Compact Ultra-wideband Monopole Research Articles

Novel Dual Band Frequency Selective Surface and its Applications on the Gain Improvements of Compact UWB Monopole Antenna

In this work, a highly directional ultra-wideband (UWB) microstrip patch antenna as a single-element is suggested. The proposed antenna’s gain is enhanced with a novel dual-band frequency selective surface (FSS) placed beneath it. The FSS design has a hexagonal structure with meander line inductances and a capacitance-like structure connecting all of the corners to the middle. There is no metallic layer on the other side of the substrate, which shows transmission zeros at 4.95 GHz and 12.7 GHz, and a modified U-shaped monopole antenna is developed. First, the performance characteristics of the antenna and FSS are analyzed from the simulation results, and they are validated experimentally after fabrication, followed by measurement. The compact configuration comprises an antenna loaded with the proposed FSS results S11 less than -10 dB from 3.15 GHz to 22.65 GHz, covering the UWB band together with the X, Ku-band with a bandwidth of 19.5 GHz (151.16% FBW). The antenna’s overall physical dimensions would be 38.8 mm×38.8 mm×25.2 mm (0.407λo×0.407λo×0.265λo), with λo denoting the lowest frequency’s free-space wavelength. The FSS loading results in a 9.9 dBi maximum gain at 10 GHz. The antenna’s small size increases bandwidth, and its high peak gain makes it ideal for use in real-time applications.

Compact UWB Monopole Antenna with Tunable Dual Band Notched Characteristics for WiMAX and WLAN Applications

The present work shows a planar compact ultra-wideband (UWB) monopole antenna with controllable dualband-notch frequencies at 3.3 GHz for WiMAX and 5 GHz for WLAN. In the proposed antenna, the lower notchband (at a frequency of 3.3 GHz) is made by cutting a thin horizontal strip on top of the radiating patch. The uppernotch band (at a frequency of 5 GHz) is made by putting two narrow parasitic strips in the shape of an “I” oneither side of the radiating patch. The incorporation of three varactor diodes between the radiating patch and three metallic strips provides the flexibility of adjusting the notch frequencies. The notch band tunability between 3.15 GHz and 3.69 GHz and between 4.93 GHz and 5.59 GHz, respectively, is achieved by changing the bias voltageof the varactor diode between 0 V and 30 V. The gain and efficiency characteristics of the designed antenna alsoexhibit band rejection at the respective notch frequencies. The design principle is validated by fabricating andmeasuring a prototype of the proposed dual-band, notched UWB antenna. For three different bias voltages of thevaractor, the simulated and experimental findings are in reasonable agreement. The proposed works demonstratebetter-notch characteristics as compared with other reported works over the UWB range

Miniaturized Ultrawideband Microstrip Antenna for IoT-Based Wireless Body Area Network Applications

In this paper, we present an extremely compact ultrawideband (UWB) monopole microstrip patch antenna for a wireless body area network (WBAN). The proposed antenna is fabricated on a flexible Rogers RT-5880 dielectric substrate of thickness 0.5 mm and has an overall size of 20 × 15 × 0.5 m m 3 . The proposed antenna achieves a wideband characteristic with the help of a modified ground plane with a monopole pair. The monopole antenna is fed through a microstrip line and has a good impedance matching over a frequency band of 3.2 to 15 GHz (and beyond), with an axial ratio below 3 dB and a high efficiency of 77–95%. This antenna is designed to cover almost the complete UWB range; bandwidth for antenna is 11.52 GHz (3.48-15 GHz). The antenna has a realized gain of 2.3–7.2 dBi throughout the frequency band and has been tested for conformality. Measured results are found to be in good correlation with the simulated results. The antenna has also been tested for specific absorption rate (SAR) values within the simulation to compare with Federal Communications Commission (FCC) limits and verify their suitability for the Internet of Things- (IoT-) based wearable body area network.

