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In this article, a novel vertical wire-bonding interconnect structure is intelligently modeled and optimized with general artificial neural network (GRNN) and genetic algorithm (GA) for multilayered system in package. A compensation structure is constructed with a hybrid inductive and capacitive technique, while a capacitive stripline with series inductive short-end via is designed underneath the 50-Ω transmission line. The GRNN algorithm is employed to build the electromagnetic model databases during the procedure of GA optimization. In comparison with the conventional optimization algorithm, the output performances can be directly achieved with collaboratively combined methods, which can significantly reduce the calculation time. From the measurement results, the return loss is improved significantly while the parasitic inductive behavior of the bonding wire is eliminated with the presented design. Moreover, compared with the traditional compensation techniques, no additional area is occupied on the surface plane of the wire-bonding interconnection, which is more suitable for the high-integrated circuit system.

On the basis of first-principles calculations, we investigate the electronic and magnetic properties of 1T phase chromium sulfide halide CrXY (X = O, S, Se; Y = Cl, Br, I) monolayers in CrCl2 structure with the P$$\overline{3}$$ 3 ¯ m1 space group. Except for the CrOI monolayer, all CrXY monolayers are stable and ferromagnetic semiconductors. Our results show that the ferromagnetic coupling is dominated by the kinetic exchange between the empty eg-orbital of Cr atoms and the p-orbital of anions under the three-fold rotational symmetry. In this context, the coupling strength allows for being greatly enhanced by turning the nature of Cr–X bonds, i.e., increasing the covalent contribution of the bonds by minimizing the energy difference of the coupled orbitals. As we illustrate for the example of CrOY, the Curie temperature (Tc) is nearly tripled by substituting O by S/Se ion, eventually reaching the highest Tc in CrSeI monolayer (334 K). The high stabilities and Curie temperature manifest these monolayer ferromagnetic materials feasible for synthesis and applicable to 2D spintronic devices.

Defects have a significant impact on the performance of semiconductor devices. By using the first-principles combined with one-dimensional static coupling theory approach, we have calculated the variation of carrier capture coefficients with temperature for the interfacial defects $\textit{P}_{b0}$ and $\textit{P}_{b1}$ in amorphous-SiO$_2$/Si(100) interface}. It is found that the geometrical shape of $\textit{P}_{b0}$ and $\textit{P}_{b1}$ defects undergo large deformations after capturing carriers to form charged defects, especially for the Si atoms containing a dangling bond. The hole capture coefficients of neutral $\textit{P}_{b0}$ and $\textit{P}_{b1}$ defects are largest than the other capture coefficients, indicating that these defects have a higher probability of forming positively charged centres. Meanwhile, the calculated results of non-radiative recombination coefficient of these defects show that both $\textit{P}_{b0}$ and $\textit{P}_{b1}$ defects are the dominant non-radiative recombination centers in the interface of a-SiO$_2$/Si(100).

In this letter, a compact microstrip comb array antenna with high sidelobe suppression is presented for a 24 GHz radar sensor. Based on the printed circuit board process, several series-fed microstrip comb lines are designed on the substrate to form linear antenna arrays. Chebyshev distribution is adopted for the nonuniform excitation of each antenna element to achieve a very low sidelobe level (SLL). The excitation amplitude is adjusted by tuning the feedline width between the adjacent elements. Under such circumstances, a slimmer array with a tapering distribution is realized. The proposed linear comb array consists of eight elements and is further extended to 8 × 2 and 8 × 8 planar arrays to meet different requirements. The proposed antenna arrays are verified by the simulation and measurement, which are in good agreement. The measured SLLs are better than −28 dB. The measured gains of 8 × 1, 8 × 2, and 8 × 8 comb arrays at 24.125 GHz are 12.2, 15.0, and 19.8 dBi, respectively. The return losses are better than 10 dB and the broadside gains remain stable within the regulated industrial scientific medical band from 24 to 24.25 GHz.

