Fast S-parameter Convolution for Eye Diagram Simulations of High-speed Interconnects.

With the increase in signal frequency and the complexity of high-speed interconnects, signal integrity has become a prominent issue in modern electronic devices

A CPW-Fed Quasi-PIFA Antenna Using Quasi-Lumped Resonators for Mobile Phones

A novel single CPW-fed Quasi-Planar Inverted-F Antenna (PIFA) using quasi-lumped elements is developed for mobile communication handheld terminals operating at 2.6GHz.The antenna is composed of an inductor covered by a set of interdigital and parasitic capacitors.The proposed antenna achieves a measured bandwidth of 11% for return loss with the antenna gain of about 4 dBi.The antenna is designed in single layer (zero height) which is appropriate to be used in thin devices where a small room is considered for the antenna.The proposed antenna is suitable for use in Long Term Evolution band 7.The operating frequency of introduced antenna depends on the number of interdigital fingers and inductor length rather than the total resonator patch only, so that the operating frequency can be altered while the total patch size remains unchanged. The calculated operating frequency is confirmed by simulation and measurement. Also the dipole-like simulated radiation pattern is confirmed by measurement

A novel-fed fixed frequency-source dielectric resonator for frequency stability-dependent applications

Abstract: A simple and novel microstrip-fed dielectric resonator (DR) as fixed frequency source is proposed design. The feed mechanism consists of three microstrip line sections, each of a width approximately equal to its characteristic impedance. The DR located at the centre of the grounded laminate Roger RO4003C Duroid microwave board of size 18 × 18 sq. mm, with a substrate height of 0.813 mm, dielectric constant εr = 3.38 ± 0.05, and a metallization of 35μm is excited by these microstrip lines such that port 1 and 2 are oppositely edges-coupled to the DR in a balanced parallel arrangement, whereas, the third microstrip line is orthogonal to the microstrip feed line excited by port 2. Each of the feed line are located at a coupling space (β) of 0.24 mm away from the DR, whereas, the third orthogonal microstrip line is capacitively coupled through the excitation of port 1 and 2. Both the measured and numerical results agreed reasonably

The use of carbon black-TiO2 composite prepared using solid state method as counter electrode and E. conferta as sensitizer for dye-sensitized solar cell (DSSC) applications

In this paper, counter electrodes based on carbon black (CB)-TiO2 composite are proposed as a cost-effective alternative to conventional Pt counter electrodes used in dye-sensitized solar cell (DSSC) applications. CB-TiO2 composite counter electrodes with different weight percentages of CB were prepared using the solid state method and coated onto fluorine-doped tin oxide (FTO) glass using doctor blade method while Eleiodoxa conferta (E. conferta) and Nb-doped TiO2 were used as sensitizer and photoanode, respectively, with electrolyte containing I −/I− 3 redox couple. The experimental results revealed that the CB-TiO2 composite influenced the photovoltaic performance by enhancing the electrocatalytic activity. As the amount of CB increased, the catalytic activity improved due to the increase in surface area which then led to low charge-transfer resistance (RCT) at the electrolyte/CB electrode interface. Due to the use of the modified photoanode together with natural dye sensitizers, the counter electrode based on 15 wt% CB-TiO2 composite was able to produce the highest energy conversion efficiency (2.5%) making it a viable alternative counter electrode

Application of a Stable Latency Insertion Method for Simulations of Power Distribution Networks

This paper presents an application of a stable implementation of the latency insertion method for simulations of power distribution networks (PDN). Traditionally, simulations of PDNs poses a considerable challenge due to their large circuit sizes. While the latency insertion method can be applied to simulate these networks, the existence of low latency elements results in a more stringent stability criterion which reduces the efficiency of the method. Using the improved formulation, a latency insertion method that is free from the stability criteria is obtained, which results in no limitation on the size of the time step

A nested square-shape dielectric resonator for microwave band antenna applications

In this paper, a nested square-shape dielectric resonator (NSDR) has been designed and investigated for antenna applications in the microwave band. A solid square dielectric resonator (SSDR) was modified systematically by introducing air-gap in the azimuth (ϕ-direction). By retaining the square shape of the dielectric resonator (DR), the well-known analysis tools can be applied to evaluate the performance of the NSDR. To validate the performance of the proposed NSDR in antenna applications, theoretical, simulation, and experimental analysis of the subject has been performed. A simple microstrip-line feeding source printed on the top of Rogers RO4003 grounded substrate was utilized without any external matching network. Unlike solid square DR, the proposed NSDR considerably improves the impedance bandwidth. The proposed antenna has been prototyped and experimentally validated. The antenna operates in the range of 12.34GHz to 21.7GHz which corresponds to 56% percentage bandwidth with peak realized gain 6.5dB. The antenna has stable radiation characteristics in the broadside direction. A close agreement between simulation and experimental results confirms the improved performance of NSDR in antenna applications

