November 2012

Doc ID 023812 Rev 1

1/29

AN4190

Application note

Antenna selection guidelines

By Placido De Vita

Introduction

The antenna is a very important component of communication systems. By definition, an

antenna is a device used to transform an RF signal, travelling on a conductor, into an

electromagnetic wave in free space (transmit mode), and to transform an RF

electromagnetic wave into an electrical signal (receive mode).

The choice of antenna is very important for a transmitting - receiving communication

system. The antenna must be able to radiate or receive efficiently so the power supplied is

not wasted.

This application note describes the most important parameters to consider when deciding

what kind of antenna to use in a short range device application.

In the first section of this application note the antenna theory is covered. The main antenna

parameters such as radiation pattern, gain, impedance matching, bandwidth, size and

others are discussed.

In the second part of this document different antenna types are presented.

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