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In recent years there has been a surge of interest in various disciplines within applied electromagnetics, including electrically small antennas, MIMO antennas, periodic structures and metamaterials. Though a multitude of interesting applications have arisen, there still remain numerous fundamental questions regarding these burgeoning areas of research. We show how a characteristic mode analysis can...
This paper compares the port and radiation pattern performance of a metal-loaded dielectric resonator antenna predicted using three different computational methods and obtained through measurement. Such comparisons between results acquired using different modelling techniques are possible these days due to the availability of commercial codes, and serve to provide an indication of the modelling error.
In this paper, the study of the radiation performance of a single band wearable cuff button antenna is presented. The radiation element is designed as a G-shaped structure excited by a printed microstrip feeding line placed on a RT/duroid® microwave material to operate at 2.45 GHz for WLAN/Bluetooth applications with omni-directional radiation patterns that are required for data transmission with...
With the increased proliferation of array antennas, for a myriad of wireless applications, the monitoring and correction of array element failure is becoming more critical. In this paper, a fast Support Vector Machine (SVM) classifier, based on low-degree polynomial kernel is developed, to expeditiously detect and locate the failed elements of an arbitrary analog array, while categorizing the level...
In this paper, a novel dual mode circular waveguide antenna is proposed. The antenna generates both TE11 and TE21 modes with a quadrature phase difference and different amplitude ratios. A single slot is used to generate the TE21 mode along with a single choke with a circular cross-section. The amplitude mode ratios are then controlled by the height and angular width of the slot. All simulations are...
In this paper, an algorithm for a novel SPICE model for single layer power distribution planes is presented. The power plane is modeled as a grid of transmission line segments and a delay-extraction based representation is used to model the transmission line network. The proposed macromodel is compared with the HSPICE's W-element and numerical examples prove that the proposed model provides similar...
A frequency selective surface (FSS) based on switchable slots on the ground plane is presented. The switching is done using an actuating MEM bridge over the slot. The intent is to demonstrate the control of the resonance frequency of the FSS by deflecting the bridge. It is shown that by applying a voltage between the bridge and the ground plane, the bridge displaces and changes the capacitance of...
The use of wireless devices around critical-care medical equipment poses the risk that the electric field strength will exceed the immunity of the equipment, potentially resulting in equipment failure and possibly harming the patient. As medical staff and visitors carrying wireless transmitters move through the hospital, there may be times when number and type of transmitters near a medical device...
An efficient domain decomposition approach for electromagnetic field analysis of complex 3D antennas is presented. The method combines the Moment Method (MM), the Multilevel Fast Multipole Algorithm (MLFMA), Physics Optics (PO) and the Domain Decomposition Method to provide fast and accurate analysis of arbitrary metallic and dielectric/magnetic structures, and to solve very large scattering problems...
Microstrip line fed slot antenna arrays are low profile structures that are easy to manufacture with low cost and they can be easily integrated with the feed network and/or the microwave front end circuits. Due to these features they are widely used in various applications. It is well known that a slot antenna positioned perpendicular to the microstrip feed line can be modeled by a series impedance...
When using computational electromagnetics (CEM) for performance analysis of radar and high-gain microwave antennas, the necessary detailed specifications and computer-aided design (CAD) drawings of these systems are seldom readily available from the original equipment manufacturer (OEM). A reasonable estimate of the electromagnetic (EM) field levels radiated by these types of antennas may be computed...
In this article it is presented an analytical method to model a source with circular polarization and the space distribution of the incident and reflected waves through a fine dielectric layer. The model is based on the wave concept. Mathematical expressions for the transmitted and reflected waves are formulated in the frequency domain. An inverse Fourier modal transform is applied to the waves in...
In this paper the transients in gain compensated negative group delay (NGD) circuits are investigated. The study is conducted on an active unity gain NGD circuit with an RLC resonator integrated in the feedback loop of an operational amplifier. The circuit operates at a center frequency of 454MHz, and it is cascadable. The single stage circuit exhibits a NGD of 1.52ns and a gain of 0.69dB, with a...
An inductance sensor based on a microwave interferometer capable of detecting magnetic markers in a microfluidic suspension is presented. The sensor can continuously detect micron-size superparamagnetic beads suspended in a microfluidic channel as they pass over a planar electrode loop. An estimated resolution of 1fH/√(Hz) was achieved, which is close to single particle resolution. The system relies...
In order to model nanosecond pulse electroporation of the cell membrane the effect of dielectric relaxation of membrane molecules has to be considered. Since the formation of pores is a nonlinear process the dielectric relaxation effects have to be incorporated as dispersion in the time-domain. This paper presents the time-domain implementation of a second-order Debye dispersion model for a single-shell...
A novel circularly polarized sectoral antenna on a Metallic Partially Reflective Surface (M-PRS) for wireless application within [5.15-5.35] GHz is proposed. By using double layers of M-PRS working on orthogonal polarizations as a superstrate with a single patch feeding by two ports, circular polarization is achieved. This antenna provides two perpendicular polarizations, vertical and horizontal,...
An array of surface-wave launcher (SWL) sources is presented for surface-wave (SW) control and beam steering on a grounded dielectric slab (GDS). Specifically, a four element array configuration of non-directive SWLs is investigated. By varying the relative phase difference and magnitude between SWL elements, the excited SW field distribution on the guiding surface can be steered and controlled. Simulations...
The design, fabrication, and characterization of an ultra-wide band antenna for near-field microwave imaging are presented. The focus is on an application in microwave breast tumor detection. The new antenna operates as a sensor with the following properties: 1) direct contact with the imaged body, 2) more than 90% of the microwave power is coupled into the tissue, 3) ultra-wide band performance,...
This paper introduces an ultra-miniature UHF antenna. The design combines different technologies to reduce the size:(meta-material inspired shape, use of a magneto-dielectric material as antenna support, use of an active component and a passive matching network for frequency tuning and impedance matching over the whole UHF band.) This antenna has been simulated and measured on nomad type terminal...
We present the design and fabrication of an electrically-small printed spherical helix antenna. The antenna consists of 6 helical arms printed onto a hemispherical substrate. It is designed to operate at 1 GHz, and the minimum radius sphere that circumscribes the antenna is 1.73 cm (ka = 0.36). The antenna is fabricated using a new direct transfer patterning process capable of printing ≈ 1μm feature...
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