Dielectric will introduce reconfigurable manifold combiners for multi-station RF facilities that bring system expandability to manifold designs previously only expandable by adding constant impedance filter units. This innovation offers an attractive option for sites installing new master broadcast antennas that can quickly add future tenants without the space constraints and assembly labor that CIF-based expansion requires.
Dielectric’s reconfigurable manifold combiners are essentially modular fixed units built to specification. For example, a site owner with five broadcasters today and a goal of seven total tenants can specify a manifold combiner with seven ports. Dielectric builds the initial system with five filters and protects the two open slots with shorted ports, or “shorts.” The site owners remove the shorts when adding filters for the new tenants to the manifold combiner. Dielectric can also build the filters in advance. Dielectric calculates how site owners can add other broadcast frequencies in the market in various combinations, even looking beyond what the site owner may have originally envisioned as the maximum number of tenants.
Creating space for new tenants
“We first provide an analysis of the market that confirms how many potential stations in the market can logically join the master antenna system,” said Keith Pelletier, president of Dielectric. “We may find that number to be ten broadcasters. The site owner ultimately decides how many broadcasters they want to accommodate immediately and how many they want to add later. Using our high-frequency simulation software tools, we can calculate how each possible frequency will affect the combiner’s output splines. New tenants can be added quickly and easily by simply removing a shorted port, plugging in a new filter and changing some transmission lines. As long as the site can physically accommodate more tenants, we can add new modular units with ports to our manifold combiner.”
Using manifold combiners increases the likelihood of having extra site space because they offer a considerably smaller footprint than alternatives, including CIF systems. “A typical CIF unit has two filters and input/output hybrids for each station,” said Pelletier. “A manifold combiner requires only one filter for each channel plus an output spline. The part count and footprint are substantially lighter.”
Manifold combiners also allow consistent electrical specifications across all stations on the system, with similar loss and electrical characteristics across the chain. That means that stations further from the antenna in the combiner chain will not be affected by higher group delays or signal loss that can ultimately degrade signal quality.
Dielectric will exhibit its manifold combiners at the 2023 NAB Show at Booth W3601 in the West Hall of the Las Vegas Convention Center.