《Antenna Measurement with Network Analyzer》.pdf

Design Note DN001 Antenna Measurement with Network Analyzer By Audun Andersen Keywords • Antenna • Return Loss • Network Analyzer • Reflection • Measure • Impedance 1 Introduction The performance of an antenna will impact and thus the field strength of the radiated the communication range of a RF system. signal will be reduced. RL describes how Since range is often a critical factor when much of the available power is reflected at designing RF systems, it is important to be the feed point of the antenna. This able to characterize the antenna. One document describes how RL can be parameter that is important, and which can measured, with a network analyzer, and easily be measured is the return loss (RL). how to interpret the result. The Impedance mismatch between the feeding measurement technique described in this transmission line and the antenna causes document is only applicable to single reflection at the feed point of the antenna. ended antennas. A brief explanation on Because of this reflection not all of the how to tune the antenna impedance is available power will reach the antenna, also described. SWRA096 Page 1 of 10 Design Note DN001 Table of Contents KEYWORDS 1 1 INTRODUCTION 1 2 ABBREVIATIONS 2 3 IMPEDANCE MATCHING 3 4 HOW TO MEASURE RET