LEMO 3M.204 Multi-Coaxial Connector Expands Series M for High-Frequency Systems

LEMO Adds Multi-Coaxial Option to Series M Connectors

High-frequency data links are becoming standard in places where space is at a premium. UAV payloads, military radios, and airborne communications modules all need to push more data than ever, but they do so in environments where heat, vibration, and weather are unavoidable. That puts a lot of pressure on the connector. It must deliver the necessary bandwidth while remaining small and lightweight enough not to compromise the system it sits inside.

Compact Multi-Coaxial Design With Rugged Features

LEMO’s answer is the 3M.204 configuration, the latest addition to its Series M range. It takes the coaxial capability engineers usually expect from bulkier MIL-DTL-38999 connectors and fits it into a smaller, lighter format. Even with the reduced size, the connector hasn’t lost the traits that make it field-ready. The ratchet coupling holds fast under vibration, the body is sealed to IP68, and shielding runs a full 360 degrees to keep interference out. Materials are chosen to survive oils, fuels, and salt spray, while the connector is rated for more than 3000 mating cycles across temperatures from –55 °C to +200 °C.

On the signal side, the 3M.204 accommodates four coaxial contacts that operate up to 26.5 GHz with low VSWR. For projects that need more, the LM.232 variant expands this to twelve contacts. What this means in practice is that engineers can run high-speed digital or RF signals through a connector that doesn’t overload their size and weight budget, an important shift for SWaP-conscious systems like UAV avionics or mobile communication gear.

Flexibility and Applications

Not every system will use every position, and LEMO has accounted for that. Dummy inserts are available to block unused cavities, keeping the environmental rating intact while giving designers room to change layouts without redesigning the hardware around the connector.

That flexibility opens the door to a wide range of uses. The new configuration is aimed at:

• Radar equipment
• Secure military radios
• UAV payloads and comms modules
• Aerospace control systems
• Outdoor 5G infrastructure

Why It Matters

For many engineers, connectors are a limiting factor. They decide how compact a system can be and how well high-frequency signals will travel once the design leaves the lab and faces real-world conditions. By introducing this multi-coaxial option, LEMO gives designers a smaller footprint without forcing them to give up the durability and frequency range they need. It’s not a headline-grabbing change, but it’s the kind of incremental improvement that makes future systems lighter, tougher, and more capable.

Learn more and read the original announcement here.