proposed antenna provides an average gain of 4.4 dB over the entire band of operation for without band notched antenna. The radiation patterns are also observed to be omni-directional and bidirectional at lower frequencies with some distortions at higher frequencies. Non-band reject antenna configuration provides a fidelity factor of 90% along with a constant group delay over the entire operating band. The effect of various critical parameters on antenna performance is also analysed.

CPW-fed star shaped UWB antenna with and without band-notch characteristics

A CPW-fed star shaped slot like monopole antenna with and without ITU-8 band notch characteristics for ultra wideband communication are proposed. They comprise a stage 1 Koch fractal star shaped radiating patch, modified feedline and slot loaded CPW ground plane. The band notch characteristic is achieved by loading the radiating patch with half wavelength long meander line slot. An impedance bandwidth of 3.1-17.6 GHz with band rejection for 8-9 GHz band (ITU-8 band) (S11 ≤ -10 dB) is achieved. The band notch characteristic is modeled by an equivalent RLC resonant circuit. The equivalent circuit is validated with simulated input impedance and VSWR results. The proposed antenna provides an average gain of 4.4 dB over the entire band of operation for without band notched antenna. The radiation patterns are also observed to be omni-directional and bidirectional at lower frequencies with some distortions at higher frequencies. Non-band reject antenna configuration provides a fidelity factor of 90% along with a constant group delay over the entire operating band. The effect of various critical parameters on antenna performance is also analysed.

UWB MIMO HIGH DIVERSITY ANTENNA OF FOUR RADIATORS WITH SINGLE-BAND-REJECTION FOR WIRELESS APPLICATIONS

In this paper, Ultra-Wideband Multi-Input-Multi-Output (UWB-MIMO) antenna with band-notched features is introduced. The band notch of the antenna is designed by inserting T-strip into the radiating patch to eliminate the interference with WiMAX applications from 3 to 4 GHz. To improve the isolation and the diversity between the radiators, the antenna radiators are arranged orthogonally and decoupling structure is added between them. The proposed antenna has a compact size of 42 × 42 mm2 and its bandwidth extends from 2.5 GHz up to 12 GHz. This antenna has been manufactured and its characteristics have been measured. The results showed that the proposed UWB-MIMO antenna has a good performance with bandwidth from 2.5 GHz to 12 GHz, excluding the notched band for WiMAX applications. Furthermore, it has high isolation with a value higher than 18 dB and with a correlation coefficient lowers than 0.05 through the operated frequency bands. These properties made it good candidate for diversity

8-Port MIMO Antenna Having Two Notched Bands for Chipless UWB-RFID Tags

An 8-element Multiple Input Multiple Output (MIMO) antenna is implemented for Chipless-RFID Tags (CRT) that function in the Ultra-Wideband (UWB) frequency range. The single UWB antenna contains a rectangular radiator in which two ellipses are cut from the two lower corners. Also, two circles are etched from the upper corners of the ground. This antenna is designed by placing eight antenna elements at 45∘ direction (clockwise and anticlockwise) and a thin line-shaped decoupling structure is used to enhance isolation at lower frequencies. Also, a T-shaped structure is used to enhance the notched band characteristics. The working frequency of the antenna is from 3.5 GHz to 10.5 GHz with WiMAX and WLAN notched bands using U-slot and Split Ring Resonator (SSR) metamaterial, respectively. The antenna obtains a peak gain of 5 dB (single element). This antenna has radiation efficiency from 76.4% to 92.7%. This antenna design will inspire the designers of chipless RFID (CRFID) to produce low-cost tags.

Novel Compact UWB Band Notch Antenna Design for Body-Centric Communications

In this paper, a novel and compact ultra-wideband (UWB) antenna with band-notched characteristics for body-centric communication is examined and implemented. The shape of the designed antenna looks like a ‘swan’ with a slotted patch. The performance parameters of this antenna for both the free space and on-body scenario for body-centric communication are analyzed and investigated through the simulation process using Computer Simulation Technology (CST). This antenna can avoid the interference caused by Wireless Local Area Network (WLAN) (5.15–5.825 GHz) and Worldwide Interoperability for Microwave Access (WiMAX) (5.25–5.85 GHz) systems with a band notch because of newly designed UWB antenna is revised small form factor sized. At first, the performance parameters like return loss response, gain, radiation patterns, and radiation efficiency on the free space of this UWB antenna are evaluated. After that, the on-body performance parameters of the antenna are also examined to place the antenna at various distances like 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm away from 3-layers of phantom body model at frequencies of 3.5 GHz, 5.2 GHz, 5.8 GHz, 8 GHz, and 10 GHz. All the on-body performance parameter results are compared and analyzed with free space performance parameter results. Lastly, by changing patch slot length and ground plane length, parametric studies were done for performance comparison. Due to its compact size, novel shape and significant on-body performance, the proposed antenna is very suitable for multi-purpose healthcare applications and sports performance monitoring.

