Architecture · Passive

Passive DAS

A single bi-directional amplifier distributes public-safety signal over coaxial cable, the most cost-effective path to fire-code compliance. Play the signal flow to follow it from the roof donor antenna to every floor antenna.

Best fitUp to 250,000 sq ft
DistributionAll-RF over coax
Core unitSingle BDA
MonitoringDry contacts → FACP
Band700/800 MHz

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How it works

System components

Coaxial / Fiber DistributionLow-loss cabling in fire-rated pathways with proper grounding per code.

Passive DAS signal chain: a roof donor antenna feeds a single 700/800 MHz bi-directional amplifier, which feeds five passive 2-way splitters over coax; each splitter feeds two ceiling dome antennas, for ten antennas in total. The amplifier reports by dry contact to the fire alarm control panel.
Stage	Element	Feeds	Role
1	Donor antenna	BDA	Roof donor antenna, aimed at the public-safety simulcast site
2	BDA	S1–S5, annunciator	COMBA class A bi-directional amplifier, 700/800 MHz, the single active element in the system
3	Splitters S1–S5	A1–A10, two each	Passive 2-way splitter, divides RF power to the floor run, no power required
4	Antennas A1–A10	Floor coverage	Ceiling dome antenna, radiates and receives on the floor
—	Annunciator	FACP	Dry contact alarms to the fire alarm control panel: AC fail, battery, donor loss, amplifier fail

Passive DAS · All-RF over coax · Single BDA · Dry contacts → FACPClick any node — or any step or component below — to inspect it. Illustrative topology; antenna count and run lengths are set by the RF design.