Doug Lung / 04.24.2009 12:00AM
NAB: Antenna Engineers Push Circular Polarization
All of the major antenna manufacturers were recommending full circular polarization (CP) to provide the best possible Mobile DTV coverage.
Antenna manufacturers showed an interest in Mobile DTV at the NAB Show. All of the major antenna manufacturers were recommending full circular polarization (CP) to provide the best possible Mobile DTV coverage. While it may be impractical for broadcasters operating at the maximum UHF power of 1,000 kW to implement CP without reducing coverage or doubling transmitter size, stations operating at lower power and 700 MHz licensees with a limit of 50 kW effective radiated power should be able to implement CP without much difficulty.
I've discussed the advantages of CP or the compromise elliptical polarization (EP) in past RF Technology columns. At NAB, thanks to a series of presentations organized by Richland Tower, I was able to learn about some new tests that show the value of CP. How about rotating a car on top of a turnstile at an RF test range? I'll have more in my RF Technology column.