It is proposed that the application of defected ground structures (DGS) and electromagnetic bandgap (EBG) reduce the phase velocity, increase effective permittivity of microstrips and reduce the effective the wavelength which eventually lead to the reduction of overall length of Wilkinson power dividers. Furthermore, the adjacent strip lines may approach each other, which cause coupling problem...

Non-linear models for microwave and millimetre wave devices are commonly based on DC and S-parameter measurements, due to the absence of vectorial large-signal measurements in the past. At present, accurate prototype measurement systems are being developed, which implies that new non-linear modelling techniques can be explored. We will show experimental results of a method that allows the direc...

Numerical time–domain methods for electromagnetic field simulations typically provide very broad band frequency–domain characterizations as well as transient response with a single simulation and without in general requiring any pre–processing. However long simulation times and large memory requirements arise for the case of electromagnetic structures characterized by low loss (high quality fac...

This paper presents the rationale for the use of method of moments for evaluation of electromagnetic field scattered by dielectric random fractal surfaces. Derivation of the algorithm is given along with a reliable fractal profile generation procedure. Choice of key parameters pertinent to method of moments is also discussed. Numerical results are finally used to investigate the behaviour of th...

A large family of noncommutative Einstein-Maxwell null pp -waves to order one in the noncommutativity parameters is constructed. They are solutions to the Einstein and field equations for general relativity coupled to a Seiberg-Witten electromagnetic field. Noncommutativity enters the spacetime metric through a conformal factor and is responsible for dilating/contracting the separation between ...

We have developed a correlation radiometer at 33 GHz devoted to the search for the residual polarization of the Cosmic Microwave Background (CMB). The two instrument’s outputs are a linear combination of two Stokes parameters (Q and U, or U and V). The instrument is therefore directly sensitive to the polarized component of the radiation (respectively linear and circular). The radiometer has a ...

The transport equations for polarized radiation transfer in non-Riemannian, Weyl-Cartan type space-times are derived, with the effects of both torsion and non-metricity included. To obtain the basic propagation equations we use the tangent bundle approach. The equations describing the time evolution of the Stokes parameters, of the photon distribution function and of the total polarization degr...

This paper presents a model of the Stokes vector emission from the ocean surface. The ocean surface is described as an ensemble of facets with Cox and Munk’s Gram-Charlier slope distribution. The study discusses the impact of different up-wind and cross-wind rms slopes, skewness, peakedness, foam cover models and atmospheric effects on the azimuthal variation of the Stokes vector, as well as th...

The article gives an introduction to classical vector radiative transfer theory (RTT). It comprises a brief summary of the fundamental quantities in RTT and the corresponding definitions. Based on these quantities, the transfer equation for radiation will be introduced in its basic form for a plane-parallel, horizontally homogeneous atmosphere. Polarization and the Stokes vector are introduced,...

This paper focuses on the extraction of an accurate small-signal equivalent circuit for metal-oxide-semiconductor field-effect transistors (MOSFETs). An analytical modeling approach was developed and successfully validated through the comparison between measured and simulated scattering parameters. The extraction of the equivalent circuit elements allowed for the estimation of the intrinsic uni...