L-shaped Slots Research Articles

Bandwidth and Gain Improvement of an L-Shaped Slot Antenna With Metamaterial Loading

A metamaterial-based wideband and high-gain circularly polarized (CP) mushroom antenna is proposed and analyzed in this letter. The proposed antenna consists of a $4 \times 4$ mushroom-cells array and an L-shaped slot coupling-fed layer. The metamaterial-based mushroom cells are adopted to adjust the axial ratio (AR) to realize wideband CP and high gain. With the optimization, the proposed dielectric-filled mushroom antenna is with a low profile of $0.08{\lambda _0}$ ( ${\lambda _0}$ is the operating wavelength in free space) while covering an area of $60\,{\text{mm}} \times 60\,{\text{mm}}$ only. The measured impedance bandwidth of the proposed antenna is 48.2% (5.2–8.5 GHz), and the measured 3 dB AR bandwidths are 35.5% (5.8–8.3 GHz). Moreover, the antenna performed a stable high gain which is better than 10.5 dBic from 6 to 7.5 GHz across the CP region.

Dual-Frequency Circularly Polarized Truncated Square Aperture Patch Antenna with Slant Strip and L-Shaped Slot for WLAN Applications

This research proposes a dual-frequency circularly polarized truncated square aperture patch antenna with slant stripline and L-shaped slot for WLAN applications. In the antenna design, the parameters were optimized and the WLAN-enabled dual-frequency (2.4 and 5.8 GHz) antenna was realized. Simulations were subsequently carried out for the impedance bandwidth (S11) < −10 dB, axial ratio (AR) ≤ 3 dB, optimal gain, and bidirectional radiation pattern. To validate, an antenna prototype was fabricated and the experiments were undertaken. The simulated and experimental results are in good agreement. In essence, the proposed WLAN-enabled dual-frequency circularly polarized antenna is most suited for applications in the vertically and horizontally elongated areas, including in the tunnel, train carriage, and buildings.

A new inset-fed UWB printed antenna with triple 3.5/5.5/7.5-GHz band-notched characteristics

A novel low-profile inset-fed ultrawideband printed antenna with triple band-notched characteristics is proposed. Wide inverted U-shaped and crescent-shaped slots are used to achieve first and second notched bands in the 3.3--3.7 GHz and 5.1--5.9 GHz ranges for WiMAX and WLAN systems, respectively. Additionally, an altered ground plane with an open-ended L-shaped slot generated a third notched band in the 7.25--7.85 GHz range for downlink of X-band satellite communication systems. The center frequencies of the stop bands are adjusted by altering the parameters of corresponding slots. The antenna prototype is built on a 28 mm $\times $ 24 mm Rogers RT/duroid 5880 ($\varepsilon_{r}$ = 2.2) substrate over a partial ground plane. Two concave circular curves were deployed on the patch with an inset feeding in order to obtain wideband performance in the 2.5--12 GHz (VSWR $

A Circular Disc Microstrip Antenna with Dual Notch Band for GSM/Bluetooth and Extended UWB Applications

A microstrip antenna with a circular disc design and modified ground is proposed in this paper. Circular shapes of different size have been slotted out from the radiating patch for achieving extended ultra wideband (UWB) with GSM/Bluetooth bands with maximum bandwidth of 17.7 GHz (0.88-18.6 GHz). Further, characteristic of dual notch band is achieved, when a combination of T and L-shaped slots are etched into the circular disc and ground plane respectively. Change in length of slots is controlling the notch band characteristics. The proposed antenna has rejection bandwidth of 1.3-2.2 GHz (LTE band), 3.2-3.9 GHz (WiMAX band) and 5.2-6.1 GHz (WLAN band) respectively. It covers the frequency range of 0.88-18.5 GHz with the VSWR of less than 2. Also, an equivalent parallel resonant circuit has been demonstrated for band notched frequencies of the designed antenna. The gain achieved by the proposed antenna is 6.27 dBi. This antenna has been designed, investigated and fabricated for GSM, Bluetooth, UWB, X and Ku band applications. The stable gain including H & E-plane radiation pattern with good directivity and omnidirectional behavior is achieved by the proposed antenna. Measured bandwidths are 0.5 GHz, 0.8 GHz, 1.1 GHz and 11.7 GHz respectively.

