An RF connector, by definition, is that part of the transmission line by which transmission system components (cables) are attached or decoupled. Unlike electrical connectors which handle low frequency electrical signals (usually 60 hertz) - RF connectors are used to transmit RF energy over a wide frequency range up to 18 billion cycles per second (18 giga-hertz) and beyond. Typical applications include radar, shipboard and vehicular communications, data transmission systems and aerospace equipment. The basic design of coaxial connectors starts with a center conductor in
which the male and female center contacts are terminated. Next, as in the cable, is the dielectric, or insulator, and then the outer contact. This outside portion serves the sane purpose as the outer shield of the cable; namely, to carry a signal, to act as a shield, or to act as a grounding member of the circuit.
To select the coaxial connector that best matches the coax cable being used, the aim is to provide an uninterrupted path for radio-frequency signals to follow, minimizing disruptions. Therefore, select as simple a connector as possible, and one whose electrical properties closely match those of the cable. Important selection criteria to evaluate, on a step-by-step basis, include the following.
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Connector series available, classified according to physical size.
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Electrical application of the connector, including close impedance matching, high voltage, and OC pulse circuit requirements
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Coupling method desired, from a choice of bayonet, threaded, or quick disconnect (push to mate, pull to unmate) types
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Solder or crimp type terminations
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Cost and availability
Soldering and crimping are two popular methods for attaching cable to RF connectors. The main advantage of crimp terminations is faster assembly time (30 seconds vs. between 5 to 10 minutes for a standard solder-and-clamp type connector, plus related cost savings. Both types can be designed with equal electrical characteristics, though crimp terminated connectors usually provide better mechanical characteristics than comparable solder types. Nemal offers a complete selection of crimping and termination tooling for all connector types.
If pressure differential is above 15 psi or the enclosure contains a vacuum that must not be contaminated by even a single air molecule, you must use a hermetic connector. The hermetic part of the connector is the seal between the contact pins and the insulator, and between the insulator and the shell. The mating half of a separable connection need not be hermetic.
Nemal designs and manufactures hermetic connectors in a wide range of connector series.
In applications involving large fluctuations of ambient temperature, captive contacts prevent disconnects due to cable
contraction. A shoulder positions the contact axially, preventing movement. Captive contact designs are available in a wide range of connector series.
Polarized connectors are used where two or more lines are brought into the same point and it is essential to prevent cross-mating. Polarized BNC's are distinguished by a band of red diemaker's ink, and are not intermateable with nonpolarized
BNC's.
