Showing papers on "Folded inverted conformal antenna published in 2018"
TL;DR: In this paper, the direction-of-arrival (DOA) estimation of a conformal antenna array with directive elements is studied in a communication and the two-dimensional Cramer-Rao lower bound is derived by using the active directive radiation patterns of the array elements and compared with the isotropic ones.
Abstract: The direction-of-arrival (DOA) estimation of a conformal antenna array with directive elements is studied in this communication. The two-dimension Cramer–Rao lower bound (CRLB) is derived for a conformal antenna array by using the active directive radiation patterns of the array elements and compared with the isotropic ones. Moreover, the MUSIC method is used to confirm the CRLB results. Without loss of generality, the CRLB of a truncated hexagonal pyramid conformal array with seven patches is investigated which verify the significant effect of the directive elements in the DOA estimation accuracy rather than that of the isotropic ones. The simulation results prove that this conformal array achieves better DOA estimation performance rather than that of the planar array antenna especially at the horizon angles. Moreover, the conformal antenna array tilt angle is studied to achieve the optimum conformal array structure which depicts a tradeoff between the DOA estimation accuracy at low and high $\theta $ incident angles.
29 citations
TL;DR: In this paper, a multi-polarized quad-band planar circular disc monopole antenna consisting of a parasitic double T-stub and parasitic long and short inverted L-stubs is presented.
Abstract: A multi-polarised quad-band planar circular disc monopole antenna consisting of a parasitic double T-stub and parasitic long and short inverted L-stubs is presented. By loading parasitic multistubs along the y-axis behind a circular patch, the antenna can yield four resonance modes at 2.5, 4.5, 5.7, and 7.7 GHz frequencies while keeping the size of 30 × 40 mm2. The proposed antenna has been fabricated and experimentally studied. The measured impedance bandwidths of 290 MHz (2.36–2.65 GHz), 540 MHz (4.28–4.82 GHz), 530 MHz (5.47–6.0 GHz), and 780 MHz (7.28–8.06 GHz), for Bluetooth, 2.4/5.8 GHz wireless local area network, 2.5/5.5 GHz worldwide interoperability for microwave access, 5.9 GHz intelligent transportation systems (ITS), downlink of Indian National Satellite System and X-band satellite applications. The 3 dB axial ratio bandwidth is 280 MHz (5.79–6.07 GHz) for the 5.9 GHz ITS band. The antenna E-field radiation has y-directed (vertical linear) polarisation at first, second, third resonance bands and slant + 45° linear polarisation at the fourth resonance band. At the ITS band, the E-field radiation has right-handed circular polarisation. In addition, the design procedure, electrical model and effects of parasitic stub dimensions on the antenna characteristics are discussed.
20 citations
TL;DR: Four different hybrid artificial intelligence network models are suggested for optimization, these are particle swarm optimization, differential evolution, grey wolf optimizer and vortex search algorithm, and they are combined with artificial neural network for the purpose of estimating dimension of patch.
Abstract: This study proposes a very compact coaxial-fed planar antenna for X band applications. The antenna design includes a tulip-shaped radiator on the FR4 dielectric substrate. The antenna parameters, such as return losses, bandwidth and operating frequency, have close relationships with patch geometry. In order to obtain desired antenna parameters for X band application, patch dimension is necessary to be optimized. In this article, four different hybrid artificial intelligence network models are suggested for optimization. These are particle swarm optimization, differential evolution, grey wolf optimizer and vortex search algorithm. Also, they are combined with artificial neural network for the purpose of estimating dimension of patch. Therefore, the comparison of different proposed algorithms is analyzed to obtain higher characteristics for antenna design. Their results are compared with each other in HFSS 13.0 software. The antenna with the most suitable return loss, bandwidth and operating frequency is selected to be used in antenna design.
10 citations
TL;DR: Simulation results show the superiority of the proposed algorithms compared to simulated annealing algorithm and traditional genetic algorithm as well as convex optimization combined with local search and local search assisted genetic algorithm.
5 citations
01 Jan 2018
TL;DR: In this article, a modified E-shaped and a crown-shaped microstrip patch antenna with excitation frequency of 1.2 GHz were derived from a Rogers RT/Duroid 6202 laminate substrate.
Abstract: This paper describes the design and analysis of a modified E-shaped and a crown-shaped microstrip patch antenna with excitation frequency of 1.2 GHz. Both the antennas are derived from a Rogers RT/Duroid 6202 laminate substrate (dielectric constant = 2.94 and loss tangent = 0.001). The simulation is achieved using the software Ansoft Nexxim. From the simulation results it is observed that the crown-shaped antenna exhibits 20.15 dB better return loss and 50% more gain than the modified E-shaped antenna. Furthermore, better impedance matching is observed for the crown-shaped antenna exhibiting that the crown-shaped antenna finds better applications than the modified E-shaped antenna to be effectively used for wireless application.
