Compact Ultra-wideband Antenna Research Articles

A Novel Compact Ultra-Wideband Antenna with Quad Notched Bands Based on S-SCRLHs Resonator

In this paper, a novel compact ultra-wideband (UWB) antenna with a quad band-notched function using S-SCRLHs (splited simplified composite right/left-handed) resonator is presented. The S-SCRLHs resonator, which exhibits quadruple resonance, is realized by coupling double S-SCRLH resonator. Then, the S-SCRLHs resonator is integrated into a UWB antenna consisting of modified circular patch. The proposed UWB antenna operates under the frequency range of 3.0–10.7 GHz. This proposed antenna displays a VSWR < 2(the voltage standing wave ratio) across the entire UWB band and compact dimensions of 25 × 20 mm2, which is 0.2λ (free space) at 3.0 GHz. By changing the dimension of S-SCRLHs resonator, the notched frequencies can be adjusted appropriately in four bands of 3.6–3.8 GHz (WiMAX), 4.5–4.9 GHz (C-band), 5.6–6.0 GHz (WLAN), and 7.2–7.6 GHz (X-band). The antenna can be applicable in the UWB receiver systems where the four kinds of interference signals corresponding to the four bands can be suppressed. The gain varies from 2.1 to 4.5 dBi with gain values of −2.8, −2.6, −1.5 and −2.4 dBi at respective four notch frequencies. The radiation efficiency is no less than 84% throughout the operational bandwidth. The proposed antenna achieves omnidirectional radiation patterns while also providing rejection at desired notches.

Compact UWB Antenna with High Rejection Triple Band-Notch Characteristics for Wireless Applications

In this paper, small printed flower-shape triple notch ultra-wideband (UWB) monopole antenna with high band rejection is presented. Notch bands include WiMAX (IEEE802.16 3.30–3.80 GHz), WLAN IEEE802.11a/h/j/n (5.15–5.35, 5.25–5.35, 5.47–5.725, 5.725–5.825 GHz), and X-band downlink satellite system (7.1–7.9 GHz). By including inverted T-shape stub and etching two C-shaped slots on the radiating patch, triple band-notch function is obtained with measured high band rejection (VSWR = 14.52 at 3.58 GHz, VSWR = 15.88 at 5.69 GHz and VSWR = 6.95 at 7.61 GHz) and covers a UWB useable fractional bandwidth of 114.30% (2.74–10.57 GHz = 7.83 GHz). In short the antenna offers triple band-notch UWB systems as a compact multifunctional antenna to reduce the number of antennas installed in wireless devices for accessing multiple wireless networks with wide radiation pattern. The proposed antenna has a small size of about 0.25λ × 0.30λ at 4.2 GHz (first resonance frequency), which has a size reduction of 30% with respect to the earlier published antenna. Both the experimental and simulated results of the proposed antenna are presented, indicating that the antenna is a good candidate for various UWB applications.

A Modified Compact Ultra Wideband Antenna with Band Rejection for WLAN Applications

In this paper, a circular ultra wideband antenna is considered which comprises of a planar circular patch element on grounded FR4 substrate of 1.6 mm thickness generating the bandwidth of 6.8 GHz. To enable its extensive use in Wireless Local Area Network (WLAN) applications, it is modified by modulating the microstrip line to generate stopband from 5.9 to 9 GHz rejecting the extended C band and X band. The antenna ground plane is then drilled to form holes implementing EBG structures to obtain desired passband characteristics, from 1.97 to 2.65 GHz and 3.12 to 5.86 GHz suitable for WLAN(2.40–2.484/5.150–5.350/5.725–5.825 GHz) applications. The designed antenna shows good passband and stopband characteristics and return loss S11 and nearly omni-directional field pattern over the frequency band of the passband.

A Simple Design of Compact Size UWB Microstrip Antennas with Improved Performance

A compact size ultra-wideband (UWB) microstrip antenna with improved performance is proposed in this communication. In this article, the design of the antenna, which is based on the interaction between the circular patch and the rectangular slot cutting in the metal ground plane, as a result the required starting frequency can be achieved due the coupling between the metal ground plane and patch. UWB microstrip antenna is studied and designed using computer simulation. For verification of simulation results, the antenna is fabricated and measured. The simulation and measured results as reflection coefficient and radiation pattern are presented. Its measured results indicate that the proposed antennas achieve UWB from 1.49 GHz up to 18 GHz with improved the radiation pattern performance in the upper frequency range(up to 10 GHz). Proposed antenna achieve many wireless services including wireless local area (WLAN 2.5 or 5.6 GHz), GSM (1.71-1.88 GHz), PCS (1.93-1.99 GHz), Multiband GNNs, UWB (3.1-10.6 GHz), and for see through wall and concrete application.

