There are a number of other BNC variant connectors that use a bayonet-type of connection. They all abide by the United States military standard MIL-PRF-39012 for entitled Connectors, Coaxial, Radio Frequency and General Specification.
Twin BNC or Twinax
Twin BNC (also known as twinax) connectors use two independent contact points, one male and one female. This allows the connection of a 75 ohm or 95 ohm shielded differential pair such as RG-108A. Twin BNC connectors have a lower frequency range and voltage, typically maxing out 100 MHz and 100 volts. Read More.