Radio Frequency (RF) & Wireless Design

Created by Steven Minichiello on 27 April, 2018

Why you should pick the coax cable type *before* you pick the coax connector.

I have noticed that many engineers will design around an RF circuit, then perform the layout, choosing an RF connector that fits on the PCB, but choose the RF cable types as an after-thought.


Choosing a cable *must be* the main decision before any connections and/or connectors are involved.


The major issues of concern are :

  • Cable impedance (e.g. 50 ohms)
  • Dielectric loss of material (e.g. PTFE otherwise known as Teflon)
  • Conductor DC loss (e.g. milliohms per foot)
  • Types of Shielding (e.g. double braiding)
  • Attenuation @ Frequency (e.g. 42.7 dB/100 ft @ 750 MHz)


Once these issues are resolved by selection of a cable, only then can cable connectors be chosen to accommodate modularity.


This wiki reference is useful for a tabulation of various RF coaxial cable types :

https://en.wikipedia.org/wiki/Coaxial_cable#Standards


NOTE : this listing is NOT exhaustive by any means and there are other specialized and custom design that can be ordered depending on specific requirements of the application. - - - As customary, please check with manufactured cable vendor Field Application Engineers (FAEs) for your specific application and cost requirements.