Elliptical slot based polarization insensitive compact and flexible chipless RFID tag

A miniaturized, polarization insensitive, and fully passive chipless radio frequency identification tag is proposed in this research article. The realized tag is based on slotted elliptical structures in a nested loop fashion with identical lengths and widths of slot resonators. Alteration of data sequence is accomplished by addition and elimination of nested resonators in the geometric structure. The tag is capable to encode 10 bits of data and covers spectral range from 3.6 to 15.6 GHz. The formulated structure demonstrates polarization insensitive characteristic. The data encoding structure is analyzed and optimized for different substrates that are, Rogers RT/duroid/5880, Rogers RT/duroid/5870, and Taconic TLX‐0 over the miniaturized footprint of 22.8 × 16 mm². The presented tag is robust, novel, compact, and flexible exhibiting a stable response to impinging electromagnetic waves at various angles of incidence.     

Plasmomechanical Systems: Principles and Applications

Extreme confinement of electromagnetic waves and mechanical displacement fields to nanometer dimensions through plasmonic nanostructures offers unprecedented opportunities for greatly enhanced interaction strength, increased bandwidth, lower power consumption, chip-scale fabrication, and efficient actuation of mechanical systems at the nanoscale. Conversely, coupling mechanical oscillators to plasmonic nanostructures introduces mechanical degrees of freedom to otherwise static plasmonic structures thus giving rise to the generation of extremely large resonance shifts even for minor position changes. This nanoscale marriage of plasmonics and mechanics has led to the emergence of a new field of study called plasmomechanics that explores the fundamental principles underneath the coupling between light and plasmomechanical nanoresonators. In this review, both the fundamental concepts and applications of plasmomechanics as an emerging field of study are discussed. After an overview of the basic principles of plasmomechanics, the active tuning mechanisms of plasmonic nano-mechanical systems are extensively analyzed. Moreover, the recent developments on the practical implications of plasmomechanic systems for such applications as biosensing and infrared detection are highlighted. Finally, an outlook on the implications of the plasmomechanical nanosystems for development of point-of-care diagnostic devices that can help early and rapid detection of fatal diseases are forwarded.     

High-frequency micromechanical columnar resonators

Abstract

High-frequency silicon columnar microresonators are fabricated using a simple but effective technological scheme. An optimized fabrication scheme was invented to obtain mechanically protected microcolumns with lateral dimensions controlled on a scale of at least 1 μm. In this paper, we investigate the influence of the environmental conditions on the mechanical resonator properties. At ambient conditions, we observed a frequency stability δf/f of less than 10^?6 during 5 h of operation at almost constant temperature. However, varying the temperature shifts the frequency by approximately ?173 Hz °C^{? 1}. In accordance with a viscous damping model of the ambient gas, we perceived that the quality factor of the first flexural mode decreased with the inverse of the square root of pressure. However, in the low-pressure regime, a linear dependence was observed. We also investigated the influence of the type of the immersing gas on the resonant frequency.     

Computing unstable resonator modes

The potential of the so-called ‘eigenvector method’ (here called the direct eigenvector method (DEM)) for computing the modes of unstable resonators in two transverse dimensions is examined, and a detailed comparison with the traditional Fox–Li approach undertaken. The memory requirements of the DEM are potentially enormous and, if high-resolution patterns are needed, the Fox–Li approach must remain the method of choice. However, the DEM has the important advantage that higher order modes can be generated as easily as the fundamental mode, and this provides an incentive for exploring its capabilities. With the help of some simple devices for limiting the memory requirements, we have obtained DEM results in hexagonal geometry that display an impressive level of detail.     

TLM modeling of a probe‐coupled cylindrical cavity based on compact wire model in the cylindrical mesh

This article describes an implementation of a compact wire model into the three‐dimensional transmission‐line matrix (TLM) cylindrical mesh for the purpose of an efficient analysis of probe‐coupled cylindrical microwave cavity devices. Because of a cylindrical grid structure and empirical nature of the compact model, this implementation has to take into account a change of wire model parameters with a variable cross section of the TLM nodes through which a wire conductor passes. The model accuracy has been experimentally verified and compared with the corresponding results reached by the TLM method based on a rectangular grid in order to consider its advantages. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

基于单平面双螺旋谐振单元左手传输线研究

单平面双螺旋谐振单元是一种左手单元,具有不需缺陷地结构和小型化的特点.该文主要对由单平面双螺旋单元组成的对称和非对称两种传输线形式进行了仿真研究.利用电磁仿真工具,仿真分析了两种形式传输线的回波损耗和插入损耗特性.由仿真结果可知,非对称形式传输线的电磁性能较好.该文设计了两组对比仿真实验,即对称和非对称形式传输线结构相位特性对比,一、四单元非对称传输线相位特性对比,对传输线结构的相位特性进行了分析.结果表明,基于单平面双螺旋结构的非对称形式传输线具有左手效应.     

基于CSRR的带通滤波器小型化设计

介绍了一种新型的互补开环谐振器(Complementary Split Ring Resonators,CSRR),用此新型谐振器和1/4波长传输线变换器制作了波导带通滤波器.在此基础上为了使滤波器更小型化,设计了挡板结构,改进了滤波器的1/4波长传输线变换器.通过对两种结构的仿真比较得出,新型结构的滤波器在满足设计需...     

A Micromachined Reconfigurable Metamaterial via Reconfiguration of Asymmetric Split‐Ring Resonators

A micromachined reconfigurable metamaterial is presented, whose unit cell consists of a pair of asymmetric split‐ring resonators (ASRRs); one is fixed to the substrate while the other is patterned on a movable frame. The reconfigurable metamaterial and the supporting structures (e.g., microactuators, anchors, supporting frames, etc.) are fabricated on a silicon‐on‐insulator wafer using deep reactive‐ion etching (DRIE). By adjusting the distance between the two ASRRs, the strength of dipole–dipole coupling can be tuned continuously using the micromachined actuators and this enables tailoring of the electromagnetic response. The reconfiguration of unit cells endows the micromachined reconfigurable metamaterials with unique merits such as electromagnetic response under normal incidence and wide tuning of resonant frequency (measured as 31% and 22% for transverse electric polarization and transverse magnetic polarization, respectively). The reconfiguration could also allow switching between the polarization‐dependent and polarization‐independent states. With these features, the micromachined reconfigurable metamaterials may find potential applications in transformation optics devices, sensors, intelligent detectors, tunable frequency‐selective surfaces, and spectral filters.     

A novel semi-analytic method for the analysis of scattering by dielectric objects immersed in uniform media

The method for the solution of scattering problems with homogeneous dielectric scatterers based on a single coordinate multipole expansion, the Stratton-Chu integral and Maxwell's equations in the integral form is proposed in this paper. Its convergence is proved. The sources of ill-conditionality of constitutive algebraic systems are established. The method of their regularization based on the use of a scalar control parameter is suggested. For the sake of validation, the numerical analysis is performed for different testing objects.