Highlight of Less Common RF Adapters & Connectors

NMO Mount Connector

There have been many innovations and adaptations of coaxial cable and RF Connectors since their inception in the early 20th century. Hence, there are many varieties of RF Adapters to efficiently transition among the wide range of RF coaxial connectors. Among these are the common coaxial connector types, such as SMA, N-type, BNC, 3.5 mm, 1.85 mm, DIN 7/16, 4.3-10, D-Sub, MCX, SMB, UHF etc. However, there are also many less common coaxial, rf connector, and RF adapter types.

For instance, most coaxial connectors and adapters are based on male/female plug/jack configurations with either threaded, push connector, or bayonet connector attachment. With this basic design there is a male pin that is inserted into a female contact for the center conductor connection and a ground connection made by threading the outer housing of the coaxial connector. There are cases where this polarity is inverse, reverse polarity connectors, however the basic premise is the same.

This is not the case for a certain type of coaxial connector called hermaphroditic connectors, where both mating connectors are identical. An example of this is NMO Mount Connectors, which are often used as antenna mounts that may often be swapped or for antenna mount bases that can connect to several possible antenna types. Hermaphroditic connectors often use a flat-face center contact that is aligned by an outer threaded nut that also doubles as the outer conductor.

Another example of RF connectors and contacts that aren’t as common are banana connectors, either Banana Plug Connectors or Double Banana BNC Binding Post. Though these connectors aren’t strictly RF connectors, they can be connected to coaxial cables and RF signal paths to inject DC or extract DC signals. These are most often used in test and measurement environments where it is useful to have DC signals present in a coaxial environment, even if RF signals are not also present. There are RF components that can allow for DC injection or extraction and also allow for RF signals, Bias-Ts or Bias-Tees.

Lastly, there are less common snap-on type connectors that are more often used with circuit board test points, board-to-board connections, and as low-cost blind mate interconnect. Of these MMBX Connectors are used for small board-to-board distances and small pitch  applications to just over 12 GHz (12.4 GHz). These snap-on connectors are smaller and more expensive than other varieties of snap-on connectors, such as MCX, but exceed MCX  and MMCX frequency range of 6 GHz.