Miniaturized Novel UWB Band-Notch Textile Antenna for Body Area Networks

This paper presents the design and analysis of a miniaturized and novel wearable ultra-wideband (UWB) band-notch textile antenna for Body Area Networks (BANs). The major goal of building the antenna for wearable applications with band notch in X-band is to reject the downlink band (7.25 to 7.75 GHz) of satellite communication in the UWB frequency ranges of 3.1–10.6 GHz to keep away from interference. Computer Simulation Technology (CST) TM Microwave Studio, which is user-friendly and reliable, was used to model and simulate the antenna. The radiating element of the antenna is designed on Jeans’ textile substrate, which has a relative permittivity of 1.7. The thickness of the jeans’ fabric substrate has been considered to be 1 mm. Return loss, gain, bandwidth, impedance, radiation, and total efficiency, and radiation patterns are presented and investigated. The antenna is simulated placed on the three layers of the human body model, and the on-body results are summarized in comparison with free space. Results and analysis indicate that this antenna has good band-notch characteristics in the frequency range of 7.25 GHz to 7.75 GHz. The parametric study varying the relative permittivity of Jeans’ fabric substrate of this antenna is also evaluated. In addition, effects on the antenna parameters of variation of ground plane size have been reported. The antenna is 25 mm × 16 mm × 1.07 mm in total volume. Results reveal that this antenna achieves the design goal and performs well both in free space and on the body.

Sprocket gear wheel shaped printed monopole ultra‐wideband antenna with band notch characteristics: Design and measurement

A compact ultra-wideband (UWB) printed monopole UWB with dual band-notched characteristics has been designed and investigated in this manuscript. The Wi-MAX and wireless local area network (WLAN) band rejection characteristics have been obtained by employing the circular ring and arc-shaped slot along with rectangular slot in radiating patch. Overall size of proposed UWB antenna is 27 × 27 × 1.6 mm3, which consists of sprocket gear wheel shaped structure as a core radiating patch element and excited by using 50 Ω coplanar waveguide feed. The proposed antenna exhibits the UWB frequency spectrum from 3.1 to 10.6 GHz along with Bluetooth frequency range 2.4–2.48 GHz without disturbing overall dimensions of antenna. Proposed antenna reveals the measured VSWR operating bandwidth of 10.0 GHz in the frequency range from 2.0 to 12.0 GHz along with Wi-MAX and WLAN rejected bands. Moreover, proposed antenna adorns the measured gain of −8.28 and − 9.98 dBi at rejected frequency bands, whereas, at other frequencies, it changes between 1.5 and 5.0 dBi. The radiation efficiency of proposed UWB antenna varies from 84% to 97% except rejected frequency bands. Group delay and radiation pattern have also been analyzed and found appropriate for the current UWB applications. Finally, the optimized structure of antenna with dual band rejection characteristics has been fabricated and tested for the authentication of simulated results. Both the results are compared and are found in good agreement with each other.

Infinite length slotted ultra-wideband monopole antenna using step-feed with band notch characteristics

AbstractIn this work, a printed ultra-wideband (UWB) antenna has been proposed exhibiting band notch characteristics. The proposed design covers the entire UWB band except for the 3.5 GHz band providing the band notch for the WiMAX band. This design consists of two-quarter elliptical patches placed symmetrically over the FR4 substrate. The elliptical shape of the patch is responsible for the UWB band achieved. The slot has been created on the optimized patch area to achieve the desired characteristics providing a notch for the WiMAX band. The slot in the patch is so perfectly designed that it gives the patch a perfect shape of butterfly wings. After designing, the proposed antenna was simulated and then fabricated. The fabricated and simulated results are in close agreement with each other which shows, the proposed UWB antenna is good enough for biomedical applications.

