Mudrik Alaydrus

A bandpass filter based on square open loop resonators at 2.45 GHz

A bandpass filter based on square open loop resonator is designed at 2.45 GHz. To enhance the filter selectivity around the pass band two transmission zeros are introduced and also additional tranmission zeros inserted apart from the pass and to guarantee the rejection there. This six pole filter with four transmission zeros is implemented in microstrip technology. The simulation and measurement results show a very well reflection characteristics, whereas they show relative big insertion loss of about 3.6 dB in simulation and 6.3 dB in measurement. The bandwidth obtained by simulation and measurement is about 72 to 86 MHz. Moreover we see a shift of measurement againts the simulation result, which probably due to mechanical tolerances and tolerances of the relative permittivity of the subtsrate used.

Designing cross-coupled bandpass filters with transmission zeros in lossy microstrip

Bandpass filters play a significant role in many wireless communication systems. The filters pass desired signals and reject unwanted one. In this paper, we design a four-pole bandpass filter using a rigorous computer simulation. The resonators used are square open-loop resonators. To get a sharper selectivity around the pass band, transmission zeros though cross-coupling between resonators are introduced. In simulation, we compare the results for relative permittivity 4.4 and 4.9, and for tangent loss 0.025 (lossy) and 0.0 (lossless). The simulation shows, the required specifications are fulfilled for lossless case, whereas for lossy case, an insertion loss of 8.3 dB observed. For verification, the bandpass filter is built in FR4. In this lossy microstrip, a measurement shows, we get an insertion loss of about 6.64 dB and a bandwidth of about 120 MHz.

Performance analysis of VoIP client with integrated encryption module

The number of VoIP users in Indonesia is very low, although the cost offered by VoIP is smaller than using pulsed phone. One of the reason is security provided by the VoIP service provider is still lacking. VoIP users have not received yet the security service to ensure the security of communications. This study tries to secure communications between VoIP users using encryption module that is integrated with VoIP client Sipdroid running on Android Smartphone. It is possible for VoIP users because VoIP client that can only be accessed by VoIP users. The result obtained after integration with encryption module using three encryption schemes, they are AES, DES, and RC4. Sipdroid able to resist passive attack from tapping information (eavesdropping) during the communication session. And the result of QoS measurements is an increase delay of 0.01 ms and no significant change in the throughput and the packet loss, for throughput generated about 78 kbps, and for the average packet loss is 0.8%. However there is a noise that follows the communication on Sipdroid integrated with the encryption module due to the wave skew from the increase time during the encryption process.

Effects of polarization and radiation diagram of antennas in RFID systems for positioning purposes

Radio Frequency Identification (RFID) is a wireless system designed to identify the presence of objects attached by tags. In recent times, RFID is also used for positioning purposes. We show a scenario of wireless propagation observed by eight antennas with different polarization located in different positions. In this way, the polarization and diagram radiation of the antennas will play a significant role in producing electromagnetic field in the region.

Designing multiband multilayered microstrip antenna for mmWave applications

Due to the increasing interest in millimeter wave spectrum regions in the next generation of communication systems, there is a need to analyze and design antennas appropriated for this purpose. Microstrip antenna array with a multi-layer structure is a potential candidate. The antenna should work in a wide spectrum interval and should be multiband. The proposed antenna system consists of three layers. In the middle layer, there are two rectangular microstrip patches, which are fed by an electromagnetic coupling through some slots from the bottom layer. On the top of the patches, a gridded structure with 6×3 rectangular microstrip patches is built to enhance the gain. This paper calculates the antenna system with a commercial software package. The calculation results show the antenna system operates in three frequency bands in the spectrum range of 40 GHz - 80 GHz. The gain obtained in the simulation is about 8.65 dBi.

An analysis of Haar Wavelet Transformation for androgenic hair pattern recognition

To identify criminal or pedophile in online child pornography images and video is a challenging task when the faces and other distinguish features are not shown. To address these kind of problems, the system of recognition using androgenic hair pattern is being developed. The system of recognition presented in this paper used three main parts of methods, pre-processing methods, feature extraction with Haar Wavelet Transform level 1 decomposition and classification using Nearest Neighbor. Using 400 images of lower right legs with controlled condition, the system was analyzed. The Haar Wavelet Transformation for level 1 decomposition gave 83.48 % of average recognition precision when using 10-fold cross validation with nearest neighbor classification.

Determining the conductivity and relative permittivity of fluids in microwave frequencies using waveguide structures

Dielectrics play in many telecommunication and sensor applications a significant role. The interaction between electromagnetic fields with the dielectrics can change the characteristics of both of them. In order to set up the system correctly, the knowledge about the field distributions and the material constants is very important. With the help of a waveguide structure, some material characteristics of fluids will be measured. The measurement is done indirectly through the so-called scattering parameters of the propagating electromagnetic waves at the ports. We simulate analytically and numerically several conditions to get some preliminary results for getting some initial information for next observations

The effect of thickness on microwave absorbing properties of barium ferrite powder

We have investigated the effect of thickness on microwave absorbing properties of barium ferrite (BaFe12O19) powder prepared by a solid-state reaction method with a sintering temperature of 1100°C for 5 hours. The sample was analyzed using XRD, SEM, PERMAGRAPH, and vector network analyzer (VNA). The microwave absorbing properties were measured at the frequency in the range of 8.2 – 12.4 GHz. Permeability, permittivity and reflection loss (RL) were calculated at a given thickness based on transmit line theory. The results show the optimal RL of −23.07 dB can be obtained at 10.72 GHz with a thickness of 3.0 mm, bandwidth with RL less than −5 dB and −10 dB can reach 1.2 GHz (10.4−11.6 GHz) and 0.8 GHz (10.6−11.4 GHz), respectively.