A Compact UWB Monopole Antenna with Triple Band Notches

This article presents an ultra-wideband (UWB) monopole antenna with triple band notch characteristics. The proposed antenna consists of an octagonal patch, fed with a 50 Ω line, which occupies a compact size of 40 mm × 29 mm (0.36λ × 0.26λ, λ is computed using 2.7 GHz frequency) and resonances at a relatively low frequency (2.94 GHz). Specifically, an L-shaped stub, an inverted C-shaped slot, and a pair of U-shaped resonating structures are introduced into the design, which allow antenna to generate three band notches at 3.22-3.83 GHz, 4.49-5.05 GHz and 7.49-8.02 GHz, corresponding to WiMAX band, Indian national satellite (INSAT) band, and X-band satellite frequencies, respectively. In the center of the notched band, the antenna has lower efficiency and gain, essentially indicating that the antenna has good interference rejection performance. To evaluate its performance, the proposed antenna has been fabricated and measured, and the relevant functional parameters, such as S-parameters, voltage standing wave ratio (VSWR) and radiation property, have been studied.

Compact ultra-wideband monopole antenna with tunable notch bandwidth/frequency ratio

Abstract A compact tunable notch band ultra-wideband (UWB) antenna is implemented. The band notch characteristics have been obtained by placing a square-shaped metallic loop in the upper ground plane connected via PIN diode. The obtained notched frequency bandwidth can be altered by changing the states of the PIN diode. UWB response with narrow-band notch operation is observed when PIN diode is in ON state. When the PIN diode is in OFF state, the bandwidth of the obtained band notch widens by suppressing the first higher-order resonance and thus a narrow dual-band response is obtained. Moreover, the ratio of the frequency of first higher-order to the fundamental mode in the pass-band can be tuned with the different values as 1.584 and 2.20 in the ON and OFF state of the PIN diode, respectively. Furthermore, the antenna structure offers a compact geometry for the operation with the UWB response with band notch characteristics.

A compact UWB monopole antenna with penta band notched characteristics

A modified rectangular monopole ultra-wideband (UWB) antenna with penta notched frequency bands is presented. An inverted U shaped and slanted U-shaped on the radiating patch are inserted to achieve WiMAX and ARN bands rejection respectively, two mirrored summation Σ-shaped and four mirrored 5-shaped slots are inserted on the partial ground to achieve WLAN and X-band bands rejection respectively, finally rectangular shaped slot with partially open on the feed is inserted to achieve ITU-8 band rejection. The proposed antenna which was simulated has a compact size 30×35×1.6 m3. It is operated with impedance bandwidth 2.8-10.6 GHz at |S11| < −10 dB, that supported UWB bandwidth with filtering the five narrowbands that avoid the possible interference with them. The simulated resonant frequency for notched filters received 3.55, 4.55, 5.53, 7.45, 8.16 GHZ, for WiMAX, ARN, WLAN, X-Band, ITU-8 respectively. The proposed antenna is suitable for wireless communication such as mobile communication and internet of everything (IoE). Throughout this paper, CST-EM software package was used for the design implementation. Surface current distributions for all notched filters were investigated and shown that it is concentrated around the feeding point and the inserted notched slots proving that there is no radiation to the space due to maximum stored electromagnetic energy around each investigated notch slot, proving that the slots play a role of a quarter wavelength transformer which generates for each notched band, maximum gain, and radiation pattern are also investigated.

Compact Ultra-Wideband Monopole Antenna Loaded with Metamaterial.

A printed compact monopole antenna based on a single negative (SNG) metamaterial is proposed for ultra-wideband (UWB) applications. A low-profile, key-shaped structure forms the radiating monopole and is loaded with metamaterial unit cells with negative permittivity and more than 1.5 GHz bandwidth of near-zero refractive index (NZRI) property. The antenna offers a wide bandwidth from 3.08 to 14.1 GHz and an average gain of 4.54 dBi, with a peak gain of 6.12 dBi; this is in contrast to the poor performance when metamaterial is not used. Moreover, the maximum obtained radiation efficiency is 97%. A reasonable agreement between simulation and experiments is realized, demonstrating that the proposed antenna can operate over a wide bandwidth with symmetric split-ring resonator (SSRR) metamaterial structures and compact size of 14.5 × 22 mm2 (0.148 λ0 × 0.226 λ0) with respect to the lowest operating frequency.