The structural evolutions and electronic properties of AulPtm (l + m ≤ 10) clusters are investigated by using the first-principles methods. We use the inverse design of materials using the multi-objective differential evolution (IM2ODE) package to globally search the equilibrium structures and investigate the evolving trend from a two-dimensional structure to a three-dimensional structure on horizontal extension and vertical extension for AulPtm (l + m ≤ 10) clusters. The three-dimensional stable geometry of Au8Pt and Au8Pt2 is discovered for the first time in our work. We also notice that the equilibrium structures of AulPtm (l + m = 10 and l ≤ 8) tend to form a tetrahedral geometry and can be obtained by replacing the Au atom in the most stable structure of Aul+1Ptm-1 with the Pt atom, where Pt atoms assemble together and occupy the center of clusters and Au atoms prefer to lie on the vertex or edge position. The average binding energy (Eb) is mostly decided by Pt-Pt bond numbers, namely the numbers of Pt atoms, followed by Au-Pt bond numbers. The second-order energy difference (Δ2Ev and Δ2Eh) and the nearest-neighbor energy difference (Δ4Enn) show that Au6Pt, Au4Pt2, Au3Pt3, Au2Pt4 and AuPt7 clusters exhibit high relative physical stability, so we suggest that these clusters could be defined as the magic number clusters for AulPtm (l + m ≤ 10) clusters. The HOMO-LUMO energy gap (Eg), adiabatic ionization potential (AIP) and the adiabatic electron affinity (AEA) are also investigated to elaborate the relative electronic stability of all the clusters.

In this brief, a compact ultra-wideband monolithic microwave integrated circuit single pole double throw (SPDT) switch with high isolation level and low insertion loss is presented. A ${\pi }$ -type topology, consisted of a transmission line with an electrical length of less than 90° and two parallel grounded metal-insulator-metal capacitors, is employed to replace the conventional $\lambda $ /4 transmission line between the adjacent parallel field effect transistors of the serial parallel SPDT switch. In comparison with the traditional method, an ultra-wideband high isolation behavior and the reduced dimension is achieved simultaneously with the proposed SPDT switch. Furthermore, the equivalent circuit model is built to interpret the mechanism of the improved technique. A chip sample is fabricated with Gallium Arsenide processing with a size of $1.25\times 1.05$ mm2. The measured insertion loss is less than 1.9 dB and the isolation is better than 36 dB from DC to 30 GHz. Good agreements are observed between the simulated and measured results.

This letter proposes a novel trisection filter by stacking three substrate-integrated waveguide (SIW) cavities vertically. The trisection topology can be divided into two cascaded second-order topologies in the vertical direction, which can make the filter structure more compact. Moreover, two transmission zeros can be controlled independently by changing the signs of coupling coefficients between the adjacent stacked SIW cavities. Finally, a third-order filter sample is fabricated using printed circuit board (PCB) technology, and the measured S-parameters have good agreement with the simulated ones.

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.

In this paper, an improved genetic algorithm (GA) for automatically optimizing electromagnetic bandgap (EBG) structure with good power integrity performance is presented. The traditional GA is improved in several ways including Hamming Distance initialization, elite selection and non-repeating crossover, which can generate initial population charactering solution space in detail, increase crossover efficiency, and accelerate convergence. Furthermore, an EBG structure for power distribution network is optimized with the presented GA method to improve the performances of power integrity. The simultaneous switching noise propagation can be prohibited from 0.38 GHz to 20 GHz with a suppression level of -60 dB. Good agreements between the measured results and the simulation ones are observed.

In this paper, a compact electromagnetic bandgap (EBG) structure for mitigating simultaneous switching noise (SSN) in high-speed mixed signal systems is proposed. Only one spiral slot is etched on the square patch, which constitutes the unit cell of the presented EBG pattern. The equivalent circuit model is developed to interpret the mechanism of the proposed power distribution network structure. By etching slot in the square patch of the EBG pattern, a high impedance is provided for prohibiting the SSN propagation. Furthermore, the capacitance is increased correspondingly, which can enlarge the bandwidth of the SSN suppression performance. An ultrawideband SSN suppression property is achieved from 0.35 to 20 GHz under the suppression level of −40 dB. In comparison with the traditional multiturns spiral EBG structure, not only the bandwidth but also the rejection level can be improved significantly with the presented design. Moreover, the SI performance is investigated, and the corresponding improvement measure is presented. Good agreements are observed between the simulation and measured results.

On the basis of the first-principles calculation, single transition-metal (TM) atoms of first and second transition series are anchored on the β12 phase of the boron monolayer (BM) electrocatalyst ...

