Design and analysis of a novel tri-band flower-shaped planar antenna for GPS and WiMAX applications

This paper presents the design of a tri-band flower-shaped planar monopole antenna operating at three frequencies i.e. 1.576 GHz (GPS), 2.668 GHz and 3.636 GHz (Mobile WiMAX). The radiating element of the antenna is backed by a 1.6 mm thicker FR-4 substrate having a dielectric constant of 4.3. The substrate is backed by a truncated ground plane. The antenna is fed through a 50 Ω microstrip line. The flower shape of the radiating element is derived from the basic circular shape by introducing in it rounded slots of various radii. The upper part of the antenna is flower-shaped while the lower part comprises a microstrip feed line and two branches, each having two ‘leaves’ at the end. The leaves and branches contribute in the impedance matching of the lower (1.576 GHz) and middle (2.668 GHz) frequency bands. The antenna gives an acceptable simulated efficiency >70% in the three frequency bands. Suitable gains of 1.63, 2.59 and 3.23dB are obtained at 1.576 GHz, 2.668 GHz and 3.636 GHz, respectively. The antenna matched with a VSWR<1.2 in the three frequency bands. The prototype of the antenna is fabricated and tested in the laboratory, and good agreement in simulated and measured results is achieved. The proposed design is a visually appealing and may find uses as an external antenna in GPS and WiMAX applications

A Review on Different Techniques of Mutual Coupling Reduction Between Elements of Any MIMO Antenna. Part 2: Metamaterials and Many More

This two‐part article presents a review of different techniques of mutual coupling (MC) reduction. MC reduction is a primary concern while designing a compact multiple‐input‐multiple‐output (MIMO) antenna where the separation between the antennas is less than λ0/2, that is, half of the free‐space wavelength. The negative permittivity and permeability of artificially created materials/structures (Metamaterials) significantly help reduce MC among narrow‐band compact MIMO antenna design elements. In this part two of the review paper, we will discuss techniques: Metamaterials; Split‐Ring‐Resonator; Complementary‐Split‐Ring‐Resonator; Frequency Selective Surface, Metasurface, Electromagnetic Band Gap structure, Decoupling and Matching network, Neutralization line, Cloaking Structures, Shorting vias and pins and few more

Nature-inspired Electro-textile Antennas for Passive UHF RFID

Antennas are usually hidden from sight. However, it is possible to design antennas that look visually appealing and socially accepted, while also have the same wireless performance as traditional antenna designs. Literature shows versatile nature-inspired antennas that have leaves and plants as design models. Most of such antennas are used in wideband, broadband, ultra-wideband, wireless local area networks, as well as 4G and 5G networks. The existing implementations do not employ ultra-high frequency (UHF) radio frequency identification (RFID), which, however, is a versatile technology that has taken a growing role for example in the areas of the Internet of Things, wearables, and e-health. Passive UHF RFID-based communication is challenging due to noisy and unstable signals, which sets high requirements on antenna designs. This paper aims to design and fabricate (from electro-textiles) nature-inspired passive UHF RFID tag antennas and evaluate their wireless performance. Each antenna is made in two sizes, a small and a big version. In wireless evaluation, all the nature-inspired antennas show read ranges and radiation patterns suitable for practical use, while the bigger size antennas perform better than the smaller counterparts in terms of read range. In addition to their traditional wireless functionality, these antennas can also have an ornamental function in clothing and can be designed in such a way that enhances the aesthetics and fashionability of wearables or smart clothing.acceptedVersionNon peer reviewe

Super compact UWB monopole antenna for small IoT devices

This article introduces a novel, ultrawideband (UWB) planar monopole antenna printed on Roger RT/5880 substrate in a compact size for small Internet of Things (IoT) applications. The total electrical dimensions of the proposed compact UWB antenna are 0.19 λo × 0.215 λo × 0.0196 λo with the overall physical sizes of 15 mm × 17 mm × 1.548 mm at the lower resonance frequency of 3.8 GHz. The planar monopole antenna is fed through the linearly tapered microstrip line on a partially structured ground plane to achieve optimum impedance matching for UWB operation. The proposed compact UWB antenna has an operation bandwidth of 9.53 GHz from 3.026 GHz up to 12.556 GHz at -10 dB return loss with a fractional bandwidth (FBW) of about 122%. The numerically computed and experimentally measured results agree well in between. A detailed time-domain analysis is additionally accomplished to verify the radiation efficiency of the proposed antenna design for the ultra-wideband signal propagation. The fabricated prototype of a compact UWB antenna exhibits an omnidirectional radiation pattern with the low peak measured gain required of 2.55 dBi at 10 GHz and promising radiation efficiency of 90%. The proposed compact planar antenna has technical potential to be utilized in UWB and IoT applications

