chapter
A high resolution interpolation scheme for use with the FDTD method at ELF frequencies under water is described. Since the interpolation is applied after the FDTD Simulation, it adds very little to the computation time or resources.
chapter
In this paper, a novel ldquogreenrdquo inkjet-printed monopole antenna topology for integrated RFID-reader and cellular communication functionalities is presented. The antenna is loaded with a parasitic strip to fulfil the design requirements for the required dual-band operation. The design characteristics of the antenna are verified for paper-based substrates through extensive simulated parametric...
chapter
In this paper, the integration of a flexible RFID tag with an inkjet-printed Single Walled Carbon Nanotube (SWCNT) film in a chipless sensor node for toxic gas detection was introduced for the first time. The whole module is realized on a "green" low-cost paper substrate. Carbon nanotube composites change their electric properties (e.g. resistance, dielectric properties) in the presence...
chapter
The efficient calculation of the electromagnetic interactions with dielectric objects is always a challenge to CEM (computational electromagnetics). Among the numerical exact methods, the method of moment (MoM) is considered to be more preferable than finite element method (FEM) and finite difference method (FDTD) for its high precision and discretization on the geometry model instead of the field...
chapter
In this paper, we propose a high-speed FDTD algorithm for GPU. Our algorithm includes two important techniques: coalesced global memory access on a GPU board and the improved cache block algorithm for GPU which resembles that for the central processing unit (CPU). Our algorithm achieved an approximately 20- fold improvement in computational speed compared with a conventional CPU at the maximum computational...
chapter
A fully functional internal DTV diversity antenna has been designed and tested. The proposed internal balanced dipole antenna was integrated with a DTV module in a notebook computer. The results demonstrate that a balanced dipole antenna for noise suppression and diversity reception enable high quality reception of a DTV signal even though we trade-off some antenna performance after packaging in notebook...
chapter
Microwave tomographic imaging has long been plagued by problems of converging to unwanted solutions or "local minima". For a variety of real- world system implementations, these issues were partially overcome by the use of good starting guesses or a priori information to the iterative reconstruction process. Poor convergence was recognized in early 2D imaging efforts and still persists as...
chapter
A new approach for obtaining metasurfaces realized by employing Frequency Selective Surfaces (FSSs) with small periodicity printed on a new class of high dielectric constant materials is presented. The synergic use of ad-hoc engineered materials and innovative electromagnetic design provides an improvement of the overall device in terms of size reduction and radiative properties.
chapter
This paper presents several variants of the approach which can determine near-optimal radiation patterns under the constraint that the apertures (and therefore currents) for the elements do not overlap. Computational examples show that some of the methods can consistently provide performance which rivals that achievable with the optimal results for overlapping currents.
chapter
A novel wrist conformal dual-band antenna structure is proposed for application in watch-type wireless devices. Simulation results show that this structure can achieve good performance in dual GSM bands and high efficiency when worn on hand. Based on this structure, a dual-element diversity antenna is also proposed. More research regarding this novel structure will be done in the future.
chapter
A large but finite array of waveguides, cascaded with an FSS with dissimilar periodicity, is analyzed in this paper by using a combination of the mode matching-finite element method, spectral decomposition (MM-FEM-SD) and method of moments (MoM).
chapter
A low-profile, wide-band antenna array with side-lobe control is presented. The array consists of tapered slot elements fed by a planar microstrip power divider. The power divider incorporates two- dimensional amplitude tapering through a series of unequal T- junctions which gives side-lobe levels of -20 dBi. The number of elements in the array is 8 by 8, and it operates from 12 GHz- 18 GHz. Measured...
chapter
For convenient portability mobile devices need to be small. To reduce their size, a small antenna is strongly required because the antenna is one of a mobile device's largest components. In addition, the antenna's bandwidth needs to be wide because the recent development of many kinds of multimedia services requires a large bandwidth. Designing a small antenna with a wide bandwidth is not easy, however,...
chapter
An ultra-wideband antenna array design concept is presented that achieves the same functionality of traditional single-element-based ultra-wideband arrays using multiple elements that are scaled in size from the base high-frequency element, resulting in significantly fewer elements overall. This novel array design leads to a significant reduction in weight and most importantly - a significant reduction...
chapter
Using an equivalent circuit, a new wideband array was examined using physically realizable tightly coupled dipoles. A miniaturized element using inductive and capacitive loading was used to suppress ground plane effects for a broadband conformal array. Serial inductance was demonstrated to effectively miniaturize the radiating element and lead to even greater bandwidth as compared to the CSA array...
chapter
In this paper, we present a new UWB integrated filter-antenna. This allows optimizing the size, the performances, and the characteristics of the UWB system. The antenna is a rectangular slot fed with a microstrip rectangular patch by coupling effect. The second important element is an UWB filter with highly band rejection. It is designed using interdigital hairpin resonators. Both antenna and filter...
chapter
Low-sidelobe radiation patterns with good directivity can be generated by antennas consisting of a linear array of parasitic dipoles in front of a smaller linear array of active dipoles fed uniform voltages, a configuration that facilitates the task of feed network design. The fundamental effect of the parasitic array is to allow the length of the active array to increase by a factor of 2 or more,...
chapter
A varactor-loaded left handed loop antenna that has reconfigurable radiation patterns is described. The loop antenna uses a left-handed transmission line which is loaded with series capacitors and shunt inductors in a number of unit cells. The two wire transmission line is formed into a loop and fed at the break in the outer loop. The antenna has eight varactors in the four unit cells. Different radiation...
chapter
This paper investigates the redundancy and loss reduction in reconfigurable antenna structures. We use graph models as tools to understand and optimize reconfigurable antenna structures. Examples are given and formulas are suggested to be used by reconfigurable antenna designers to obtain non redundant structures.
chapter
In this paper the ability of SCT to simulate 1-D non-uniform finite patch arrays is demonstrated. It is shown that SCT has better convergence than the FEM based method which makes it a suitable tool for simulating large and complex structures. Moreover the modular nature of the SCT can be exploited toeconomize both memory and processing resources therefore making it an ideal design and optimization...
