As announced at NAB 2004, Harris Corporation has developed new technology that offers FM stations a significantly more efficient method of transmitting an HD Radio(tm) signal. The patents-pending approach of the company’s new Split-Level Combining System can reduce an FM station’s energy costs by as much as 25 percent over High-Level Combining, and enables stations to continue using existing FM analog transmitters that are already operating near peak capacity.
“This new, more efficient method of adding HD Radio to FM stations is sparking great interest among FM broadcasters,” said Jeremy C. Wensinger, president, Harris Broadcast Communications Division. “Our engineers estimate that a station’s overall power consumption could be between 5 and 25 percent less than with High-Level Combining.”
Split-Level Combining utilizes the existing FM transmitter and a new common-amplification FM/HD Radio transmitter to generate the required FM analog power. Driving both ports of the high-power combiner with analog FM power improves combining efficiency, reduces combiner losses, reduces existing FM transmitter power requirements and improves overall system efficiency, resulting in lower monthly operating costs. With the Split-Level Combining System, the analog transmitter is no longer required to operate at higher-than-normal power levels to offset combining losses.
Split-Level Combining also allows a station to use the existing transmission line and antenna system for optimum radiation of both the digital and analog signals. Additionally, for stations with physical space constraints at their transmitter site, Split-Level Combining allows broadcasters to remove the current backup transmitter and utilize the common amplification FM/HD Radio transmitter as a lower power backup FM transmitter.