Effect of Calcination Temperature on Dielectric Properties of CaCu3Ti4O12 Ceramics

AbstractThe effect of calcination temperature on the properties of CaCu3Ti4O12 (CCTO) ceramics was studied. CCTO ceramics were prepared using solid state reaction method. The raw materials of CCTO were wet mixed for 24 hours and was dried overnight. CCTO powders were then calcined at three different temperature which is at 900̊C, 930̊C and 985̊C for 12 hours. The calcined powders were compacted at 250 MPa and then were sintered at 1040̊C for 10 hours. X-Ray Diffractometer (XRD) analysis showed the formation of CCTO phase and secondary phases of CuO for C900 calcined powder but single phase of CCTO was obtained by C930 and C985 calcined powders. Single phase of CCTO also were seen for all sintered samples. Observation on Scanning Electron Microscopy (SEM) micrographs showed abnormal grain growth or large grain size was seen in C900 sample and finer grain size was observed for C930 and C985 sintered samples. C900 sintered sample obtained the highest dielectric constant (10,462) and the lowest dielectric loss (0.061) measured at 1 MHz

EYE-HEIGHT/WIDTH PREDICTION USING ARTIFICIAL NEURAL NETWORKS FROM S-PARAMETERS WITH VECTOR FITTING

Artificial neural networks (ANNs) have been used to model microwave and RF devices over the years. Conventionally, S-parameters of microwave/RF designs are used as the inputs of neural network models to predict the electrical properties of the designs. However, using the S-parameters directly as inputs into the ANN results in a large number of inputs which slows down the training and configuration process. In this paper, a new method is proposed to first disassemble the S-parameters into poles and residues using vector fitting, and then the poles and residues are used as the input data during configuration and training of the neural networks. Test cases show that the ANN trained using the proposed method is able to predict the eye-heights and eye-widths of typical interconnect structures with minimal error, while showing significant speed improvement over the conventional method

Photoplethysmogram Based Biometric Identification Incorporating Different Age and Gender Group

Biometric is the authentication and identification of a person by measuring or estimating their physiological characteristics. First generation biometric such as fingerprint, signature and voice have drawback and easily can be duplicated which lead to serious identity theft crime. Therefore, second generation of biometric was introduced by using bio-signal. This study evaluates the possibility of applying PPG as biometric identification system incorporating different age, gender group, and time variability. A total of 36 subjects were involved in this study consists of 18 males and 18 females for age difference and gender analysis. The PPG signals were taken in resting state by using pulse oximeter. The PPG signal was differentiated twice in order to form APG signal. These signals then undergo preprocessing and the segmentation process was done by using MATLAB. The highest peaks from the signal was used as reference point to determine the appropriate distance for one cycle of both signal. Then, the signals were classified by four commonly used classifiers which are Bayes Network, Naïve Bayes, Multilayer Perceptron, and Radial Basis Function. The outcome from this study suggested the accuracy up to 100% for different age group, 91.11% for female subjects and 95% for male subjects

Persepsi Pengguna Internet di Malaysia Semasa Pandemik COVID-19

Internet dilihat sebagai alat komunikasi yang telah mempercepatkan, memudahkan perhubungan dan capaian maklumat secara meluas. Semenjak wabak COVID-19 menyerang pada awal tahun 2020 masyarakat hidup dalam perubahan yang berterusan. Perkembangan tahun- tahun terakhir dalam bidang komunikasi, teknologi, maklumat dan pemasaran telah menciptakan perubahan baru dalam cara pengguna internet dalam membeli produk dan perkhidmatan tertentu. Kajian yang dijalankan ini merupakan satu kajian deskriptif dimana kajian ini menggunakan reka bentuk kajian kuantitatif dan borang soal selidik sebagai instrumen kajian. Sasaran responden bagi kajian ini adalah pengguna internet di seluruh Malaysia. Selain itu, kajian ini turut memperlihatkan persepsi pengguna internet di Malaysia semasa pandemik COVID-19. Kajian yang dijalankan melalui edaran borang soal selidik secara atas talian kepada pengguna di Malaysia sebagai sasaran kajian. Keputusan daripada kajian tersebut telah menunjukkan persepsi pengguna internet di Malaysia semasa pandemik COVID- 19 menunjukkan bahawa internet merupakan satu keperluan utama dalam menjalankan tugas harian. Berdasarkan soal selidik, 91.3% responden yang menyatakan bahawa mereka sangat setuju bahawa internet merupakan keperluan utama. Walau bagaimanapun, dalam perubahan ini, pelbagai masalah, isu dan kesan akan timbul dalam kalangan individual atau masyarakat di negara ini