Joseph D. Brunett

Do Media Players Cause Interference with Pacemakers

Electrical devices generate electromagnetic fields that may interfere with pacemakers. Media players cause telemetry interference with pacemakers, but it is not known whether they cause direct interference with pacemakers. The purpose of this study was to examine the interaction between pacemakers and 3 different media players.

On measurements for EIRP compliance of UWB devices

This paper discusses issues, methods, and limitations of using scalar near field measurements for determining radiator EIRP. Standard measurement methods and extrapolations used in compliance testing of UWB devices are reviewed. Next, measurements are performed which examine field attenuation rates in the near field of different radiating sources. Finally, these field attenuation rates are reviewed in relation to demonstrating DUT compliance.

Extrapolating near-field emissions of low-frequency loop transmitters

This paper investigates the emission of fields and field attenuation rates from electrically small transmitting loop antennas in the presence of a general half-space. Considerations are made for the practical effects of antenna loop dimension and source-to-sensor impedance coupling. The resulting field attenuation rates correlate well with open area test site (OATS) measurements. The tables provided may be readily used to extrapolate measured low-frequency emissions to common regulatory limit locations.

The effects of ground permittivity and surface roughness on multi-path measurements at K-band

A number of automotive radar systems have been designed with application to adaptive cruise control, road surface monitoring, accurate speed measurement, and potential application to collision avoidance. In order to construct these high-tech radar systems for the automotive market, a thorough understanding of the residential and highway environments in which they would operate is required. In this paper, a versatile open-ended waveguide measurement technique is used to determine the effective dielectric permittivity of various ground types. From this information, K-band LOS (Line-Of-Sight) propagation above different ground materials are calculated and compared with outdoor measurements. Here the influence of ground permittivity, surface roughness, and ground layer thickness on K-band propagation is presented.

Measuring Radiation Characteristics of Remote Keyless Entry Transmitters

In this paper a simple technique to determine real world radiation characteristics of portable communications devices is outlined, with particular emphasis placed on the measurement of remote keyless entry (RKE) hand-held transmitters. Device radiation pattern and polarization are characterized without the need of error causing feed cables or disparate time coherent sources, making it particularly useful when measuring sources that couple to the human body. Polarization purity is collected in a single measurement spin, making characterization of multiple on-body scenarios practical with human subjects.

Simulation and measurement of low frequency open surface magnetic field shielding

This paper details the simulation and measurement of low frequency (LF) magnetic field shielding by open surface structures. The approach of this paper is to develop equivalent electric sheet impedance boundary conditions for use by LF surface based electric field integral equation (EFIE) solvers. From these sheet impedance forms, a figure of merit is developed to determine the boundary condition applicability. Next, transmitting and receiving coil designs are analyzed and modifications are made to eliminate shield currents in measurement. Finally, simulated and measured magnetic field shielding is compared for electrically small open surface material disks.

Reducing SIE solution time via a multilevel geometry description and split basis assembly

This paper outlines the advantage of applying domain decomposition to arbitrary surfaces via a multilevel geometry description (MLGD). By constructing the desired simulation surface from embedded lists of subsurface location vectors and orientation matrices; storage, compute, and matrix fill time formulations can be significantly reduced. We discuss proper formation of a multilevel geometry and outline a real-time method for determination of the minimal interaction set within the structure. Basis assembly performed both interior and exterior to the matrix-vector product allowing application of multipole acceleration to bases spanning multiple subdomains is also detailed.

Multi-Facet Representation of Arbitrary Surface Geometries

This paper discusses the extension of array redundancy minimization techniques to arbitrary contiguous surfaces. By constructing a surface from an assemblage of facets and assigning each facet a location and orientation in global space, storage, compute time, and matrix fill time can be reduced. Included are general geometric formulations necessary to construct an arbitrary surface from preexisting facets, and discussions with regard to mesh integrity and storage reduction. The application of this technique to open surface PEC structures using moment method is illustrated

A quadruple-gap loop antenna for low frequency radiated emission measurements

This paper discusses the detailed design and optimization of a four-quadrant loop antenna with interchangeable feed. This antenna is designed to minimize electric field sensitivity while maintaining superior magnetic field response in both the transmitting and receiving modes. Direct tradeoffs between magnetic and electric field sensitivity, field uniformity, antenna dimension, feed design, and operational bandwidth are discussed. Finally, the antenna factor of the quadruple-gap loop antenna is directly compared with theoretical formulations. The discussions put forth are directly applicable when considering loop antennas in low frequency radiated emission testing.

An off-vehicle measurement procedure for predicting on-vehicle tire pressure transmitter performance

This paper outlines the development of an off- vehicle measurement procedure to ensure on-vehicle tire pressure transmitter performance. Measurements of electrically small transmitters mounted on a rim and tire are made on an Open Area Test Site (OATS) and in an anechoic chamber. Comparing emissions data collected along with in-vehicle performance, an optimal measurement procedure is selected. This procedure successfully correlates off-vehicle and on-vehicle sensor perfor- mance, allowing evaluation without full vehicle testing.