Compact Dual Band-Notched Characteristics UWB Antenna Using Nested G-Shaped Slots

This paper presents a dual band-notched characteristics ultra-wideband (UWB) printed monopole antenna with a compact size for wideband wireless communication applications. The proposed antenna has a leaf shape patch with nested G-shaped slots and a partially grounded plane fed with 50 Ω microstrip feed line. The designed antenna has a wide bandwidth of more than 9.86 GHz (2.3 GHz – 12.16 GHz). The return loss of the antenna is less than -10 dB except at the frequencies from 3.18 to 3.7 GHz for rejecting WiMAX and from 5.5 to 5.95 GHz for rejecting WLAN signals. The rejected frequency bands have been created using simple G-shaped slots etched within the patch. Multi notched bands are employed by nesting multi G-shaped slots without enlarging the antenna whole size. The central frequency of the notched bands is fully controlled by the G-slots dimensions. The proposed antenna has a compact size of 21×27 mm2. Extensive simulations are carried out using 3D full-wave FEM-based EM simulator. Parametric analyses to optimize the antenna parameters are performed. The proposed antenna exhibits nearly Omni-directional radiation pattern over the whole desired frequency bands. The measurements and EM simulations are in good agreement.

Design and analysis of triple band-notched micro-strip UWB antenna

Abstract In this paper, a compact ultra-wideband (UWB) antenna with triple notch bands is proposed. By etching out two ESRR of different dimensions in the radiating patch, two band-notched properties in the Wi-MAX (3–3.7 GHz), WLAN (5.125–5.825 GHz) are obtained. Furthermore, by placing SIR near the feed line–patch junction of the antenna, band notch property for the 7.9–8.4 GHz (X-band) frequencies is achieved. Design guidelines for implementing the notch-bands at the desired frequency regions are provided. The notched frequencies can be adjusted according to specification by altering the parameters of the ESRR and SIR. The effects of the key design parameters on band notch characteristics are also investigated. The realized antenna achieved an operating bandwidth (VSWR < 2) ranges from 2.94 to more than 11.3 GHz with triple notched bands of 3.0–3.7, 5.2–6.1, and 7.9–8.7 GHz. The proposed antenna is well designed and extensively investigated. The experimental results are given to verify that the proposed antenna with a wide bandwidth, three designated band-notched function which is suitable for modern high data rate UWB communication applications. The maximum simulated gain of the antenna is around 10.02 dBi with an average efficiency above 82.2% throughout the bandwidth.

A Compact UWB Koch Fractal Antenna for UWB Antenna Array Applications

In this paper, compact ultrawideband (UWB) antennas (1-Element and 2-Element) are presented in order to demonstrate application of fractal geometry in UWB antenna design, which helps to improve the antenna characteristics in a given smaller area. Some features of Euclidean shape geometry are improved after the application of fractals at the edges of the polygon. It is demonstrated that the application of Koch fractal in the antenna design helps to achieve the desired miniaturization, compactness and wideband operability due to its self-similar and space filling characteristics. An analytical expression is provided to calculate the effective length and area of the structure with the increase in iteration's order. Its performance is further compared with other fractal geometries such as Minkowski and Sierpinski curve. It is observed that the proposed Koch fractal based antenna yields the widest bandwidth and better gain compared to other fractal geometry based antennas. In addition, the time-domain analysis of the antenna is performed in terms of fidelity factor and its values are better than 0.81. 1-Element antennas shows operational bandwidth from 2.3 to 13.2 GHz with a maximum gain value of 3.8 dB, whereas in case of 2-Element antenna operating bandwidth is 2.3?14 GHz with a maximum gain value of 7.2 dB. Moreover, the radiation patterns of the single element and 2-Element are nearly omnidirectional. These characteristics offer opportunities to explore the proposed UWB antenna for various applications such as WPAN, WBAN, etc.

