Simultaneous Switching Noise Coupling Research Articles

A Novel Automatically Designed EBG Structure by Improved GA for Ultrawideband SSN Mitigation of System in Package

In this article, a novel automatically designed electromagnetic bandgap (EBG) structure is presented to prohibit the simultaneous switching noise (SSN) propagation of a system in package. The tool employed for the automatic EBG design is the improved genetic algorithm (GA), which has the advantages of rapid convergence and high precision by combining several improvements reasonably. Meanwhile, the equivalent circuit model and the dispersion diagram of the proposed structure are established to interpret the electromagnetic characteristics of the designed power distribution network (PDN). By removing some patches in a specific area determined by the GA, the surface impedance of PDN can be increased to reduce the SSN coupling. The SSN transmission can be suppressed from 0.37 to 20 GHz at a mitigation level of -50 dB. The measured results agree well with the simulated ones.

Suppression of Wideband Simultaneous Switching Noise Through Application of a Partial Electromagnetic Band-Gap Structure in Multilayer Printed Circuit Boards

Adding mushroom-like electromagnetic band-gap (EBG) structures to split power planes can produce wideband suppression of ground bounce noise in high-speed printed circuit boards. Practical equations are used to estimate the stop-band performance of EBG structures within parallel power planes. In this article, a mushroom-like EBG and power-bus structure are derived using the modified nodal analysis (MNA) method. Equations calculated using the MNA method are easily programmable. The partial EBG structures developed in this article can suppress noise from electromagnetic (EM) interference within parallel plates in the power bus. Several examples below show that similar results can be obtained in measurements, in EM simulations software, and in derived equations. The proposed structure enhanced the suppression of simultaneous switching noise coupling (≤-40 dB) within the range of 260 MHz to 10 GHz.

Modeling and Quantification for Electromagnetic Radiation of Power-Bus Structure With Multilayer Printed Circuit Board

The ground bounce noises in a power distribution network of multilayered stack-ups in electronic packages and boards will cause simultaneous switching noise coupling, high insertion loss degradation of signal via, and stray radiation. These lead to signal integrity, power integrity, and electromagnetic compatibility problems. This paper presents an efficient numerical method for evaluating the radiation emission from power-bus structure in complex electronic packaging of high-speed integrated circuit system. It is based on the discretization technique and the boundary integral equation. First, the variational field distribution on the peripheral surfaces of power-bus structure induced by the return current is calculated by using the Helmmholtz equation and boundary conditions. The peripheries of power–ground (P/G) planes and via are discretized into small elements. Then, the changing transient impedance at the edge of antipad plate caused by displacement current through P/G planes is calculated with the assumptive exciting current 1 mA. Finally, the far field radiation is obtained through equivalent magnetic current of edge field. Cavity-model analysis is used to verify, and the good agreement with the theoretical prediction validates the correctness and efficiency of the present analysis.

Vertical Stepped Impedance EBG (VSI-EBG) Structure for Wideband Suppression of Simultaneous Switching Noise in Multilayer PCBs

In this paper, we propose a vertical stepped impedance electromagnetic bandgap (VSI-EBG) structure with a stopband enhancement and a size reduction for a wideband suppression of simultaneous switching noise (SSN) coupling in multilayer printed circuit boards (PCBs). The proposed VSI-EBG structure forms the stepped impedance EBG structure of power planes, which is implemented with a vertical branch, high-impedance (hi- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> ) and low-impedance (low- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> ) metal patches on different layers. Test vehicles are fabricated using a multilayer PCB process to verify the proposed VSI-EBG structure. Through experimental measurements, we verified the enhanced suppression of SSN coupling (below -40 dB) between 650 MHz and 20 GHz. In addition, we demonstrated that <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fL</i> is reduced from 2.4 GHz to 650 MHz compared to the previous EBG structure, which allows an approximately 86% size reduction.

An On-Chip Electromagnetic Bandgap Structure using an On-Chip Inductor and a MOS Capacitor

An on-chip electromagnetic bandgap (EBG) structure using a CMOS process is proposed. The proposed structure is the first EBG structure devised to suppress simultaneous switching noise coupling in an on-chip power distribution network (PDN). The on-chip EBG structure utilizes an on-chip inductor and a MOS capacitor to generate a stopband with a range of several GHz in an extremely small size; thus, the EBG structure can be embedded in on-chip PDNs. The proposed on-chip EBG structure was fabricated using a MagnaChip 0.18 μm CMOS process, and we successfully verified a 9.24 GHz stopband, from 1.26 to 10.5 GHz, with an isolation level of 50 dB.

A Wideband and Compact Partial Electromagnetic Bandgap Structure With a Narrow Via Pitch for a Signal Via Shield

A wideband and compact partial electromagnetic bandgap (PEBG) structure and a corresponding stopband-estimation model are proposed for the suppression of simultaneous switching noise (SSN) coupling in a multilayer printed circuit board. The proposed PEBG structure achieves a wide stopband with a compact size by adopting a geometric arrangement of patches that allows for a periodic narrow via pitch (NVP). In addition, the lumped capacitance model of the previously reported effective phase constant equation is replaced with the resonant cavity model to obtain the precise impedance of the patch in high frequency. Finally, it was successfully verified that, by applying the NVP-PEBG structure, wideband suppression of SSN coupling to the signal via is achieved with a bandwidth of 11.2 GHz below -40 dB. The proposed estimation model was validated through experimental measurements.

