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In this article, an efficient approach based on the parallel alternating direction implicit (ADI) method is presented for the transient thermal simulation of liquid-cooled 3-D integrated circuits (ICs). To accurately characterize the thermal behaviors, a compact thermal model based on finite-difference approximation is established. The ADI method with linear time complexity is utilized to reduce computational cost, which can easily deal with large-scale problems. To suppress the oscillations of transient results in the case of large time steps, an effective technique using the exponentially expanding subtime steps is introduced, which improves the accuracy of results significantly. In addition, taking the advantage of parallel computing, the transient simulation is further accelerated by the parallel cyclic reduction (PCR) algorithm implemented on graphics processing units (GPUs). The accuracy and efficiency of the proposed method are demonstrated by several numerical examples. [ABSTRACT FROM AUTHOR]

In this article, an electrothermal co-design of substrate integrated waveguide (SIW) slot antenna array combined with fin-shaped heatsink is proposed. The antenna array is constructed by 4 $\times8$ SIW slot elements. The heatsink structure above the antenna array not only improves the radiation performance of the antenna array but also enhances the electromagnetic compatibility (EMC) and the heat dissipation capability of the whole structure. The measured realized gains over the operating frequency range increase from 15.4–18.1 to 16.1–19.7 dBi when the heatsink is mounted on the antenna array. Meanwhile, the enclosed heatsink reduces the hotspot temperature rise of the system by 57%. The measured results are in good agreement with the simulated ones. [ABSTRACT FROM AUTHOR]

In this article, the average power handling capability (APHC) of microstrip lines is studied which considers both the heat convection and self-heating effects (SHEs) with temperature-dependent resistivity. A modified parallel-plate model (MPM) is developed to improve the prediction accuracy of APHCs. First, an effective thermal conductivity is used as correction in the original parallel-plate model. After that, the impact of heat convection on the microstrip line is combined in MPM, which matters in realistic situations. Finally, MPM is extended to account for SHEs of metal lines with temperature-dependent resistivities. For validation, APHCs of several microstrip lines with different dielectric substrates are investigated. The results agree well with those simulated by the commercial multiphysics solver, which confirms the validity and accuracy of the model. [ABSTRACT FROM AUTHOR]

An analytical thermal model for AlGaN/GaN high-electron-mobility transistors (HEMTs) is proposed in this article. By means of the conformal mapping technique, the device structure is transformed into a simplified geometry, and the solution to the heat conduction equation is easily obtained. The model is capable of accurately predicting the maximum temperature rise of the device channel. Moreover, based on the superposition principle, this model provides an accurate estimation of thermal coupling between the gate fingers of multifinger devices, as well as the temperature rise of each gate finger. In addition, the temperature-dependent and orthotropic properties of thermal conductivity can also be taken into consideration. The proposed model provides an efficient prediction of hot spots in AlGaN/GaN devices. The accuracy of this model is verified by the simulation results and experimental data. [ABSTRACT FROM AUTHOR]

In this article, a new type of Vivaldi antenna with heat dissipation enhancement is proposed and manufactured based on 3-D printing and printed circuit board (PCB) technologies. A longitudinal slot on substrate integrated waveguide (SIW) is employed to feed Vivaldi radiation structure, which replaces the balun structure of traditional Vivaldi antennas. The measured 10 dB bandwidth of antenna element reaches up to 34.48% (21.77–30.39 GHz) and the in-band realized boresight gain is 6.5–8.8 dBi. The $1\times 4$ Vivaldi antenna array with 28.72% (21.63–28.81 GHz) bandwidth and a gain range of 10.5–12.5 dBi is achieved. The fin-shaped structure of the antenna array further enhances the heat dissipation while increasing the gain up to the range of 13.4–15.5 dBi. The measured results are in good agreement with the simulated ones. The proposed antenna array has important application potential in 5G millimeter-wave systems. [ABSTRACT FROM AUTHOR]

