Ahmad Zaidi Abdullah

Performance of Sugarcane Bagasse and Rubber Tire Dust Microwave Absorber in Ku Band Frequency

The electromagnetic interference (EMI) absorbing materials in various microwave frequency were required most now due to increasing demand of electromagnetic compatibility (EMC) for electronic devices with various electromagnetic environments. So, absorber materials are needed in RF/Microwave to eliminate and absorb electromagnetic energy. Absorbers can be used to create a free space environment in anechoic chamber. This work describes the performances which are the reflection loss and absorption for composite of sugarcane bagasse mixed with rubber tire dust microwave absorber in Ku Band frequency (12.4–18 GHz). The parameters such as dielectric properties, reflection coefficient (S11) and transmission coefficient (S21) were investigated. The main objectives of this research are to design and develop a microwave absorber with new green materials which are sugarcane bagasse and other waste material such as rubber tire dust. These agricultural wastes can help save the nature and the fabrication cost of microwave absorber can be reduced. Based on the result, it proved that the sugarcane bagasse-rubber tire dust can be a good alternative material to be used as microwave absorber and can operate in frequency range between 12.4 and 18 GHz.

Composites Based on Rice Husk Ash/Polyester for Use as Microwave Absorber

This paper is to study the dielectric properties and microwave absorption of rice husk ash/polyester (RHAP) composites. The RHAP composites prepared with different weight ratio (40–80 wt. %) of rice husk ash (RHA) loading into polyester was fabricated. A rectangular waveguide transmission line method was used to measure the dielectric properties of the RHAP composites. The RHAP samples were designed and simulated with different thickness and percentage of RHA loading by using Computer Simulation Technology Microwave Studio (CST-MWS) software. The materials, their dielectrics properties measurement and microwave absorption result over 12.4–18 GHz (Ku-Band) frequency range are discussed. The dielectric properties of composites increase with increasing loading the RA wt%. The RHAP sample with different thickness was investigated in Ku-Band. The microwave absorption was up to 99.84 %, using 80 % loading of RHA with thickness 15 mm at 13.81 GHz, and showing the RHAP composites is applicable as microwave absorber.

Study of TiO2 Energy Gap Based Temperature Annealing for High Performance Solar Cells

This paper describes the TiO2 performance based energy gap related to its annealing process. TiO2 is one of the comprehensive band gap semiconductor materials which has been under extensive investigation in recently. This is due to its application in various fields such as photo electrolysis, photo catalysis, dye sensitized solar cells, gas sensor, optical fibers etc. Furthermore, advent of nanotechnology increases its applications many fold and different types of TiO2 have been used for different types of sensing applications. The TiO2 exists in different crystalline forms such as anatase, rutile and brookite. Solar cells consists of mono-crystalline, thin films, dye sensitized solar cells and multi-junction. TiO2 can be produced by using techniques like sputtering, vacuum evaporation, pulse laser deposition, molecular beam epitaxial, sol-gel and chemical bath deposition. Successful annealing process leads to a high performance solar cells. To fabricate the solar cells, there are four types of ways which are doctor blading, spin coat, sol-gel and screen printing. A comparison of annealing process, nanoscale structure and performance output powers been done successfully. The produced TiO2 also been tested with a high power performance.

Investigation of Rice Husk/CNTs Composites Performance in Microwave Properties

This paper is to study the performance of rice husk and carbon-nanotubes nanotubes (RH-CNTs) composite material as a microwave absorber. The rice husk (RH) is a lossy material that contains dielectric properties which suitable used as microwave absorber. The dielectric properties are playing a main role in microwave absorption of any material. The dielectric properties of materials were measured using an Agilent dielectric probe. The microwave absorption performance of rice husk and CNTs composites was investigated by using rectangular waveguide transmission line in simulation. The microwave absorbers were designed and simulated using the Computer Simulation Technology Microwave studio software (CST-MWS). The ability of microwave absorption between rice husk and RH-CNTs was compared in 8.2–12.4 GHz. The microwave absorption with different thickness of RH-CNTs samples was investigated. The results show that the RH-CNTs composites have a better ability of microwave absorption compared than pure rice husk.