A miniaturized UWB-MIMO antenna with quadruple band-notched characteristics

AbstractA simple multiple-input-multiple-output (MIMO) antenna with quad-band-notched characteristics for ultra-wideband (UWB) system is proposed and tested in the article. Based on two similar radiators, the UWB-MIMO system only occupies 22 mm × 28 mm. By etching an inverted L-like meander slot, two inverted L-shaped slots, and adding a C-shaped stub beside the feeding line, four notched bands are realized (3.25–3.6, 5.05–5.48, 5.6–6, and 7.8–8.4 GHz) to suppress interference from WiMAX, lower WLAN, upper WLAN, and uplink of X-band satellite communication system. With a T-like stub extruding from the ground plane, port isolation is effectively improved. The results show that the antenna covers 3.1–10.6 GHz UWB frequency band except four rejected bands and has high isolation of better than −20 dB over most of the frequency band. Moreover, envelope correlation coefficient and good radiation patterns also prove that the introduced antenna is suitable for UWB applications.

Broadband CPW-Fed L-Shaped Slot Antenna with T-Tuning Stub for IMT Applications

International Journal of Computer Sciences and Engineering (A UGC Approved and indexed with DOI, ICI and Approved, DPI Digital Library) is one of the leading and growing open access, peer-reviewed, monthly, and scientific research journal for scientists, engineers, research scholars, and academicians, which gains a foothold in Asia and opens to the world, aims to publish original, theoretical and practical advances in Computer Science,Information Technology, Engineering (Software, Mechanical, Civil, Electronics & Electrical), and all interdisciplinary streams of Computing Sciences. It intends to disseminate original, scientific, theoretical or applied research in the field of Computer Sciences and allied fields. It provides a platform for publishing results and research with a strong empirical component. It aims to bridge the significant gap between research and practice by promoting the publication of original, novel, industry-relevant research.

Design and Analysis of Compact Triple Band Microstrip Patch Antenna for Multiband Applications

In this article, a novel design of multiband microstrip patch antenna has been presented for multiband applications. The Shirt shape antenna is designed on FR-4 substrate and is fed through 50 ohm microstrip feed line. Two l-shape slots are introduced in antenna for size reduction and to provide multiband characteristics while DGS (defected ground structure) is used to achieve bandwidth enhancement. The simulated results show that the antenna operates in three different frequency bands having resonance frequencies at 4.4GHz, 6.2GHz and 8.5GHz. The antenna exhibits good return loss of -21.1dB @4.4Ghz, -15dB @6.2GHz and -30.5dB @8.5GHz. The proposed antenna has stable radiation patterns and gain values which are 5.3db at 4.4GHz, 5.03dB at 6.2GHz, 5.27 at 8.5GHz. The VSWR is also less than 2 and has good efficiency values at the operating bands 62%, 89% and 93% respectively. The Shirt shape antenna finds its applications in commercial WLAN, Wi-MAX and in Radar application.

A fractal quad-band antenna loaded with L-shaped slot and metamaterial for wireless applications

