Circular connectors with a metal shell, multiple contact points for coaxial and signal connections, and EMC shielding are specialized connectors designed for high-performance applications where reliable signal integrity and protection from electromagnetic interference (EMI) are critical. These connectors are often used in fields such as military, aerospace, telecommunications, and high-end industrial applications.

Key Features:

1. Metal Shell:

   • Robust Construction: The metal shell provides strong mechanical protection, making these connectors suitable for harsh environments where physical durability is essential.
   • Electromagnetic Interference (EMI) Protection: The metal shell, combined with internal EMC shielding, helps to protect the internal signals from external electromagnetic fields, ensuring stable and reliable signal transmission.

2. Multiple Contact Points for Coaxial and Signal Lines:

   • Coaxial Contacts: These connectors can include coaxial contacts designed for high-frequency signal transmission, such as RF (Radio Frequency) signals, where maintaining signal integrity is crucial.
   • Signal Contacts: Alongside coaxial contacts, these connectors may also include standard signal contacts, allowing for the simultaneous transmission of power, data, and high-frequency signals through a single connector.
   • Mixed Layouts: The connector can have a mixed layout, combining coaxial and standard signal pins, providing versatility in applications requiring both types of connections.

3. EMC Shielding:

   • 360-Degree Shielding: The connector provides comprehensive EMC shielding, covering all directions, which is essential in environments with significant electromagnetic interference.
   • Signal Integrity: The shielding helps to minimize crosstalk between different signals within the connector and protects sensitive signals from external EMI, ensuring reliable and accurate data transmission.

4. High-Frequency Performance:

   • Coaxial Contacts: Designed to handle high-frequency signals, these connectors are ideal for RF applications, ensuring minimal signal loss and reflection.
   • Gold-Plated Contacts: Often, the contacts are gold-plated to ensure low resistance, high conductivity, and resistance to corrosion, enhancing the performance and longevity of the connector.

5. Environmental Protection:

   • Sealing Options: These connectors often come with sealing options (such as IP67 or IP68 ratings) to protect against dust, moisture, and other environmental factors, making them suitable for outdoor and harsh environments.

Applications:

• Military and Aerospace: Used in communication systems, avionics, and radar systems where high-frequency signal integrity and environmental durability are critical.
• Telecommunications: Employed in base stations, antennas, and other communication equipment where both coaxial and signal connections are needed in a compact, robust form factor.
• Broadcasting: Utilized in professional broadcasting equipment where high-quality signal transmission is necessary, and where EMI protection is crucial.
• Industrial Automation: Suitable for applications where robust and reliable connections for both power and signal lines are needed, often in environments with significant electromagnetic noise.

Brands and Manufacturers:

1. LEMO: Offers high-performance circular connectors with mixed coaxial and signal contacts, suitable for demanding applications requiring EMC shielding.
2. Amphenol: Known for their versatile range of circular connectors that can be configured with multiple contact types, including coaxial and signal contacts, with robust EMC protection.
3. HUBER+SUHNER: Specializes in RF and high-frequency connectors, providing options for circular connectors with coaxial and signal capabilities.