Zhaowen Yan

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.

EMI and PI analysis of analog board

The analysis object of this paper is a four-layer analog PCB board. First, EMI analysis was done by simulating the radiation of this board with the hyperlynx software. Thus the biggest radiation net and the longest net could be selected. Near field radiation, far field radiation and S parameters analysis then would be performed to these two nets in SIwave. And in Cadence software, power integrity simulation is done. By setting the target impedance, this paper compares the performance of the power supply board with the target performance curve. An improved method is put forward after each analysis.

A Simple Miniature Ultrawideband Magnetic Field Probe Design for Magnetic Near-Field Measurements

A simple miniature magnetic-field probe for near-field measurements in 9-kHz-20-GHz bandwidth, which is applied to highspeed circuits, has been proposed and manufactured. The magneticfield probe is built on a four-layer printed circuit board (PCB) using high-performance and low-loss Rogers material (εr = 3.48 and tan δ = 0.0037). Electric field coupling can be suppressed by PCB shielding structure of the magnetic-field probe. Coax-thru-hole via array technique is used to achieve impedance match. The resonance in working frequency band is suppressed through via fence, making |S21| rather smooth in the operation band. Experimental results show that the working frequency band is up to 9 kHz-20 GHz.

An Improved Miniaturized Three-Layer Embedded Electromagnetic Bandgap Structure

A miniaturized planar electromagnetic bandgap (EBG) structure with embedded meander line as bridge is proposed. The dimensions of the unit cell of the proposed EBG structure are 15 mm × 15 mm × 0.36 mm. Simulation and measurement of the noise transmission coefficient (S21) have been performed for the structure. And good agreement can be seen. According to the measured results, the -30 dB noise suppression bandwidth ranges from 0.97 to 21.54 GHz, which cover almost the whole noise band in ultrawideband applications. However, difficulties arise when the EBG structure is put in a stripline-like environment; the embedded EBG structure loses the noise filtering function. This communication proposed a solution by interconnecting the top and bottom planes of the embedded EBG structure with vias. The bandwidth and depth of noise suppression of the embedded EBG structure can be improved by the location and number of the vias. Simulation and measurement results demonstrate that the proposed embedded EBG structure can be effective for the desired noise isolation, which proved the correctness of the design of the three-layer embedded EBG structure.

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.

A novel segmented equivalent circuit modeling method of TSV in 3D-IC

This paper proposed a novel segmented equivalent circuit modeling method of TSV, which is the key technology of 3D-IC. The electrical parameters of TSV are extracted firstly and then used to finish the equivalent circuit of single TSV and double TSVs structure. The segmented modeling method is realized by segmenting the TSV structure into three parts, namely the top, middle and bottom of the TSV structure. The electrical parameters of the middle part are obtained by analytical formulas, while the parameters of the top and bottom parts are obtained by 3D field solver more accurately. The equivalent circuit of TSV got by this novel method is more accurate compared with the general method. The simulation results of S parameter of the equivalent circuit model are matched well with the simulation results of HFSS while the simulation time is much shorter, and the simulation results show that the equivalent model can reflect the transmission characteristics of TSV accurately.

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.

A behavioral quantification analytical method of electromagnetic susceptibility at board level

This paper presents the behavioral quantification analytical method of electromagnetic susceptibility (EMS) for electronic devices at board level. A full-wave electromagnetic modeling technique coupled with a circuit-based method is used in this paper to quantitatively describe the interference immunity of sensitive components in the circuit board. The behavioral model for quantitative analysis of electromagnetic susceptibility is established. Hence, the prior design of electromagnetic susceptibility at board level can be achieved.

A novel Electromagnetic Bandgap Structure used in mitigating the ultra-high frequency and high frequency noise of PDS

Power/Ground plane structure is the best configuration of the modern plane power distribution system. But in the high speed circuit, the resonant modes of the P/G planes can be excited when the high speed signal changes the reference plane. Thus it brings the GBN and SSN problems. This paper presents a novel Electromagnetic Bandgap Structure which can suppress the high frequency and ultra-high frequency GBN and SSN using a special S shape slender to connect the EBG unit. The measurement results show that two stop band are obtained, one is from 0.8GHz to 1.6 GHz and the suppression depth is −30dB, the other one is from 4.5 GHz to 30 GHz and the suppression depth is almost −30 dB. At the same time, the etched slots area of this structure is very small so it will be easy to allocate the components in the PCB.

Three-dimensional ray tracing in International Reference Ionosphere

International Reference Ionosphere and ray tracing algorithm are discussed in the paper. Three-dimensional real-time ray tracing method is illustrated In accordance with International Reference Ionosphere, ray tracing equations are resolved by Runge-Kutta method. Based on International Reference Ionosphere and ray tracing algorithm, the three-dimensional ray tracing simulation software is presented. The three-dimensional ray trace and the group path are estimated by the simulation software. The effectiveness and accuracy of the simulation results are verified by comparing with the experimental results.