Background Immune cell infiltration and neuroinflammation are heavily associated with spinal cord injury (SCI). C-C motif chemokine ligand 2/C-C chemokine receptor type 2 (CCL2/CCR2) axis has been identified as a critical role player during the invasion of immune cells to lesions in many diseases. γδ T cells, a subgroup of T cells, manage the course of inflammation response in various diseases; however, it remains unknown whether γδ T cells are recruited to injury site through CCL2/CCR2 signaling and exert the regulation effect on neuroinflammation after SCI. Methods Basso Mouse Scale (BMS), regularity index, cadence, max contact area, and motor-evoked potential testing (MEP) were measured to determine the neurological function recovery after spinal cord injury. Nissl staining was performed to identify the number of surviving motor neurons at lesion epicenter. Immunofluorescence, Western blot, enzyme-linked immunosorbent assays (ELISA), and quantitative real-time polymerase chain reaction (QRT-PCR) also were employed to evaluate the expression of associated proteins and genes. Results In this study, we demonstrated that TCRδ−/− mice present improved neurological recovery after SCI. γδ T cell recruitment to the SCI site was significantly reduced and motor functional improvement enhanced in CCL2−/− and CCR2−/− mouse strains. Furthermore, reconstitution of TCRδ−/− mice with γδ T cells extracted from CCR2−/− mice also showed similar results to CCL2 and CCR2 deficient mice. Conclusions In conclusion, γδ T cell recruitment to SCI site promotes inflammatory response and exacerbates neurological impairment. CCL2/CCR2 signaling is a vital recruitment mechanism of γδ T cells to the SCI site, and it may be taken as a novel therapeutic target for future SCI.

This paper studies the broadband circularly polarized antenna used in micro base stations. The antenna consists of a pair of rectangular loops. The ring patch is used to form circular polarization, and a pair of open resonant ring parasitic elements are loaded between the two rectangular rings to increase the bandwidth. By introducing balun feed to increase bandwidth, good impedance matching can be obtained. Add a metal reflector at the bottom of the antenna to form directional radiation. The antenna was printed on the Rogers RO4003 substrate, and the results showed that the -10dB return loss bandwidth was 43.4% (1.86-2.89GHz), and the -3dB axial ratio bandwidth was 41% (1.9-3GHz). The gain of the antenna in the frequency band is greater than 9dBi.

The feasibility of an antenna-in-package (AiP) concept is demonstrated for automotive radar sensors at the 77 GHz-band. Infineon’s embedded wafer level ball grid array (eWLB) is employed as packaging technology. We developed a E-shape patch antenna in 6×6 mm2 eWLB package that include 2×2 mm2 dummy Si chips. From the simulated results of the proposed E-plane patch antenna, provides a wide bandwidth of 19.2% (|S11

This paper presents a power divider which realizes the average energy distribution of input signals, a fixed phase difference of output signals and filtering. The signal interference technology is used to realize the filtering function. The input and output of the filter have a phase difference of 90°, with 70.7 ȍ port impedance, which replaces the traditional Wilkinson 1/4 wavelength transmission line. A rectangular slot is engraved on the ground below the coupling line to enhance coupling. The T-shaped open steep impedance resonator (SIR) loaded transmission line is used to achieve the phase shifter. The simulation results shows that the filtering bandwidth with 10 dB return loss is 32.7% and phase shifting is 30° ± 5°. The band isolation is better than -10 dB. Hence, the proposed structure is suitable for the application of single-layer circuitry integration.

This paper designs a CPW-fed single-fed single- layer dual-frequency antenna for 5G applications. The overall size of the antenna is only 23×30.5×0.254mm3. The antenna consists of an improved folded rectangular slot, a Y-shaped monopole radiator fed by a coplanar waveguide (CPW) with cross-notched slots, and a curved sub-ring slot for isolating frequency bands. The dual frequency characteristics are realized by deformed folded rectangular grooves and Y-shaped monopoles with split ring grooves and cross grooves. By adjusting the position and size of these structures separately, two working frequency bands can be realized. Reduce the size of the antenna by folding the rectangular ground slot to increase the surface current (6.92 λ 0 × 9.17 λ 0 × 0.08 λ 0 ). The simulation results show that the working bandwidth of the antenna is 2.82- 3.84Ghz (31.58%) and 4.48-5.53Ghz (25.68%) respectively. It not only covers 5G bands 3.4-3.8Ghz and 4.8-5.0Ghz, but also covers up to part of the working frequency band of WLAN and WiMAX. The antenna has a good omnidirectional radiation pattern. The antenna is small in size, easy to integrate, and is well-suited to 5G wireless communication equipment.