Design of a co‐planar waveguide‐fed flexible ultra‐wideband ‐ multiple‐input multiple‐output antenna with dual band‐notched characteristics for wireless body area network

In this article, a co-planar waveguide-fed ultra-wideband (UWB) multiple-input multiple-output flexible antenna with dual band-notched characteristics on liquid crystal polymer substrate with high isolation for wireless body area network application is designed and fabricated. Two fan-shaped monopole UWB antenna elements are designed and placed vertically, with tampered feeder, asymmetrical ground plane and two C-shaped slots on the radiation patch. The measured working bandwidth can reach 2.63–11.6 GHz and the rejection bands are 3.25–4.36 and 5.41–6 GHz. The port isolation (S21) is better than −22 dB. When the bending radius is 35 and 45 mm, the antenna is measured for flexibility. In addition, the antenna is placed on human tissue to test its performance. All the results show that it has good radiation, high isolation and flexibility, and has broad application prospects in the wearable field.

An ultra‐wideband multiple‐input multiple‐output antenna with dual band‐notched characteristics

In this paper, an ultra-wideband multiple-input multiple-output antenna with dual band-notched characteristics is proposed. The radiating element is an octagonal structure using a tapered microstrip line to feed. A multimode resonator is introduced on one side of the microstrip feed line to achieve dual band-notched characteristics, which eliminates the interference of wireless local area network band and X satellite communication frequency band. By using a diamond-shaped defect ground structure and extending a parasitic branch at the centre axis of the ground, the mutual coupling of the antenna is reduced to −20 dB. The proposed antenna has a compact size of 30 × 35 × 0.8 mm3. The measured results are in good agreement with the simulation results. The proposed antenna covers 3.1–10.6 GHz with dual notched-band characteristics and the mutual coupling below −20 dB. The antenna has a good diversity performance as the envelope correlation coefficient <0.03. The antenna is suitable for ultra-wideband communications.

Miniaturized self-isolated UWB MIMO planar/cuboidal antenna with dual X-band interference rejection

The work presents two configurations of four-port UWB MIMO antenna designs with dual notched features. Firstly, a planar four-port UWB MIMO antenna (Design-1) of dimension 31.5 × 34 × 0.8 mm3 is designed by placing four F-shaped radiators over the FR4 substrate board orthogonally. Further, to achieve band-notched characteristics at 7.3 GHz and 8.2 GHz, a pair of mushroom EBG structures and a folded U-shaped slot are positioned over the substrate layer coupled to the feedline and above the radiator, respectively. Secondly, a four-port cuboidal MIMO antenna (Design-2), of dimension 20.8 × 20.8 × 19 mm3 is designed to exhibit band-notched characteristics within the same frequency bands (7.3 GHz and 8.2 GHz). The performance parameters for these designs including the envelope correlation coefficient (ECC) and the diversity gain (DG), are also evaluated and compared. ANSYS HFSS V14.0 tool is used for simulating the designs. For validation purposes, the two prototypes are fabricated and characterized. The measured results are found to be very close to their simulated counterparts.

A Compact Printed UWB MIMO Antenna with Electronically Reconfigurable WLAN Band-Notched Characteristics

In this research paper, a simple design of an ultra-wideband (UWB) multi-input multi-output (MIMO) antenna with low envelope correlation coefficient (ECC), high isolation, enhanced gain, radiation efficiency and reconfigurable band notching functionality is proposed. Two symmetrical slots are carefully integrated into the partial ground plane of the conventional monopole to provide a notched band at 5.8[Formula: see text]GHz for the WLAN system. This notching method is simple and does not endure negative effect performance or any design complexity. The notched band is then controlled using PIN diodes. A complete biasing circuit is integrated on the same partial ground plane to bias the PIN diodes in forward and reverse directions. To reduce the complexity of the design that may be increased due to the reconfiguration circuit, isolation enhancement is accomplished by orthogonal placement of the elements rather than using any additional decoupling structures. A prototype of the MIMO UWB structure is fabricated and its performance parameters are experimentally tested. The captivating agreement between simulation and measurement demonstrates that the proposed antenna system is a good candidate for UWB applications with an operating band extending from 3 to 11[Formula: see text]GHz, notch-band reconfiguration freedom, and isolation of more than 20[Formula: see text]dB.

