meet the many classes of physical installation priorities. Designers must therefore first select the appropriate connector family to meet the design requirements and then the style within that family. This article will look at five widely used gigahertz (GHz) range, RF connector families. It will also look at the closely related issue of complete cable assemblies terminated with the chosen connector, using components from the various families from Würth Elektronik.
elements in almost any product design. The “ideal” connector offers critical mechanical attributes such as convenient mating and unmating, mechanical and electrical integrity, and it should be electrically invisible with no DC ohmic resistance or RF impedance discontinuities. The challenges of designing, manufacturing, and using connectors increase with operating frequency. As their required operating frequency extends into the RF domain, into and above the gigahertz (GHz) range, their mechanical construction by necessity becomes increasingly precise, with many critical performance attributes and parameters.
Classic connectors such as the BNC (Bayonet Neil-Concelman), offered in 50 Ω and 75 Ω versions (the latter for video and TV), have been widely used since the 1950s and are still in use (Figure 1). This locking connector features a one-third turn, quick-connect/ disconnect action via a “bayonet” system. Although the frequency response is formally rated to 4 GHz, the connector’s losses increase to often unacceptable levels at higher frequencies. Physically, it is not a good fit for today’s compact, densely packed designs due to its relatively large size and the large minimum bending radius of a complete cable assembly.
The basics of RF connectors
It’s important to clarify connector- related terminology. A “connector” is the metal termination which can be mated and unmated as needed, while the “cable” is the coaxial wire consisting of an inner copper conductor, spacing dielectric, outer shield, and insulation to which the connector is attached. A “cable assembly” is the combination of a cable with a connector at one or both ends. However, the term “cable” is often used in place of “cable assembly” in casual conversation, and the actual meaning is usually clear from the context. We will use these terms in their strict sense in this article. While connectors are passive components and don’t provide any signal processing or enhancement, they are essential
Figure 1: The BNC connector includes a bayonet body lock and has been widely used since its development in the early 1950s, but it is not a good electrical or mechanical fit for many of today’s high-frequency, space-constrained applications. A male plug is usually used with cable assembles (left); a female jack (right), for use on instrument panels. (Image source: Wikipedia; Pinterest)
we get technical
63
Powered by FlippingBook