In this paper, a novel broadband Coplanar Waveguide(CPW)-fed slot antenna working at Ka-band is presented. A wideband performance is realized by slot coupling between the rectangular stub and the surrounding ground plane for millimeter wave applications. Meanwhile, an asymmetric CPW structure is introduced to improve the antenna bandwidth, by adjusting the width of the rectangular stub, two different resonance frequencies of the narrow slots around the stub are generated close to the center frequency to achieve a wider band-width. The designed CPW slot antenna exhibits a wide impedance bandwidth over 42.4% and an average gain of 3 dBi.

It is essential to explore high efficient catalysts for nitrogen reduction in ammonia production. Based on the first-principles calculation, we find that B/g-C2N can serve as high performance photocatalyst in N2 fixation, where single boron atom is anchored on the g-C2N to form B/g-C2N. With the introduction of B atom to g-C2N, the energy gap reduces from 2.45 eV to 1.21 eV and shows strong absorption in the visible light region. In addition, N2 can be efficiently reduced on B/g-C2N through the enzymatic mechanism with low onset potential of 0.07 V and rate-determining barrier of 0.50 eV. The “acceptance-donation” interaction between B/g-C2N and N2 plays a key role to active N2, and the BN2 moiety of B/g-C2N acts as active and transportation center. The activity originates from the strong interaction between 1π1π* orbitals of N2 and molecular orbitals of B/g-C2N, the ionization of 1π orbital and the filling of 1π* orbital can increase the N≡N bond length greatly, making the activation of N2. Overall, this work demonstrates that B/g-C2N is a promising photocatalyst for N2 fixation.

Cylindrical grating angle sensor is a common angle measuring device with high precision. Due to the reflecting arc surface of the cylindrical grating the effects of relative displacement of graduation line and gap variation will interact. Significant residual errors still exist even with high precision cylindrical grating and multiple reading heads around the scale disc .In this paper, based on the principle of circumference closure, the principle of self-calibration is deduced and analyzed in detail. The calibration curve is obtained by obtaining the deviation between the certain position and an ideal position of the graduation line position in real time. A simple self-calibration method of cylindrical grating is acquired. It can calibrate random errors and system errors with time and improve the angle measurement accuracy. The method has the advantages of simple structure and strong maneuverability, and provides technical means for the miniaturization and high precision of cylindrical grating.

The catalytic properties of the magic gold-platinum bimetallic clusters (Au4Pt2 and Au6Pt) for the reduction of SO2 by CO, without or with preadsorbing CO molecules, are firstly investigated using density functional theory calculations. We find that the catalytic activities improve effectively with the preadsorption of CO onto the catalysts and that the catalytic activities of Au6Pt(CO)n are better than those of Au4Pt2(CO)n as more CO molecules are adsorbed onto the catalysts. During the reaction process, the Au4Pt2(CO)n clusters always keep two-dimensional morphologies except for when n = 5 and the Au6Pt(CO)n clusters have three-dimensional geometries except for when n = 0. The most stable adsorption site for SO2 molecules on the catalysts is the site of preadsorbing the next CO molecule on the corresponding catalysts. The largest activation energy (E) is related to the metal 5d (M-5d) band center and the charge transfer (Ct) as well as the bond length (Rb) between COS and the catalyst contribute to the desorption energy (Ed) of COS corporately. We propose that Au6Pt(CO)6 is a cost-effective gold-platinum bimetallic catalyst for the reduction of SO2 by CO.

A compact tapered electromagnetic bandgap (EBG) structure by using complementary split-ring resonator (CSRR) is presented. By employing CSRRs, open stubs, and spurline, three transmission zeros are introduced to improve performances of the EBG structure. Chebyshev tapering distribution reduces the ripples within the passband. In construct with the traditional EBG structure, the slope from the stopband to passband transition can be increased from 12.59 to 45.95 dB/GHz with the presented design. An ultrawide fractional bandwidth of 112.91% within the stopband below −20 dB is also obtained. The measurements agree well with the simulation results.

A general AzePhenol dinuclear zinc catalytic system has been successfully developed and applied into the asymmetric Michael addition of 4-hydroxyl pyrones and 4-hydroxycoumarins to β,γ-unsaturated α-keto esters. Excellent yields (up to 99%) and high enantioselectivities (up to 94% ee) are obtained for a wide range of substrates under mild conditions in the absence of additives. This bimetallic catalytic approach represents a new and effective asymmetric synthetic protocol to access a variety of bioactive compounds with pharmacological interest. The possible mechanism is proposed to explain the origin of the asymmetric induction.