Simulation-driven design of compact ultra-wideband antenna structures

Purpose – The purpose of this paper is to investigate strategies and algorithms for expedited design optimization and explicit size reduction of compact ultra-wideband (UWB) antennas. Design/methodology/approach – Formulation of the compact antenna design problem aiming at explicit size reduction while maintaining acceptable electrical performance is presented. Algorithmic frameworks are described suitable for handling various design situations and involving simulation models without and with response gradients available. Numerical and experimental case studies are provided demonstrating feasibility of solving real-world miniaturized antenna design tasks. Findings – It is possible, through appropriate combination of the global and local optimization methods, surrogate modeling techniques and response correction methods, to find optimum dimensions of antenna structures that minimize antenna size while maintaining acceptable electrical performance. Design optimization can be performed at practically feasible computational costs. Research limitations/implications – The study summarizes recent advances in miniaturization-oriented design optimization of UWB antennas. The presented techniques reach far beyond the commonly used design approaches based on parameter sweeps and similar hands-on methods, particularly in terms of automation, reliability, and reduction of the computational costs of the design processes. Originality/value – The proposed design problem formulation and algorithmic frameworks proved useful for rapid design of compact UWB antenna structures, which is extremely challenging when using conventional methods. To the knowledge, this is the first attempt to efficient solving of this type of design problems, especially in the context of explicit antenna size reduction.

Investigations of triple band artificial magnetic conductor back plane with UWB antenna

ABSTRACTA triple band polarization insensitive compact artificial magnetic conductor (PI‐AMC) structure is investigated as a back plane of a compact ultrawideband (UWB) antenna in low profile configuration for the performance analysis. The AMC bands observed about 4, 7.2, and 10.5 GHz. The AMC bands can be tuned independently with the help of the PI‐AMC shape parameters. With the use of the PI‐AMC as a back plane for an UWB monopole antenna, the lower operating frequency decreased compared to the PEC back plane. Further, radiation in the forward direction and gain improvement over the UWB is observed due to AMC back plane. The details of the design, simulation, and measurement of the proposed PI‐AMC structure and UWB antenna with PI‐AMC structure are presented. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1900–1906, 2016

Compact band-notched UWB antenna for MIMO applications in portable wireless devices

A compact 5.5 GHz band-notched ultra-wideband (UWB) 2-element antenna with high isolation for multiple-input multiple-output (MIMO) portable wireless devices in wireless personal area network (WPAN) application is proposed. The MIMO antenna is designed for 3.1–10.6 GHz range on Neltec substrate with compact dimension of 43 × 20 mm2 and is tested experimentally. For the rejection band at 5.5 GHz, a slot of length 1.0 λ is etched into the radiator. Simple structure, i.e., receded steps at ground are used to improve isolation by 3 dB between two UWB antennas. The simulated and measured results show |S11| ≤ −10 dB and |S21| ≤ −20 dB in most of the frequency range excluding the reject band at 5.5 GHz in UWB range. The measured, simulated and calculated results show that the proposed UWB MIMO antenna is a good candidate for UWB MIMO systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1390–1394, 2016

Quadruple Band-Notched Trapezoid UWB Antenna with Reduced Gains in Notch Bands

A compact ultra-wide band antenna with a quadruple band-notched characteristic is proposed. The proposed antenna consists of a slotted trapezoid patch radiator, an inverted U-shaped band stop filter, a pair of C-shaped band stop filters, and a rectangular ground plane. To realize the quadruple notch-band characteristic, a U-shaped slot, a complementary split ring resonator, an inverted U-shaped band stop filter, and two C-shaped band stop filters are utilized in this antenna. The antenna satisfies the –10 dB reflection coefficient bandwidth requirement in the frequency band of 2.88–12.67 GHz, with a band-rejection characteristic in the WiMAX (3.43–3.85 GHz), WLAN (5.26–6.01 GHz), X-band satellite communication (7.05–7.68 GHz), and ITU 8 GHz (8.08–8.87 GHz) signal bands. In addition, the proposed antenna has a compact volume of 30 mm× 33.5 mm× 0.8 mm while maintaining omnidirectional patterns in the H-plane. The experimental and simulated results of the proposed antenna are shown to be in good agreement.

