679 research outputs found
Determination of Spectral Focusing Features of a Metamaterial Slab
No full textThe realization of flat superlenses is a major application area of metamaterials. A slab of double negative (DNG) material is capable of imaging with a resolution below the diffraction limit. The focusing quality depends primarily on the amount by which the original spectrum of the source is restored behind the lens. Even a small deviation from the ideal case limits the spectrum of the transmitted field, which may result in a significant degradation of the focusing quality. In this work we determine the width of the transmitted spectrum as a function of the configuration parameters and establish a relation between the spectrum width and the imaging quality. Restrictions imposed on the focusing characteristics and difficulties arising in full wave simulations will be pointed out
Measurement of Radiated Cyclostationary EMI
No full textWe have extended the method for modeling the stocha
stic EM near-field which has already been
described for stationary stochastic fields to the case
of cyclostationary fields. Areas of application are the
modeling of the electromagnetic interference radiated by
digital circuitry inside the system and also into
the environment, where the period of the cyclostationar
y EMI is given by the clock frequency of the digital
circuits. Stochastic electromagnetic fields with Ga
ussian amplitude probability distribution can be fully
described by auto- and cross correlation spectra of
the field components. The
cross correlation spectra
have to be known for the pairs of field components ta
ken at different spatial points (Russer et al., 2015a,
b).
We present methods for measurement and evaluati
on of stationary and cyclostationary stochastic
electromagnetic fields. The radiated electromagnetic inte
rference (EMI) of electroni
c circuitry is recorded
by two-point measurements of the t
angential electric or magnetic fi
eld components and by evaluating the
field autocorrelation functions and for each pair of field sampling points also the cross correlation
functions (Russer and Russer, 2015). In case of di
gital circuitry clocked by a single clock pulse, the
generated EMI is a cyclostationary process where the ex
pectation values of the EMI are periodically time
dependent according to the clock frequency and which have to be considered in modeling the EMI.
In this contribution we present the experimental char
acterization of cyclostationary radiated EMI by two-
point correlation measurements. The radiated EMI is
measured simultaneously by two field probes. The
measured signals are recorded by a digital sampling
oscilloscope and the cycl
ostationary auto- and cross
correlation spectra are computed from the measured da
ta. From this the propagation of the radiated EMI
is computed using the CTLM method (Russer et al., 2016).
References
Russer, J. A. and Russer, P.: Modeling of Noisy EM Fi
eld Propagation Using Correlation Information, in
IEEE Transactions on Microwave
Theory and Techniques, 2015.
Russer, J. A., Russer, P., Konovalyuky, M., Gorbuno
va, A., Baev, A., and Kuznetsov, Y.: Analysis of
Cyclostationary Stochastic Electromagnetic Fields, in
: International Conference on Electromagnetics in
Advanced Applications (ICEAA), 2015
Russer, J. A., Russer, P., Konovalyuky, M., Gorbuno
va, A., Baev, A., and Kuznetsov, Y.: Near-Field
Propagation of Cyclostationary Stochastic Electrom
agnetic Fields, in: International Conference on
Electromagnetics in Advanced A
pplications (ICEAA), 2015, 2015.
Russer, J. A., Cangellaris, A., and Russer, P.: Corre
lation Transmission Line Matrix (CTLM) Modeling of
Stochastic Electromagnetic Fields, 10 in: Proceeding
of: IEEE International Microwave Symposium, IMS,
San Farncisco, CA, USA, 2016
Correlation Transverse Wave Formulation (CTWF) for Modeling of Stochastic Electromagnetic Fields
No full textIn this work we apply the Correlation Transver
se Wave Formulation (CTWF) method for direct
computation of the auto- and cros
s correlation functions (ACFs and
CCFs) of stationary stochastic
electromagnetic fields. These ACFs and CCFs are com
puted from the Johns matrices, i.e. the discrete-
time TWF Green's functions and are directly related to the EMI power spectra.
Radiated EMI is represented by stoc
hastic EM fields. For efficient EMI compliant design and optimization
of circuits and systems the si
mulation methodologies based on the field autocorrelation and cross
correlation spectral densities are required. Semi-ana
lytic numerical methods based on Green's function
formalism already were presented in
(Russer and Russer, 2011a, 2015).
The Transmission Line Matrix (TLM) method is an e
fficient time-and space discrete numerical method for
modeling of complex electromagnetic structures (R
usser and Russer, 2011b, 2014). Introducing network
models allows the application of correlation matrix met
hods for the modeling of stochastic fields. This can
be done either by method of moments as discussed in
(Russer and Russer, 2015) or by applying network
oriented space discretising methods for EM field computation as for example the TLM method (Russer et
al., 2016).
