Connectivity Options For RF Switch Applications

This article is part 3 of the Guide to Selecting an RF Switch. This 5-part guide is an accumulation of insightful content that will arm you with the necessary knowledge to design your RF switch network. This section will provide you with an overview of the smaller but equally important components that form a part of the switch network, such as cables, and connectors.

Click here for Understanding Key RF Switch Specifications, part 1 of this 5-part series.

Introduction

When designing an RF switch system, it is easy to focus on the performance of the switch module while neglecting smaller system components such as cables and connectors. However, it is important to understand that each piece of an RF system contributes to signal degradation in the form of reflections and losses. For this reason, in order to obtain optimal system performance you must place as much attention on choosing the right cable and connectors for your system as you would on choosing the right switch module. If care is not taken when doing so, overall system performance can be severely affected. To learn how to choose the right cables and connectors for your system, it is important to understand the advantages and disadvantages of the various options available.

Cables

Most RF systems use coaxial cables for signal transmission. The three main parts of a coaxial cable are its center conductor, outer shell, and dielectric which acts as an electrical insulator by preventing the current dissipation between the center conductor and outer shell. Because coaxial cables contain the propagating electromagnetic signal on their insides (the inner conductor in the figure below), they do not radiate noise and are less susceptible to picking up other signals that may persist in the vicinity.

Click here for Effects Of Impedance Matching And Switch Quality On RF Test System Performance, part 4 of this 5-part series.