A Metamaterial-Based Compact Planar Monopole Antenna for Wi-Fi and UWB Applications.

Ultrawideband (UWB) antennas are widely used as core devices in high-speed wireless communication. A novel compact UWB monopole antenna with an additional narrow band for Wi-Fi applications comprising a metamaterial (MTM) is proposed in this paper. The antenna has a compact size of 27 × 33 mm2 and consists of a V-shaped slot with two rectangular slots in the radiation patch. The inductance and capacitance develop due to the V-shaped slot in the radiation patch. The proposed antenna has −10 dB bandwidths of 3.2 GHz to 14 GHz for UWB and 2.38 GHz to 2.57 GHz for narrowband, corresponding to 144% and 7.66% fractional bandwidths, respectively. The measured gain and efficiency meet the desired values for UWB and Wi-Fi applications. To verify the performance of the antenna, the proposed antenna is fabricated and tested. The simulated and measured results agree well at UWB frequencies and Wi-Fi frequencies, and the antenna can be used as a smart device for portable IoT applications.

Multi-Band Notched Antennas for UWB Applications

A compact ultra-wideband circular monopole antennas with single, dual, triple and quad-band rejection characteristics are proposed in this paper. The antenna units are designed using RT/DUROID substrate with permittivity 2.2 and all are fed through a coplanar waveguide (CPW). In the proposed antennas splitted concentric rings (SCR) are used to achieve band rejection characteristics. The proposed antennas will reject the existing WLAN (Wireless Local Area Network), WiMAX (World Wide Interoperability for Microwave Access), X-band downlink satellite communication and radio-frequency channel arrangements for fixed wireless systems to avoid interference. Simulations are carried out using CST Wave Studio Suite 2016. Antenna performance parameters like return loss, VSWR, radiation pattern and gain are evaluated for all the antenna units. The antenna units having dimensions of 30×23×1.57 mm3 are fabricated and tested. The simulated and tested results are compared and reported. These antenna units provide good gain and a larger bandwidth over the frequency range 3–11.6 GHz.

Compact UWB monopole antenna with reconfigurable band-notch characteristics

AbstractA compact ultra-wideband (UWB) monopole antenna with reconfigurable band-notch characteristics is demonstrated in this paper. It is comprised of a modified rectangular patch and a defected ground plane. The band-notch property in the WiMAX and WLAN bands is achieved by etching an open-ended slot on the radiating patch and an inverted U-shaped slot on the ground plane, respectively. To obtain the reconfigurable band-notch performance, two PIN diodes are inserted in the slots, and then the notch-band can be switched by changing the states of the PIN diodes. The antenna has a compact size of 0.47 λ1 × 0.27 λ1. The simulated and measured results indicate that the antenna can operate at a UWB mode, two single band-notch modes, and a dual band-notch mode. Moreover, stable radiation patterns are obtained.

Compact ultra‐wideband antenna: improvement of gain and FBR across the entire bandwidth using FSS

In this paper, a highly compact ultra-wideband (UWB) monopole antenna with high gain is proposed. The UWB monopole antenna consists of U-shaped radiating patch. The ground plane comprises of edge-truncated partial rectangular metallic plane with a rectangular slot at the centre of the top edge. The proposed antenna having a very compact dimension of 16 mm × 22 mm × 1.6 mm is compatible and highly suitable for compact wireless systems. Further for enhancement of directivity of the UWB antenna, a patch type frequency selective surface (FSS) is placed below the antenna. The combined FSS-antenna structure operates with high gain (peak gain of 9.4 dBi) across the entire UWB range (3.1-18.6 GHz). The proposed design also offers an appreciably high front-to-back lobe ratio of ~10 dB across the entire UWB range. The simulated results are verified experimentally and the results are discussed in detail. The overall dimension of the proposed FSS integrated composite antenna is 52 mm × 62.5 mm × 23.2 mm, which is highly relevant for high-gain applications.