Wireless Sensor Network Design for Earthquake’s and Landslide’s Early Warnings

Received Mar 3, 2018 Revised Apr 11, 2018 Accepted Apr 21, 2018 Paintball has gained a huge popularity in Malaysia with growing number of tournaments organized nationwide. Currently, Ideal Pro Event, one of the paintball organizer found difficulties to pair a suitable opponent to against one another in a tournament. This is largely due to the manual matchmaking method that only randomly matches one team with another. Consequently, it is crucial to ensure a balanced tournament bracket where eventual winners and losers not facing one another in the very first round. This study proposes an intelligent matchmaking using Particle Swarm Optimization (PSO) and tournament management system for paintball organizers. PSO is a swarm intelligence algorithm that optimizes problems by gradually improving its current solutions, therefore countenancing the tournament bracket to be continually improved until the best is produced. Indirectly, through the development of the system, it is consider as an intelligence business idea since it able to save time and enhance the company productivity. This algorithm has been tested using 3 size of population; 100, 1000 and 10,000. As a result, the speed of convergence is consistent and has not been affected through big population.N. N. S. Abdul Rahman, N.M. Saad, A. R. Abdullah, M. R. M. Hassan, M. S. S. M. Basir, N. S. M. Noor 1,2,4,6Faculty of Electronic and Computer Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia 2,3Center for Robotics and Industrial Automation, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia 3,5Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, MalaysiaLight rail transit (LRT), or fast tram is urban public transport using rolling stock similar to a tramway, but operating at a higher capacity, and often on an exclusive right-of-way. Indonesia as one of developing countries has been developed the LRT in two cities of Indonesia, Palembang and Jakarta. There are opinions toward the development of LRT, negative and positive opinions. To reveal the level of LRT development acceptance, this research uses machine learning approach to analyze the data which is gathered through social media. By conducting this paper, the data is modeled and classified in order to analyze the social sentiment towards the LRT development.Mohamad, S., Nasir, F.M., Sunar, M.S., Isa, K., Hanifa, R.M., Shah, S.M., Ribuan, M.N., Ahmad, A. 1,4,6,7,8Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, Johor, Malaysia 1,2,3UTM-IRDA Digital Media Centre, Media and Game Innovation Centre of Excellence, Universiti Teknologi Malaysia, Johor, Malaysia 1,2,3Faculty of Computing, Universiti Teknologi Malaysia, Johor, Malaysia 5Centre for Diploma Studies, Universiti Tun Hussein Onn Malaysia, Johor, Malaysia 6Research Centre for Applied Electromagnetics, Universiti Tun Hussein Onn Malaysia, Johor, MalaysiaReceived Jan 31, 2018 Revised Apr 21, 2018 Accepted Apr 30, 2018 Bluetooth is an emerging mobile ad-hoc network that accredits wireless communication to connect various short range devices. A single hop network called piconet is the basic communication topology of bluetooth which allows only eight active devices for communication among them seven are active slaves controlled by one master. Multiple piconets are interconnected through a common node, known as Relay, to form a massive network called as Scatternet. It is obvious that the performance of Scatternet scheduling is highly dependent and directly proportionate with the performance of the Relay node. In contrary, by reducing the number of Relays, it may lead to poor performance, since every Relay has to perform and support several piconet connections. The primary focus of this study is to observe the performance metrics that affects the inter-piconet scheduling since the Relay node’s role is like switch between multiple piconets. In this paper, we address and analyze the performance issues to be taken into consideration for efficient data flow in Scatternet based on Relay node.

Analisa Saluran Transmisi Nonhomogen dengan Metoda Persamaan Integral

Saluran transmisi adalah salah satu komponen penting di teknik elektro, baik untuk mentransmisikan energi ataupun informasi. Saluran transmisi yang memiliki besaran karakteristik yang tidak homogen (nonhomogen) biasa digunakan untuk rangkaian matching, delay equalizer, filter, wave shaping, pemprosesan sinyal analog dan interkoneksi VLSI . Metoda persamaan integral digunakan untuk menganalisa struktur saluran transmisi ini. Metoda persamaan integral yang diimplementasikan dengan metoda momen memberikan hasil yang sangat baik. Kasus kanonikal, saluran transmisi homogen dengan dan tanpa kerugian untuk kondisi matching dan tidak matching memberikan verifikasi program komputer yang dikembangkan, bekerja dengan baik, hasil yang didapatkan sejalan dengan apa yang didapatkan secara teoretis. Pengamatan saluran transmisi nonhomogen melibatkan saluran transmisi dengan besaran karakteristik yang berubah secara perlahan dan yang berubah secara mendadak. Analisa struktur filter lolos bawah memberikan hasil yang secara kualitatif sama dengan yang diberikan di pustaka.