When we treat the shielding effectiveness measurement with a uniform field, the results are similar for both near and far fields. Kermit O. Phipps and Philip F. Keebler EPRI EMC Laboratory, Knoxville, TN, USA INTRODUCTION Traditionally Schelkunoff’s shielding effectiveness equation is used universally in teaching and practice throughout the EMC community as a whole. In this … [Read more...]
UK Telecom Regulator Ofcom Announces Outcome of Radio Spectrum Auction
British telecom regulator Ofcom has announced the outcome of its fifth auction of radio spectrum. The auction was for spectrum in the 1452- to 1492-MHz band, known as the L-band. This part of the spectrum is well suited for offering services such as mobile television, wireless broadband, and satellite radio. One notable winning bidder was Qualcomm UK Spectrum Ltd, which paid … [Read more...]
Overview of Standards Organizations
The IEEE Standards Organization has posted an informative overview of the world’s standards development organizations including the International Electrotechnical Commission (IEC), the International Organization for Standardization (IOS), the ISO/IEC Joint Technical Committee 1 (ISO/IEC JTC 1), the International Telecommunication Union (ITU), the International Telecommunication … [Read more...]
DARPA Seeks to Use EM Waves to Extinguish Fires
DARPA, the Pentagon’s Defense Advanced Research Project Agency, has announced a new research program into “Instant Fire Suppression.” The agency noted that “Fire especially in enclosed military environments such as ship holds, air craft cockpits, and ground vehicles, continues to be a major cause of material destruction and loss of warfighter life. Essentially, there have been … [Read more...]
Snap-In Flange Mount Filters Target High Current Applications
The PBH filter series from Power Dynamics, Inc. (PDI) targets applications with high current (16/20 A) requirements. These filters are available with varying configurations of components and termination styles. They are available in flange mount or snap-in types. The medical filters offer a maximum leakage current of 2 µA at 120 VAC at 120 VAC, 60 Hz. A ground choke can be … [Read more...]
New EMI Filters Comply with DOD’s COTS Directive
The new VPT10-28 (10 A) and the VPT2028 (20 A) have been added to its COTS product line by VPT, Inc. These filter modules provide compliance to MIL-STD-461 C/D/E for conducted emissions in military and avionics DC power systems. Both devices fulfill the DOD’s COTS (commercial-off-the-shelf) directive in terms of cost and stringent military and avionics performance standards. … [Read more...]
Extensive Line of Custom EMI Filters Available
WEMS EMI/RFI Filter Division designs and manufactures high reliability input, output, power line, and signal filters intended for military, aerospace, and high end industrial applications. WEMS services include filter circuit design and analysis, filter packaging and layout, prototype/first article, EMI test assistance, environmental tests, source control drawings, acceptance … [Read more...]
AT&T Signs Five-Year Telecom Contract with Shell
AT&T Inc. has announced that it has won a $1.6 billion contract to provide Royal Dutch Shell Plc., the Netherlands-based oil and gas giant, with advanced telecommunications services. The five-year agreement will see AT&T providing, managing, and maintaining Shell’s worldwide communications infrastructure, while looking after its global mobility needs.AT&T says that … [Read more...]
Magnetic Shielding Design for Manufacturing
Sensitive electronic devices require protection from radiating magnetic fields. David Grilli Magnetic Shield Corporation, Bensenville, IL, USA Magnetic shielding for static and low frequency (<100 kHz), time-varying magnetic fields is accomplished by containing a specific device or item within a sheet metal enclosure of high permeability material. Typically, a sensitive … [Read more...]
Designing an RF Shielded Enclosure
Ron Brewer EMC/ESD Consultant Shielding has been with us a long long time. Early AM radios had shielded RF and IF transformers, shielded electron tubes, and compartmentalized shielded chassis. These shields were necessary to prevent RF pickup, feedback, and oscillation by the electron tubes, radiation from the local oscillator, RF contamination of the IF strip, and crosstalk … [Read more...]
- « Previous Page
- 1
- …
- 254
- 255
- 256
- 257
- 258
- …
- 267
- Next Page »