Mode matching is the superposition of modal field solu
tions. If an electromagnetic structure is subdivided
into substructures and complete sets of modal field
solutions are known for the sub-domains, these modal
solutions form a complete basis and allow to expand the field solutions into these basis functions.
Choosing modal functions as the basis functions ensure
s that these functions are
already solutions within
the respective regions and we need
only to care that the boundar
y conditions are fulfilled. The mode
matching method is potentially exact if we allow infi
nite series expansions. Considering the modal basis
functions as the basis of a function space, Hilbert
space methods, in particular the method of moments
(Harrington, 1968), can be applied. Baudrand and Baj
on introduced Hilbert space methods to transform
integral formulations of electromagnetic field pr
oblems into algebraic ones (Baudrand, 2001). An
extension of this method has been given in the transve
rse wave formulation (Wane et al., 2003). Now, we
extend the Transverse Wave Formulation method to
compute auto- and cross correlation functions of
stationary stochastic
electromagnetic fields.
References
Baudrand, H.: Introduction au Calcul des Elements de
Circuits Passifs en Hyperfreequences, Cépaduès-
Éditions, Toulouse, 2001.
Harrington, R. F.: Field Computation by Mom
ent Methods„ IEEE Press,
San Francisco, 1968.
Russer, J. A. and Russer, P.: Stochastic electrom
agnetic fields, in: German Microwave Conference
(GeMIC), pp. 1-4, 2011a.
Russer, J. A. and Russer, P.: Modeling of Noisy EM
Field Propagation Using Correlation Information, in
IEEE Transactions on Microwave
Theory and Techniques, 2015.
Russer, J. A., Cangellaris, A., and Ru
sser, P.: Correlation Transmission Line Matrix (CTLM) Modeling of
Stochastic Electromagnetic Fields, in: Proceeding o
f: IEEE International Microwave Symposium, IMS,
San Francisco, CA, USA, 2016.
Russer, P. and Russer, J.: Transmission Line Matrix (TLM) and network methods applied to
electromagnetic field computation, in: Micr
owave Symposium Digest (MTT), 2011 IEEE MTT-S
International, pp. 1-4, IEEE,
doi:10.1109/MWSYM.201
1.5972622, 2011b
Numerical analysis of focusing by a metamaterial lens
No full textOver the last several years there has been a surge of interest in artificial materials because of their potential to expand the range of electromagnetic properties in materials. The so called metamaterials, also known as left-handed (LHM) or double-negative (DNG) materials with negative permittivity
and permeability have attracted growing interest. An important application area is the realization of flat superlenses with imaging properties beyond that of conventional lenses. This work investigates the focusing properties of a lossless planar DNG slab with a relative permittivity and permeability both approaching the value -1. The relation between the imaging quality and the material parameters is examined both analytically and numerically. Results obtained from numerical simulations via the transmission line matrix method are compared to the analytical solution
Hybrid space discretizing-integral equation methods for numerical modeling of transient interference
No full text
Efficient analysis of microstrip radiation by the TLM integral equation (TLMIE) method
No full textMicrostrip lines are widely used in microwave and millimeter-wave integrated circuits. In this paper we present an accurate analysis of the EM near and far field radiated by a microstrip line. The EM analysis is developed by a novel method, the Transmission Line Matrix Integral Equation (TLMIE) method. This method combines the advantages of the TLM method, which is very flexible for the modeling of general structures with arbitrary shapes, and the advantages of the integral equation (IE) method, which allows one to incorporate the treatment of large free space region
Rigorous design of magnetic-resonant wireless power transfer links realized with two coils
No full textMagnetic resonant wireless power transfer has been typically realized by using systems of coupled resonators. We show that the essential elements are only the coupled inductances. In fact, by starting from coupled inductances, and by introducing their conjugate image impedances, we can derive the series and parallel matching topologies that realize maximum wireless power transfer. By sacrificing some efficiency we show that we can realize a matched (lossless case) mid-range wireless power transfer link by using just one inductive coil on the secondary side and having the required capacitances all on the primary side (or viceversa). The proposed topology greatly simplifies the design; in addition, when tuning is required due to coils misalignment or to link distance variation, it can be attained without the need for a feed-back through the communication link. A preliminary experimental verification of the proposed approach is also presented
- …
