M. Habib Ullah

Design of environmental friendly hybrid electric vehicle

Hybrid electric vehicles (HEVs) powered by electric machines and an internal combustion engine (ICE) are a promising mean of reducing emissions and fuel consumption without compromising vehicle functionality and driving performances. This paper presents the design of an environmental friendly hybrid car that feature the gasoline engine and batteries pack. The fuel consumption benefited by hybridization are benchmarked to conventional Gasoline and Diesel fueled vehicles. The relationship between fuel consumption and vehicle weight is investigated for Gasoline as well as for Diesel fueled vehicles. Although the automobile manufacturers have reduced the greenhouse gases such as hydro-carbons, carbon monoxide, carbon dioxide, etc., from the vehicle, they cannot produce a zero-emission vehicle unless they produce an electric vehicle (EV). An electric vehicle is an emission free, environmental friendly vehicle. The proposed design of HEV intelligently gets around the individual problems associated with the gasoline engine and the electric vehicle. It diminishes the production of emissions and the use of fuel. The problem of batteries for the electric vehicle is conquered. An HEV charges itself; it never has to be plugged in. When it does not provide power, the motor can run as a generator to transfer energy from regenerative braking and from the gasoline engine to the batteries.

Analysis of a ceramic filled bio-plastic composite sandwich structure

Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5 GHz.

A parametric study of high dielectric material substrate for small antenna design

A parametric study on three different high dielectric substrate materials for antenna miniaturization is conducted in this paper. The antenna substrates of three different dielectric materials in 2 GHz frequency ranges from 7.5 GHz to 9.5 GHz are investigated. Rectangular microstrip antenna on Aluminium oxide, Rogers RT Duroid 6010 and Silicon substrate is designed at the three resonant frequencies of 8.95 GHz, 8.79 GHz and 8.15 GHz respectively. The antenna is designed and analyzed by using three dimensional full-wave electromagnetic field simulators. The performances of the proposed antenna are analyzed using finite element method formulation within the volumetric region. The overall result shows that, aluminium oxide material substrate performs better in terms of bandwidth, gain and radiation characteristics compare to other two substrate materials.

Analysis of a dual-resonant multiple split-ring patch antenna

The design and analysis of a new 0.06λ×0.09λ compact circular polarized square-shaped dual-resonant multiple split-ring patch antenna on a 1.905-mm-thick high-dielectric ceramic-polytetrafluoroethylene composite is presented. The proposed antenna was designed and analyzed by using a high-frequency electromagnetic simulator based on the finite element method and was fabricated on a printed circuit board. The measured -10dB return loss bandwidths were 44.44% 0.7-1.1GHz and 34% 2.25-3.1GHz at 0.9 and 2.5GHz center frequencies, respectively. The measured radiation patterns with 5.9 and 4.0dBi maximum gains were symmetric and steady, making the proposed antenna suitable for radio frequency identification, wireless local area network, wireless body area network, Low Rate-Wireless Personal Area Network LR-WPAN, and so on. The effects of linewidth, dielectric property of the substrate materials, and number of split rings on the return loss were investigated. The surface current distribution over the radiating patch and the characteristics of the Resistance, Inductance, Capacitance RLC equivalent circuit of the proposed antenna were also analyzed. Copyright

Bandwidth Enhancement of a Dual Band Planar Monopole Antenna Using Meandered Microstrip Feeding

A meandered-microstrip fed circular shaped monopole antenna loaded with vertical slots on a high dielectric material substrate (ε r = 15) is proposed in this paper. The performance criteria of the proposed antenna have been experimentally verified by fabricating a printed prototype. The experimental results show that the proposed antenna has achieved wider bandwidth with satisfactory gain by introducing meandered-microstrip feeding in assistant of partial ground plane. It is observed that, the −10 dB impedance bandwidth of the proposed antenna at lower band is 44.4% (600 MHz–1 GHz) and at upper band is 28% (2.25 GHz–2.95 GHz). The measured maximum gains of −1.18 dBi and 4.87 dBi with maximum radiation efficiencies have been observed at lower band and upper band, respectively. The antenna configuration and parametric study have been carried out with the help of commercially available computer-aided EM simulator, and a good accordance is perceived in between the simulated and measured results. The analysis of performance criteria and almost consistent radiation pattern make the proposed antenna a suitable candidate for UHF RFID, WiMAX, and WLAN applications.

