Connectors Lighten the SWaP Burden in UAV/MUMT Aircraft Electronics

Combat is being transformed by Manned-Unmanned Teaming (MUMT) and Unmanned Aerial Vehicle (UAV) technologies that improve a warrior’s situational awareness. When a multi-platform communications system is employed, operators get the big picture of the entire fight as it unfolds. The time between sensors detecting threats and operators making decisions is dramatically slashed.

With MUMT, an immense amount of information, including video, and intelligence, surveillance, and reconnaissance (ISR) data—obtained from high-bandwidth sensors—is rapidly routed between manned and unmanned airborne platforms, satellites, ground radar, remote command and control centers, and integrated tactical networks (ITNs). Compact electronics employing advanced connectors with reduced SWaP profiles make today’s UAV innovations possible.

Solving SWaP Challenges from the Ground Up

With all the advantages of having multiple eyes in the sky, there’s an age-old disadvantage: the size, weight, and power (SWaP) of electronic gear. Weight limits mobility, and mission endurance is a perennial problem for aircraft and for infantry.

Modern-day electronic devices may be lighter than the javelins and bazookas that burdened soldiers in ancient Rome and World War II. But today, all the batteries, GPS, smartphones, tablets, weapon optics, and night-vision and imaging devices can add up to 20 pounds to the “Nett Warrior’s” field gear.

Traditional MIL-SPEC connectors contribute to the weight burden. While well-known MIL-DTL-38999 circular connectors are still used in many applications, they are relatively large, heavy, and not suited for embedded high-speed systems. To reduce the load, smaller, more conformal fitting, and lighter weight connectors and assemblies are now available.

Figure 1. Small circular connectors support high speeds for end-to-end connectivity in cramped applications. (Courtesy TE Connectivity)

For example, compared to common aluminum 38999 connector shells, shell designs that use composite materials—such as Polyetheretherketone (PEEK), Polyetherimide (PEI), or Liquid Crystal Polymer (LCP)—can cut connector weight by as much as 30%. Another example: Miniature circular connector designs in micro D- or nano D-type styles derived from MIL-DTL-38999 are nearly 50% shorter, 33% smaller in diameter, and 300% lighter while increasing contact density for higher throughput.

Higher-Level SWaP Challenges in UAV/MUMT Applications

Employing advanced connectors to reduce SWaP in electronic combat gear is important; in UAV and MUMT systems, it’s critical. Optimizing SWaP in UAVs improves the fuel-to-weight ratio, which enables longer flight and surveillance periods and potentially smaller aircraft. In addition, minimizing thermal and electromagnetic interference (EMI) signatures is essential to reduce the chances of being detected and shot down.

UAVs—also described as small unmanned air systems (UAS) or micro air vehicles—can be classified by size: Nano-UAS, micro-UAS, or larger tactical UAVs. Each platform employs electronics at different scales that impose unique SWaP challenges for connectors.

Connector SWaP Challenges in Tactical UAVs

Aligning with the miniaturization trend in military equipment design, UAVs are getting smaller and more powerful. Tactical UAVs are not only less visible than larger conventional drones, they provide increased surveillance and reconnaissance capabilities. Payloads may include multiple cameras and sensors for infrared, thermal, and visible light, as well as sophisticated embedded computing and storage devices.

Figure 2. The extremely small profiles of Microdot and Nanonics connectors (top) and Nano CeeLok FAS-T connectors (bottom) are well-suited for tight spaces. (Courtesy TE Connectivity)

Along with lightweight connectors to reduce weight to extend flight time, robust board and backplane connectors are needed to handle the required bandwidth. For example, the Gorgon Stare airborne surveillance platform can cover a 100 km2 area with an ARGUS imaging system. The system’s 368 5-megapixel cameras can generate 1.8-billion-pixel images and video at 12 frames per second. Several terabytes of data are generated per minute. To handle the bandwidth, a VPX backplane is needed that employs advanced board-level optical and RF connectivity.

Connector SWaP Challenges in Micro UASs

Micro-UAS can operate in swarms allowing a cluster of individual units to communicate and function as a team. Reducing SWaP is critical for micro UASs. Some weigh less than three pounds and can be carried on a soldier’s utility belt. Nano UASs are even smaller, hand-sized units using microelectromechanical systems (MEMS) such as miniaturized accelerometers and gyroscopes.

Onboard sensors and intelligence can be used for obstacle-avoidance and target-following capabilities. Small embedded computing can support artificial intelligence for adaptive formation flying, self-healing, collective decision-making, and encrypted network communications. Micro-drone swarms are useful in intelligence, surveillance, and reconnaissance (ISR), but they are often considered expendable. If one goes down, just send up another. In these applications, designers may employ compact, commercial off-the-shelf (COTS) and COTS+ connectors.

Connector SWaP Challenges in MUMTs

At the opposite end of the nanoscale, MUMT architectures involve multiple UAV platforms covering an entire battlefield formation and networked over an airborne data link system. MUMT systems empower warriors with a tactical control system (TCS). That provides several levels of UAV interaction, from receiving and transmitting imagery and data to full function and control of UAV payloads, take offs, and landings.

Consequently, advanced connectivity solutions are needed to support a wide range of bandwidth-hungry applications that can include: sensor data from multiple airborne platforms, IP-enabled network-centric operations, multi-band antennae, data link subsystem processors, Digital Video Recorder (DVR) storage, and full motion video (FMV) to the tactical edge. A high-bandwidth board-level connector solution is presented below.

Solutions to Connector SWaP Challenges

To optimize SWaP in UAV/MUMT applications, designers can work with a wide variety of connectivity options:

  • For “micro” circular connectors based on MIL-DTL-38999 Series 3: Micro circular connectors such as the DEUTSCH Wildcat Micro connector offer a significantly reduced shell size with two housing sizes and four layouts accommodating 3, 5, or 9 contacts.

  • For small, micro- and nano-miniature connectors: Compact rectangular, coax, and sealed circular connectors offer extreme weight and space savings. Small form factor rectangular connectors (369 series) are fully sealed and accommodate blind mating. Smaller scale connectors, like Nanonics connectors, are designed to fit micro miniature D, subminiature and ultra-miniature coaxial needs. The circular 8-position CeeLok FAS-T Nano connector features a 0.30-inch (7.6 mm) diameter and supports 10 Gigabit Ethernet.

  • For compact fiber connectivity: ARINC 845-compliant EB termini (EB16) combine high performance and non-contact vibration resistance in mini sizes for single-mode and multimode fiber. Advanced transceiver modules like ParaByte feature a small thermal signature and support up to 12.5 Gb/s transmission rates per channel.

  • For less bulky cabling: Cross-linked insulation in Raychem cabling is mechanically tough, thermally stable, and much lighter compared to thick-walled soft-polymer insulation in conventional cables.

  • For compact power distribution: Advanced high-voltage KILOVAC relays allow smaller wire gauges to be used to create lighter, smaller harnesses.

  • For space-efficient board-to-board & box-to-box connectivity: Light, next-generation high-speed backplane connectors, such as the MULTIGIG RT 3 connector, that comply with the VITA 46 VPX standard are available with reliable quad-redundant contacts and support for data speeds up to 25+ Gb/s.

To meet demanding SWaP requirements, designers can consult with experts in the many advanced standard-compliant connectors now available — along with COTS and COTS+ options — to facilitate UAV and MUMT innovations.

This article was written by Matt McAlonis, Engineering Fellow, TE Connectivity (TE) (Berwyn, PA). For more information, visit here .