RF Shorts: Other Items of Interest - Dec. 10, 2009

If you've been reading RF Report over the last several weeks, you know that there is an effort to take spectrum away from free off-air TV broadcasting purposes so that it can be auctioned to wireless carriers who will use it to sell you pay broadband and subscription multimedia services. Holman W. Jenkins, in his Wall Street Journal article The Rabbit-Ear Wars doesn't see broadcasters giving up the spectrum as easily as the FCC's Blair Levin imagines.

"For the truth is, broadcast offers impressive economies for distributing rich media content compared to the Internet," said Jenkins. "An infinity of users can be served by a single bitstream. It doesn't matter how many receivers tune into a TV broadcast. It never gets overloaded."

As if to underscore the point, additional stories on the topic appeared Wednesday, such as this one: AT&T considers incentives to curb heavy data usage on CNET news, showed that streaming video over the Internet was not a cost-effective way to deliver wireless multimedia content. We should learn more about the FCC's broadband plans in its Dec. 16 open Commission meeting [PDF].

About 15 years ago, Cree, a North Carolina-based semiconductor manufacturer, was demonstrating silicon-carbide transistors which were being mentioned as the solution for high power solid-state TV transmitters. A prototype unit was even displayed at NAB. The high-temperature silicon carbide transistors haven't displaced LDMOS as the architecture of choice for high power solid-state devices, but Cree hasn't given up on RF.

Last week it acquired a portfolio of patents and related applications for higher-end RF silicon-carbide chips using a process called vanadium doping from Daimler AG. Cree has previously licensed that technology.

"Silicon Carbide is typically an electrically conductive material when it is grown," said Michelle Murray from Cree's corporate communications department. "Adding vanadium allows one to easily convert the SiC [silicon carbide] from a conductor to an insulator. Semi-insulating SiC is preferred for high-power RF transistor applications such as cellular communications or military radio broadcast."

See the Cree press release Cree Acquires Semi-Insulating Silicon Carbide and Power Device Patent Portfolio from Daimler AG and Cree acquires package of patents for producing high-power chips on LocalTechWire.com for more information.

Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack.
A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.