A compact fractal UWB antenna with reconfigurable band notch functions

ABSTRACTIn this paper, a compact reconfigurable single/dual notch band ultrawideband (UWB) antenna with triple notch band characteristics is presented for portable UWB applications. The desired compactness and wideband is achieved using fractals in antenna design. It has the compact dimensions of 24.5 mm × 20 mm. The single/dual notch band reconfigurability is demonstrated in WiMAX band as well as in X‐band using two p‐i‐n diodes for efficient utilization of UWB bands in case of no interference scenarios. The band rejections are obtained by introducing two C‐shaped slots in the fractal monopole, whereas band rejection in WLAN band is achieved by placing two C‐shaped single split ring resonator on either sides of feed line. In addition, the time‐domain characteristic of antenna is also evaluated in terms of fidelity factor, which is more than 0.71. These results illustrates that the presented antenna is appropriate candidate for portable UWB applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:509–514, 2016

Half-Mode Substrate-Integrated-Waveguide Cavity-Backed Slot Antenna on Cork Substrate

A wideband half-mode substrate-integrated-waveguide cavity-backed slot antenna covering all Unlicensed National Information Infrastructure (U-NII) radio bands (5.15-5.85 GHz) is designed, fabricated, and validated. By a half-mode implementation of a multimoded cavity with nonresonant slot, a compact ultrawideband antenna is obtained with very stable radiation characteristics, owing to the excellent antenna/platform isolation. Cork material is applied as antenna substrate, making the proposed antenna suitable for integration into floors or walls. In free-space conditions, an impedance bandwidth of 1.30 GHz (23.7%), a radiation efficiency of 85%, a front-to-back ratio of 15.0 dB, and a maximum gain of 4.3 dBi at 5.50 GHz are measured. Performance is also validated when the antenna is deployed on various dielectric or conducting platforms and underneath different dielectric superstrates. Only the latter slightly detunes the antenna's impedance bandwidth. Yet, the complete frequency band of interest remains covered, owing to additional design margins incorporated in the requirements. Its compactness, unobtrusive integration potential, and stable high performance in different environments make this antenna topology an ideal candidate for Internet of Things applications.

A Very Compact and Low Profile UWB Planar Antenna with WLAN Band Rejection.

A low-cost coplanar waveguide fed compact ultrawideband (UWB) antenna with band rejection characteristics for wireless local area network (WLAN) is proposed. The notch band characteristic is achieved by etching half wavelength C-shaped annular ring slot in the radiating patch. By properly choosing the radius and position of the slot, the notch band can be adjusted and controlled. With an overall size of 18.7 mm × 17.6 mm, the antenna turns out to be one of the smallest UWB antennas with band-notched characteristics. It has a wide fractional bandwidth of 130% (2.9–13.7 GHz) with VSWR < 2 and rejecting IEEE 802.11a and HIPERLAN/2 frequency band of 5.1–5.9 GHz. Stable omnidirectional radiation patterns in the H plane with an average gain of 4.4 dBi are obtained. The band-notch mechanism of the proposed antenna is examined by HFSS simulator. A good agreement is found between measured and simulated results indicating that the proposed antenna is well suited for integration into portable devices for UWB applications.

A compact UWB antenna with reconfigurable dual notch bands

ABSTRACTTo effectively utilize the entire ultrawideband (UWB) spectrum in case of no interference scenarios, a UWB antenna having reconfigurable dual band notch characteristics at WiMAX and WLAN band of frequencies is presented in this article. The p‐i‐n diodes and capacitors are properly placed in the UWB antenna to achieve the reconfigurable band notch function. The proposed antenna has the wide impedance bandwidth of 8 GHz (from 2.7 to 10.7 GHz). The four possible combinations of three p‐i‐n diodes are used to obtain single/dual reconfigurable notch bands in entire UWB band. The rejected WiMAX and WLAN band of frequencies are centered at 3.6 GHz and 5.5 GHz, respectively. The size of the proposed antenna is 27 × 32 mm2. The measured results are in good agreement with the simulated results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2737–2742, 2015

Compact microstrip omnidirectional ultrawideband antenna with dual broadband nested U‐shaped slots and flat frequency response

ABSTRACTIn this article, we present a compact ultrawideband antenna with dual broadband‐notched characteristics centered at 3.4 and 5.5 GHz. The proposed antenna consists of a rectangular patch with a modified ground plane structure and 50 Ω microstrip‐fed line. By etching two opposite U‐shaped slots in the radiating patch, the notched bands of 3.375–3.945 GHz for WiMAX and 5.425–6.150 GHz for WLAN and HYPERLAN/2 were achieved. The antenna also offers a flat frequency response so minimizing the formation of spurs and precursors that ensures optimal time domain performance for ultrawideband radio applications. The return loss was measured to better than −10 dB over the entire band from 3.1 to 10.6 GHz. The antenna gain was larger than 2 dBi all over the frequencies with a flatness of 2.5 dB and an omnidirectional radiation pattern in the H‐plane. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2854–2856, 2015