Compact UWB monopole antenna with quadruple band notched characteristics

ABSTRACTA compact planar Ultrawideband (UWB) monopole antenna with quadruple band notch characteristics is proposed. The proposed antenna consists of a notched rectangular radiating patch with a 50 Ω microstrip feed line, and a defected ground plane. The quadruple band notched functions are achieved by utilising two inverted U-shaped slots, a symmetrical split ring resonator pair (SSRRP) and a via hole. The fabricated antenna has a compact size of 24 mm × 30 mm × 1.6 mm with an impedance bandwidth ranging from 2.86 to 12.2 GHz for magnitude of S11 < −10 dB. The four band notched characteristics of proposed antenna are in the WiMAX (worldwide interoperability for microwave access) band (3.25–3.55 GHz), C band (3.7–4.2 GHz), WLAN (wireless local area network) band (5.2–5.9 GHz) and the downlink frequency band of X band (7–7.8 GHz) for satellite communication are obtained. The measured and simulation results of proposed antenna are in good agreement to achieve impedance matching, stable radiation patterns, constant gain and group delay over the operating bandwidth.

Combined triple band circularly polarised and compact UWB monopole antenna

A new design of a compact ultra-wide band (UWB) monopole antenna with triple-band, triple-sense circular polarisation (CP) is presented here. It is composed of a compact quad-circular monopole, a fractal parasitic ring resonator, a triangular ring resonator, rectangular ring resonator, and modified `T' and `I' shaped slots on the ground plane along with a rectangular stub with `E'-shaped slot on the right side of the monopole. The proposed antenna radiates left-hand circularly polarised (LHCP) wave at lower and mid-frequency bands, while right-hand circularly polarised (RHCP) wave at upper frequency band. The results show that the antenna covers an ultra-wide bandwidth from 3.1 to 11 GHz (112%). Moreover, the proposed antenna achieves good CP characteristics at Citizens Broadband Radio Services in USA (3.55-3.72 GHz), artificial magnetic conductors and WLAN upper frequency spectrum (4.81-5.61 GHz), VSAT services & Satellite Communication and Ground Surveillance RADAR (9.29-10.95 GHz), respectively. Novelty of this article lies in designing a compact printed UWB monopole antenna with combined triple band CP characteristics controllable by adjusting the antenna design parameters. The simulated and measured results of the antenna have been compared and seen to be in reasonable agreement.

Design of Compact Ultra-Wideband Monopole Semi-Circular Patch Antenna for 5G wireless communication networks

Design of Compact Ultra-Wideband Monopole Semi-Circular Patch Antenna for 5G wireless communication networks

Design a Compact UWB Monopole Antenna with Triple Band-Notched Characteristics Using EBG Structures

Abstract In this paper, a compact ultra-wideband (UWB) monopole antenna with triple band-notched characteristics is presented. These triple band rejections are produced by inserting the Complementary Co-directional Split-Ring Resonator (CC.SRR) on the radiating element for WiMAX/WLAN (3.4–3.95 GHz/5.35–5.9 GHz) and Electromagnetic Band Gap (EBG) structure in the vicinity of transmission line for X-band satellite communications (6.7–7.7 GHz). The proposed antenna with a total size of 18×20.9×1.63 mm3 has been constructed and tested. An equivalent RLC circuit model is proposed and investigated. The simulated and measured results show that the proposed antenna has an impedance bandwidth (VSWR&lt;2) extanding from 3.05 GHz to 14 GHz with triple notched bands of [3.3–3.9 GHz], [5.25–5.86 GHz] and [6.7–7.7 GHz]. The triple band notched characteristics and the good radiation patterns make the proposed antenna a good candidate for the UWB applications.

