Economizing with Shortwave Array Antenna Systems Flexibility and Variability: Aspects of Slewing
Your shortwave antenna system can be an important source of making additional savings in the running costs of your high power station. A wise choice of high power antenna broadcast system can not only bring you interesting savings on running costs, but also
considerably reduce your expenditures for investment and maintenance. The key is system efficiency, flexibility and variability. Shortwave array antenna systems, and especially rotatable array systems, offer the ideal solution to meet these requirements.
Shortwave array antenna systems are highly flexible when it comes to accommodating a large number of frequencies. They are also highly variable with respect to changing the main radiation direction upon demand. It is obvious that the higher the ability to change the azimuthal main lobe direction of an antenna, the less numbers of antennas will be needed to cover the same target direction.
For broadcasters with target areas spanning a large azimuth, slewable array antennas are the best solution to reduce the required number of antenna systems. Depending on antenna type, a proper choice of phasing lines in the antenna internal RF feed system can allow a change in the azimuthal direction of the main lobe of up to 30̊!
Nowadays the newest and highly sophisticated RF simulation tools together with fast computer technology can make an antenna analysis more realistic and more accurate than in the past. State-of-the-art “Method-of-Moments” computer models of shortwave array antennas even include the antenna phasing and power dividing components. This gives the RF engineer a more precise idea of the antenna radiation characteristics.
For maximum system efficiency, it could be very useful to investigate the application of slewable antennas.
The above items were reprinted from Radio News, SUMMER 2007
Published by Thomson Broadcast & Multimedia
For more information, contact: radiotransmission@thomson.net
(Source: August News NASB)