Doug Lung / 11.21.2012 12:32PM
RF Shorts for Nov. 21, 2012
A review of RF-related news during the past week.
Viasat-1 and Exede Win
Popular Science Award
Viasat announced last week ViaSat-1
and Exede Service Win 2012 Popular Science Best of What's New Award.
“This is a great honor that adds to the very positive
feedback we’re seeing in the marketplace for the new brand of high-speed
satellite services that ViaSat-1 is enabling,” said Mark Dankberg, chairman and
CEO of ViaSat. “The conceptualizing, design, building, and launch of the system
took an extraordinary effort by so many of our people and this award is a great
testimony to what they accomplished.”
ViaSat's announcement explained that, “ViaSat-1, the highest
capacity satellite in the world, is part of a system that is transforming the
economics and quality of service that satellite broadband can provide. The
technology is elevating satellite into a much more competitive position in the
broadband service marketplace with approximately 40 percent of new Exede
Internet subscribers switching from slower DSL and wireless services. Exede
Internet is four times faster than average DSL speed according to an FCC
Broadband study, and eight times faster than traditional satellite Internet
service. ViaSat-1 is now hosting service for nearly 150,000 Exede Internet
households after its first six months in operation.”
Playing With Antennas
I managed to find Kenneth Wyatt's Playing
with antennas - part 2 on the Test and Measurement World web
site. Wyatt explains how to build “a simple DIY EMC measurement antenna that is
adjustable from about 85 to 200 MHz (depending on the telescoping antennas
used), and is small enough to throw into your EMC troubleshooting kit. It also
includes a 1:1 balun and additional ferrite choke to suppress common-mode
currents from flowing on the outside of the coax shield.”
In Playing
with antennas - part 1, which you will want to consult after
building your DIY EMC measurement antenna, Wyatt explains how to characterize
an antenna using a 20 dB coupler and a spectrum analyzer with a tracking
generator. That one brought back memories, as almost 20 years ago, in the April
1993 issue of TV Technology I wrote about using a sideband
adapter and mixer as a sweep generator to sweep tube cavities
and antennas. Note that the link is to an FTP site, since in 1993 the World
Wide Web wasn't widely used and I was making my articles available via FTP on
the Internet before getting the transmitter.com domain and setting up a Website.
One of these days when I get some time I'll move those articles to a Website.
Comments and RF related news items are welcome. Email me at dlung@transmitter.com.