A novel concept of using fractal antenna with metamaterial and slot to achieve multiband operation is investigated. The antenna consists of an L-shaped slot, Sierpinski triangle (used as fractal) as the radiating part and metamaterial circular split ring resonator (SRR) as the ground plane. The introduction of metamaterial in the ground plane makes the antenna operate at 3.3 GHz (middle WiMAX). The etching of Sierpinski triangle and L-shaped slot in the radiating monopole perturbs the surface current distribution; thereby increasing the total current path length which tends the antenna to further operate at 5.5 (upper WiMAX), 7.3 (satellite TV) and 9.9 GHz (X-band), respectively. The extraction of medium parameter of a circular SRR through waveguide medium is discussed in detail. The antenna has a compact dimension of 0.33λ0 × 0.27λ0 × 0.01λ0 = 30 mm × 24.8 mm × 1.6 mm, at a lower frequency of 3.3 GHz. Under simulation, antenna operates at 3.3, 5.5, 7.3 and 9.9 GHz with S11 < −10 dB bandwidth of about 5.9% (3.24–3.44 GHz), 5.6% (5.31–5.62 GHz), 7.3% (6.99–7.52 GHz) and 3.02% (9.78–10.08 GHz), respectively. In measurement, antenna exhibit resonances at 3.1, 5.52, 7.31, 9.72 GHz with S11 < −10 dB bandwidth of about 3.5% (3.04–3.15 GHz), 5.01% (5.44–5.72 GHz), 13.2% (6.76–7.72 GHz) and 5.77% (9.42–9.98 GHz), respectively. Good impedance matching and stable radiation characteristics are observed across the operational bandwidth of the proposed configuration.

Design of a 2.4GHz-Microstrip Line Filter Using the Semicircle Defected Ground Structure

A design and simulation for L-shaped slot microstrip line antenna with semicircle defected ground structure has been researched, the main purpose is suppressing the existence of higher order harmonic. In this paper, simulated soft (Ansoft HFSS V.6.0) used to be simulated the frequency response under different parameters such as dimensions, amounts of SDGS. The results show good performance of SDGS in higher resonant frequency suppression. Final, an antenna with 2.4GHz center frequency had been design and fabricated.

A Dual-band Microstrip Slotted Antenna for UHF and Microwave RFID Readers

In this paper a new and simple dual-band microstrip slot antenna design combined with two inverted L-shaped slots integrated in the radiating patch is presented. This antenna is suitable for operating at 915 MHz and 2.45 GHz in order to cover the Radio Frequency Identification (RFID) frequencies bands. By optimizing the structure design, good performances in term of return loss radiation pattern and efficiency are achieved. The simulation results were obtained by using ADS and CST Microwave Studio electromagnetic solvers. The proposed antenna is mounted on an FR4 substrate with dielectric permittivity constant 4.4, thickness of 1.6 mm and loss tangent of 0.025 and a total area of 48×47 mm2. The design methodology used to achieve the dual-band antenna and both experimental, simulated results are presented.

A New Dual Band Printed Metamaterial Antenna for RFID Reader Applications

<span lang="EN-US">In this paper, we present a new dual band metamaterial printed antenna for radio frequency identification applications. The proposed antenna consists of two L-shaped slot in the radiating element for dual band operation and a complementary split ring resonator etched from the ground plane for size miniaturization. This antenna is designed and optimized by CST microwave studio on FR-4 substrate with thickness of 1.6 mm, dielectric constant of 4.4 and tangent loss of 0.025. A microstrip line with characteristic impedance of 50 ohms is used to feed this antenna. A prototype of the proposed antenna is fabricated to validate the simulation results. The measured and simulated results are in good agreement. </span>

Broad-range microstrip patch refflectarray element loaded with multiple L-shaped slots

A single-layer microstrip patch unit element, which is loaded with eight concentric L-shaped slots, is proposed for reflectarray design. In this case, the lengths of the inner and outer slots are varied concurrently to function as the phase-shifting geometrical parameters. The reflection characteristics of the element are analyzed using the waveguide method, and the simulation results have been verified with experiments. A broad reflection phase range of 631.83° with slow gradient has been successfully achieved with the use of the slotted patch with constant size. Parametric analysis has been performed and it is found that the S-curve can be easily fine-tuned by changing some of the design parameters.

