Characterizing the Electric Field Coupling from IC Heatsink Structures to External Cables Using TEM Cell Measurements

One method for evaluating the unintentional radiated emissions from integrated circuits (ICs) involves mounting the IC on a printed circuit board (PCB) embedded in the wall of a transverse electromagnetic (TEM) cell. The signal voltages on the IC and its package produce electric fields that can couple to cables and other structures attached to the PCB, inducing common-mode currents that can be a primary source of unintentional radiated emissions. The signal currents in the IC and its package produce magnetic fields that can also result in common-mode currents on larger radiating structures. This paper describes a TEM cell measurement method employing a hybrid to separate the electric field coupling and the magnetic field coupling. The results of this measurement can be used to determine the product of the IC\u27s self-capacitance and the effective voltage that drives this capacitance. This voltage-capacitance product characterizes the IC\u27s ability to drive common-mode currents onto cables or enclosures due to electric field coupling. This information can then be used to estimate the resulting radiated emissions

Impedance Transformers

Non

Mobile array designs with ANSERLIN antennas and efficient, wide-band PEEC models for interconnect and power distribution network analysis

A mobile, wide-band antenna system has been developed around the ANSERLIN antenna element and a 3-dB splitter design. The size of the antenna elements was reduced over previous versions by introducing dielectric substrates. Additionally, new variations of the antenna were designed to influence radiation characteristics. To further reduce the number of components in the array, a very low profile splitter was designed and mounted below one of the antenna elements, doubling as the return plane for the antenna. The partial-element equivalent circuit (PEEC) method has been used for 3D interconnect analysis and numerous other applications. Being based on the same ideas as the method of moments, the PEEC method generates dense matrices for its cell interactions. This thesis contains research focused on efficiently using a limited number of cells for accurate results. This has been approached with a hybrid method and also with grid refinements. Additionally, the accuracy of PEEC coupling over electrically long distances has been addressed using wide-band accurate partial parameter calculations --Abstract, page iii

Antenna-coupled TES bolometers used in BICEP2, Keck array, and SPIDER

We have developed antenna-coupled transition-edge sensor (TES) bolometers for a wide range of cosmic microwave background (CMB) polarimetry experiments, including BICEP2, Keck Array, and the balloon borne SPIDER. These detectors have reached maturity and this paper reports on their design principles, overall performance, and key challenges associated with design and production. Our detector arrays repeatedly produce spectral bands with 20%-30% bandwidth at 95, 150, or 220~GHz. The integrated antenna arrays synthesize symmetric co-aligned beams with controlled side-lobe levels. Cross-polarized response on boresight is typically ~0.5%, consistent with cross-talk in our multiplexed readout system. End-to-end optical efficiencies in our cameras are routinely 35% or higher, with per detector sensitivities of NET~300 uKrts. Thanks to the scalability of this design, we have deployed 2560 detectors as 1280 matched pairs in Keck Array with a combined instantaneous sensitivity of ~9 uKrts, as measured directly from CMB maps in the 2013 season. Similar arrays have recently flown in the SPIDER instrument, and development of this technology is ongoing.Comment: 16 pgs, 20 fig

Contribution to the characterization of stratified structures : electromagnetic analysis of a coaxial cell and a microstrip line

The objective of this dissertation is the development of electromagnetic modelling software specific to the cells of microwave material characterization. This development is based on numerical methods that are alternative to finite element method which is widely used in commercial software. For the need to extract the properties of materials by inverse modelling methods, research into the numerical efficiency of direct analysis is the focus in this thesis. The characterization targeted cells in this work concern a coaxial cell and a planar line. The presence of an unknown material is modelled by a stratified heterogeneous transmission structure. The application of the transverse operator method (TOM) on the multi-layered coaxial cell allowed the determination of the propagation constant of fundamental mode and its corresponding field distribution of the electromagnetic fields, and the characteristics of higher-order modes for the need of the characterization of discontinuities between empty line and loaded line. In the case of the microstrip line, the use of the modified transverse resonance method (MTRM) allowed the determination of characteristics of the fundamental and higher order modes. Since each cell consists of several different sections, the matrix S of the set will be determined by the use of the several modal methods, such as modal connection method (''mode matching'') and multimodal variational method (MVM). The direct analysis codes are coupled with several optimization programs to constitute the software for extracting the material parameters. These are applied to material samples in cylinder form holed by the coaxial cell, or thin rectangular wafer by the microstrip line. Broadband extraction results were obtained, values are comparable with those published. Both high-loss dielectrics and nanostructured materials have been studied by our method

Comparison of Field-To-Line Coupling Models: Coupled Transmission Lines Model versus Single-cell Corrected Taylor Model

International audienceModels for field-to-line coupling are interesting be- cause they help to predict the immunity of PCBs and explain the relation between routing and immunity. In this article a meandered PCB trace illuminated by EM field in a TEM cell is analysed. The near-end and far-end coupling is predicted using two models: a detailed and an approximative one. The detailed model is a circuit of coupled multi-conductor transmission lines evaluated with a circuit simulator. The approximative model consists of a single Taylor cell with an analytical modification evaluated using a numerical computing tool. Both predictions are compared with measurements and turn out to be equally precise. The advantage of the coupled lines model is its flexibility, the advantage of the modified Taylor model is its ease of use