Dielectric Strengthens VHF Portfolio For Impending TV Spectrum Repack

New broadband antenna, tunable filter bring higher efficiency, greater flexibility to broadcasters transitioning from UHF and/or sharing RF plants

Dielectric, a pioneer in purpose-engineered antennas and RF systems for TV and radio broadcasters, has innovated a new broadband TV delivery system that provides a tunable, bandwidth-efficient option to high-band VHF broadcasters. The complete system, to be unveiled at the 2016 NAB Show (April 18-21, Las Vegas Convention Center) includes a new slotted, sidemount antenna and compact RF filter to support single- and multi-channel TV operations. Dielectric will display both products, also available separately,at Booth C2213.

Engineered for flexibility across Channels 7-13, the low-power solution is ideal for UHF broadcasters transitioning to high-band VHF as part of the TV spectrum repack, the multi-year government initiative that will free existing UHF spectrum for other wireless communications needs. The system also gives VHF broadcasters that share transmission sites a more cost-friendly, operationally efficient way to multiplex more than one channel through the same RF infrastructure.  

The new antenna and filter introduce key Dielectric innovations for VHF that retain the company’s trademark engineering quality, which accentuates longevity and reliability at an affordable cost for the over-the-air broadcaster. These innovations include a stripline slot design for the new TLSV-BB Series antenna, which simplifies frequency tuning across the high VHF band. This broadband approach eliminates manufacturing costs associated with the production of frequency-specific antennas, and establishes a foundation to support two or more VHF broadcasters from a shared site.

“Historically, VHF antennas were either large dipole arrays or panel antennas, while slotted antennas have mostly offered narrowband designs,” said John Schadler, VP of Engineering, Dielectric. “We have extended the more efficient slotted UHF antenna design pioneered by Dielectric to VHF, and innovated new techniques to evolvestripline technology into a broadband system. This ensures we can accommodate every channel in the high VHF band from a common design.”

Broadcasters sharing sites or transmitting more than one VHF channel can amplify that efficiency through Dielectric’s new MT6E6-4K Tunable VHF Filter.

The MT6E6-4K introduces a compensated resonator design that cleanly filters one or more channels through the same architecture. This design effortlessly adapts to environmental changes such as temperature and humidity, ensuring that harsh conditions do not adversely affect channel tuning as signals move through the RF filtering process. A compact, “folded” design returns precious real estate to broadcasters inside the RF plant, with flexible options for floor, ceiling or cabinet-mounted installations.

Other benefits of the new Dielectric broadband VHF systems include:

• The TLSV-BB Series antenna lowers wind load by up to 75 percent compared to panel antennas, reducing weight
• Lower wind load potentially reduces tower reinforcement costs and requirements during UHF-to-VHF channel changes
• Cardioid azimuth pattern optimally supports sidemount installation for directional, hemispheric coverage, minimizing tower structure-based interference
• Compact MT6E6-4K filter footprint reduces number of resonators and components
• Convection-cooled design better compensates for varied high-band VHF temperatures throughout the filtering process