RF Shorts – July 22, 2011
July 22, 2011
Interesting Look at LightSquared GPS Interference Negotiations
Eric Gakstatter has an excellent overview of negotiations over the impact of LightSquared's proposed terrestrial network on high-precision GPS in the GPS World Survey Scene – LightSquared: 1, High-Precision GPS:0. He questions how the US GPS Industry Council (USGIC) became GPS user's representative with LightSquared in interference negotiations. He notes, however, that the USGIC agreement negotiated several years ago was for a system much different than what LightSquared is proposing now. "To be further fair, the Industry Council did negotiate an agreement several years ago with a former version of LightSquared (under different ownership then) and with the FCC, along certain business terms and technical parameters. That agreement did not harm GPS users in any way; in fact, it contained some inherent protections for GPS users. The current version of LightSquared has completely changed both its business plan and those technical parameters — turned them on their heads, as a matter of fact — but blithely continues to claim that this was all worked out and agreed to previously."
Gakstatter notes the issues could have been avoided if LightSquared had negotiated with the right organizations, saying, "The reason LightSquared is in this controversial and expensive predicament today is because it chose the incorrect organization to negotiate with. Perhaps on purpose, so it could maintain later that it had negotiated with someone."
Taoglas Limited's New Surface Mount Antenna Claims 70 Percent Efficiency in LTE and Cellular Bands
Taoglas announced its "Viking" antenna delivers an efficiency of over 70 percent in a small surface mount antenna that covers 700 to 960 MHz and 1710 to 2170 MHz. The size is only 40x6x5 mm and it's made of dense, high-grade ceramic. Dermot O'Shea, Director, Taoglas, said, "Product manufacturers are struggling to find LTE antennas in small enough sizes to fit into tight, challenging spaces and still deliver high performance. The PA.700.A Viking improves on the best features of our PA.25.A which is used by the world's leading auto and medical device makers in extreme environments. A comparative antenna to the Viking, with more traditional materials such as metal or FR4 would have a reduced efficiency in this configuration for the same size. No other SMT antenna can match the PA.700.A Viking for the combination of size, durability, frequency range and efficiencies of over 70% on all bands including LTE." The press release did not say how the efficiency was calculated or give efficiency numbers for classic antenna designs like a resonant monopole or dipole.
Stupid Tech Tricks
PC World's 4 Stupid Tech Tricks, Tested looks at the advantage of adding aluminum foil to TV antennas, pointing your car's key fob at your head to increase its range, amplify Wi-Fi with a fork and blowing into NES game cartridges to solve problems with them. The short answer is the aluminum foil does help (although correctly positioning the antenna may be more important), holding your car's key fob to your head appears to work, and the fork test had mixed results (more access points appeared, but overall it weakened field strength). For test details and other options that might work better, see the article.