IonField Systems (United States)

This paper describes an articulated arm spherical near-field scanner design which transports a probe over a hyper-hemispherical surface that surrounds a stationary test antenna. Surface profile data collected with a laser tracker is presented and a parametric study performed to investigate the viability of testing at mm-wave frequencies is described. Parameters such as probe radial distance, and angular positioning are investigated to assess to what extent spherical near-field testing can be performed using this structure.

A truncation study is presented to assess the impact of theta truncation in a spherical near-field antenna test system. The study is relevant for antennas with broad beams in the plane of truncation and where antenna weight prevents alternate mounting options, while facility space limitations necessitate truncation.

Attempts to produce robust, objective, quantitative measures of comparison between data sets using statistical methods have been widely reported in the literature [1, 2]. Recently [3], techniques have been developed that require the antenna pattern functions to be converted into histograms before the comparison, i.e. the measure of adjacency, is made.

Abstract Exploration and Production projects can potentially create adverse health impacts for workers and surrounding communities unless appropriate malaria control programs are designed, implemented and monitored on an ongoing basis. These company based control programs often contain measures that often are not evidence-based and that may actually impair community malaria control efforts. This paper will present strategies and tools for use in developing effective malaria prevention and control programs through reviewing the current literature regarding: Malaria educationBite prevention and vector controlChemoprophylaxisDiagnosis and treatment These strategies can result in cost effective mitigation of potential adverse health impacts by implementing scientifically based programs developed for the specific malaria risk in the defined geographic area.

The current vs. voltage and electrical breakdown behavior for devices with micron and sub-micron gaps between conductors is studied. The limitations of the well-known but often-misinterpreted Paschen curve are discussed. The little-known modified Paschen curve, that includes field emission effects so important in understanding breakdown behavior for devices with sub-micron gaps, is described. Current vs. voltage measurements across metal-air-metal, metal-insulator-metal and metal-insulator-air-insulator-metal gaps with gaps ranging from 4 nm to 4 μm are reported. The breakdown voltage for an air gap of 0.9 μm was found to be 150 V, far below the Paschen curve minimum breakdown limit, and field emission behavior was confirmed via the Fowler-Nordheim plot. Metal-insulator-metal gaps with a diamond-like carbon thin-film with a thickness of 4 nm had a breakdown voltage of only 1V. SEM and AFM analysis show that the breakdown damage is crater-like and through the carbon layer. Other characterization of the damage caused by breakdown is presented. Tribocharging, electrostatic induction, and other ESD-related phenomena, are discussed for several devices with sub-micron gaps. It is concluded that devices with sub-micron gaps can face a serious challenge due to electrical breakdown during manufacturing, handling and operation. These devices include photolithographic reticles, magnetic recording heads, MEMS and field emission displays.