Trends in Military Communication Systems
By Chris Heavens, Vice President and General Manager, AR Modular RF

Military communications is no different to the rest of the world’s communications; they want it smaller, lighter, cover more bands and carry more voice and data than the last generation of products. But there are other changes that are potentially much more profound that will eventually change the way that battle- front communications is carried out.

Traditional tactical communications has been via specialized individuals or locations that were the hubs for information exchange using terrestrial links, or more recently, a combination of ground and UHF SATCOM uplinks. AR Modular RF has been making man-pack 20 Watt KMW1030 and man portable/vehicle KMW2030 and KMW2050 125/200 Watt units for a number of years to address the traditional hub and spoke kind of communications. These kinds of systems are still the backbone of military communications, but the wind of change is already blowing and vendors like AR Modular RF are constantly looking into the future for product enhancements and new product developments.

New and Improved Multiband Tactical Communication Amplifiers
A fairly recent product improvement to reduce operator controls and interface has been to make these units auto tuning, such as our recently upgraded man pack, the KMW1031. This 3rd generation unit provides a minimum of 20 Watt output for only 1 Watt input, making it operable with just about any single or multiband “handie-talkie” transceiver. High speed electronically switched filters ensure that the system can keep up with hopping modes of operation and keep “friendly interference” to and from other nearby communications systems to an absolute minimum. With 20W available across the full band 30-512 MHz, all current tactical modes are possible. This high gain unit (minimum of 13dB) will give potentially up to 4 times the operational reach of a 1 Watt handheld unit used under the same terrain conditions. We’ve had reports of 1-2W SINCGARS systems that were reaching about 2km without an amplifier that became 7-8km after adding the amplifier to the system. This is a very substantial increase in the operational area.

Recent improvements include a new power supply module that allows the unit to operate from both 12 and 24 Vdc supplies. It also has vehicle power spike suppression circuits included, so that the unit can be run from vehicle supplies without fear of damage from power surges. The unit is smaller and lighter than the old one and consumes only about half the current, which allows it to be operated from a single tactical battery, such as the many variants of the military XX90 series batteries, while still providing 20W output. Battery use management software maximizes operational life when operated on batteries. In line with its predecessors, this unit is fully submersible to 66 feet.

There are also new vehicle mounted or base amplifiers, such as the AR-50 or AR-75 systems, that provide 50 and 75 Watt outputs with inputs of only a few watts so that they can be operated from either a handheld or a vehicle mounted transceiver. The units can be mounted directly to vehicle structures or can use custom shock mounting kits as needed, they are both water resistant and, like their sibling the KMW1031, the AR-50 can be used on both 12 and 24Vdc vehicles without any additional hardware. Both the AR-50 and AR-75 have dual antenna ports for Line of Sight (LOS) and Satellite (SATCOM), have switchable low noise amplifiers (LNA), and offer 3 levels of RF output power management as standard features. The AR-75 also offers an optional remote control system.

In addition to making both of these units automatic band switching and capable of full band filtered operation in the SINCGARS 30 to 88MHz band, they have been designed using the latest generation semiconductor devices, making them significantly more efficient. Therefore they use less vehicle power or need fewer batteries per mission, the latter of which is a vital consideration as more “electronic gadgets” are carried by frontline troops.

Legacy Systems Still Need Support
Old HF and low band VHF equipment for voice have been augmented or replaced by multi-band voice and data VHF/UHF systems with frequencies up to 512MHz using both old legacy modulation as well as modern complex modulations. High density designs are even allowing full coverage of the HF, VHF, and UHF bands all in one system. The use of 3G Automatic Link Establishment on HF has given that band a new lease of life, too. Like HF radio, not all legacy communication products are dead yet and AR Modular RF has supported a number of programs to provide modern power amplifier designs to support older legacy government communication systems. Amplifier systems such as our 100 Watt KMW2025 covering 30 to 512MHz, the 100 Watt KMW2040M14, covering 225 to 450MHz and the custom designed, rack mounted 500 Watt KAW4040M13 offer the high performance necessary for modern modulation formats and give years of new life to older legacy products for a relatively low investment. Custom configured designs like our 50 Watt KMW2040M13, covering the 200 to 400 MHz band include RF switch transmit/receive switching and the ability to survive +80C case temperatures.

Ever Higher Frequencies and Secure Modulation Formats
Frequencies are climbing up the spectrum and, in the near future, designs will have to go up to 3GHz and be able to handle a multitude of secure modulation formats in order to be “multi-national” in nature. It’s now becoming essential that our military groups can communicate with other “friendly forces” as well as our own Homeland Security groups in times of war or national emergency. All of which means more modes of operation, new frequency bands, and or spectrum for our new systems to handle.

Next Generation IP Systems are Needed
We are working on the next generation of highly mobile frontline communications which are tending to move away from the high power single line of contact methods toward a more low power “mesh” system, where more operators are linked together by means of a multi-node mesh system. Usually working in the high UHF or low SHF bands, these systems will be less susceptible to single points of failure and will be self healing in that the communications packets find the best route to the destination based on traffic levels and available system bandwidth. Additionally, these new systems will need to be IP compliant and have a network port into the “IP pipe in the sky,” thus being able to carry encrypted voice and data information instantly to and from locations all over the planet. PDA devices, laptops, head-up displays, surveillance radars, scopes, and other frontline systems will all connect seamlessly into the communications pathway, allowing individuals to be better informed of the big picture as well as allowing the big picture guys to see/hear the details at the source of the action.

Satellite Links are a Vital Part of Communications for a Highly Mobile Force
UHF SATCOM “on the move” systems are a vital part of modern, highly mobile forces. So, in addition to the multimode systems discussed above, dedicated UHF communication amplifiers like the legacy KMW 2050 can provide up to 200 Watt uplink power, thus allowing relatively “minimal gain” antenna systems. Plus, a variety of custom configured “embeddable” SATCOM modules such as the KMW2040M17 can provide up to 100 Watt with VSWR and automatic level control (ALC) built right into the unit, allowing it to be neatly integrated into a larger and multi-functional communications package. Designed to be rugged, these systems meet applicable sections of the MIL STD 810F environmental specifications.

Converged Communications and Countermeasures
The need for converged communications and electronic war systems such as jammers exists, too. The use of a combination of software defined radio (SDR) and broadband amplifiers like AR Modular RF’s KMS1033 20 to 2500MHz, or one of our KMW1090 series 10 to 1000MH amplifiers allow multi carrier communication and jamming to be carried out simultaneously by a single operator in the band 30 to 2500MHz. New high efficiency amplifier designs use the latest generation GaN devices, offering high efficiency and tolerance to high temperature without threatening the system reliability. Our future soldiers will be better informed and better protected than at any time in history due to the high tech systems that they carry in their backpacks or on the dashboard of their vehicles, and AR Modular RF will be there to support them.

AR Modular RF
www.ar-worldwide.com
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