Design of integrated low noise amplifiers (LNA) using embedded passives in organic substrates

The noise figure of a low noise amplifier (LNA) is a function of the quality factor of its inductors. The lack of high-Q inductors in silicon has prevented the development of completely integrated complementary metal oxide semiconductor (CMOS) LNAs for high sensitivity applications like global system for mobile communications (GSM) (1.9 GHz) and wideband code-division multiple-access (W-CDMA) (2.1GHz). Recent developments in the design of high-Q inductors (embedded in low cost integrated circuit (IC) packages) have made single-package integration of RF front-ends feasible. These embedded passives provide a viable alternative to using discrete elements or low-Q on-chip passives, for achieving completely integrated solutions. Compared to on-chip inductors with low Q values and discrete passives with fixed Q/sub s/, the use of these embedded passives also leads to the development of the passive Q as a new variable in circuit design. However, higher Q values also result in new tradeoffs, particularly with respect to device size. This paper presents a novel optimization strategy for the design of completely integrated CMOS LNAs using embedded passives. The tradeoff of higher inductor size for higher Q has been adopted into the LNA design methodology. The paper also presents design issues involved in the use of multiple embedded components in the packaging substrate, particularly with reference to mutual coupling between the passives and reference ground layout.     

Global variations in cancer survival. Study Group on Cancer Survival in Developing Countries

Population-based cancer registries from Algeria, China, Costa Rica, Cuba, India, the Philippines, and Thailand are collaborating with the International Agency for Research on Cancer in a study of cancer survival in developing countries. Comparisons with the SEER program results of the National Cancer Institute in the United States, and the EUROCARE study of survival in European countries revealed considerable differences in the survival of patients with certain tumors associated with intensive chemotherapeutic treatment regimes (Hodgkin's disease and testicular tumors), more modest differences in the survival of patients with tumors for which early diagnosis and treatment confer an improved prognosis (carcinomas of the large bowel, breast, and cervix), and only slight differences for tumors associated with poor prognosis (carcinomas of the stomach, pancreas, and lung). With limited resources to meet the challenge of the increasing incidence of cancer expected in the next few decades, health authorities in developing countries should be aware of the importance of investing in a range of cancer control activities, including primary prevention and early detection programs as well as treatment.     

Influence of limit stress states and yield criteria on the prediction of forming limit strains in sheet metals

Several researchers have proposed analytical methods for predicting the forming limit curve (FLC), which has been successfully used as a diagnostic tool in sheetmetal forming. However, these approaches lack ease of adaptability to various situations and also involve considerable complexity. Sing and Rao proposed a new FLC modeling approach based on limit stress states derived from yield criterion and material properties from a simple tensile test. The first aspect of this study addresses the influence of the shape of the forming limit stress curve (FLSC) upon the FLC. The FLC modeled from a singly linear FLSC exhibits good agreement with the experimental curve, unlike those modeled from an elliptical or a piecewise linear FLSC. It is, thus, established that a linearized limit stress locus describes adequately the actural localized neck condition for the materials chosen in this study. Second, the study focuses on the suitability of the different cases of Hill’s yield criterion for satisfactory prediction of FLCs. The FLCs predicted using different cases of Hill’s criterion are compared with experimental FLCs in the case of steel and copper. Different cases of Hill’s criterion provide a wider choice for FLC modeling for different classes of materials. The sensitivity of Hill’s stress exponent is also thoroughly explored for achieving a close correspondence between the predicted and experimental FLCs.     

A double line SIW cavity backed antenna for WLAN applications

A compact double line substrate integrated waveguide (DLSIW) cavity backed antenna is realized using half mode SIW technology for WLAN applications. The existing single line SIW antennas for WLAN applications have low gain and less efficiency. To overcome this limitation, DLSIW structure is proposed. The new DLSIW structure simultaneously achieves better gain, radiation efficiency, and good front to back ratio (FTBR) with compact size. To improve the FTBR, ground extension is made. The size reduction of the proposed design is implemented with half mode SIW topology. The gain and efficiency improved new DLSIW antenna is fabricated using FR4 material and it resonates at 5.27GHz WLAN frequency. The size of antenna is 44 mm × 18.75 mm × 1.6 mm and it has the gain of 5.824 dB. The radiation efficiency and FTBR of the antenna are 69.13% and 13.65 dB, respectively. The design is experimentally tested and compared with earlier WLAN antennas. There is a better accordance between simulated and measured results.     

