By Brian Galante
Special to TECH ROUNDUP
RAYMOND, ME. — The Sinclair Broadcast Group subsidiary known for its antennas and RF systems for broadcast radio and television has finalized the installation of a broadband FM antenna system for two major operators in Western Australia’s largest market. And, the work from Dielectric was made possible thanks to a partnership with broadcast and telecommunications infrastructure and wireless products partner BAI Communications (BAI).
The broadband FM antenna system will be put to use by the Australian Broadcasting Corporation (ABC) and the Special Broadcasting Service (SBS), each of which serve the Perth market.
BAI chose a Dielectric DCR-U ring-style antenna to transmit up to six FM services from a single antenna. Three existing FM services will operate from the antenna initially, with the capacity to add three more in the future.
The choice of a ring-style antenna is a somewhat rare choice in Australia, where panel antennas tend to be favored for their broadband capabilities. Dielectric’s DCR antenna family expands broadband capacity for ring-style antennas beyond previous capabilities, providing a lightweight, side-mounted product that meets the same requirements as a panel array. This opens new opportunities for customers like BAI who are challenged with strict tower weight requirements that a panel array would exceed, RF Engineering Manager Matt Betts explains. “Structural standards have evolved since this tower was first built in the 1960s, and we needed to reduce the weight and wind load to maintain compliance. That required taking a fresh look at design options beyond the panel array for a secondary antenna. The ring-style design both kept us in compliance and was a perfect design choice as we needed to install the system on a sloping section of the tower. Dielectric’s engineering team also developed a futureproof design with capacity to add future services on any channel within the FM band.”
The DCR-U will ultimately serve as a secondary antenna to a panel array currently being installed. The DCR-U will operate in primary mode before the panel is installed and operational, bringing ABC and SBS Audio services to more than 2 million listeners. The BAI team collaborated with Dielectric engineers to specify the DCR-U antenna design to optimize FM coverage, carefully blending horizontally and vertically polarized elements. The antenna’s design elements were engineered based on intensive coverage planning that considered strong coverage for the Perth region north and south, especially along the coast where most of the population resides. SixArms drone measurements were used to verify the antenna patterns.
“Our previous secondary antenna system was strictly horizontal and also unable to operate at full power,” said Betts. “Dielectric has supplied us with a circularly polarized antenna with the capacity to support six 20kW services and reliably radiate the full power of our FM transmitters. The antenna’s sturdy design, streamlined componentry and center-fed design also gives us the confidence in the system’s longevity and low risk of failure.”
