Dielectric has also included its patented parasitic dipole in the Pylon antenna, which adds a vertical component to the existing horizontal signal.
Dielectric will display its new FM Pylon antenna at NAB 2022, which will represent the broadcast industry’s first slot cavity microstrip FM antenna product line.
The event will take place from April 24-27 at Las Vegas Convention Center.
Benefits include multicasting, pattern flexibility, increased reliability and small tower footprint to high-power FM broadcasters.
Speaking about the new product, Keith Pelletier, Vice President and General Manager, Dielectric, said: “Television broadcasters have long valued pylon antennas for their straightforward designs, versatility and structural benefits such as low wind load. The cylindrical design attributes of pylon antennas historically translated to narrow bandwidth characteristics that were impractical for FM signals. Dielectric’s engineering breakthroughs introduce techniques to increase that bandwidth, making full-band FM operation in pylon antennas a reality.”
It includes reducing the antenna Q factor, which improves the bandwidth from one to 20%; and stabilizing the H:V ratio across the band. The 20% bandwidth translates to full FM band operation, which is the key goal of the FMP antenna’s design. Dielectric has also included its patented parasitic dipole, which adds a vertical component to the existing horizontal signal. This creates more pattern options for FM broadcasters, including elliptical and circular polarisation, and contributes to the substantial bandwidth increase.
While Dielectric’s special pylon designs for FM radio differ from TV systems, the FMP family carries over many traditional pylon antenna benefits including optimal downward radiation, smaller size and lower weight. For example, FMP antennas reduce the number of parts used in equivalent ring-style antennas by more than 60%. The streamlined componentry also improves reliability over the long term as there are far fewer parts to repair or replace.
The pylon design also provides broadcasters and tower crews with top-mounting options, in addition to the traditional side-mounted configurations of ring antennas. This claims to be suitable for high-power FM stations that want a top-mounted omnidirectional antenna. The FMP can handle input powers of 100kW and higher, which also makes the antenna excellent for the combined operation of multiple stations.
Dielectric’s FMP designs use full-wavelength spacing between antenna elements. This reduces the number of antenna elements required compared to ring-style designs, which require half-wavelength spacing, hence more elements, to cover the full FM band. Antennas are built-in four-layer building blocks and can be increased to eight or 12 bays to suit higher power requirements and elevation pattern gains.
Dielectric recently established a team of specialised engineers to create new designs quickly and efficiently using HFSS (High-Frequency Simulation Software), which accelerated the development process.
Pelletier added: “We are always looking at ways that we can bring antenna design concepts from one market to another and advance the technology for modern and future broadcast systems. We have now adopted what was long a solution for mostly single-channel TV operations for both broadband TV and FM broadcasting, which very much differentiates our product portfolio from competitors.”