Radio frequency identification (RFID) excelled in automatic identification and data collection industry through its speed, agility and endurance. RFID of objects and people and remote control of devices has become very popular in logistics, inventory management and bio-engineering applications. RFID system which works on the basis of alternating electromagnetic fields mostly consists of two vital components - a RFID tag (transponder) and a RFID interrogator (reader). As this is a contact less technology, both of these components should have independent antennas to transfer data among them. This paper reviews the recent developments of the tag antennas focusing different technologies and architectures in recent years on the basis of recent published manuscripts and patents. Moreover, projections on future development trends are also provided.
This paper presents an overview of security threats in cryptographic devices due to side-channel attacks. The mechanisms of power analysis attacks and their relationship to the underlying CMOS technology are considered. Specifically, differential power analysis is a statistical analysis attack that is successful in breaking the security of cryptographic devices, such as smart cards and even various embedded portable devices. The paper discusses the most significant patents related to the power analysis attacks mechanism and the most significant patents developed for the purpose of hardware based countermeasures against these attacks. The security of communication on all cryptographic devices is paramount and it is important to use the right techniques to accomplish the highest level of security.
LEDs for lighting application are becoming widely adopted due to economic, energy and environmental reasons. LEDs are conventionally powered by DC sources or AC sources with AC-DC converters. More and more recent research works have been focusing on direct AC powering LEDs without AC-DC converters. Enhanced reliability, lower cost and easy to replace existing lighting fixtures due to the elimination of AC-DC converter are advantages of AC LEDs. DC LED drivers architectures including AC-DC converter based LED drivers are reviewed and compared with direct AC powering LEDs. Issues like flicker effects, current limiting and protection, efficiency and LEDs reverse break down in AC LEDs and recent AC LEDs patents are discussed.
There is expanding interest in developing THz spectrum instruments for biochemical agent spectroscopy, environmental monitoring and medical imaging. This paper presents a brief review of recently published patents that target innovations for making improvements to THz radiation sources, which is one of the essential modules for building sensing and imaging systems. This analysis will summarize the novel physical aspects and/or innovative design methodology associated with each patent concept. The approaches presented include photonic crystal, ultrafast photoconductive switch, slow-wave structure, photo-mixing in piezoelectric material, stimulated Raman effect, multiquantum well multiplier, and Josephson Junction device.
Multi-core system is the future of the embedded processor design for its power efficiency, multi-thread parallelization and flexibility. Meanwhile, with the improvement of the video processing algorithm, the processing capability requirement is also on the increase to meet such high processing capability requirement, the embedded multicore processor is developed as an appropriate choice. To better improve the performance of such systems, heterogeneous multi-core is preferred than homogeneous multi-core. For the design of such heterogeneous multi-core systems for video processing, the first and the most important step is to implement the system-level design and this paper gives an overview of such system-level design methodologies and some new methods for both cycle-approximate transaction-level modeling and cycle-accurate transaction-level modeling are given in detail. In addition, the system-level design framework for such systems is proposed and a case study of a heterogeneous multi-core h.264 video decoder shows that it can be used to design such systems effectively. The recent patents used for such designs are also listed accordingly.
Rate-equation model with a four-level system is used to study relative intensity noise (RIN) in III-nitrides quantum-dot (QD) lasers. These levels are: the ground- and excited-states in the QD, the wetting layer (WL) and separate confinement heterostructure (SCH) layers. The most possible relaxation paths and carrier transport are considered in two types of QD structures: GaN/AlxGa1-xN/AlN and InxGa1-xN/ In0.04Ga0.96N /GaN. Effect of: QD and WL compositions, QD sizes, doped and undoped active regions is studied. The RIN is shown to be reduced with higher Al content in the WL, while an increased is shown for InGaN QD structures. RIN decreases with size reduction. Increased doping until 12 acceptors/QD reduced RIN also. The article presents some promising patents on Quantum-Dot Lasers.
MPSoC is becoming popular in all computing domains. However, the speed gap between processor and memory is increasing due to heavy access contention from multiple processors. Therefore, in MPSoC systems, one of the most critical components is memory systems, which dominate the speed, power, cost, and area. In order to narrow the gap and reduce the costs, two effective memory architectures are adopted in MPSoC-based platform architecture: cache-based and scratch-pad-memory-based architectures. Cache-based hierarchy, as a traditional technique, is widely employed in general-purpose systems. However, in embedded systems, to meet the rigorous power and cost constraints, scratch-padmemory- based architecture is preferred due to its flexibility and higher power efficiency. A short review is presented to introduce these two types of memory systems with some useful patents and researches in the field of MPSoC systems.
Linear and nonlinear gain spectra are studied in Sb-based quantum-dot (QD) semiconductor optical amplifiers (SOAs). Quantum size, homogenous linewidth and effect of Sb-composition in the QD, wetting and barrier layers are studied also. InSb and InAs0.3Sb0.7 QD-SOAs give enough gain saturation. The study covers (1000-7000nm) wavelength range. This work covers some new patents in this field.