Antenna Measurement Techniques (1)

Part I: Theory & Principles

Antennas are devices for transmitting and/or receiving electromagnetic energy
through a medium or media at a given frequency band. Most antennas are used
to transmit and receive electromagnetic waves that carry information over a distance away from each others.Antennas can appear in a great variety of
forms depending on their applications

Theory

Fundamental Principles of the antennas are described by the following four mathematical Equations often referred to as Maxwell’s Equations

Antenna Types 

    Resonant Antennas                                                   

        Dipoles, Yagi-Uda arrays
        Loops
        Micro-strip Patches

   Travelling Wave Antennas

         Horns; Log-period antennas
         Rhombic antennas

Quasi-optical Beam Forming Antennas

          Parabolic reflector antenna, Array antenna

Antenna Polarization

Linear polarization: The electric field always lies on a line within the period (commonly referred)

Circular Polarization: The electric field uniformly changes its direction 360 degrees with a constant magnitude during a time-varying period (CW, CCW)

Elliptical Polarization: The electric field uniforml changes its direction and magnitude during a time varying period (generic antenna properties) A term to define the electric field orientation within a time-variation period of the electromagnetic wave