VSWR of Electrical Cables

elspec Whitepaper

Introduction

When measuring pre-assembled coaxial cables with the network analyzer, it is important to understand that the matching read-out on the analyzer results from the superposition of the signals reflected by the connectors on both ends of the cable. The dB (short for decibel) is a unit we constantly encounter carrying out such procedures.

Let’s have a quick look at the „decibel“ and how the calculation using it works: the Bel (that is the original designation) presents power relationships on a logarithmic scale. Since the Bel is somewhat cumbersome to use, a tenth of a Bel was adopted as a more conducive unit. Thus the deci-„Bel“ (dB) has established itself as the common measure.