A Novel Hammer-Shaped UWB Antenna with Triple Notched-Band for Rejecting RLS, WLAN and XSCS bands

A novel hammer-shaped UWB printed antenna with triple notched stop bands is presented and fabricated on FR-4 substrate with size of 40×40×1.6 mm3. The proposed antenna is composed of hammer-shaped patch with C-shaped slot, U-shaped slot on feed line, and inverted stepped notch and bevel edges with pair of L-shaped slots in partial ground plane. The fabricated antenna is tested and obtained impedance bandwidth 2.89 ̶ 11.6 GHz with three notched stop bands 3.15 ̶ 3.7 GHz, 5.45 ̶ 6.8 GHz, and 7.5 ̶ 8.8 GHz, for radiolocation system (RLS), wireless local area networks (WLAN), and X-band satellite communication system (XSCS) bands, respectively. Moreover, the antenna result shows omnidirectional radiation pattern, average gain of 3.10 dBi over the whole UWB band except at the notched frequency bands.

Design of Multi-band Microstrip Antenna for Wireless Communications and ITU Applications

A multi-band microstrip patch antenna for WiMAX, WLAN and ITU-Region1 applications is presented in this letter. The proposed antenna consists of FR4 substrate with dimensions of 15 × 15 × 1.6 mm3, ground plane and radiation patch that fed by 50 Ω microstrip line. This antenna with two symmetry of L-shape and U-shape slots and folded strip lines in the configuration of radiation patch, cover 3.5 GHz frequency for WiMAX, two 5.2 and 5.8 GHz frequencies bands for WLAN and 4.3 GHz for ITU-Region1 applications to consider simulated and measured results. The omnidirectional radiation pattern characteristics and −10 dB return loss for all frequencies bands are obtained in this antenna.

Design of Compact Quad-Band Notched UWB-MIMO Antenna

With quad-notched band characteristic, a compact ultra-wideband (UWB) multiple-input-multiple-output antenna is proposed in the article. There are two identical monopole elements in the system. By inserting symmetrical L-shaped slots, complementary split-ring resonators) and C-shaped stubs in each element, four notched bands are achieved to filter 3.5 GHz WiMAX, 5.25 GHz lower WLAN, 5.8 GHz upper WLAN, and 7.5 GHz X-band. Without decoupling structures, the antennas were placed vertically to obtain high isolation. Results indicate that the antenna operates from 2.6 to 13 GHz except four rejected bands, and port isolation (S21) is better than −25 dB, envelope correlation coefficient is below 0.002 in UWB spectrum frequency of 3.1–10.6 GHz.

Compact Tri-Band Notched Characteristics UWB Antenna for WiMAX, WLAN and X-Band Applications

Compact microstrip-fed printed monopole antenna with triple band-notched characteristics is suggested for ultra-wideband (UWB) applications. The antenna is constructed of a conventional rectangular microstrip patch antenna with partial ground plane and T-shaped strip employed in the ground plane as well as an inverted Ω- and L-shaped slots incorporated within the radiated element. The notched functions are created by the inverted Ω- and L-shaped slots, which are realized for WiMAX (from 2.69 to 4.5 GHz) and WLAN (from 5.49 to 6.37 GHz). The T-shaped parasitic strip generates the third notch for the X-band uplink satellite communication (from 8.15 to 9.61 GHz). The measured operating -10 dB bandwidth of the proposed antenna extends from 2.39 to more than 18 GHz except at the notched bands. The prototype antenna has a total area of 20×20×1.6 mm3. Electromagnetic (EM) simulations are carried out using 3D full-wave FEM-based simulator. EM simulation results are in good agreement with measurement results. The radiation pattern of the proposed antenna is nearly Omni-directional over the whole targeted band.

