Diamond Antenna & Microwave of Littleton, Massachusetts builds long life microwave rotary joints for mission critical applications like Air Traffic Control. While Diamond Antenna designs and builds the RF transmission components in house, customers require a way to transfer power, signal and data as well. The traditional solution for these requirements had been to use a slip-ring. However, due to their inherent wear related issues slip-rings did not match the long life performance of the Diamond Antenna RF rotary joint.
Slip-rings utilize composite solid "brushes" that are sprung to gradually wear against a stainless, silver or gold plated slip-ring rotor to enable power, signal and data to pass between the stationary and rotating elements. As the slip-ring rotates the brushes wear creating debris that requires periodic cleaning to prevent performance degradation and safety hazards like arcing between channels.
Slip-ring brushes continue to wear becoming smaller and smaller which requires maintenance downtime for replacement. If the brushes are not replaced in time the slip-ring rotor can become damaged to the point the slip-ring rotor requires replacement or overhaul. The combination of periodic maintenance and the risks of failure from slip-rings did not match the maintenance free and long life performance of the Diamond Antenna RF rotary joint.
After evaluating the available options to replace slip-rings Diamond Antenna & Microwave bought Roltran, a company that designed and built Roll-Rings. In 2001 Diamond Antenna integrated Diamond Roltran Roll-Rings® into an RF rotary joint destined for air traffic control service. Diamond Roll-Rings® have several advantages over slip-rings which make them ideal for mission critical applications like air traffic control.
Diamond Roll-Rings®, by their design, do not create wear debris like slip-rings. Diamond Roll-Rings® roll between the rotor and stator, a design based on a ball bearing but made of a ring-shaped flexible copper alloy and made to contact the rotor and stator in a manner to produce long life without generating wear debris that requires maintenance.
Diamond Roll-Rings® and the grooves they run in are plated to prevent corrosion and maintain a low resistance interface over the life of the device. Slip-rings, by contrast, are generally plated with materials that will oxidize over time thus requiring the brushes to wear against the slip-ring rotor to constantly remove the oxide layer to expose a conductive surface and enable a low resistance connection. Roll-Rings with their non-oxidizing surfaces and flexible ring enable long life without wear which matches the long life of the Diamond air traffic control rotary joint.
Nineteen countries around the globe successfully use Diamond Antenna & Microwave rotary joints with Diamond Roll-Rings® for mission critical Air Traffic Control radar installations. The long life of both Diamond Antenna rotary joints and Diamond Roll-Rings® are a substantial benefit for mobile and fixed installations to increase mission readiness, reduce downtime and reduce maintenance costs.
Diamond Roll-Rings® are found in mission critical performance applications the world over. For RF antenna applications Diamond Roll-Rings® are available only through Diamond Antenna and as of March 2012 are also available through Diamond Antenna Europe, a joint venture between AML of Metz, France and Diamond Antenna & Microwave.