5 citations
01 Jan 2018
TL;DR: In this paper, a hexagonal-shaped structure printed over FR4 substrate was used to achieve the ultra wideband (UWB) spectrum as well as discusses the phenomena of frequency interference within UWB antennas.
Abstract: This chapter addresses an approach to achieve the ultra-wideband (UWB) spectrum as well as discusses the phenomena of frequency interference within UWB antennas. The antenna consists of a hexagonal-shaped structure printed over FR4 substrate. For bandwidth improvement, defected ground structure (DGS) was first introduced, and, secondly, a stub was added in the feeding strip to achieve a larger bandwidth. To achieve the frequency band-notched characteristics, a half hexagonal slot was etched on the radiator, which creates a notch at 5.2 GHz, and then by introducing a full hexagonal slot, another rejected band was produced at 10 GHz. The outcomes also confirm the proposed UWB antenna design can achieve superior dual band-notch performance at desired frequency bands.
3 citations
TL;DR: A miniaturized UWB antenna with multiple notch bands with good radiation characteristics with very large bandwidth including three notch bands and suppressed cross-polarization level up to − 35 dB is proposed for modern wireless applications.
Abstract: A miniaturized UWB antenna with multiple notch bands is proposed for modern wireless applications. The proposed microstrip-line-fed antenna consists a Y-shaped strip supported by defected ground structure. Procedure of bandwidth enhancement with multiple notch bands is presented. 163.6% of impedance bandwidth ranging from 1.5 to 15 GHz with three notch bands at 3–3.6, 6–6.8 and 9.2–9.8 GHz is achieved with gain of 2–6 dBi within the band. Accurate equivalent circuit model is presented for proposed antenna structure. Proposed antenna shows good radiation characteristics with very large bandwidth including three notch bands and suppressed cross-polarization level up to − 35 dB. The designed antenna is tested experimentally and measured results are verified with the simulated and theoretical results.
3 citations
TL;DR: In this paper, a compact active integrated antenna (AIA) consisting of class-A power amplifier (PA) and stepped impedance planar inverted-F antenna (PIFA) is presented.
Abstract: This paper presents a compact active integrated antenna (AIA) comprising of class-A power amplifier (PA) and stepped impedance planar inverted-F antenna (PIFA). In the proposed design, a common ground is used for both PA and PIFA, resulting a compact antenna of size 0.14λ 0 × 0.11λ 0 × 0.01λ 0 (λ 0 is free space wavelength at 0.85 GHz). Moreover, it is demonstrated that by using the stepped impedance radiator the operating frequency of the active PIFA is shifted down from its natural resonant frequency of 1.36 GHz to 0.85 GHz, offering an extensive size reduction of 80%. This active integration increases the passive antenna gain through the effective loading of the antenna to the power amplifier. The measured result indicates that the active and passive antennas achieved the gain of 15.7 dB and 3.81 dBi, respectively after the integration. In addition, the maximum SAR value of antenna is found to be 0.64 W/kg.
2 citations
TL;DR: In this article, the design and simulation of a planar dipole antenna for Global System Mobile GSM application using Computer Software Technology CST studio software is presented, where two types of feeding configuration are designed to feed the antenna in order to match 50 ohm transmission lines which are viahole integrated balun and quarter wavelength open stub.
Abstract: This research work focuses on the design and simulation of a planar dipole antenna for 1800MHZ Band for Global System Mobile GSM application using Computer Software Technology CST studio software. The antenna is structured on a fire resistance FR4 substrate with a relative constant of 4.3 S/m. Two types of feeding configuration are designed to feed the antenna in order to match 50 ohm transmission lines which are via-hole integrated balun and quarter wavelength open stub. The via-hole is capable to provide maximum return loss of 25dB, bandwidth of 18.4 percent and the voltage standing wave ratio (VSWR) of 1.116 V at optimum dimension of length 59mm and width 4mm, the bandwidth is improved 25 percent to 30 percent by extending the width of the antenna 8 mm to 10 mm followed by deterioration of return loss value to 15dB. While the open stub at length of 67 mm, the width of 6 mm and height 1.6mm will provide max return loss of 47.88dB and bandwidth of 17 percent with VSWR 1.008 less than 2. The way that the antenna substrate has influenced the performance of the antenna. The lower relative constant will result in the higher return lows, narrower bandwidth and better radiation pattern in trade-off the resonant length Via-hole and then the quarter wave open stub are most convenient for practical implementation.