In this work, a novel Robin transmission condition (RTC)-enhanced discontinuous Galerkin (DG) method is proposed for the dc IR-drop analysis of power distribution networks with Joule heating effects included. Unlike the conventional DG method, the proposed DG method straightforwardly applied to discretize the second-order spatial partial differential governing equations for the electrostatic potential $\Phi $ and the steady-state temperature $T$. The numerical flux in DG used to facilitate the information exchange among neighboring subdomains introduces two additional variables: the current density $J$ for the electrical potential equation and the thermal flux $q$ for the thermal equation. To solve them, at the interface of neighboring subdomains, an RTC is presented as the second equation to establish another connection for solutions in neighboring subdomains. With this strategy, the number of degrees of freedom (DoFs) involved in the proposed RTC-DG method is dramatically reduced compared with the traditional DG method. The finalized matrix system is solved in an finite-element tearing and interconnecting (FETI)-like procedure, namely the unknowns are obtained in a subdomain-by-subdomain scheme. Finally, the accuracy and the efficiency of the proposed RTC-DG method are validated by several representative examples. [ABSTRACT FROM AUTHOR]

A challenge for frequency-reconfigurable antennas is how to realize miniaturized structures while preserving satisfying radiation performance in whole operation bandwidth. To address this problem, we apply planar periodic slow-wave structure (PSWS) with controlled dispersion features for miniaturization of antenna. Due to the subwavelength property and large propagation constant, this design holds a much more compact size than conventional microstrip structures. The proposed antenna consists of a double-layered dielectric substrate with the tunable patch on the top and a bias network combining with the feeding part on the bottom. The operating frequency is electronically controlled by the varactors shortened to the ground on nonradiating edges. It ranges from 4.87 to 5.52 GHz when the bias voltage varies from 9 to 16 V. Both simulated and measured results show that the proposed antenna maintains acceptable gains and similar radiation patterns while shrinking the size effectively. The proposed miniaturized and frequency-reconfigurable antenna holds potential applications in the ultracompact frequency hopping communication systems. [ABSTRACT FROM AUTHOR]

In this article, an efficient numerical algorithm is proposed to capture the thermal profile of AlGaN/GaN high electron mobility transistors (HEMTs) with nonlinear electrothermal coupling effects. The finite element method is employed to solve the steady heat conduction equation with different kinds of boundary conditions. To accurately evaluate the temperature distribution of AlGaN/GaN HEMTs, the temperature-dependent properties of both thermal conductivity and heat source are taken into consideration. In order to accelerate the convergence in simulation, the Anderson acceleration (AA) scheme is utilized to solve the nonlinear coupling problems. Numerical examples demonstrate the high accuracy and excellent convergence of the proposed method for nonlinear thermal analysis of AlGaN/GaN HEMTs. [ABSTRACT FROM AUTHOR]

In this communication, a novel fin-shaped heatsink antenna array is designed and fabricated by 3-D printing and low-temperature cofired ceramic (LTCC) technologies. Its structure consists of 16 rectangular air cavities in the bottom base, which are used to form the open-ended rectangular waveguide antennas. Combined with the waveguide and metallic fins, a step-profiled horn is formed as the antenna element, which further enhances the radiation performance. This heatsink antenna array is soldered on an LTCC substrate and the feeding network is realized by the substrate integrated waveguides (SIWs) with numerous metallic vias. These metallic vias inherently provide an effective path for transferring the heat from chips to the heatsink. The simulated performance of this heatsink antenna array is in good agreement with the measured one. The measured broadside gain is 18.1 dBi at 60 GHz, and the 10 dB relative impedance bandwidth is 11.7%. [ABSTRACT FROM AUTHOR]

Crosstalk noise suppression is a crux in the high-speed integrated circuit design, which requires weak-coupling between transmission lines (TLs) over a wide band. To overcome the difficulty, this article presents a novel method to suppress the broadband crosstalk noise between a single TL and the differential pair based on spoof surface plasmon polaritons (SPPs). Due to the subwavelength feature of spoof SPP TLs, a natural mode mismatching between the spoof SPP TL and conventional microstrip (MS) brings a broadband suppression of near-field coupling. In order to verify the crosstalk suppression effect, four different kinds of prototypes are discussed and compared. The simulated and measured results in the frequency domain and time domain demonstrate that the proposed scheme achieves more than 83% far-end noise peak suppression than the traditional MS technology by replacing the single MS TL to the spoof SPP TL. Accordingly, the time-domain crosstalk noise is significantly suppressed without any extra costs, demonstrating its potential applications in ultracompact high-speed integrated circuits. [ABSTRACT FROM AUTHOR]