Modeling and Analysis of Power Supply Noise Imbalance on Ultra High Frequency Differential Low Noise Amplifiers in a System-in-Package

In this paper, we analyze the power supply noise imbalance and its effects on simultaneous switching noise coupling to an ultra high frequency differential low noise amplifier (LNA) in a system-in-package (SiP) through an off-chip power distribution network (PDN). On and off-chip sources of power supply noise imbalance in a LNA in a SiP were analyzed. A simultaneous switching noise coupling coefficient for the differential LNA output caused by power supply noise imbalance was simulated through co-modeling a hierarchical on and off-chip PDN. The simulation results were validated by measuring the simultaneous switching noise coupling voltage at the differential LNA output. Further validation of four types of a LNA with different PDN designs demonstrates that simultaneous switching noise coupling to the differential LNA output caused by power supply noise imbalance highly depends on the design of the PDN of the SiP.

Modeling, Quantification, and Reduction of the Impact of Uncontrolled Return Currents of Vias Transiting Multilayered Packages and Boards

The returning displacement currents of vias transiting multilayered stack-ups in electronic packages and boards excite parasitic transverse electromagnetic modes in power-ground plane pairs, causing them to behave as parallel-plate waveguides. These waves may cause significant coupling in the power-ground cavity, leading to electromagnetic reliability (EMR) issues such as simultaneous switching noise coupling, high insertion loss degradation of signal vias, and stray radiation from the periphery/edges of the package/board. In this contribution, we model and quantify EMR problems caused by uncontrolled return currents of signal vias in conventional multilayer stack-ups. Traditional methods used to minimize these problems, and their limitations are discussed. We propose a low-cost layer stack-up, which overcomes most of the limitations of conventional stack-ups by providing well-defined return-current paths for microstrip-to-microstrip via transitions. Test samples of the proposed configuration are designed, fabricated, and measured. Very good correlation is obtained between measurement and simulation. Finally, a circuit model for the microstrip-to-microstrip via transition, considering the return-current paths, is developed and the circuit parameters are analytically calculated. Conventional closed-form expressions used for the extraction of these parameters, particularly the via capacitance, are extended and modified.

Double-Stacked EBG Structure for Wideband Suppression of Simultaneous Switching Noise in LTCC-Based SiP Applications

We propose a novel electromagnetic bandgap (EBG) structure with a significantly extended noise isolation bandwidth, called a double-stacked EBG (DS-EBG) structure, fabricated on a low-temperature co-fired ceramic (LTCC) multilayer substrate. The DS-EBG structure was devised for wideband suppression of simultaneous switching noise (SSN) coupling in system-in-package (SiP) applications. Our design approach was enabled by combining two EBG layers embedded between the power and ground planes. The two EBG layers had different bandgaps from using different cell sizes. Enhanced wideband suppression of the SSN coupling was validated using a 11.4-GHz noise stop bandwidth with 30-dB isolation in time and frequency domain measurements up to 20GHz

Modeling and measurement of simultaneous switching noise coupling through signal via transition

The signal via is a heavily utilized interconnection structure in high-density System-on-Package (SoP) substrates and printed circuit boards (PCBs). Vias facilitate complicated routings in these multilayer structures. Significant simultaneous switching noise (SSN) coupling occurs through the signal via transition when the signal via suffers return current interruption caused by reference plane exchange. The coupled SSN decreases noise and timing margins of digital and analog circuits, resulting in reduction of achievable jitter performance, bit error ratio (BER), and system reliability. We introduce a modeling method to estimate SSN coupling based on a balanced transmission line matrix (TLM) method. The proposed modeling method is successfully verified by a series of time-domain and frequency-domain measurements of several via transition structures. First, it is clearly verified that SSN coupling causes considerable clock waveform distortion, increases jitter and noise, and reduces margins in pseudorandom bit sequence (PRBS) eye patterns. We also note that the major frequency spectrum component of the coupled noise is one of the plane pair resonance frequencies in the PCB power/ground pair. Furthermore, we demonstrate that the amount of SSN noise coupling is strongly dependent not only on the position of the signal via, but also on the layer configuration of the multilayer PCB. Finally, we have successfully proposed and confirmed a design methodology to minimize the SSN coupling based on an optimal via positioning approach.

Analysis and suppression of SSN noise coupling between power/ground plane cavities through cutouts in multilayer packages and PCBs

The authors introduced a model of simultaneous switching noise (SSN) coupling between the power/ground plane cavities through cutouts in high-speed and high-density multilayer pack-ages and printed circuit boards (PCBs). Usually, the cutouts are used in multilayer plane structures to isolate the SSN of noisy digital circuits from sensitive analog circuits or to provide multiple voltage levels. The noise-coupling model is expressed in terms of the transfer impedance. The proposed modeling and analysis results are compared with measured data up to 10 GHz to demonstrate the validity of the model. It is demonstrated that the cutout is the major gate for SSN coupling between the plane cavities, and that substantial SSN coupling occurs between the plane cavities through the cutout at the resonant frequencies of the plane cavities. The coupling mechanism and characteristics of the noise coupling, from which a method of suppression of the SSN coupling evaluated was also analyzed and discussed. Proper positioning of the cutout and the devices at each plane cavity achieves significant noise suppression at certain resonant frequencies. The suggested suppression method of the SSN coupling was successfully proved by frequency domain measurement and time domain analysis.