A Compact UWB Monopole Antenna with Rejected WLAN Band using Split-Ring Resonator and Assessed by Analytic Hierarchy Process Method

The design of a compact micro strip line-fed Ultra-Wideband (UWB) monopole antenna with a notched-band characteristic is presented in this letter. The rejection frequency band occurs around 5- 6 GHz, which is appropriate for wireless local area network (WLAN) applications and is obtained by a split-ring resonator on the antenna ground. The proposed antenna is printed on FR4 substrate material with a dielectric constant of 4.4. The dimension of the proposed antenna is 24×16×0.8 mm 3 . Radiating patch has a combined geometry realized by a half-circular ring and half-square ring. To achieve a proper impedance matching and increased bandwidth with (Voltage standing wave ratio) VSWR ≤ 2, the study made use of an L-shaped element which was connected to the ground; moreover, the researchers added a split-ring resonator onto the ground to obtain one notched band. The comparison of the proposed antenna performance with previously presented UWB monopole antennas, was performed by using Analytic Hierarchy Process (AHP) method. A good agreement was observed between simulated and experimental results. .

Design and Development of a Compact UWB Monopole Antenna With Easily-Controllable Return Loss

This communication presents a novel cactus-shaped ultrawideband (UWB) monopole antenna fabricated on liquid crystal polymer (LCP). The proposed antenna is a very compact design, since it can be fabricated on a board with dimensions only $20\times28$ mm $^{2}$ , while the three linear segments that comprise the cactus-shaped monopole provide a direct control on antenna matching. The proposed antenna is operating from 2.85 to 11.85 GHz and it presents very consistent omnidirectional patterns throughout the UWB frequency range. Return loss and pattern measurements are presented and the operation principles are discussed in detail. The simplicity of this topology, with the easily controllable return loss, allows for its easy implementation for various UWB subband designs, just by building suitable monopole versions, for which the only difference is the length of the three linear segments.

Rapid dimension scaling for notch frequency redesign of UWB band-notch antennas

One of important issues in the design of ultra-wideband (UWB) antennas is implementation of band-notch capability, critical to avoid interference with other standards such as WLAN. At the same time, appropriate dimension adjustment of antenna geometry parameters for precise frequency allocation of the notch and to ensure sufficient reflection level in the UWB band is quite challenging. For the sake of reliability it has to be based on full-wave electromagnetic (EM) simulations of the structure at hand. In this letter a simple technique for dimension scaling of UWB antennas is proposed that allows for rapid reallocation of the band-notch to a required frequency. Our methodology exploits a fast inverse model established using several reference designs obtained for coarse-discretization EM model of the antenna of interest as well as appropriate correction techniques that allows us to apply the model for antenna scaling at high-fidelity EM simulation level. The proposed procedure is demonstrated using a compact UWB monopole with the band-notch scaling range from 5 to 8 GHz. Simulation results are validated using physical measurements of the fabricated antenna prototypes.

Rapid Multiobjective Antenna Design Using Point-By-Point Pareto Set Identification and Local Surrogate Models

Antenna design is inherently a multicriterial problem. Determination of the best possible tradeoffs between conflicting objectives (a so-called Pareto front), such as reflection response, gain, and antenna size, is indispensable from the designer’s point of view, yet challenging when high-fidelity electromagnetic (EM) simulations are utilized for performance evaluation. Here, a novel and computationally efficient methodology for multiobjective optimization of antenna structures is presented. In our approach, the tradeoff designs are obtained by moving along the Pareto front and identifying the subsequent Pareto-optimal solutions using surrogate-based optimization techniques. Computational efficiency of the process is achieved by employing coarse-discretization EM simulations and local response surface approximation (RSA) models. The proposed approach is demonstrated using a compact ultrawideband (UWB) monopole antenna with a representation of the Pareto front obtained at the cost corresponding to just a few dozen of evaluations of the high-fidelity EM antenna model. Experimental validation is also provided.

Compact UWB monopole antenna for internet of things applications

A structure of a compact ultra-wideband monopole antenna has been presented. The antenna consists of a microstrip-fed rectangle radiator as well as a ground plane with a rectangle slit and an L-shaped stub. The critical factor in achieving a small size is a careful design procedure involving numerical optimisation of all geometry parameters of the antenna aiming at explicit size reduction while maintaining acceptable electrical performance. The final design exhibits dimensions of only 9.45 × 18.5 mm and a footprint of 175 mm 2 . Experimental validation and comparisons with competitive designs are also provided.