A novel compact compensation inductance structure optimized by genetic algorithm (GA) for right-angle bended transmission line is proposed to mitigate differential-to-common mode conversion noise in this paper. In comparison with the previous suppression method, high suppression level and large bandwidth are obtained with the proposed structure. Simultaneously, the differential return loss and insertion loss have been minimized by GA, leading to an overall improved signal integrity (SI). Furthermore, the proposed structure places inside the transmission line and does not occupy extra wiring space. Finally, the differential-to-common mode conversion can be prohibited from DC to 11 GHz with a suppression level of - 23.13 dB. The measured results agree well with the simulated ones.

In this paper, a compact power distribution network (PDN) structure with ultra-wideband simultaneous switching noise (SSN) mitigation for antenna in package is presented. Only one spiral slot is etched on the square patch of the EBG pattern, which is constituted the presented PDN structure. The equivalent circuit model is developed to analyze the mechanism of the electromagnetic compatibility behavior that a high-impedance is provided for reducing the SSN coupling. An ultra-wideband SSN mitigation performance is obtained from 0.35 GHz to 20 GHz under the suppression level of −40 dB. Good agreements are observed between the simulated and measured results.

This paper presents the electromagnetic characteristic of the reverberation chamber (RC) excited by two transmitting antennas. We simulate the RC that changed the polarization and phase of transmitting antennas in four cases. The results show that the electric field strength can be improved by adjusting the polarization of transmitting antenna. The field uniformity can meet the IEC 61000-4-21 standard.

It is important for environmental protection to search for catalysts with excellent performance and cost-effective to reduce SO2 by CO. In this work, using first-principles calculation, we have studied the catalytic performance of Au5 Mn (M = Ni, Pd, Pt, Cu, Ag, Au; n = 1, 0, −1) clusters, and showed that, by giving a negative charge to the Au5 M (M = Cu, Ag, Au, Pd) clusters, we could improve the selectivity of SO2 and avoid effectively catalyst CO poisoning simultaneously. At the same time, the catalytic reaction rate for the reduction of SO2 by CO with Au5 M − (M = Cu, Ag, Au, Pd) clusters is greatly improved when the Au5 M clusters are charged. These advantages can be well explained by the charge transfer between the clusters and adsorbed molecules, which means that we can effectively control the performance of the catalyst. The equilibrium structures of Au5 Mn (M = Ni, Pd, Pt, Cu, Ag, Au; n = 1, 0, −1) clusters without or with adsorbed SO2 or CO molecule are also discussed, and the most stable geometrical structures of Au5 Mn -ML (ML = SO2, CO, SO, and COS) can be explained very well by the match of orbitals symmetry and density of electron cloud through their frontier molecular orbitals. Considering the catalyst cost (Cu is much cheaper than Ag and Au), selectivity of SO2, and effectively avoiding the catalyst CO poisoning, we propose that Au5Cu− is an ideal catalyst for getting rid of SO2 and CO simultaneously.

Water samples were collected in summer, autumn, winter, and spring in Beihai Lake for the analysis of water quality and microbial community structure. It was found that the water quality in summer and autumn was worse than in winter and spring, and TN and TP were the most important factors affecting the water quality. The microbial community structure was investigated using MiSeq high-throughput sequencing. It was found that the phyla Cyanobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes were abundant in all the samples, whereas their relative abundances differed among the four seasons. In summer and autumn, the microbial diversities were higher, and the phylum Cyanobacteria was most abundant, with the genus

In this paper, a capacitance compensation structure for wire-bonding interconnection in multi-chips module is investigated. The equivalent circuit model is built to analyze the characteristics of the wire-bonding interconnection. Furthermore, the relationships between the structure parameters and the transmission behaviors of the bonding wire are discussed. In order to meet the impedance matching of the wire-bonding at high frequency, a capacitance compensation structure is presented. In comparison with the uncompensated structure, the parasitic effects of the bonding wire is minimized and the return loss is increased about 20 dB with the proposed design.