Due to the temperature-dependent resistivity of power distribution network (PDN) interconnects, a wiser and necessary strategy is to proceed the electrical–thermal cosimulation in order to include the thermal effects caused by Joule heating. As a natural domain decomposition method (DDM), in this article, a discontinuous Galerkin (DG) method is proposed to facilitate the steady-state electrical and thermal coanalysis. With the intention to avoid solving a globally coupled steady-state matrix system equations resulted from the implicit numerical flux in DG, the block Thomas method is deployed to solve the entire domain in a subdomain-by-subdomain scheme. As a direct solver, the block Thomas method is free of convergence problem frequently occurring in iterative methods, such as block Gauss–Seidel method. The capability of the proposed DG method in handling multiscale and complex 3-D PDNs is validated by several representative examples. [ABSTRACT FROM AUTHOR]

In this article, an efficient approach based on Laguerre-based finite-element method (LBFEM) is proposed for transient thermal simulation of integrated circuits (ICs) and packages. The unconditionally stable marching-on-in-order scheme is developed by the weighted Laguerre polynomials and Galerkin testing procedure. In order to handle complicated ICs and packages, the finite-element method (FEM) is employed for spatial discretization and to obtain the Laguerre coefficients. The treatment of different kinds of boundary conditions is also discussed in detail. The accuracy and efficiency of the proposed method are demonstrated by numerical examples. [ABSTRACT FROM AUTHOR]

This paper presents the integration of ${S}/\textit {Ka}/{D}$ -band antennas in a low-temperature cofired ceramic (LTCC) package. Three types of antennas, microstrip patch, grid array, and step-profiled horn, operating at different bands are compactly assembled in the same substrate. For electromagnetic isolation, a specific layout and extra-shielding structures, such as fences of metallic vias and air cavities, are designed to reduce the unwanted coupling between antennas. In addition to the antennas, a cylindrical radome is introduced closely attached to the surface of the LTCC substrate. Since radome acts as a dielectric superstrate, its influence on radiation performance is also taken into consideration, especially for ${D}$ -band operation, where a ring-shaped cavity is introduced to suppress the detrimental propagation of surface waves inside radome and enhance the gain as a consequence of dielectric loading effect. Measured results agree well with simulation. Proposed triband antennas, working at three frequencies 3, 30.5, and 120 GHz, achieve broadside gains of 6.51, 9.74, and 13.36 dBi with −10 dB fractional impedance bandwidths of 15.3%, 6.1%, and 6.5%, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the transient electromagnetic–thermal simulation is performed for dispersive media using the discontinuous Galerkin time-domain (DGTD) method. Both the frequency-dependent and temperature-dependent properties of dispersive media are considered in the modeling. Instead of executing the complex convolution in the time domain, an auxiliary differential equation (ADE) method is employed to manipulate dispersive media, where the polarization current density is introduced as an auxiliary variable. While dealing with the thermal issue by the DGTD, the heat flux is utilized to construct the ADE for solving the thermal conduction equation. As the heat source in electromagnetic–thermal simulation, the transient power loss density for three typical dispersive media (Debye, Lorentz, and Drude) is derived by the electrodynamic approach and also explained with equivalent circuit models. The validity and accuracy of the proposed electromagnetic–thermal co-simulation method are demonstrated by the numerical examples. [ABSTRACT FROM AUTHOR]

In this paper, a novel semianalytical gradient model (SAGM) for characterizing conductors with surface roughness is presented. Based on the linear function of conductivity, the governing equation of the magnetic field is reduced to the modified Bessel equation, which has an analytical solution. With the piecewise linear approximation technique, the SAGM is derived to deal with arbitrary functions of conductivity. Three typical distributions, including the uniform, normal, and Rayleigh distributions, are investigated. The proposed SAGM is employed to evaluate the propagation properties of typical transmission line structures with different surface roughness profiles. The simulation results agree well with those from measurements, which confirm the validity and accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