A Novel UWB Reconfigurable Filtering Antenna Design With Triple Band-Notched Characteristics By Using U-Shaped Coppers

This paper proposed an UWB antenna with triple reconfigurable notch filters. By presenting there U-shaped coppers in the design, the potential triple interference in UWB applications can be rejected. Six PIN diodes are putted on the coppers to represent the OFF and ON tunable status in order to add reconfigurable characteristics to the UWB antenna. By using this ON and OFF tunable method, the current distribution of the proposed design changes and enables the antenna to have eight operation modes. The results prove that the proposed design can operate over the entire UWB frequency range (3.1 GHz to 10.6 GHz) and can filter out the target signals from the WLAN upper band (5.725 to 5.825 GHz), WLAN lower band (5.15 to 5.35 GHz) and X band frequency system (7.9 to 8.4 GHz) in one of the tunable configuration

Slotted log periodic fractal koch antenna for ultra high frequency digital television application

The Ultra High Frequency (UHF) band has long been used for voice, data and video communications. For the terrestrial television broadcasting, the lower frequency band of the UHF is used which ranges between 470 to 890 MHz. The conventional UHF antennas for receiving TV signals are quite large. One method that can be utilized is by using a compact and directional antenna that can be easily fabricated. The geometry used in this antenna design is Koch curve fractal structure. The advantage of using fractals in designing the antenna is to minimize the antenna size. The Log Periodic Antenna (LPA) is chosen because it had a wide bandwidth. This thesis describes the design of the planar fractal Koch antenna with slots for the UHF band. Four different iterations which is 0th iteration, 1st iteration, 2nd iteration and series iteration have been designed and simulated. The simulation process was done using Computer Simulation Technology (CST). The antenna has been fabricated on the Flame Retardant 4 (FR4) laminate microstrip board with dielectric constant of 5.4 and thickness of 1.6 mm. The simulation results show that the Koch curve technique can be used to minimize the length of the arm LPA, but the lower frequency tends to shift to the higher frequency as the number of iterations increases. Thus, a slot is introduced at each of the element of the Log Periodic Antenna in order to avoid the lower designed frequencies from shifting to higher band. A 28.7% reduction of the antenna size has been achieved by using slotted fractal Koch technique at the 2nd iteration. All antennas have been tested and measured in terms of reflection coefficient, radiation pattern and its realized gain. The simulation and measurement results have been compared and analyzed. A good agreement was achieved with reflection coefficient, S11< -10 dB for the entire UHF digital television band frequency design, directional radiation patterns with beamwidth of 75°, wide bandwidth up to 95% and an average gain of 6 dBi along the frequency range. This proposed antenna suitable for the intended application

Parity Splitting and Polarized-Illumination Selection of Plasmonic Higher-Order Topological States

Topological states, originated from interactions between internal degree of freedoms (like spin and orbital) in each site and crystalline symmetries, offer a new paradigm to manipulate electrons and classical waves. The accessibility of spin degree of freedom has motivated much attention on spin-related topological physics. However, intriguing topological physics related to atomic-orbital parity, another binary degree of freedom, have not been exploited since accessing approaches on atomic orbitals are not well developed. Here, we theoretically discover spectral splitting of atomic-orbital-parity-dependent second-order topological states on a designer-plasmonic Kagome metasurface, and experimentally demonstrate it by exploiting the easy controllability of metaatoms. Unlike previous demonstrations on Hermitian higher-order topological insulators, radiative non-Hermicity of the metasurface enables far-field access into metaatomic-orbital-parity-dependent topological states with polarized illuminations. The atomic-orbital parity degree of freedom may generate more intriguing topological physics by interacting with different crystalline symmetries, and promise applications in polarization-multiplexing topological lasing and quantum emitters.Comment: 19 pages, 4 figure