HIGH FREQUENCY COMMON-MODE NOISE IN SERDES CIRCUITS’ OPTIMIZED INTERCONNECTIONS

According to the requirements imposed by the new four-level pulse amplitude modulation (PAM4) standard for high-speed data transfer and processing, electrical constraints and manufacturing tolerances in integrated electronic packages impose accurate electromagnetic simulations and new S-parameters analysis, saving time and financial resources for next-generation switches, routers or data centers circuits implementation. The complexity of the advanced networking class circuits’ encapsulation substrates massively increases due to the large number of differential signals that it integrates. Differential signaling has replaced single-ended transmission in high-speed circuits due to their many advantages, including increased immunity to crosstalk and electromagnetic interference, but common-mode noise due to timing skew or amplitude unbalance differences can still affect them. This work tests five different models, identifies and optimizes the 45° bends, structures that commonly affect the reflections in a differential stripline. Then it studies differential transmission lines in stripline topology, implemented in a 12-layered flip-chip package, using S-parameters, inspecting and comparing the common-mode noise. In this way, the paper combines microwave theory with a real chip packaging design in an innovative way, using finite element analysis of electromagnetic field simulation and mixed-mod scattering parameters of differential topologies, towards an optimized structure design

Compositional Quality of Bazna Pork Meat: Comparative Studies with Genetically Improved Breeds

Pork meat is considered one of the most consumed food products around the world. Pork meat industry is in continuous development because of the high demand on the market. The quality of pork meat is known to be related not only to the breeding conditions but also to the breed. Our study aimed to investigate the differences in compositional parameters of Bazna pork meat and the genetically improved breeds, which are now the main source of meat on the market. Results show that the meat provided by Bazna breed is superior from the compositional aspect from that found on the market. It is therefore important to stimulate and develop the breeding systems of Bazna pig

MAC Protocol for Data Gathering in Wireless Sensor Networks with the Aid of Unmanned Aerial Vehicles

Data gathering in wireless sensor networks by employing unmanned aerial vehicles has been a subject of real interest in the recent years. While drones are seen as an efficient method of data gathering in almost any environment, wireless sensor networks are the key elements for generating data because they have low dimensions, improved flexibility, decreased power consumption and costs. This paper addresses the communication at the Medium Access Control (MAC) layer between static deployed sensors and a moving drone whose unique role is to collect data from all sensors on its path. The most important part of the proposed protocol consists of prioritizing the sensors in such a manner that each of them has a fair chance to communicate with the drone. Simulations are performed in NS-2 and results demonstrate the capabilities of the proposed protocol

Synthesis of wo3 nanogranular thin films by hot-wire CVD

By resistively heating tungsten filaments in a constant air flow under a reduced pressure, nanogranular amorphous WO3 thin films are deposited on glassy carbon substrates. The substrate surface temperature is monitored by a thermocouple. For deposition times of 15 min and longer, the films show crystallization into a monoclinic nanocrystalline WO3 phase due to thermal radiation from the filaments. The thin films thus deposited consist of very small grains with sizes of 8-16nm for a film deposited in 5 min, and to sizes of 20-42nm for a film deposited in 60 min. By heating the bottom of the substrate to 950°C, the grains sinter to nanorods with diameters of 146±26nm with lengths of up to 750 nm. The morphology, the film thickness, the grain and the nanorod sizes of the depositions are characterized by high-resolution scanning electron microscopy (HRSEM), and the atomic species present in the films by energy-dispersive X-ray spectroscopy (EDS). The number of atoms in the films is determined by Rutherford backscattering spectrometry (RBS). The results are combined with measurements of the physical thicknesses, and thus the mass densities of the deposited films are obtained. X-ray diffraction (XRD) and Raman spectroscopy are used to characterize the deposited films crystallographically and chemically, respectivel