An efficient algorithm based on the contour integral method (CIM) is presented in this letter for the modeling of lossy multiconductor transmission lines. Different from the volume integral equation, the CIM only discretizes the contour of the cross section of each conductor, which significantly reduces the number of unknowns in the resultant system equations. The solution of the CIM is accelerated by the hierarchical-matrix ( \mathcal H-matrix) algorithm for the extraction of the per-unit-length resistance and inductance parameters of massively coupled transmission lines. The procedures for the \mathcal H-matrix-based solution are optimized to keep its optimal computational complexity. The numerical results from the proposed method agree well with those from the commercial software. The complexities of CPU time and memory cost for the construction of the \mathcal H-matrices are both $O(N\log {}N)$, and the complexity of the solution for parameter extraction is $O(N\log ^2{}N)$. [ABSTRACT FROM AUTHOR]

Reliable and efficient identification of spectrum access opportunities is crucial for cognitive radio ad hoc networks (CRAHNs). A promising method to improve sensing reliability is CSS, where sensing data from multiple secondary users is combined to facilitate decision making. However, the performance of CSS algorithms in CRAHNs is limited by two challenges. First, the spectrum occupancy status in CRAHNs is spatially heterogeneous. Second, malfunctioning nodes or malicious attackers may falsify the true sensing results. To handle both these challenges, inspired by image segmentation in computer vision, we propose a novel graph-cut CSS algorithm. This algorithm is robust in the presence of false sensing data reports, computationally efficient (with polynomial worst case time complexity), and can be implemented distributively. Theoretically, it can be regarded as a new data fusion scheme that is generalized from classical likelihood ratio tests when sensing information is fully exploited, or from the majority fusion rule, when thresholded sensing information is utilized. Introduction [ABSTRACT FROM AUTHOR]

In this paper, several important aspects associated with the modeling and fast simulation of global multiwalled carbon nanotube (MWCNT) interconnects are studied in detail. The MWCNTs are characterized by both the multiconductor circuit (MCC) model and the simplified equivalent single conductor (ESC) model. With two different circuit models, the impacts of intershell tunneling conductance and imperfect contact resistance on electrical performance of both single and coupled MWCNT interconnects are investigated. Based on the ESC model, an efficient algorithm combining modal decoupling and delay extraction techniques is presented for fast transient simulation of MWCNT interconnects. The numerical results illustrate that different locations of imperfect contact resistance may exert apparent effects on transient response of MWCNT interconnects. Nevertheless, these effects can be reduced by intershell tunneling conductance in the MCC model. The accuracy and efficiency of the proposed method are also demonstrated by the numerical examples. [ABSTRACT FROM AUTHOR]

This paper presents a systematic electromagnetic-circuit method for efficient simulation of coupled interconnects on dispersive dielectrics in the presence of electromagnetic interference. The dispersive substrate of coupled interconnects is characterized by the multiterm Debye or Lorentz formula. According to the differential equations derived from the equivalent circuit modeling of dispersive media, the full-wave finite-difference time-domain algorithm is utilized to capture accurate field in a dispersive substrate. The effects of incident field, under the quasi-TEM assumption, are then represented by the distributed sources along transmission lines. An efficient algorithm based on the waveform relaxation with transverse partitioning (WR-TP) is employed for fast simulation of coupled transmission lines. A simple and clear derivation of the relaxation sources in WR-TP is described and the compact results are given. The impact of dispersive dielectrics on the incident field, and thus to the transient response of interconnects, is investigated by comparison with conventional techniques. Several numerical examples are given to illustrate the accuracy and efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

A passive magnetostatic microelectromechanical systems (MEMS) switch using only one electroplated soft magnetic layer of nickel–iron (\Ni80\Fe20) alloy was designed, fabricated, and characterized. The switch is composed of an electroplated \Ni80\Fe20 plate supported by a pair of torsion bars from two sides. The \Ni80\Fe20 plate is patterned into long and narrow strips to improve the sensitivity. The switch is actuated by bringing an external magnet closer to the switch. Therefore, no internal electrical power is consumed by the device for actuation. The magnetic field required to turn on the switch is 4.8 mT, and the initial contact resistance is 0.5 \Omega with gold contacts. The switch has been tested to pass more than 34 million hot-switching cycles at 2-mA current at room temperature when packaged at the wafer level with SU-8 sealing. The die size is 2.1 \times 1.94 \times 1.1\ \mm^3. The magnetic switch of this paper has the potential to replace the conventional reed switch in portable electronics such as laptops, cellular phones, personal data assistants, pacemakers, and hearing aids. \hfill[2009-0301] [ABSTRACT FROM PUBLISHER]

