Toyobur Rahman

A novel EBG structure with embedded meander bridge for broadband suppression of SSN

A planar Electromagnetic Bandgap (EBG) structure with embedded meander bridge for broadband suppression of simultaneous switching noise (SSN) in power/ground plane pairs is proposed. Simulation results show that the -30 dB suppression bandwidth of the novel structure is from 500 MHz to 14.5 GHz. Effects of the proposed EBG structure on signal integrity (SI) are investigated and methods for SI improvement are also concluded. Finally, measurement results are compared with simulation results to verify the structures good performance of SSN suppression.

Prediction of the HF Ionospheric Channel Stability Based on the Modified ITS Model

Since the narrowband ionospheric channel model is applicable only to a limited set of actual conditions, in 1997 the Institute for Telecommunication Science (ITS) (Vogler and Hoffmeyer) developed a wideband HF ionospheric model, the so-called ITS model. However, the widely used ITS model has some restrictions in application: the parameters are complex and difficult to obtain; only the undisturbed situation is considered; and the multipath delay is fixed and cannot represent the stochastic behavior of the ionosphere. In this paper, the ITS model is modified by introducing the International Reference Ionosphere (IRI) and adding a parameter amending module to provide more accurate parameters, and based on the ITS mathematical and modeling structures, a wideband HF random time-varying ionosphere channel model is presented. With this model, the characteristics of the ionospheric channel under different conditions have been analyzed, and the simulation results show that it can represent the ionospheric channel more accurately and has good consistence with the measured data.

Design of a novel monopole antenna with 5.5 GHz band-notch characterization for UWB applications

In this paper, a new ultra-wideband (UWB) monopole antenna with band-notch characteristic is presented. This antenna is designed to cover the federal communications commission (FCC) bandwidth for UWB applications (3.1-10.6 GHZ) with WLAN frequency band rejection. The band-notch effect is obtained by introducing a U-shaped slot on the radiating part of the antenna.

Prediction of Group Delay Distribution Around Receiving Point Using Modified IRI Model and IGRF Model

The international reference ionosphere (IRI) model is generally accepted standard ionosphere model. It describes the ionosphere environment in quiet state and predicts the ionosphere parameters within a certain precision. In this paper, we have made a breakthrough in the application of the IRI model by modifying the model for regions of China. The main objectives of this modification are to construct the ionosphere parameters foF2 and M (3000) F2 by using the Chinese reference ionosphere (CRI) coefficients, appropriately increase hmE and hmF2 height, reduce the thickness of F layer, validate the parameter by the measured values, and solve the electron concentration distribution with quasi-parabolic segment (QPS). In this paper, 3D ray tracing algorithm is constructed based on the modified IRI model and international geomagnetic reference field (IGRF) model. In short-wave propagation, it can be used to predict the electromagnetic parameters of the receiving point, such as the receiving area, maximum useable frequency (MUF) and the distribution of the group delay etc., which can help to determine the suitability of the communication. As an example, we estimate the group delay distributions around Changchun in the detection from Qingdao to Changchun using the modified IRI model and IGRF model, and provide technical support for the short-wave communication between the two cities.

Signal integrity for high speed digital design

In an era of compact design and higher clock speed signal integrity is an ever increasing concern for high speed digital design. For any high speed design it is very important to do the signal integrity analysis. In this paper the importance, measurement technique and simulation tools of signal integrity for high speed digital design has been presented in a short and simple way.

Structure optimization of through silicon via (TSV) interconnect as transmission channel for 3D integration

Through silicon via is the latest interconnect technology mainly targeted for 3-D integration. Though the technology is yet to be matured enough, but researchers from both academic and industries are putting their highest effort to make the best use of it. The different design parameter and structural geometry has a great effect on the performance of TSV. This paper is intended for modeling and optimization of different TSV geometry structure for higher performance based on 3D full wave simulation and circuit simulator. The TSV structures have been modeled and simulated using 3-D EM field simulator HFSS and circuit simulator ADS has been used to simulate the electrical circuit model of the structure. From the simulation result it is seen that the insertion loss varies minimum in cylindrical TSV. The simulation results also show that for same TSV parameters (height, diameter, and insulation gap) the cylindrical TSV performs better than that of other type of structure.

Designing of a voltage monitor for measuring the voltage of sensitive component on the PCB in EM environment

It is important to monitor the voltage and other parameters of the electronic devices on the PCB for ensuring the better performance and to understand the robustness of the devices in the EM environment This paper presents a novel design of a voltage monitor circuit to monitor the voltage signal of the sensitive components on the PCB in disturbed environment Through the actual test, and analysis the voltage curve can be found, which can help to understand the interference voltage noise on the component of the PCB.