Passive Intermodulation at Contacts of Rough Conductors

Passive intermodulation (PIM) is a niggling phenomenon that debilitates performance of modern communications and navigation systems. PIM products interfere with the information signals and cause their nonlinear distortion. The sources and basic mechanisms of PIM were studied in literature but PIM remains a serious problem of signal integrity. In this paper, the main sources and mechanisms of PIM generation by joints of good conductors are discussed. It is shown that the passive electrical, thermal and mechanical nonlinearities are intrinsically linked despite their distinctively different time scales. The roughness of the contact surfaces plays an important role in PIM generation by conductor joints. A review of the PIM phenomenology at contacts of the good conductors suggests that novel multiphysics models are necessary for the analysis and reliable prediction of PIM products generated by several concurrent nonlinearities of diverse physical nature

METAMORPHOSE VI - The Virtual Institute for artificial electromagnetic materials and metamaterials

In this paper, we outline the background, mission, and activities of the Virtual Institute for Artificial Electromagnetic Materials and Metamaterials (METAMORPHOSE VI). This international association, founded in the framework of the FP-6 Network of Excellence METAMORPHOSE, aims at promoting and developing research, training, and dissemination activities in the emerging and highly dynamic field of advanced electromagnetic materials and metamaterials at both European and International levels. More than 300 researchers are currently associated with the METAMORPHOSE VI which networks them together in a learnt society. After a brief description of the association and its mission, we present an overview of the activities developed by the METAMORPHOSE VI, with a particular emphasis on the coordination of the European Doctoral Program on Metamaterials (EUPROMETA) and the organization of the International Congress on Advanced Electromagnetic Materials in Microwaves and Optics - metamaterials congress.Peer reviewe

Modeling of Impedance-Loaded Sub-Wavelength Metasurfaces

In the context of the optimization of a versatile type of metasurface consisting of inter- twined spirals printed on a dielectric substrate and loaded with discrete impedances, we propose a sim- ple development of the method of moments inter- action matrix that allows obtaining the scattered field almost instantly for any distribution of discrete loads. Simulation results for a sample design are presented to illustrate the effectiveness and validity of the method

Phase Gradient Discontinuity Metasurface with Intertwined Spiral Arrays

A reflect-type metasurface with phase gradient discontinuity is proposed. It is formed by planar intertwined spiral conductors loaded with inductors. A pattern of conductors is initially designed under the assumption of locally periodicity and the phase response of uniform arrays. Simulations are performed with a fast proprietary code based on the periodic Method of Moment and the Array Scanning Method. Macro-cells, containing 70 identical micro-cells with different loads, have been analysed, and it is found that the reflected power only partially goes into the desired non-specular Floquet mode