CHEMANDY ELECTRONICS Suppliers of the unusual

 

 LATEST ARTICLE

Radiation Polarisation


<

 LATEST CALCULATOR

Round Wire Impedance Calculator

How Does an Antenna Work?

There are many theories as to how an antenna works, some of which are amazingly complicated and difficult to understand, some are totally inaccurate and some are so weird that they are amusing. It does not help to refer to the antenna text books that are full of very advanced  mathematics and difficult to comprehend concepts which the average person would not even attempt to understand. In order to investigate the reality of radiation a series of measurements and articles have been made to prove the fundamental radiation mechanism. These articles build up to give an overall picture as to the real behaviour of a grounded monopole antenna and are intended to be a reference point for those who wish to understand how an antenna really transmits.

 

Index

Article Paragraph Page
     
Forward 1.1) Introduction 1
  1.2) Present Understanding 1
  1.3) Study Structure 1
Current Distribution 1.1) Introduction 1
  1.2) Conventional Distribution 1
  1.3) Comparing Current Curves 1
  2.1) Understanding the Current Measurement Method 2
  3.1) Point of Reflection 4
  3.2) Preparation of Samples 4
  3.3) Reflection Measurement 4
  4.1) Antenna Current Distribution Measurements 5
  4.2) Toroidal Ferrite Probe 5
  4.3) Flat Plate Probe 5
  4.4) Comparing phases of measured difference current with an ideal vector difference current 6
  4.5) Calculation of INCIDENT and REFLECTED Currents 6
  5.1) Current Analysis 7
  5.2) Phase Analysis 7
  5.3) Conclusions 7
Voltage Distribution 1.1) Introduction 1
  1.2) Conventional Voltage Distribution 1
  1.3) Classical Voltage Curves 1
  2.1) Antenna Voltage Distribution Measurements 1
  2.2) Low Capacitance Probes 2
  2.3) Measured Vector Sum Voltage 2
  2.4) Voltage Drop Calculation 3
  2.5) Vector Voltage Calculation 3
  3.1) Phase Distribution 3
  4.1) Power Distribution 4
  5.1) Impedance Distribution 4
  6.1) Voltage analysis 4
  6.2) Phase Analysis 4
  6.3) Measurement and Calculation Logic 4
  6.4) Conclusions 4
Near Field Radiation 1.1) Introduction 1
  1.2) Measurement Principle 1
  1.3) Measurement Equipment 1
  1.4) Measurement Test Circuit 1
  1.5) Sample Antenna 1
  2.1) Radiation Upwards 2
  2.2) Radiation Downwards 2
  3.1) Analysis 2
  3.2) Conclusions 2
Radiation Elevation 1.1) Introduction 1
  1.2) Measurement Equipment 1
  1.3) Measurement Test Circuit 1
  1.4) Sample Antenna 1
  2.1) Measurements 2
  3.1) Analysis 2
  3.2) Conclusions 2
Polarisation 1.1) Introduction 1
  2.1) Establishing if Upwards and Downwards Radiations Cancel 1
  2.2) Diametrically Opposed Antennas Measurement Test Circuit 1
  2.3) Sample Antennas 1
  2.4) Measurements 2
  3.1) Diametrically Opposed Antenna Results 2
  4.1) Rotation Measurement 2
  4.2) Rotation Results 2
  4.3) Rotation Analysis 2
  5.1) Swept Frequency Phase Measurement 2
  5.2) Swept Frequency Analysis 2
  6.1) Conclusions 2

Technical Article Index