Design and research of a miniaturized four notch UWB antenna

In order to effectively suppress the interference of narrow-band communication systems such as WiMAX band, international satellite band, X band and the ITU band, this paper designs a miniature ultra wideband (UWB) antenna. The improved rectangle is used as the radiation patch. The semicircular groove is dug in the upper part of the rectangle and the two corners below are cut off. The long triangle is also cut on both sides of the end of the microstrip line. The fish bone groove is well modified in the middle of the rectangular ground plate to obtain the perfect ultra wideband characteristics. By digging a semi-circular groove on the radiation patch to introduce T-shaped branches, and opening an inverted U-shaped groove in the center of the radiation patch, introducing symmetrical C-shaped open branches on both sides of the feeder line and etching U-shaped narrow gaps on the feeder line, four band notch characteristics of 3.24−3.8 GHz, 4.5−4.97 GHz, 7.24−7.76 GHz and 8.0−8.54 GHz are produced, which better suppresses the interference in the notch band, shows that the antenna can work normally in the frequency band of 3.0−13.09 GHz, and the four notch baud property of the antenna also expands the application field, which is suitable for many ultra wideband communication systems.

Tunable Inverted U-shaped Dual Band Notch Monopole Antenna for Ultrawideband Applications

This work presents a planar ultra-wideband (UWB) monopole antenna with controllable dual-band notches. In the proposed design, the lower and upper notch characteristics are realized by placing an inverted U-shaped slot on the radiating surface and another inverted U-shaped strip near to microstrip feed line, respectively. The controllable dual-notch frequencies are attained by placing varactor diodes at an appropriate position on the inverted U-shaped slot and inverted U-shaped strip, respectively. Simulation results show that the proposed antenna design has tunable band-notch characteristics from 5.58 GHz to 5.91 GHz and 7.02 GHz to 7.45 GHz, by decreasing the capacitance value from 2.67 pF to 0.63 pF. The fabricated prototype of the optimized design is characterized in three cases. A fairly good agreement is observed between the simulated and experimental results in all three cases. To the best of the authors’ knowledge, the dual tunable band rejects UWB is proposed for the first time in this paper.

Notched Integrated Planar Antenna for UWB Application

A new ultra-wideband antenna (UWB) with band notch characteristics has been studies in this work. The propose structure has constructed using air gap between two layer, defected ground structure (DGS) and shorting post. The structure covers frequency ranges from 4.61 GHz to 9.85 GHz. The radiation pattern is quite stable throughout the whole operating range. The antenna operates in C band of frequency spectrum and provides wide impedance bandwidth of 72%. 5.5GHz frequency has been notched and an average gain around 5.8 dBi has been achieved which is very useful for enormous data handle in modern wireless communication. All the simulation has been carried out using High Frequency Structural Simulator (HFSS) software.

Design and packaging of polarization diversity 3D-UWB MIMO antenna with dual band notch characteristics for vehicular communication applications

In this article, the design, fabrication, testing, and packaging of a Substrate Integrated Waveguide(SIW) based polarization diversity 3D eight-port Ultra-Wideband (UWB) MIMO antenna introduced with dual-band notch characteristics for vehicular communication applications. In this proposed UWB MIMO design, we employed a SIW technique to achieve UWB bandwidth with a compact size of 60 × 60 mm3. The SIW based metallic via integrated with L-shaped parasitic slot stub and radiator to notch the WLAN and L-shaped stub connected at the ground plane to notch the X-band. The SIW based radiators are placed in the vertical and horizontal plane to realize the polarization diversity. In addition to providing polarization diversity, the antenna’s direction also contributes a reliable link with communication equipment. The antenna performance metrics such as reflection coefficient(Sii), mutual coupling(Sij), the peak gain, radiation pattern, radiation efficiency, Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Total Active Reflection Coefficient (TARC), Channel Capacity Loss (CCL) and Mean Effective Gain(MEG). The proposed 3D antenna performance analyzed when mounted inside the different types of housing. Hence, the proposed polarization diversity antenna is suitable for vehicular communication applications.

