Recent Patents on Electrical & Electronic Engineering (Formerly Recent Patents on Electrical Engineering) - Volume 5, Issue 2, 2012

In this work different patented optical sensing solutions are reviewed, mostly for their application of measuring fluid level within tanks, containers or bio-mass boilers in condominiums, thus providing an intrinsically safe sensing scenario within harsh and hazardous environments, due to the passive nature of light. In general, the intensity modulation of the light is very attractive since it is simple in concept, reliable, and can produce optical sensors which offer a wide range of applications at lower costs, thus facilitating their final commercialization and market spread. The optical sensing solutions discussed in this work include a fiber-optic sensor for fluid detection/level with intrinsic self-referencing property thus solving one of the main drawbacks when using intensity-based sensors, namely the undesirable and unexpected optical power fluctuations when operating. Moreover, a low-cost intensity-based POF sensor for fuel level measurements in paramotoring and powered paragliding is presented. It features a very simple and a very low-cost solution for these sports, attending the increasing demand of new and more sophisticated embedded sensors in the flight instrumental. Going on from this, a fiber-optic fluid level sensor for a range greater than 2m is described. The system uses a single lens and a single fiber but being possible to increase the measuring safety area by optical multiplexing. Finally, a fluid level sensor based on a Light Dependent Resistor (LDR), which includes a temperature control scheme, is presented. Its final embodiment design is also shown and described.

In this paper, we will review the recent developments of high-power continuous-wave (CW) Er-Yb codoped fiber amplifiers (EYDFAs). Several related patents and a couple of methods of improving the performance of high-power EYDFAs are reviewed. Current research results show that the Yb-band amplified spontaneous emission (Yb-ASE) is the main reason that limits the efficiency and stability of an EYDFA at high pump power. Several methods and experimental results dedicated to suppress the Yb-ASE are introduced. Current and potential future developments of high-power EYDFAs are summarized in the last part of this paper.

Magnetostriction is a property exhibited by numerous metallic materials. It refers to the relationship between specific mechanical characteristics of these materials and their internal magnetization. In particular, changing internal magnetization of magnetostrictive elements (due, for instance, to exposure to ambient magnetic fields) results in modification of their dimensions and vice-versa. Among others, this thoroughly documented magneteto-mechanical (or magnetoelastic) coupling of magnetostrictive materials has been exploited in the design of applications for non-contact detection and measurement of quantities (for instance, temperature, hazardous chemical substances and so on), or for energy harvesting from vibrational motion. Relevant characteristic patents and research papers proposing applications based on the magnetoelastic principle are presented and commented upon in the current study. The central part in all applications examined is the structure (referred to as platform) involving the elements of magnetostrictive material. Hence, the applications are distinguished in groups and reviewed according to their platform’s structural and functional parameters, namely its mechanical attributes, texture/size and so on. The aim is to designate solutions with similar platform characteristics, which perform well in a variety of different applications (medical, chemical, electrical and so on). Identifying these globally best practices and solutions should provide the reader with useful ideas for the design and development of devices operating on the magnetoelastic principle.

This review paper reports on recent patents regarding integrated optical active devices, namely amplifiers and lasers based on silicon. It is crucial to point out a standard and unique platform for integrating optic and electronic components together. Nevertheless, integrated optics does not have its standard platform and it is still struggling to find the most competitive way for achieving light generation and amplification onto a single silicon chip. Different solutions have been proposed so far, and the more promising are hybrid integration and silicon photonics. Even if the first approach allowed the actual fabrication of integrated optical chips, it cannot guarantee total compatibility with current electronic fabrication methods, thus, it is expensive for large-scale production. On the other hand, silicon photonics suffers from the unsuitability of bulk silicon as emitting material, and as a consequence, several innovative solutions have been patented to achieve efficient light emission from silicon-based materials. To assure low-cost those solutions should be CMOS compatible. Here we focused on the patents that have represented a technological breakthrough or a milestone for hybrid integration or silicon photonics, highlighting advantages but also issues that have still to be addressed.

Integrating Circuit Design for Manufacturability (IC DfM) involves various methodologies, techniques, and tools to improve semiconductor reliability and fab yield metrics by optimizing device design or layout. Recent years have seen propagation of IC DfM into the multiple aspects of semiconductor product definition. In addition to the traditional, mainstream DfM related to the corrections of circuit layout by the different types of pattern resolution enhancement techniques, recent DfM disclosures related to stacked die verification, 3D die packaging, floorplanning, and wiring have been proposed to help with the growing number of IC applications. These extended categories of DfM would be useful especially for Systems-on-Chip as well as for the further pursuit of IC shrinkability, e.g. by double patterning. In this work, we discuss nineteen representative IC DfM disclosures filed or published in 2011 and 2012. Similarly, as in the previous review [1], we divided the patents into the ones pertaining to DfM definition, DfM execution, and DfM verification. The focus of the first group of patents (definition) was the correct-by-construction (CBC) architecture, e.g., of layout (active devices, metal routing), die floorplan, or package. The second group (execution) pertained to process proximity correction (mostly OPC), and the third group (verification) concentrated on process model calibration and identifying the sources of process variability. These directions of DfM development, consistent over the recent years, show the validity of the existing DfM approach to solve future design problems.

The fixed-time solutions may not be optimal, and therefore time-variations of the harmonics must be considered in the optimum harmonic filters design. The probabilistic modeling of current and voltage harmonics as an accurate estimation of power system harmonic behavior has become an important indicator for customers and suppliers alike. This patent presents an application of the probabilistic approach based mean value estimation of source and load characteristics, which is enabled by sampling measurements and statistical analysis performed on an electrical plant, which allow appropriate calculation of optimal harmonic filters parameters considering voltage harmonics and source impedance as randomly time-varying quantities. The optimization also considers practical constraints such as load power factor and total voltage harmonic distortion limitations. Also, this patent includes different optimization criteria. Finally, the effectiveness and robustness of the proposed harmonic filters are validated by means of three case studies, including a detailed comparison of the different objectives presented in this patent.

A CPW-fed circular wide slot UWB antenna with C-band, WLAN and X-band notch functions has been presented in this article. The two stop bands are obtained by etching an isosceles triangular resonator with an inner isosceles triangular stub in the circular radiation patch and a stepped impedance resonator with an inner stub in the CPW fed transmission line. The two notched bands can be tuned by changing the dimensions of isosceles triangular, stepped impedance resonator and the inner stubs to give tunable notched band functions. The proposed dual notched band UWB antenna has been designed in details and optimized by means of HFSS. The proposed antenna has a small size of 32x24x1.6mm3. The simulated and measured results show that the designed UWB antenna has an impedance bandwidth of 10.7GHz covering the frequency band from 2.8GHz to 13.5GHz for voltage standing-wave ratio (VSWR) less than 2, except the notch bands 4.0GHz-5.4GHz for C-band and WLAN, 8.2GHz-9.3GHz for X-band which are used in satellite and military communications. The article also refers some recent patents on UWB antenna design.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by different applications of electrical power supply, electrical systems, power transmission, electromagnetism, motor control process and technologies involved and related to electrical engineering.