Two Small Antenna Designs for Ultra-Wideband Wireless Systems

This chapter focuses on designing small antennas used by Ultra Wideband (UWB) wireless systems. The study has been taken from the conventional rectangular manuscript patch antenna to miniaturize the size of used antenna to be more suitable for future 5G system applications. These applications are dealing with high data transmission rates over a very large spread spectrum frequency (3.1–10.6 GHz), so that, many challenges are provided in the antenna design. The main objective of this research is to design, and analyze two small manuscript patch antennas to satisfy UWB technology requirements. Several techniques were used to optimize the UWB bandwidth performance such as radiator dimensions, planar ground plane, and unprinted gaps between ground plane and radiators. Therefore, this work introduces two designs of microstrip-fed, small, and low profile which are called ax-shaped and socket-shaped patch antennas. It has been demonstrated numerically that the proposed antennas are suitable for UWB systems. They can provide satisfactory frequency domain performance (less than −10 dB return loss), including ultra-wide bandwidth with nearly omni-directional radiation patterns, and relatively good current density over the radiator parts of the proposed antenna designs.

2 × 1 Circular Array Patch Antennas with Double Circular Slots for WLAN Application

The purpose of this paper is to presents entire design of 2 × 1 circular array patch antenna for WLAN application of 2.4 GHz. Circular array with double circular slots microstrip antenna modeled due to the low profiles and easy to fabricate. The circuit was designed by using CST Microwave Studio for the entire dimension. The simulation results of the antenna are done to observe the return loss, radiation pattern, gain, directivity and bandwidth performance. This proposed circular array patch antenna has radiate −24.707 dB at resonant frequency of 2.40 GHz. The bandwidth of this antenna is 53 MHz while the gain is 8.521 dB. Two parametric studies on the effect of the two different circular radiuses (R 1 and R 2 ) are done in this work.

Strength Pareto Evolutionary Algorithm 2 in Optimizing Ninth Order Multiple Feedback Chebyshev Low Pass Filter

Circuit design optimization has become a common research to reduce the manpower and computational resource required for circuit design industries. Despite the involvement of multiple design objectives, higher order circuit designs are often more complicated and difficult to be optimized using conventional circuit tuning method. This paper proposed Strength Pareto Evolutionary Algorithm 2 (SPEA2) to optimize a ninth order multiple feedback Chebyshev low pass filter. This research aims to search the best trade-off solution that could minimize the passband ripple, maximize the gain and achieve the targeted cutoff frequency. The NGSPICE circuit simulator is interacted with SPEA2 algorithm to perform the circuit optimization. The results obtained show the reliability of the algorithm in achieving the required optimization objectives.

CPW Circular Patch Antenna for Ground Penetrating Radar Applications

A Co-planar Waveguide (CPW) Circular patch antenna for Ground Penetrating Radar (GPR) applications is presented in this paper. The antenna is designed on Rogers substrate RO 3010 with dielectric constant of 10.2 with a thickness, h = 1.22 mm and tangent loss = 0.0022 operates from 1.1 to 5.5 GHz with the overall size is 140 mm × 140 mm. CPW was used as an input method for the antenna with 50 Ω impedance matching and Computer Simulation Technology (CST 2013) has been used as simulation tools to observe the antenna performances. In order to produce antenna with high gain performance, a reflector is located at the back of the antenna. The antenna parameters such as simulated return loss, gain, radiation pattern and current distribution of the antenna is presented.

Design of Compact Composite Microstrip Low Pass Filter Using MEMS Technology

This paper presents the design technique of a compact composite microstrip filter operating at ultra high frequency (UHF) band and its fabrication using micro-electro mechanical system MEMS technology. The fringing compensation method is applied into the design of the microstrip line transformation from lumped element. The filter lumped circuits and microstrip line circuit were designed and simulated using Advanced Design Software (ADS) and fabricated on silicon substrates to obtain the best filter characteristic based on S-parameter. The measured and simulated results have achieved a good agreement within the frequency of interest. This shows that the fringing compensation method of transforming lumped element into microstrip line is able to solve the conventional design of complexity size of circuit of composite low pass filter (LPF) into microstrip line. The proposed filter design can replace the conventional filters in wireless communication as they offer better performance at lower cost in the RF microwave communication applications.

Review of Radio Frequency for Home Appliances

Smart homes and environments have been discussed and hyped for many years now, and despite technological advances, future visions and dreams the concept of a smart home remains distant and unfamiliar. People are becoming increasingly more mobile in this fast faced society as has been seen by the number of cell phones in existence. We believe that the home of the future will have the capability of being completely controlled by some remote device using of radio frequency (RF) remote control to controls the home appliances.In this paper we describes a review of radio frequency for home appliances. The scope of this research work is based on comparison between radio frequency controller and infra red controller. The research methodology involved the limitation, specification, bandwidth range between two type controller.Finally the result, will be observe and analyze to obtain better solution in the future.