The need for high-speed connections has expanded from office environments to more difficult implementations, including those for the military. Here, Nick Harper looks at rugged high-speed data connector requirements
There have been many changes in military and security equipment in recent years, but the requirements remain constant: The end-users demand technologies and equipment that are increasingly powerful but smaller, faster, lighter, as well as more reliable in extreme conditions – so the OEM’s want connectors of reduced weight, increased robustness and simpler handling, all in a smaller space-envelope.
To this has to be added never-ending increases in high-speed data levels.
The transfer of commercial technologies into the military domain has increased the need for USB, Firewire and RJ45 connectivity, but this change has resulted in a lack of suitable connectors that achieve military ruggedness standards.
The current response has been to re-package a standard commercial connector inside a MIL-STD housing. Unfortunately, this solution, whilst functional, does not allow equipment manufacturers to reduce the size and weight of their kit, the prime demand from the end-user.
The solution
Push-pull connectors – not only are they inherently smaller than the re-packaged commercial connectors, they do not require the additional ‘finger-space’ needed by traditional MIL-STD screw or bayonet connectors, so the overall space-envelope can usually be reduced by about one-third.
So, apart from the space-saving, what turns a connector into a first-class, high-speed connection? Above all, it’s in the detail.
Materials
Weight is a prime factor for most field-use equipment. So, by using aluminium with a special, low-reflection surface, the connector is ideally suited for field use.
Naturally, the plastic insulation body must withstand the hard environmental conditions and cope with sensitive high-frequency parameters such as a stable dielectric constant and a low dielectric dissipation factor.
Data rates
Skilled contact arrangement and design optimises connection to the point that it is possible to transmit data rates of up to 10Gb/s, allowing CAT 6A quality to be achieved without the necessity of adding an expensive internal shield plate.
External shielding
Field use calls for a lot of technology in a compact package, making it critical to have 360˚ EMC shielding, blocking interference (both external and among the various systems) that could impair signal and data transmission.
Robustness
Equipment used in military and security systems face extreme conditions – so, no matter how small they are, connectors must also withstand these environments. Connectors are tested to MIL standards and have an IP68 rating to ensure that they are tightly sealed and resistant to salt-water spray. Specially designed ‘easy-clean’ versions are also available for field use.
Mating reliability
The use of both mechanical and colour coding guarantees reliable and simple handling. Also, the ‘scoop-proof’ design protects the contact pins if the connector shells are misaligned during mating. Where needed, the same connectors are available with a break-away or ‘snatch’ function.
Nick Harper is MD at ODU UK Ltd.