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This paper presents the improvement of rice husk ash (RHA) microwave absorber with adding carbon nanotubes (CNTs) into the composites. The electromagnetic properties of RHA and CNTs composites (RHACNTs) were measured using a rectangular waveguide (WR-62) transmission line technique with Agilent commercial software 85071E. The results show that, the additional 2 wt. % CNTs adding into the RHA composite...
This paper presents the performance evaluation for the simulation modeling approach of single-walled carbon nanotube (SWCNT) dipole antenna at THz and GHz frequency regimes. The equivalent nano-solid tube material (NSTM) modeling approach to the SWCNT is implemented into CST (MWS) software package. Where, the raw material of the NSTM model is derived from SWCNT material rather from other metal material...
This paper aim to present a good candidate material structure, in order to design dipole antenna at 60 GHz frequency. The single-walled carbon nanotube (SWCNT) is the basic material of this structure material. For the purpose of achieving this aim, the effective electromagnetic (EM) modeling approach for the single-walled carbon nanotube composite material (SWCNT-composite) is presented. The equivalent...
This paper presented for the purpose of study and estimates the fundamental electromagnetic properties of the bundle of single-walled carbon nanotubes with circular geometrical structure. The bundle of single-walled carbon nanotubes (SWCNTs) dipole antenna will be employed for this purpose by using Drude method at THz frequency range. The armchair-single-walled carbon nanotube (armchair- SWCNTs) will...
This paper presents the different type of microwave absorbing materials based on rice husk ash and carbon nanotubes (RHACNTs) composites. The microwave absorption and complex relative permittivity of RHACNTs composites were investigated in microwave frequency region X-band (8.2–12.4 GHz). A rectangular waveguide (WR-90) transmission line method was used to measure scattering parameter and Nicolson-Ross-Weir...
This paper has presents a novel design of compact monopole antenna fed by a coplanar waveguide (CPW) for dual-band applications that targeted to achieve the gain more than 1 dB. The proposed compact monopole antenna has been design only 20 × 35 mm in size. The monopole structure with two inverted U-shaped, L-shaped lateral and coplanar-way (CPW) feed line driven by 50 Ω on one side are designed with...
A design of modified H-shaped patch antenna with slots and modified ground plane is presented in this paper. H-patch configuration with modified ground plane is proposed to increase the directivity, bandwidth and reflection coefficient of antenna. The H-shape patch antenna is feed by transmission line. By giving extra slots on top of the patch, it can increase the reflection coefficient of antenna...
A dual-band antenna by use 2 × 2 patch array with L-slot is presented for simultaneously worldwide interoperability for Microwave Access (WiMAX) and wireless local area network (WLAN) application. This 2 × 2 Patch Array with L Slot Antenna is targeted to achieve the gain more than 2 dB for both frequencies by using array technique design. The antenna design structure has been modified by adding a...
the electrical, mechanical and physical properties of carbon nanotubes have been applied in different fields. The fabrication new composite materials of carbon nanotubes by various methods illustrates how new avenues are used in many areas of science and technology. The coating method of carbon nanotubes is one of the fabrication techniques. This review therefore, aims to present a general lid on...
This paper aims to investigate the fundamental properties of single-walled carbon nanotubes bundles dipole antenna at THz frequency band by using Drude method. Due to their metallic conducting properties, the armchair-SWCNTs will be utilized in this work to configure the bundle of SWCNTs. The cross section of bundle that will be investigated in the current work can be in a rectangular geometry filled...
Orthogonal frequency division multiplexing (OFDM) is a very interesting approach for high data rate transmission in a multipath fading environment that leads to intersymbol interference (ISI). In this paper, two steps are used to improve the error rate performance of OFDM system. First, the discrete multiwavelet transform (DMWT) is proposed instead of fast Fourier transform (FFT) to obtain high orthogonality...
For high data rate propagation and indoor obstacles in wireless ultra-wideband (UWB) communication systems, the signal fading and noises are influencing the performance of the wireless systems. In this paper, the rake-receiver was presented with the spread signal by time-hopping spread spectrum (TH-SS) technique. The adaptive filter used in rake-receiver structure was shown with adjusting the receiver...
The boron doped amorphous carbon were prepared by in-situ mixing of hydrocarbon palm oil and boron dopant and carrier gas, argon in the chamber by using bias assisted pyrolysis-CVD. The effect of substrate bias on the thickness, electrical and electronic properties of a-C:B film were investigated. The fabricated solar cell with the configuration of Au/p-C:B/n-Si/Au achieved conversion efficiency (r\)...
Surface acoustic waves (SAW) devices have been initially developed and used for the high-volume low-cost TV component. Due to the ultra-sensitivity to the surface perturbation, SAW based devices have been modified to be sensors. Initially, SAW based sensors were developed for gas detection and recently they have been moving towards biological detection. Shear horizontal surface acoustic wave (SHSAW),...
This work investigates the fundamental properties of armchair single-wall carbon nanotubes (armchair-SWCNTs) dipole antenna at THz band using Drude method. Due to their metallic conducting properties, the armchair SWCNTs will be utilized in this work. The radiation pattern, s11 parameters, phase velocity and antenna directivity are presented for this antenna. The results demonstrate that armchair-SWCNTs...
In this paper, an over-sampling inverse discrete multiwavelet transform (IDMWT) is suggested as a modulator strategy instead of inverse fast Fourier transform (IFFT) in the realization of the multicarrier code division multiple access (MC-CDMA) system. The suggested strategy was applied on the MC-CDMA with additive white Gaussian noise (AWGN) channel, flat fading channel and frequency selective fading...
Recently, many literatures were presented to mitigate the noises or to suppress inter-symbol interference (ISI) and inter-frame interference (IFI) with systems operate in time hopping spread spectrum. The structure of the conventional rake-receiver is more complex that based on large number of multiple paths in wireless ultra wideband (UWB) communication systems. In this paper we proposed low complexity...
Boron doped heterojunction of amorphous carbon solar cell were successfully fabricated using palm oil precursor in the environment of low negative bias. The open circuit voltage (Voc), current density (JSC), fill factor (FF) and efficiency (%) of boron doped without the use of negative bias (a-C/n-Si) were approximately 0.128244, 0.452821mA/cm2, 0.255398, and 0.014831%, respectively. Meanwhile, the...
The design FSS structure consists of square Frequency Selective Surface (FSS) structures placed on the FR4 and glass. The circular and square slot is added on the FSS to design and simulate by using the CST Microwave Studio software for 2.4 GHz and 5.2GHz based on industrial, scientific and medical bands (ISM) standard. The reflection (S11) and transmission (S21) of the design FSS structure is analyzed...
In recent years, the UWB technology in wireless communication systems is required for many military, civilian, and medical applications, so small and economic UWB antennas need to be produced for these purposes. Since the Federal Communications Commission (FCC) reported the UWB frequency of 7.5 GHz (from 3.1 GHz to 10.6 GHz) was licensed for high data rate wireless technology and antenna plays a very...
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