Materials
 36 results found for Materials, displaying items 1 - 20

February 2010
Partnership Results In High-Permeability Magnetic Shielding Tubing
WARWICK, RI—A.T. Wall Company has partnered with the MuShield Company to develop the MShield seamless, high-permeability magnetic shielding tubing that ranges to 20 feet in length. Depending on the welding method used, this tubing’s shielding capability promises to be 20 to 30 percent better than a formed and welded product. The tubing can hold outside and inside diameters to +/-0.002 inches along with wall thicknesses within 0.002 inches. The seamless ...  — Dawn Hightower

January 2010
EMI Shielding Maintains Strength In Harsh Conditions
TO MAINTAIN STRENGTH at elevated temperatures and under cryogenic conditions, new tubular braided electromagnetic-interference (EMI) shielding combines the conductivity of an outer metal coating with the strength, light weight, and flexibility of genuine KEVLAR fibers. Dubbed ARACON, it comes in standard inner-diameter sizes ranging from 0.62 to 2.00 in. When braided into a shield, it vows to provide impressive performance against EM and RF interference. The conductors of...  — Nancy Friedrich

December 2009
Microwave Materials Lay Foundation For PAs
Power-amplifier designers typically create a circuit based on specific active devices for the output stage. While the choice of transistor determines the ultimate performance of an amplifier, printed-circuit-board (PCB) materials can also play a major role in an amplifier design. Selecting optimum substrate materials for an amplifier can improve gain and stability, and enable the maximum output power possible for a design. High-frequency amplifier designers have a wide array...  — John Coonrod

November 2009
Making The Most Of Microwave Materials
Microwave materials provide the foundations for highfrequency circuits and packaging. Dielectric circuit materials, often referred to as laminates because of the added copper for etching transmission lines, have made progress in recent years in terms of consistency and stability as well as flexibility, with many suppliers offering a wide range of materials in support of designs from RF through millimeter-wave frequencies. High-frequency...  — Jack Browne

November 2009
Two-Sided Contacting Reduces RC Parasitics
At delft institute of Microsystems and Nanoelectronics (DIMES), RF/microwave silicon devices have been implemented in a process that allows two-sided contacting of the devices. Dubbed the back-wafer-contacted Silicon On Glass (SOG) Substrate Transfer Technology (STT), that process was developed at DIMES. Those implementations were reviewed by Lis K. Nanver, Hugo Schellevis, Tom L.M. Scholtes, Luigi La Spina, Gianpaolo Lorito, Francesco Sarubbi, Victor Gonda,...  — Nancy Friedrich

October 2009
Form GaAs/InGaAs Lasers On Virtual Ge
Reliable GaAs-based optoelectronic devices, such as GaAs/InGaAs quantum well lasers, can be realized on silicon substrates using several advanced techniques. Fabrication involves first forming germanium (Ge) stripes on a silicon dioxide (SiO2) trench-patterned silicon substrate via aspect ratio trapping (ART), where any defects originating from the Ge/Si interface are trapped by laterally confining sidewalls. Defects arising from above the...  — J. Bai , et al.

June 2009
Launching TM Mode Onto A Single Conductor, Part 2
Last month, the first part of this three-part article series introduced a transversemagnetic (TM) propagation mode that is present with the better-known transverseelectromagnetic (TEM) mode in conventional coaxial transmission line. Put simply, waves move along a conductor having no outer shielding and no insulation or special surface conditioning. Part 2 will describe the TM mode around an unconditioned conductor, backed by models and measurements ...  — Glenn Elmore

March 27, 2009
High-Frequency Laminates Showcased At CTIA 2009
 — Lisa Maliniak

March 2009
Microwave Materials Move Beyond Thermal Management
Materials are not just tasked with bonding and separating circuit traces and ground lines on circuit boards. They must also channel life-shortening heat away from components. In addition, materials must provide stable foundations for circuits over both time and temperature even as new designs call for higher power and increased thermal stability. To enable future designs, materials are growing increasingly sophisticated and promising increased...  — Nancy Friedrich

February 2009
Making Manufacturing Choices For X-Band BPFS
Bandpass filters help extract desired signals from a portion of frequency spectrum while rejecting unwanted signals. In addition, they can symmetrically or asymmetrically modify the amplitude and/or phase of a signal. They are essential to a host of commercial and military systems and have evolved over the years, so much so that a review of available filter design and materials technologies can aid engineers faced with developing high-performance bandpass filters for X-band...  — William Cuviello , et al.

