Miniaturized Bandpass Filters as Ultrathin 3-D IPDs and Embedded Thinfilms in 3-D Glass Modules

Sitaraman, Srikrishna,Sukumaran, Vijay,Pulugurtha, Markondeya Raj,Zihan Wu,Suzuki, Yuya,Youngwoo Kim,Sundaram, Venky,Joungho Kim,Tummala, Rao R. IEEE 2017 IEEE transactions on components, packaging, and ma Vol.7 No.9

<P>This paper presents the modeling, design, fabrication, and characterization of an innovative and miniaturized thin-film bandpass filter with coupled spiral structures in ultrathin glass substrates (30-100 mu m). This filter is demonstrated for two applications: 3-D integrated passive devices and embedded thinfilm filters in RF modules. A compact filter design was achieved through an integrated resonant structure that effectively utilizes the inductive and capacitive coupling between metal layers on either side of an ultrathin glass substrate or organic build-up layer. The designed filters (layout area <1 mm 2 with 80-150 mu m device thickness) were fabricated on a 30-mu m-thin glass substrate using a panel-based low-cost approach with double-side thin-film wiring processes. The effect of process variations on the performance of the proposed structures was also studied. Furthermore, an improved WLAN filter is designed and demonstrated by employing specific structural modifications. The measured frequency response of the filters shows good model-to-hardware correlation, with very low insertion loss (0.6 dB) in the passband, and high adjacent-band rejection (>25 dB).</P>

Power and Knowledge: International Relations Scholarship in the Core and Periphery

( Srini Sitaraman ) 서울대학교 통일평화연구원 2016 Asian Journal of Peacebuilding Vol.4 No.2

The field of International Relations (IR) is motivated as much by the institutional dynamics of American universities and the internal rewards structure of tenure, promotion, and merit pay, as it is by wider scholarly recognition. This article discusses how the incentives of the U.S. academe influence IR theory and how it imitates the preferences of American foreign policy. Moreover, this article denotes that IR scholarship has abstracted away from the realities of international affairs and it does not speak of, or speak to those in the far away periphery. It concludes by discussing two promising movements: Global IR and Planet Politics. Global IR involves rebuilding the theories of IR by incorporating contributions from the periphery, whereas Planet Politics is a manifesto for rewriting IR as a set of practices based on the concept of Anthropocene by proposing a new ontology that is driven by the dread of planetary extinction.

The Utility of Endoscopic Ultrasound in Patients with Isolated Elevations in Serum Amylase and/or Lipase

Lalitha M. Sitaraman,Amit H. Sachdev,Tamas A. Gonda,Amrita Sethi,John M. Poneros,Frank G. Gress 대한소화기내시경학회 2019 Clinical Endoscopy Vol.52 No.2

Background/Aims: The aim of this study was to describe the diagnostic yield of endoscopic ultrasound (EUS) in patients with isolatedelevated levels of amylase and/or lipase. Methods: A retrospective chart review was conducted at a large academic medical center from 2000 to 2016. Patients were selectedbased on having elevated amylase, lipase, or both, but without a diagnosis of pancreatitis or known pancreatobiliary disease. Patientswere excluded if they had abnormal liver function tests or abnormal imaging of the pancreas. Results: Of 299 EUS procedures performed, 38 met inclusion criteria. Symptoms were present in 31 patients, most frequentlyabdominal pain (87%). In 20 patients (53%), initial EUS most commonly found chronic pancreatitis (n=7; 18%), sludge (5; 13%), or newdiagnosis of pancreas divisum (3; 8%). In the asymptomatic patients (7), 3 had a finding on EUS, most importantly sludge (2), stone (1),and pancreas divisum (1). No patients were diagnosed with a mass or pancreatic cyst. During the follow up period, 6 patients (22%) hadcholecystectomy. Conclusions: In our study of patients with isolated elevations in amylase and/or lipase without acute pancreatitis who underwent EUS,approximately 50% had a pancreatobiliary finding, most commonly chronic pancreatitis or biliary sludge.

Increased Risk of Pancreatitis after Endoscopic Retrograde Cholangiopancreatography Following a Positive Intraoperative Cholangiogram: A Single-Center Experience

Lalitha M. Sitaraman,Rita M. Knotts,Judith Kim,Srihari Mahadev,David S. Lee 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.1

Background/Aims: To determine if patients with a positive intraoperative cholangiogram (IOC) who undergo a subsequentendoscopic retrograde cholangiopancreatography (ERCP) have an increased risk of post-ERCP pancreatitis (PEP) compared to thosewho undergo ERCP directly for suspected common bile duct stones. Methods: A retrospective case-control study was performed from 2010 to 2016. Cases included inpatients with a positive IOC atcholecystectomy who underwent subsequent ERCP. The control group included age-sex matched cohorts who underwent ERCP forcholedocholithiasis. Multivariate logistic regression was used to assess the association between PEP and positive IOC, adjusting formatching variables and additional potential confounders. Results: Of the 116 patients that met the inclusion criteria, there were 91 women (78%) in each group. Nine patients (7.8%)developed PEP in the IOC group, compared to 3 patients in the control group (2.6%). The use of pancreatic duct stents and rectalindomethacin was similar in both groups. After adjusting for age, sex, total bilirubin levels, and any stent placement, patients with apositive IOC had a significantly increased risk of PEP (odds ratio, 4.79; 95% confidence interval, 1.05–21.89; p<0.05). Conclusions: In this single-center case-control study, there was a five-fold increased risk of PEP following a positive IOC comparedto an age-sex matched cohort.