This article proposes a new class of box-like substrate integrated waveguide (SIW) filters with wide stopband. First, a two-pole doublet bandpass filter with one finite-transmission zero (FTZ) is proposed using a new planar dual-mode rectangular SIW cavity, which is realized by TE201 and TE103 modes. TE102, TE202, and TE104 modes are suppressed intrinsically by arranging feeding lines at the horizontal centerline of the dual-mode SIW cavity. Then, a four-pole box-section filter with one FTZ is proposed using one dual-mode and two single-mode rectangular SIW cavities, and the two single-mode cavities have different width-length ratios to further improve the stopband performance. To further improve the cutoff skirt, a new design method for five-pole quasi-elliptic SIW filter is proposed, which is achieved by the four-pole filter loaded by one single-mode SIW cavity. Some design examples with the center frequency of 10 GHz are presented to verify the performance of the proposed dual-mode SIW filters and the design method. [ABSTRACT FROM AUTHOR]

Upon excitation by a surface magnetic current, a power/ground plate-pair supports only $\mathrm{TM}^{z}$ modes. This means that the magnetic field has only azimuthal components permitting a simple but effective domain decomposition method (DDM) to be used. In the proximity of an antipad, field interactions are rigorously modeled by a quasi-two-dimensional (Q-2D) finite element method (FEM) making use of three-dimensional (3D) triangular prism mesh elements. Since high-order $\mathrm{TM}^{z}$ modes are confined in the close proximity of the antipad, field interactions in the region away from the antipad only involve the fundamental mode and are rigorously modeled by a 2D FEM. This approach reduces 3D computation domain into a hybrid 2D/Q-2D domain. The discretization of this hybrid domain results in a global matrix system consisting of two globally coupled matrix equations pertinent to 2D and Q-2D domains. In this article, these two matrix equations are “decoupled” using a Riemann solver and the information exchange between the two domains is facilitated using numerical flux. The resulting decoupled two matrix equations are iteratively solved using the Gauss–Seidel algorithm. The accuracy, efficiency, and robustness of the proposed DDM are verified by four representative examples. [ABSTRACT FROM AUTHOR]

The total ionizing dose (TID) test standards have been developed based on silicon devices to evaluate the TID response of MOS devices for space use. To estimate the applicability of the existing TID test standards to the wide-gap semiconductor silicon carbide (SiC) devices, 1200 V SiC n-channel MOSFETs from three manufacturers were irradiated with Cobalt-60 $\gamma $ -rays at the high radiation dose rate of 50 rad(Si)/s and the low radiation dose rate of 0.01 rad(Si)/s, respectively. The threshold voltage of devices under test (DUT) shifted toward negative due to the radiation-induced positive oxide trapped charges. Room temperature (RT) anneal of maximum time of 2100 h and high temperature (HT) accelerated anneal of maximum temperature of 105 °C were performed, causing the threshold voltage shift to recover. The synergetic effects of temperature-gate-bias stress and TID on SiC MOSFETs were experimentally studied. In conclusion, the degradation of SiC MOSFETs irradiated at high dose rate is dominated by the positive trapped oxide charges, and the existing TID test standards are applicable to evaluate the SiC MOSFETs radiation hardness level, but the threshold voltages shift due to HT-gate-bias (HTGB) should be evaluated. [ABSTRACT FROM AUTHOR]

This paper presents the fabrication process of a thin suspended membrane on normal low resistivity silicon (LRSi), which is then utilized to design millimeter-wave (mm-wave) transmission line and passive circuits with low loss. First, two redistribution metal layers are formed on a plain LRSi wafer with benzocyclobutene in-between. Then, the wafer is thinned down and etched from backside with a specific pattern. Based on this process, a volume is introduced underneath the front side structure and the lossy LRSi substrate is replaced by air, which is the ideal substrate with no loss. Using this method, the substrate loss that contributes the majority part of total loss in mm-wave circuits on LRSi is eliminated. As the operating frequency goes into mm-wave region, the circuit size is scaled down so that the suspended portion is so small that it will not increase the mechanical instability of the structure. Therefore, the proposed suspended membrane on LRSi technology provides an excellent platform to construct mm-wave components. A U-shaped slotline resonator formed on the first redistribution layer is proposed and its quality factors are studied in detail. A second-order bandpass filter is designed and implemented by cascading two such U-shape slotline resonators. The measured frequency responses exhibit good filtering performance, with fractional bandwidth of 13.9% at 126.8 GHz, midband insertion loss of 3.9 dB and passband return loss larger than 14.2 dB. It demonstrates that the proposed suspended membrane on LRSi technology is an excellent candidate for designing low loss mm-wave components. [ABSTRACT FROM AUTHOR]