A super-resolution polarimetric wavefront extraction algorithm for UWB-radar under massive interference conditions

To provide short-range super-resolution ultra-wideband (UWB) radar under multi-scattering conditions, a superior wavefront extraction algorithm is proposed in this paper. Conventional correlation-based pulse separation methods based on SAGE, CLEAN or the previously introduced superior dynamic correlation method (DCM) are revised, validated, and compared. In this paper, the DCM is improved significantly by applying the Pauli scattering matrix decomposition onto the radar data. This novel wavefront extraction algorithm is called polarimetric dynamic correlation method (PDCM) and is suitable to resolve several overlapping pulses, which consist of both strong echoes and weak echoes which are masked by the strong ones. The performance of the PDCM and the comparison with alternative algorithms is carried out by a subsequent feature extraction algorithm for visual verification. Experimental validations are performed with two complex test objects, a maximum length sequence radar device (4.5–13.5 GHz) and compact dual-polarized UWB antennas.

Microwave Imaging Sensor Using Compact Metamaterial UWB Antenna with a High Correlation Factor.

The design of a compact metamaterial ultra-wideband (UWB) antenna with a goal towards application in microwave imaging systems for detecting unwanted cells in human tissue, such as in cases of breast cancer, heart failure and brain stroke detection is proposed. This proposed UWB antenna is made of four metamaterial unit cells, where each cell is an integration of a modified split ring resonator (SRR), capacitive loaded strip (CLS) and wire, to attain a design layout that simultaneously exhibits both a negative magnetic permeability and a negative electrical permittivity. This design results in an astonishing negative refractive index that enables amplification of the radiated power of this reported antenna, and therefore, high antenna performance. A low-cost FR4 substrate material is used to design and print this reported antenna, and has the following characteristics: thickness of 1.6 mm, relative permeability of one, relative permittivity of 4.60 and loss tangent of 0.02. The overall antenna size is 19.36 mm × 27.72 mm × 1.6 mm where the electrical dimension is 0.20 λ × 0.28 λ × 0.016 λ at the 3.05 GHz lower frequency band. Voltage Standing Wave Ratio (VSWR) measurements have illustrated that this antenna exhibits an impedance bandwidth from 3.05 GHz to more than 15 GHz for VSWR < 2 with an average gain of 4.38 dBi throughout the operating frequency band. The simulations (both HFSS and computer simulation technology (CST)) and the measurements are in high agreement. A high correlation factor and the capability of detecting tumour simulants confirm that this reported UWB antenna can be used as an imaging sensor.

Ultra-wideband Antenna for WLAN, WiMAX and LTE Applications

A compact ultra-wideband antenna (UWB) is presented in this paper for WLAN, WiMAX, LTE and Smart grid applications. The proposed antenna comprises a circular patch and rectangular slot in center of circular patch and apart from this it also consists of four small rectangular slots around circular patch to provide wideband. The antenna is fabricated onto Rogers R03003 substrate with an overall dimension of 47X47 mm. The substrate has dielectric constant of 3 and thickness of 1.6 mm. The simulated experiment shows that the proposed antenna achieves good impedance matching an operating bandwidth of 2.5–8.2 GHz (106.5%) and 10-15 GHz (40%) that covers the lower UWB and higher UWB band. Thus it covers WLAN 5.2/5.8 GHz band, WiMAX 2.5/3.5/5.5 GHz band and LTE 2.5-2.69 GHz band. The gain of this antenna varies between 2-3 dBi for most of the frequency band and therefore the proposed antenna is suitable for being used in UWB communication applications.

Design of a compact UWB antenna with a partial ground plane on epoxy woven glass material

Abstract A compact ultra-wideband (UWB) antenna is presented in this paper with a partial ground plane on epoxy woven glass material. The study is discussed to comprehend the effects of various design parameters with explicit parametric analyses. The overall antenna dimension is 0.22×0.26×0.016 λ. A prototype is made on epoxide woven glass fabric dielectric material of 1.6 mm thickness. The measured results point out that the reported antenna belongs to a wide bandwidth comprehending from 3 GHz to more than 11 GHz with VSWR&lt;2. It has a peak gain of 5.52 dBi, where 3.98 dBi is the average gain. Nearly omnidirectional radiation patterns are observed within the operating frequency bands. A good term exists between simulation and measurement results, which lead the reported antenna to be an appropriate candidate for UWB applications.