Compact Mobile Quad-Band Slot Antenna Design for GPS L1, WiMAX, and WLAN Applications

In this paper, an asymmetric compact multiband slot antenna is proposed for global positioning system (GPS), worldwide interoperability for microwave access (WiMAX), and wireless area network (WLAN) applications. The top plane, a ground is composed of a rectangular slot with a trapezoidal-like stub, an inverted U-shaped slot at the right side of the rectangular slot, an inverted L-shaped slot at the left side of the rectangular slot, and three stubs. The proposed antenna is fed by an asymmetric cross-parasitic strip on the bottom plane. By properly designing the slots and stubs, four resonant frequency bands are achieved with -10 dB reflection coefficient bandwidths of 50 MHz, 400 MHz, 390 MHz, and 830 MHz in the 1.57 GHz GPS band, 2.4 GHz WLAN band, 3.5 GHz WiMAX band, and 5.5 GHz WLAN bands, respectively. The antenna has a total compact size of 13 mm × 32 mm × 0.8 mm. Simulated and measured results indicate that the proposed antenna has sufficient bandwidth and good radiation performance in each band.

A Study of Dual/Triple-Band Microstrip-Fed Slot Antenna Design for WLAN/WiMAX Communication Systems

This paper presents a study of dual/triple-band simple slot antenna fed by microstrip line for WLAN and WiMAX communications systems. The first proposed antenna consists of a rectangular slot with rectangular-ring strip at the centre of a rectangular ground plane and microstrip line feed at the centre for excitation. The simulation results of the return loss of the first proposed antenna can cover the frequency range at 2.32-2.48 GHz (WLAN 2.4 GHz), and 5.49-6.11 GHz (WLAN/WiMAX 5.8 GHz). The first proposed antenna is extended by inserting an L-shaped slot in rectangular-ring strip to create third frequency WiMAX at 3.5 GHz band and it can control resonant frequency band operations. The simulation results of the proposed antenna are analyzed by using IE3D Software. The measurement results of triple-band slot antenna of return loss (S11), the first resonant frequency has an impedance bandwidth of 240 MHz (2.45-2.69 GHz), which covers the 2.5 GHz WLAN/WiMAX bands. The second resonant frequency has an impedance bandwidth of 170 MHz (3.45-3.62 GHz) at 3.5 GHz frequency band (WiMAX 3.5 GHz). The third resonant frequency has an impedance bandwidth of 600 MHz (5.7-6.3 GHz), covering the 5.8 GHz WLAN/WiMAX bands. Moreover, the proposed antenna can control a shift of the resonant frequency. The radiation patterns of the proposed antenna in E-plane and the H-plane are bi-directional and omni-directional.

Investigation of a reconfigurable dual notched UWB antenna by conceptual circuit model and time-domain characteristics

In this paper, an ultra-wideband (UWB) antenna with reconfigurable performance is proposed. The antenna consists of a Ushaped radiation patch and a ground plane which is symmetric with the edge of the radiation patch. By using two open-ended L-shaped slots (OEL-S) and one U-shaped slot Defected Ground Structure, the dual notched bands at 3.5 GHz for WiMAX and 5.5 GHz for WLAN are obtained. Three switches are embedded in both L-shaped and U-shaped slots in order to achieve four switchable modes by switching them between ON and OFF states. There are three modes that the antenna can be switched in, which are dual, single and no band-notched modes. The measured result illustrates that the operation frequency band is from 2.7 GHz to 12 GHz ( VSWR<2). Moreover, the conceptual circuit model and time-domain characteristics of the antenna are also proposed to investigate the dual band-notched performance. (C) 2017 Wiley Periodicals, Inc.

Compact Quad Band-Notched Monopole Antenna for UWB Systems

A novel compact microstrip-fed UWB antenna with quad notched band is proposed. The antenna consists of a rectangular radiating patch with a half circle, a tapered microstrip feed-line, and a semi-elliptical ground plane. With a pair of L-shaped slots, complementary co-directional SRR and a pair of C-shaped stubs, four notched bands are created to prevent interference from WiMAX/lower WLAN/higher WLAN/X-band. Experimental results show that the designed antenna, with compact size of 20 × 30 mm2, has an ultrawide band (VSWR < 2) from 2.68 to 13 GHz, except four notched bands of 3.13–3.8, 4.87–5.52, 5.65–6.1, 7.12–8 GHz. Good radiation patterns and stable gain within the operating band have been observed.