In the application of extracting human regions from videos, many existing methods may lose their efficacy when illumination varies or the human remains still. To address this problem, we propose a method in this paper for human region detection and segmentation by constructing a generalized human upper body model. The method mainly consists of two main procedures. First, foreground connected regions are extracted by background subtraction from the current frame and classified through a human upper body model pretrained with a support vector machine to determine whether they are human regions. Second, we assign an energy function to the region contour and apply an energy minimization procedure to evolve the contour when human regions are polluted by background; for example, a change in lighting conditions. After finding the optimal contour, we update the background and repeat the procedures in next frame. This feedback strategy rectifies the mistaken background regions promptly and extracts human regions correctly. Our experimental results demonstrate that the proposed method is robust enough to handle videos of low contrast as well as normal conditions. [ABSTRACT FROM PUBLISHER]

We propose a method to construct the broadband 90° balun with low-phase-imbalance performance based on a U-shaped periodic slow wave structure (PSWS) transmission line (TL), whose dispersion curve has a linear region in a wide frequency band. By introducing meander lines and U-shaped TLs, the linearity, cutoff frequencies and slope of dispersion curves of PSWS can be controlled flexibly. Simulated and measured results show good agreements. Both reflection coefficient and isolation of the proposed balun are below −15 dB from 1.5 to 2.0 GHz. The phase deviation is within ±3°, covering a fractional bandwidth of 28.6%. Compared with that based on the traditional corrugated periodic slow wave TL unit, the operating bandwidth of the proposed balun is increased by more than six times. Moreover, the proposed PSWS keeps excellent ability of field confinement and therefore improves the isolation between the output ports. In a word, based on the proposed method, the microwave devices and circuits which realize the function of phase shifting can be designed. [ABSTRACT FROM AUTHOR]

Quantum–mechanical modeling of ballistic transport in nanodevices usually requires solving the Schrödinger equation at multiple energy points within an energy band. To speed up the simulation and analysis, the asymptotic waveform evaluation is introduced in this paper. Using this method, the wave function is only rigorously solved at several sampled energy points, whereas those at other energies are computed through Padé approximation. This allows us to obtain the physical quantities over the whole energy band with very little computational cost. In addition, the accuracy is controllable by a complex frequency hopping algorithm. The validity and efficiency of the proposed method are demonstrated by detailed study of several multigate silicon nano-MOSFETs. [ABSTRACT FROM AUTHOR]

A deficiency in proprioception caused by some nerve injuries could result in movement disorders. An effective assessment of proprioception for patients with nerve injuries is essential for their rehabilitation. When visual input is inconsistent with motor input, humans tend to depend heavily on proprioception to perform a task. Based on it, we designed a novel robot-assisted task to identify proprioceptive acuity. We developed a robotic device to provide RM of wrist and employed VR immersing technology to present VM for a user. The RM and VM were programmed randomly to be consistent or not (conflicting) for each trial. The user was required to decide whether what they were perceiving (real motion) and seeing (virtual motion) is consistent or not in a total of 36 trials. We recruited 40 healthy participants (20 males and 20 females) for the assessment validation. The outcome indicated that the novel robot-assisted identification is sensitive enough to distinguish the difference in proprioceptive acuity between males and females. The male participants have better proprioceptive acuity of the wrist than the females ($p < 0.05$), especially in the P/S motion $p < 0.005$). In addition, the gender difference was found in the sensitivity of proprioceptive acuity ($p < 0.05$) while no difference was found in the specificity ($p > 0.05$), indicating that female participants had poorer performance on the identification than the males when the RM is consistent with VM. This study indicated that the novel robot-assisted task is effective to identify limb proprioceptive acuity. [ABSTRACT FROM AUTHOR]