A winter air pollution episode was observed in Hangzhou, South China, during the Second World Internet Conference, 2015. To study the pollution characteristics and underlying causes, the Weather Research and Forecasting with Chemistry model was used to simulate the spatial and temporal evolution of the pollution episode from December 8 to 19, 2015. In addition to scenario simulations, analysis of the atmospheric trajectory and synoptic weather conditions were also performed. The results demonstrated that control measures implemented during the week preceding the conference reduced the fine particulate matter (PM2.5) pollution level to some extent, with a decline in the total PM2.5 concentration in Hangzhou of 15% (7%–25% daily). Pollutant long-range transport, which occurred due to a southward intrusion of strong cold air driven by the Siberia High, led to severe pollution in Hangzhou on December 15, 2015, accounting for 85% of the PM2.5 concentration. This study provides new insights into the challenge of winter pollution prevention in Hangzhou. For adequate pollution prevention, more regional collaborations should be fostered when creating policies for northern China.

The present study investigated the effect of rumen fluid (RF) concentration on the methane production through anaerobic digestion of wheat straw in batch mode, and compared the microbial communities in RF and RF inoculated reactors by 16S rRNA genes sequencing. Six levels of RF concentration including 1%, 5%, 10%, 15%, 20% and 25% (v/v) were used in reactors R1, R5, R10, R15, R20 and R25 respectively. The results revealed that lower than or equal to 5% RF concentrations resulted in reactor acidification and low methane production. The highest methane yield of 106 mL CH4 g VS−1 was achieved in R10, whereas higher RF concentrations than 10% could not improve the methane production significantly. Methanosarcina barkeri was abundant in the well-working reactors, and Methanobacterium was dominant in the poor-working reactors, implying the archaeal communities in reactors had changed greatly from the Methanobrevibacter-dominated RF. Although the relative abundance of Clostridium and Ruminococcus were greatly different between RF and reactors, the Bacteroidetes and Firmicutes communities were dominant in all the tested samples. The results indicated that the in vitro anaerobic conditions had altered the rumen methanogenic communities significantly and the facultative acetoclastic Methanosarcina was important for the methane production in the RF seeded reactors.

In this paper, a power plane with localized planar electromagnetic bandgap (EBG) structure is designed for suppressing simultaneous switching noise (SSN) in mixed-signal systems. Nonbianisotropic complementary split ring resonator with a bandgap behavior is used to constitute the EBG cells, which are partially located on the power plane to prohibit the noise propagation within the board. An equivalent circuit model is proposed to predict the lower cutoff frequency of the transmission behavior. From the measured results, an ultrawideband mitigation of SSN from 0.26 to 25 GHz is achieved with a high suppression level of -50 dB. Furthermore, signal integrity problem is investigated, and it is found that partial discontinuities of the proposed design can reduce the influence on signal quality compared with the traditional global EBG structure. In addition, the proposed design can lower the electromagnetic interference radiation from edges of the board.

In this letter, an ultra-wideband common mode filter is proposed for high-speed differential signal transmission. By etching a slot in the inner patch of a double slit complementary split ring resonator (S-DBCSRR), the noise rejection bandwidth can be expanded. The equivalent circuit model and surface current distribution are given to explain the working principle of the filter. From the simulated and measured results, it is found that the fractional bandwidth of the presented filter is 92% with a noise suppression level of 20 dB, and the differential signal can propagate with little degradation.

In this paper, an efficient method for mitigating simultaneous switching noise (SSN) propagation in high-speed printed circuit boards (PCBs) is proposed, using localized power plane topologies, where complementary split ring resonators (CSRRs) are partially etched on one metallic layer of the embedded capacitance. The equivalent circuit model of the proposed structure is presented to predict the lower cutoff frequency of the transmission behavior. An ultra-wideband suppression of SSN from 0.41 GHz to 15 GHz is achieved with a high mitigation level of -60 dB. The measured S-parameter of the proposed structure agrees well with the simulated one. Furthermore, signal integrity (SI) is investigated and it is found that the proposed structure has a good SI performance, because the partial CSRR structure has less influence on signal transmission along the boards than global discontinuity structure.

A compact semi-lumped lowpass filter with three lumped capacitors is presented in this paper. With this design, three transmission zeros can be obtained within the stopband to enhance its bandwidth. Furthermore, a transmission zero located near the passband is used to achieve sharp selectivity. A meander line between source and load is also introduced to get a compact size. Therefore, the proposed filter has a sharp skirt and wide stopband in comparison with traditional low-pass filters. A microstrip lowpass filter with lumped capacitors is designed and fabricated with the standard single-layered printed circuit board (PCB) technology. The measured S-parameters of the proposed filter agree well with the simulated ones, and the filter achieves the design performance.