February 2009
Form Bandpass Filters On Glass Substrates
Glass is good for more than just windows: in recent years, the material has attracted attention for its dielectric properties and cost-effectiveness as a high-frequency-circuit substrate. It features low circuit losses over wide frequency and temperature ranges and is suitable for circuit fabrication using standard integrated-circuit (IC) planar manufacturing methods. When evaluated for several high-frequency filter topologies, the performance of glass-based components has...  — D. Balasubramanyam , et al.

December 2008
ICP Etching Reduces MM-Wave Substrate Loss
FOR GALLIUM-ARSENIDE(GAAS) coplanar passive devices, the design methods used in centimeterwave frequencies have been proven to work for millimeter-wave frequencies up to W-band (75 to 110 GHz). Those same methods can be applied to CMOS coplanar devices at millimeter-wave frequencies. To demonstrate this point, two test third-order, quarter-wavelength, double-shortedstub wideband bandpass coplanar filters have been implemented at E-band by Pen-Li...  — Nancy Friedrich

December 4, 2008
DVB Library Added To VSS Software Tool
 — Jack Browne

May 2008
Chip-Scale Packaging Approach Cuts Losses
Chip-scale packaging (CSP) offers great promise for shrinking the size and cost of certain semiconductor devices. With customer pressures to reduce the size, weight, and cost of commercial semiconductors for wireless handsets, infrastructure equipment, and other commercial electronic applications, semiconductor manufacturers have sought ways to reduce the impact of packaging on their chips. Avago Technologies (...  — Jack Browne

May 2008
Multilayer Microstrip Forms Tunable Bandstop Filters
Tunable bandstop filters are useful for a wide range of applications in eliminating unwanted signals and interference. Designing such filters can be greatly simplified with a new structure fabricated on multilayer microstrip substrates with a metallic diaphragm. This new structure overcomes the limitations of traditional tunable bandstop filter designs and supports simple, low-cost manufacturing processes.1 The new tunable filter...  — Yamina Bekri , et al.

March
Microwave Materials Help Build An Industry
Materials suppliers are constantly refining their recipes in search of products that offer greater value and increased reliability for a variety of commercial, industrial, and military applications Jack Browne Technical Director Microwave materials represent building blocks for high-frequency circuits and systems. Whether they are used to hold circuit traces, absorb or suppress radiofrequency interference (RFI), or form resonant...  — Jack Browne

March
Metamaterials Show Potential For Planar Components
Metamaterials intrigue researchers for their potential to fabricate tunable and wideband passive components. Because of line parasitics, the reactive elements responsible for the left-handed (LH) band exhibit a forward or right-handed (RH) transmission band at higher frequencies. Usually, they are separated from the LH band by a stop band. Due to the composite behavior of LC loaded lines, these structures were called composite right/left-handed (CRLH) transmission lines....  — Nancy Friedrich

February 21, 2008
Fine Tuning Those Microwave Materials
 — Jack Browne

February
Gore Celebrates 50 Years Of PTFE
Most RF/microwave engineers know it by the acronym PTFE rather than the full name of polytetrafluoroethylene. The polymer is ever-present in the high-frequency industry in coaxial and fiber-optic cables, printed-circuitboard (PCB) materials, and electromagnetic-interference (EMI) shielding materials and gaskets. It is also the basis for innovative products in other industries, ranging from energy to medicine. The company behind the many applications for PTFE is W. L....  — Jack Browne

August 2007
Predict Resonances Of Shielded PCBs
Shielded enclosures are commonly used as protection for microwave printed-circuit boards (PCBs). While the enclosure can guard a PCB from environmental effects, it can also alter the electrical performance of the circuit. Understanding the effects of the enclosure and how to predict them can improve the accuracy of most modern computeraided-engineering (CAE) simulation tools. As Part 1 of this two-part article series explored last month, the effects of the shielded...  — Avinash Sharma





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