Design of a compact UWB MIMO‐diversity antenna incorporating fractal inspired isolation structure with band notch characteristics

AbstractIn this communication, a new compact ultra‐wideband (UWB) multiple‐input multiple‐output (MIMO) antenna with band notch characteristics is presented for wireless application. It comprises of two unique monopole antenna elements sharing a similar ground plane. To reduce the coupling between antenna elements, a modified T‐shaped stub equipped with Minkowski fractal shape elements are introduced on the ground plane which in turn establish a good isolation between radiating elements. A band notch is achieved at 5.45 GHz by adding two additional rectangular stubs at 45° where symmetric slots have been etched. The efficiency and gain of the antenna drops significantly at the centre of the notch band which indicates good interference suppression. Results show that the designed antenna delivers widest impedance bandwidth (−10 dB) throughout the operating band of 3.1–20 GHz (of 146% impedance bandwidth) which covers UWB as well as Ku‐band. The antenna also produces ‐18 dB isolation for most of the operating band and ‐16 dB up to 6 GHz. The optimized antenna is fabricated and tested showing |S11| characteristics below −10 dB from 3.1 to 20 GHz band. The dimension of the proposed antenna is 18 × 26 × 1.6 mm3. Results show that the simulated characteristics are in good agreement with the measured counterpart. The designed MIMO antenna is an appropriate candidate for UWB and other wireless applications.

Compact Triple Band Notched Pentagonal Shaped UWB Antenna Loaded with Slots and Parasitic Resonator

In this paper, a compact, planar printed microstrip line fed pentagonal shape ultra-wideband antenna with triple band-notched characteristics is proposed and investigated. By incorporating a pair of mirrored Γ-shape, a pair of mirrored L-shape slots in the pentagonal patch and bent C-shape parasitic strip at the backside of a patch, the tunable band notched responses are realized. The proposed antenna is fabricated on Rogers RO3003 substrate with permittivity 3.0 and thickness of 0.76 mm. The measured results indicate that the proposed antenna having dimensions of 32 × 24 × 0.76 mm3 has a bandwidth over the frequency band 2.7-10.6 GHz with S11 ≤ -10 dB (VSWR ≤ 2), except in WiMAX band (3.27-3.85 GHz), WLAN band (5.6-5.95 GHz) and ITU-T band (7.84-8.46 GHz). The presented antennas show dipole- like patterns in E-plane and omnidirectional in H-plane, minor group delay variation, and nearly constant gain at operating frequencies.

Tri-Strip Monopole Antenna for LTE, WLAN and WiMAX Communication Applications

In this research, we present a Tri-strip monopole antenna for LTE, WLAN (Wireless Local Area Network) and WIMAX (Wireless interoperability for microwave access) Applications. This is due to the fact that wireless applications is not needed to connect all operating frequencies simultaneously, Which will effect improving functionalities without increasing size of antenna. A miniaturized triple wideband coplanar waveguide-fed patch antenna with the defected ground structure isused for LTE, WLAN and WIMAX applications. The proposed antenna with overall size of 40 mm×40 mm×1mm and the design simulation are carried on a Rogers RT/ duroid 5880 substrate using HFSS v.13.0 simulation software. The proposed antenna shows the gain of 9dB at notch band frequency therefore it is good for its working conditions. Moreover, the proposed antenna is fabricated with a new metamaterial approach by placing the unit cell we have observed the triple band notch characteristics and depth in resonant frequency. There is enhancement in gain and radiation patterns, return loss is analyzed and parametric analysis is presented for optimization of antenna. The average gain that is observed through the band is 3.5dB and the average radiation efficiency that is observed for the model is 94%.

Compact Ultrawide Band Metamaterial-Inspired Split Ring Resonator Structure Loaded Band Notched Antenna

A novel compact size ultrawide band planar antenna with band notched characteristics is present. The band rejection characteristic is achieved by loading a pair of metamaterial inspired rectangular split ring resonator (SRR) near the feed line and by etching the SRR slots on a radiating patch. The simulated and measured results reveal that the proposed antenna exhibits the impedance bandwidth over the ultrawide band (UWB) frequency range from 3.1 to 14 GHz with the voltage standing wave ratio less than 2 except for band stop bands at 3.29 to 3.7 GHz (WiMAX band), 3.7 to 4.10 GHz (C-band), 5.1 to 5.9 GHz (WLAN band), and 7.06 to 7.76 GHz (downlink X-band satellite communication), respectively. The proposed antenna fabricated on low-cost FR-4 substrate has compact size of 24 × 20 × 1.6 mm3. The simulation results are compared with measured results and demonstrate good agreement with stable gain over pass bands. The proposed antenna also exhibits dipole-like radiation pattern in E-plane and omni-directional pattern in H-plane. These results led to conclusion that the presented antenna is a suitable candidate for ultrawide band UWB applications with desired band notch characteristics.