Understanding the principles of antenna theory is a first step and generally essential for the design, testing, and evaluation of antenna performance. The information you'll find here aims to provide a basic understanding of the concepts of antenna theory, essential antenna parameters, various antenna applications, and antenna measurement techniques.
Topic overview
What is an Antenna and What is it Used For?
An antenna is a crucial component in modern communication systems. Its role, the transmission and reception of electromagnetic energy, is the key to all means of wireless transfers of data, communications and more. The transformed energy can come in various forms: radio waves, cell phone signals, and radar signals.
Antennas are designed for specific applications. There are different types of antennas and they can be very small or extremely large, and their designs can vary widely from simple to complex.
This introductory article goes back to the basics of the device itself and its useful purpose.
How Do Electromagnetic Fields Relate to Antenna Operation?
Antennas are used to transmit and receive electromagnetic energy. To understand how this energy propagates through space, a few principals of electromagnetic waves and how they function is required. EM fields change as a function of both distance & time.
In this 2nd article, we will examine the case of a simple dipole antenna radiating at a single frequency to explain electromagnetic fields and their relation to antennas.
How Can we Accurately Measure an Antenna's Response?
As antennas are designed to operate at a certain distance from one another, for a measurement, we need to determine the area between them where the electromagnetic waves are flat, in other words, where they become plane waves. This is known as the far field. Ideally, we would like to measure an antenna’s response to a plane wave in any direction.
This 3rd article will delve into the importance of the electromagnetic fields, time and distances between signals, and the interferences to be avoided in order to perform accurate measurements.