Frequency Hopping Multiplexer (FHMUX) - …

1 Frequency Hopping Multiplexer (FHMUX) OverviewNorthrop Grumman's Frequency HoppingMultiplexer ( fhmux ) is a four radio to oneantenna multicoupler developed for the ArmyCommunications Electronic Command (CECOM)as an accessory to the Single Channel Ground-AirRadio System ( sincgars ) tactical VHF frequencyhopping radios deployed by the US Army and othermilitary simultaneously reduces the number ofantennae required on a command and control plat-form while suppressing and managing the effects ofcosite interference on collocated combined fhmux capabilities serve to reducethe visual antenna signature of command andcontrol assets making them a less vulnerable target,reduce command post set-up and teardown time.

2 And maximize the communications range of collo-cated radios making command and control supports a variety of users in tacticalcommand and control environments includingcombat vehicles and command post shelters wheremultiple radios must operate in close is currently in production and supportedwith over 3,000 systems delivered to the US Army,US Navy, and international customers. Variants ofFHMUX have been delivered for airborne and otherinternational Features 4:1 Antenna Reduction - Minimizes visual antenna signature- Disguises command post- Reduces remote antenna set-up and tear-down- Reduces electronic parasitic effects Cosite Interference Protection- Filters out RF interference- Manages/arbitrates Frequency conflicts- Restores lost communications range- Protects receivers from damage caused bycollocated on-channel interference Fully Qualified and in Production:- Nomenclature: TD-1456/VRC- NSN.

3 5820-01-365-2721- LIN: F99520- BOIP: C141 CACommunications 10/3/07 11:15 AM Page 1# of ActiveReceiver Range WithoutReceiver Range UsingTransmittersFHMUXFHMUX0100%100%140% 90%225%77%39%54% Frequency Hopping Multiplexer (FHMUX) For more information, please contact:Northrop Grumman CorporationElectronic SystemsXetron Campus - Business Development460 West Crescentville RoadCincinnati, OH 45246 Telephone: (513) 881-3290 Fax: (513) 881-3543e-mail: and features subject to change without ProdCardCommunications SystemsThe Cosite Interference Problem Command and control vehicles and shelterswith multiple radios have external antennasin close proximity.

4 High level transmitter fundamental signals,noise, spurious, and inter-modulationproducts couple over to nearby antennas andinterfere with sensitive receivers. The communication range of a receiver on acommand and control vehicle is dramaticallyreduced as the number of collocatedtransmitters operating on the command andcontrol vehicle increases. The impact on receiver range with as few asfour collocated radios can be 60 to 90%. The fhmux Solution to the CositeProblem fhmux reduces cosite interference bysimultaneously "cleaning-up" the transmitspectrum and "protecting" the receiver.

5 fhmux "Reactive Combining" incorporates aseries of band-pass filters connected to acommon antenna node. As transmit signals pass through these filters, fhmux removes much of the undesiredinterference. As receive signals pass though these filters, fhmux improves receiver selectivity. fhmux restores up to 50% of the lost Improves Range in Cosite EnvironmentsIn addition to reducing the number of antennas required to support command and controlmissions on the move, fhmux minimizes cosite 10/3/07 11:15 AM Page 2