Effect of pulse reversal on the properties of pulse plated CdSe x Te1−x thin films

CdSe _x Te_1–x thin films with 0 < x < 1 were deposited on titanium and conducting glass substrates by pulse electrodeposition using microprocessor control. Formation of the solid solution takes place for values of x(0 < x < 1). The films were characterized by X-ray diffraction. While the as-deposited films are cubic in nature, those annealed at 475 °C in air indicate hexagonal structure and the lattice parameters increase with increasing value of x. From the optical absorption measurements the band gap of the material was calculated. The value of the band gap varies from 1.42 to 1.70 eV as x varies from 0 to 1. The photoelectrochemical (PEC) characteristics were obtained for all compositions of CdSe _x Te_1–x (x = 0–1). The output parameters for CdSe_0.66Te_0.34 with 9% duty cycle at an intensity of 80 mW cm^–2 using 1 M polysulphide as the redox electrolyte, are V _OC of 398 mV, J _SC of 5.59 mA cm^–2, ff of 0.45, of 4.73%, R _s of 13 , R _sh of 1.50 k. The output parameters were found to increase with 60 ms pulse reversal. After photoetching for 40 s, a V _OC of 481 mV, J _SC of 16.00 mA cm^–2, ff of 0.57, of 5.46%, R _s of 6 , R _sh of 2.16 k were obtained.     

Recognition of epoxy with phage displayed peptides

The development of a general approach for non-destructive chemical and biological functionalization of epoxy could expand opportunities for both fundamental studies and creating various device platforms. Epoxy shows unique electrical, mechanical, chemical and biological compatibility and has been widely used for fabricating a variety of devices. Phage display has emerged as a powerful method for selecting peptides that possess enhanced selectivity and binding affinity toward a variety of targets. In this letter, we demonstrate for the first time a powerful yet benign approach for identifying binding motifs to epoxy via comprehensively screened phage displayed peptides. Our results show that the epoxy can be selectively recognized with peptide-displaying phages. Further, along with the development of epoxy-based microstructures; recognition of the epoxy with phage displayed peptides can be specifically localized in these microstructures. We anticipate that these results could open up exciting opportunities in the use of peptide-recognized epoxy in fundamental biochemical recognition studies, as well as in applications ranging from analytical devices, hybrid materials, surface and interface, to cell biology.     

Nuclear power plant sensor fault detection using singular value decomposition-based method

In a nuclear power plant, periodic sensor calibration is necessary to ensure the correctness of measurements. Those sensors which have gone out of calibration can lead to malfunction of the plant, possibly causing a loss in revenue or damage to equipment. Continuous sensor status monitoring is desirable to assure smooth running of the plant and reduce maintenance costs associated with unnecessary manual sensor calibrations. In this paper, a method is proposed to detect and identify any degradation of sensor performance. The validation process consists of two steps: (i) residual generation and (ii) fault detection by residual evaluation. Singular value decomposition (SVD) and Euclidean distance (ED) methods are used to generate the residual and evaluate the fault on the residual space, respectively. This paper claims that SVD-based fault detection method is better than the well-known principal component analysis-based method. The method is validated using data from fast breeder test reactor.     

Moisture-driven phase transition for improved perovskite solar cells with reduced trap-state density

We report a mechanistic understanding of a moisture-driven intermediate-phase transition that improves the quality of perovskite thin films based on a lead-acetate precursor,improving the power-conversion efficiency.We clarify the composition of the intermediate phase and attribute the transition of this phase to the hygroscopic nature of the organic product,i.e.,methylammonium acetate.Thermal annealing aids in the coarsening of the grains.These decoupled processes result in better crystal formation with a lower spatial and energetic distribution of traps.Thermal annealing of the films without exposure to air results in a faster intermediate-phase transition and grain coarsening,which occur simultaneously,leading to disorder in the films and a higher deep trap-state density.Our results indicate the need for a humid environment for the growth of high-quality perovskite films and provide insight into intermediate-phase dissociation and conversion kinetics.Thus,they are useful for the large-scale production of efficient solution-processed perovskite solar cells.