Low-Cost Dielectric Substrate for Designing Low Profile Multiband Monopole Microstrip Antenna

This paper proposes a small sized, low-cost multiband monopole antenna which can cover the WiMAX bands and C-band. The proposed antenna of 20 × 20 mm2 radiating patch is printed on cost effective 1.6 mm thick fiberglass polymer resin dielectric material substrate and fed by 4 mm long microstrip line. The finite element method based, full wave electromagnetic simulator HFSS is efficiently utilized for designing and analyzing the proposed antenna and the antenna parameters are measured in a standard far-field anechoic chamber. The experimental results show that the prototype of the antenna has achieved operating bandwidths (voltage stand wave ratio (VSWR) less than 2) 360 MHz (2.53–2.89 GHz) and 440 MHz (3.47–3.91 GHz) for WiMAX and 1550 MHz (6.28–7.83 GHz) for C-band. The simulated and measured results for VSWR, radiation patterns, and gain are well matched. Nearly omnidirectional radiation patterns are achieved and the peak gains are of 3.62 dBi, 3.67 dBi, and 5.7 dBi at 2.66 GHz, 3.65 GHz, and 6.58 GHz, respectively.

A new metasurface reflective structure for simultaneous enhancement of antenna bandwidth and gain

A new bi-layered metasurface reflective structure (MRS) on a high-permittivity, low-loss, ceramic-filled, bio-plastic, sandwich-structured, dielectric substrate is proposed for the simultaneous enhancement of the bandwidth and gain of a dual band patch antenna. By incorporating the MRS with a 4 mm air gap between the MRS and the antenna, the bandwidth and gain of the dual band patch antenna are significantly enhanced. The reflection coefficient (S11 < −10 dB) bandwidth of the proposed MRS-loaded antenna increased by 240% (178%), and the average peak gain improved by 595% (128%) compared to the antenna alone in the lower (upper) band. Incremental improvements of the magnitude and directional patterns have been observed from the measured radiation patterns at the three resonant frequencies of 0.9 GHz, 3.7 GHz and 4.5 GHz. The effects of different configurations of the radiating patch and the ground plane on the reflection coefficient have been analyzed. In addition, the voltage standing wave ratio and input impedance have also been validated using a Smith chart.

Ceramic-polytetrafluoroethylene composite material-based miniaturized split-ring patch antenna

Abstract A ceramic-polytetrafluoroethylene high-permittivity dielectric material-based split-ring patch antenna of dimensions 12 mm×16 mm is presented in this paper. The measured operating bandwidths (reflection coefficient <-10 dB) range from 5.0 to 6.5 GHz (1.5 GHz), 9.1 to 9.6 GHz (500 MHz), and 10.7 to 11 GHz (300 MHz) as observed from the proposed antennas. Average gains of 0.69, 3.52, and 3.48 dBi were measured at the first, second, and third band, respectively. Radiation efficiencies of 87.3%, 88.5%, and 93.1% were achieved at three resonant frequencies 5.6, 9.5, and 10.9 GHz, respectively. The measured symmetric and nearly consistent radiation pattern makes the proposed antenna suitable for C band and X band applications. In this paper, the effects of the dielectric properties of substrate material and design parameters have been studied.

Aerogel Poly(butylene succinate) Biomaterial Substrate for RF and Microwave Applications

Polybutylene succinate (PBS) has become a potential candidate, similar to polypropylene (PP) and acrylonitrile butadiene styrene (ABS), for use as an organic plastic material due to its outstanding mechanical properties as well as high thermal deformation characteristics. A new composition of silica aerogel nanoparticles extracted from rice waste with PBS is proposed for use as a dielectric (εr = 4.5) substrate for microwave applications. A microstrip patch antenna was fabricated on the proposed dielectric substrate for multi-resonant ultra-wideband (UWB) applications. The performance characteristics of the proposed biomaterial-based antenna were investigated in a far-field measurement environment. The results indicate that the proposed biocompatible material-based antenna covered a bandwidth of 9.4 (2.3–11.7) GHz with stop bands from 5.5 GHz to 5.8 GHz and 7.0 GHz to 8.3 GHz. Peak gains of 9.82 dBi, 7.59 dBi, 8.0 dBi and 7.68 dBi were measured at resonant frequencies of 2.7 GHz, 4.6 GHz, 6.3 GHz and 9.5 GHz, respectively.

Performance analysis of power control schemes in CDMA communication system

In CDMA cellular communication system power control is one of the most efficient methods to manage the resources, where the main capacity-limiting factor is co-channel interference. In this paper several closed loop power control algorithms are analyzed considering loop delay to cope with random changes of the radio channel and interference. Adaptive algorithms are considered that utilize ideas from self-tuning control systems. The inherent loop delay associated with closed loop power control can be included in the design process. Another problem in closed-loop power control is that extensive control signaling consumes radio resources, and thus the control feedback bandwidth must be limited. To enhance the performance of closed-loop power control in limited-feedback-case is investigated. The performances of the adaptive algorithms are investigated through both analysis and computer simulations, and compared with well-known algorithms from the literature. After proper investigation and analysis it is anticipated that significant performance improvements are achievable with the adaptive algorithms.