Considering temperature gradient or thermomigration (TM) impacts on electromigration (EM) due to Joule heating was less studied in the past. In this article, we propose a new semi-analytical stress transient analysis method to consider both EM and TM effects for general multisegment interconnects. The new method is based on the separation of variables (SOVs) approach to find the analytic solution of coupled EM-TM partial differential equation (PDE). The algorithm consists of several steps. We first develop analytic solutions to compute the steady-state temperature distribution of multisegment wires. Based on this, we derive closed-form solutions for steady-state hydrostatic stress distribution in the context of thermal gradients due to Joule heating for multisegment interconnect wires. With the steady-state stress distribution, the coupled EM-TM PDE can be homogenized and solved by the SOV method. To deal with temperature/position-dependent diffusivity of metal migration process due to nonuniform temperature distribution, we utilize a piecewise linear technique to approximate the position-dependent diffusivity. The numerical results on multisegment interconnects show that the proposed method has negligible error loss compared to commercial finite element analysis software COMSOL but is about an order of magnitude faster than COMSOL with $10\times $ less memory footprint. The numerical results further show that temperature gradient due to Joule heating indeed has significant impacts on the EM failure process. [ABSTRACT FROM AUTHOR]

In this paper, a new method to develop balanced-to-unbalanced (BTU) filtering out-of-phase power divider (PD) is presented. Based on the comparison between BTU filtering out-of-phase PD and balanced-to-balanced (BTB) filter, it is found that the BTU filtering out-of-phase PD can be constructed by combining a BTB filter and an additional parallel four-port network. The design equations are derived and corresponding circuit models are given. Finally, a prototype is designed to verify the theoretical prediction. The design procedure and parameter selection are detailed. The good performance and the consistency between the simulated and measured results verify the design theory. [ABSTRACT FROM AUTHOR]

A 4 Mbit DICE latch SRAM exhibits single event upset(SEU) cross-section of 10^14 – 10^12~\mathrm cm^2/\mathrm bit in vertically incident heavy-ion beam tests. TCAD simulations show that the DICE latch works, and that the SEU is not caused by charge sharing. Numerical simulations on particle elastic collision gives quantitative evidence that it is caused by elastic scattering between the incident ion and target nucleus. Three scenarios of elastic scattering SEU are calculated separately in order to get a deeper understanding. The upset cross-section’s dependencies on ion energy, incident angle and the distance between DICE nodes are analyzed. A designing suggestion that paired nodes of DICE latch should be at least 6~\mu \mathrm m away is firstly presented. [ABSTRACT FROM PUBLISHER]

Electrothermal characteristics of some novel 3-D carbon-based heterogeneous interconnects, consisting of vertical carbon nanotube bundle via and horizontal multilayer graphene, are investigated by utilizing in-house developed algorithm based on a finite-element method. With present fabrication capability, these heterogeneous interconnects can have larger electrical resistance but smaller thermal resistance in comparison with their Cu counterpart. Both the local on-chip interconnects for ballistic regime and global through-silicon via channel for diffusive regime are evaluated numerically, and their 3-D transient temperature distribution and hot spots are characterized and compared. During the electrothermal cosimulation, the anisotropic property of electrical and thermal conductivities of carbon nanomaterials is treated in an appropriate way. It is believed that this paper will be useful for the design as well as the realization of new generation carbon-based interconnects with high reliability and better thermal performance. [ABSTRACT FROM PUBLISHER]

A slow-wave structure (SWS) consisting of a planar helix with straight-edge connections and incorporating a coplanar waveguide feed has been designed for operation at W-band and has been fabricated using microfabrication technique. On-wafer cold measurements have been carried out on a number of fabricated SWSs, and the results are reported here for the first time. The parameters measured are return loss, attenuation, and phase velocity, and the results cover a frequency range of 70–100 GHz. Cold-test parameters of the SWS have been also obtained using simulations, and the effects of fabrication, such as surface roughness, have been accounted for by estimating effective conductivity of different parts of the microfabricated structures. The measured and simulated results match well. The effects of silicon wafer resistivity have been also discussed. Planar helical SWSs fabricated in this manner have application in traveling-wave tubes operating at millimeter wave and higher frequencies. [ABSTRACT FROM PUBLISHER]