The notion of “field” between physics, psychology and philosophy of experience

In 1920 Wolfgang Köhler published Die physischen Gestalten in Ruhe und im stationären Zustand, in which the notion of “field” introduced by J.C. Maxwell and M. Faraday played a central role. The notion of “topological field” instead became one of the focal points of Kurt Lewin’s perspective. Alongside the empirical and experimental dimension, the philosophical and theoretical aspect was an essential component of the Berlin Gestalt school. This essay examines the following aspects which, from a philosophical point of view, characterized the use of the concept of “field” within the Berlin Gestalt movement: the opposition to those investigations of experience which took mechanical physics as a model; the critique of Kant’s dualism between the form and matter of knowledge; the affirmation of the idea that the senses capture values and meanings autonomously, without top-down interventions; the introduction of the concept of “requiredness” and an objectivist vision of expressivity

Millimeter-wave FET modeling based on a frequency extrapolation approach

An empirical distributed model, based on electromagnetic analysis and standard S-parameter measurements up to microwave frequencies, is shown to be capable of accurate small-signal predictions up to the millimeter-wave range. The frequency-extrapolation approach takes advantage from a physically-expected, smooth behavior of suitably defined elementary active devices connected to a passive distributed network. On this basis, small-signal millimeter-wave FET modeling becomes an affordable task in any laboratory equipped with a standard microwave vector network analyzer and electromagnetic simulation capabilities. In the paper, wide experimental validation of the proposed model up to 110GHz is presented for PHEMT devices with different sizes and bias conditions

Global modeling approach to the design of an MMIC amplifier using Ohmic Electrode-Sharing Technology

An innovative technique for high--density, high-frequency integrated circuit design is proposed.The procedure exploits the potentialities of a global modeling approach,previously applied only at device level,enabling the circuit designer to explore flexible layout solutions imed at important reduction in chip size and cost.The new circuit design technique is presented by means of an example consisting of a wide-band amplifier,implemented with the recently proposed Ohmic Electrode-Sharing Technology (OEST).The good agreement between experimental and simulated results confirms the validity of the proposed MMIC design approach

Fringe integral equation method for a truncated grounded dielectric slab

The problem of scattering by a semi-infinite grounded dielectric slab illuminated by an arbitrary incident TM z polarized electric field is studied by solving a new set of "fringe" integral equations (F-IEs), whose functional unknowns are physically associated to the wave diffraction processes occuring at the truncation. The F-IEs are obtained by subtracting from the surface/surface integral equations pertinent to the truncated slab, an auxiliary set of equations obtained for the canonical problem of an infinite grounded slab illuminated by the same source. The F-IEs are solved by the method of moments by using a set of subdomain basis functions close to the truncation and semi-infinite domain basis functions far from it. These latter functions are properly shaped to reproduce the asymptotic behaviour of the diffracted waves, which is obtained by physical inspection. The present solution is applied to the case of an electric line source located at the air-dielectric interface of the slab. Numerical results are compared with those calculated by a physical optics approach and by an alternative solution, in which the integral equation is constructed from the field continuity through an aperture orthogonal to the slab. The applications of the solution to an array of line currents are also presented and discussed