Design and Demonstration of Power Delivery Networks With Effective Resonance Suppression in Double-Sided 3-D Glass Interposer Packages

Kumar, Gokul,Sitaraman, Srikrishna,Jonghyun Cho,Sundaram, Venky,Joungho Kim,Tummala, Rao R. IEEE 2016 IEEE transactions on components, packaging, and ma Vol.6 No.1

<P>Ultrathin 3-D glass interposers with throughpackage vias at the same pitch as through-silicon vias (TSVs) have been proposed as a simpler and cheaper alternative to the direct 3-D stacking of logic and memory devices. Such 3-D interposers provide wide-I/O channels for high signal bandwidth (BW) between the logic device on one side of the interposer and memory stack on the other side, without the use of complex TSVs in the logic die. However, this configuration introduces power delivery design challenges due to resonance from: 1) the low-loss property of the glass substrate and 2) the parasitic inductance due to additional length from lateral power delivery path. This paper presents for the first time, the design and demonstration of power delivery networks (PDNs) in 30-μm thin, 3-D double-sided glass interposers, by suppressing the noise from mode resonances. The self-impedance of the 3-D glass interposer PDN was simulated using electromagnetic solvers, including printed-wiring-board and chip-level models. The 3-D PDN was compared with that of the 2-D glass packages having fully populated ball grid array connections. The resonance mechanism for each configuration was studied in detail, and the corresponding PDN loop inductances were evaluated. High impedance peaks in addition to the 2-D PDN were observed at high frequencies (near 7.3 GHz) in the 3-D interposer structure due to the increased inductances from lateral power delivery. This paper proposes and evaluates three important resonance suppression techniques based on: 1) 3-D interposer die configuration; 2) the selection and placement of decoupling capacitors; and 3) 3-D interposer package power and ground stack-up. Two-metal and four-metal layer test vehicles were fabricated on 30and 100-μm thick panel-based glass substrates, respectively, to validate the modeling and analysis of the proposed approach. The PDN test structures were characterized up to 20 GHz for plane resonances and network impedances, with good model-to-hardware correlation. The results in this paper suggest that the ultrathin 3-D interposer PDN structure can be effectively designed to meet the target impedance guidelines for high-BW applications, providing a compelling alternative to 3-D-IC stacking with the TSVs.</P>

Glass Interposer Electromagnetic Bandgap Structure for Efficient Suppression of Power/Ground Noise Coupling

Kim, Youngwoo,Cho, Jonghyun,Kim, Jonghoon J.,Cho, Kyungjun,Kim, Subin,Sitaraman, Srikrishna,Sundaram, Venky,Raj, Pulugurtha Markondeya,Tummala, Rao R.,Kim, Joungho [Institute of Electrical and Electronics Engineers 2017 IEEE transactions on electromagnetic compatibility Vol.59 No.3

<P>In this paper, we propose glass interposer electromagnetic bandgap (EBG) structure to efficiently suppress power/ground noise coupling. We designed, fabricated, measured, and analyzed a glass interposer EBG structure for the first time. Glass interposer EBG structure test vehicles were fabricated using a thin-glass substrate, low-loss polymer layers, and periodic metal patches with through glass vias (TGVs) in glass interposer power distribution network. Using the dispersion characteristics, we thoroughly analyzed and derived f(L) and f(U) of the glass interposer EBG structure. We experimentally verified that the proposed glass interposer EBG structure achieved power/ground noise suppression (below -40 dB) between f(L) of 5.8 GHz and f(U) of 9.6 GHz. Derived f(L) and f(U) based on dispersion analysis, full three-dimensional electromagnetic (3-D-EM) simulation and measurement achieved good correlation. In the glass interposer EBG structure, tapered structure of the TGV and thickness of the low-loss polymer used for metal-layers lamination affected the noise suppression bandgap significantly. The effectiveness of the proposed glass interposer EBG structure on suppression of the power/ground noise propagation and coupling to high-speed TGV channel was verified with 3-D-EM simulation. As a result, the proposed glass interposer EBG structure successfully and efficiently suppressed the power/ground noise propagation and improved eye-diagram of the high-speed TGV channel.</P>

Glass-Interposer Electromagnetic Bandgap Structure With Defected Ground Plane for Broadband Suppression of Power/Ground Noise Coupling

Youngwoo Kim,Jonghyun Cho,Kyungjun Cho,Junyong Park,Subin Kim,Dong-Hyun Kim,Gapyeol Park,Sitaraman, Srikrishna,Raj, Pulugurtha Markondeya,Tummala, Rao R.,Joungho Kim IEEE 2017 IEEE transactions on components, packaging, and ma Vol.7 No.9

<P>In this paper, we propose glass-interposer (GI) electromagnetic bandgap (EBG) structure with defected ground plane (DGP) for efficient and broadband suppression of power/ground noise coupling. We designed, fabricated, measured, and analyzed a GI-EBG structure with DGP for the first time. The proposed GI-EBG structure with DGP is thoroughly analyzed using the dispersion characteristics and estimated stopband edges, f(L) and f(U). We experimentally verified that the proposed GI-EBG structure with DGP achieved power/ground noise isolation bandgap (below -30 dB) between f(L) of 5.7 GHz and f(U) of 11 GHz. Estimation of f(L) and f(U) using dispersion analysis, full 3-D electromagnetic (EM) simulation results, and measurement results achieved good correlation. Effectiveness of the proposed GI-EBG structure with DGP on suppression of the power/ground noise coupling to high-speed through glass via (TGV) channel is verified with 3-D EM simulation. As a result, the proposed EBG structure successfully and efficiently suppressed the power/ground noise coupling and improved the eye diagram of the TGV channel. Lastly, we embedded thin alumina film in the proposed EBG structure and achieved even broader power/ground noise suppression between 2.1 and 14.7 GHz.</P>