Amartya Banerjee

BROADBAND PERFECT METAMATERIAL ABSORBER ON THIN SUBSTRATE FOR X-BAND AND KU-BAND APPLICATIONS

A broadband Perfect Metamaterial Absorber (PMA) on FR-4 Epoxy substrate for X-band and Ku-Band applications is proposed. The unit cell structure is composed of rectangular patches of appropriate shapes and orientation on top of the metal-backed dielectric substrate having a thickness of 2.7 mm (0.16λL). The relative absorption bandwidth is 79% (more than 85% absorption) covering the entire X-band and the Ku-Band of the microwave frequencies. The surface current distributions of the top and bottom planes have been analyzed to elaborate the absorption mechanism of the structure. The broadband characteristics of the design support its claim of being useful to a wide range of applications in both commercial and research sectors. Such applications include military and stealth devices, thermal sensors and electronic-cloaking devices.

Safe registers can achieve correct implementation of peterson’s two process mutual exclusion algorithm

Most of the mutual exclusion algorithms in a shared memory system assume that memory reference to at least one shared variable used in the algorithm is mutually exclusive. However, we claim that Peterson’s two-process mutual exclusion algorithm need not assume such low level mutual exclusion for its correct implementation. It is shown that the shared variables used in this algorithm need to obey only the safe register axioms. To prove this assertion we propose a temporal logic viz., Temporal ordering Related to Observation. This logic does not allow any assertion related to the future behavior of the predicates.

CPW-fed small UWB monopole antenna for energy-harvesting applications

This article presents a small antenna for UWB applications on FR-4 Epoxy substrate material with a percentage bandwidth of 147% covering the frequencies from 3.08 GHz to 18.85 GHz. The antenna has a CPW-fed monopole-like structure that facilitates its easy fabrication and interface with other system components. The geometry offers a high frequency bandwidth and an effective matching of the radiator with the feed that is evident from the results which show that over most of the operating frequencies the return loss is −15dB or less in the plots. The antenna claims its appraisal from the fact that the design only occupies a space of 400mm2 (20mm×20mm) on the single-layered substrate — and a table of comparison is provided in the work, which compares this size reduction of the component with other literature. The article presents the simulated results, and a discussion on how the proposed structure may be utilized in the domain of energy-harvesting — along with a comparison of the work with other reports, to claim the notion of its effective size reduction.