ARRL

How Antennas Work

Introduction

Every active ham uses an antenna. But how many hams can say that they really understand what happens when they apply RF to their antenna? The RF signal somehow leaves their antenna and is picked up by an antenna on the other end of a QSO, but to many hams this is a mysterious process.

Antenna theory sounds like a boring, dry subject, but understanding how an antenna radiates, how it interacts with ground and understanding something about antenna polarization is central to being able to answer the question that most hams really have when they think about antennas -- "Which antenna is best?"

This page has pointers to a number of articles that have appeared in QST over the years on antenna theory. Reading these articles will help you answer that question for your station, and for your friends.

Articles

  • Why an Antenna Radiates
    QST November 1992, pp. 59-63
    You don't have to know how an antenna works to use one, but getting a handle on this subject can deepen your understanding of radio. Here's a searching look at the mysterious process by which our antennas hurl energy from Here to There.
  • An Analysis of the Balun
    QST April 1980, pp. 19-21
    What does a balun do for you? What happens if you don't use one? Does a balun really make a difference?
  • Why Do Baluns Burn Up?” by Zack Lau W1VT.  Janauary 2004 QEX, pages 55-58.  Balun technology typically falls short of operator expectations.

  • The Effect of Continuous, Conductive Guy Wires on Antenna Performance Members Only
    QST August 1993, 22-24
    Radio amateurs have long worked to preserve antenna patterns by installing segmented, nonresonant guys. Now, computer modeling reveals that unbroken guys can work just about as well.
  • "My Feed Line Tunes My Antenna!" Members Only
    QST November 1991, pp. 33-35
    A tutorial - Everything you should know about feed-lines.
  • Match Bandwidth of Resonant Antenna Systems Members Only
    QST October 1991, pp. 21-25
    Did you know that deliberately mismatching an antenna to it's feed line can increase its SWR bandwidth? Here's how it works.
  • Coaxial Cable -- The Neglected Link
    QST April 1981, pp. 28-31
    Is a better grade of coaxial cable worth the price difference? This analysis of the importance of shielding in coax lines explains why the answer is "Yes!"
  • Combined Vertical Directivity Members Only
    QST February 1981, pp. 19-21
    You need a low radiation angle for DX and a high angle for short skip. Most of us shoot for maximum antenna height and hope for good results. Learn how to calculate the vertical radiation patterns for various heights.
  • Vertical Array Analysis Members Only
    QST February 1981, pp. 22-25
    You can determine the radiation pattern of an experimental phased array before building it. A computer helps, but you can get the same results with a ruler and protractor.
  • Antenna Ads in ARRL Publications Members Only
    QST April 1998, pp. 54-56
    After more than 35 years, antenna manufacturers may once again advertise performance figures in League publications. Why has this changed and what should the astute amateur consumer be looking for in an antenna ad (or product brochure)?
  • An Examination of the Gamma Match Members Only
    QST April 1969, pp. 11-15, 57
    An in-depth theoretical discussion of the gamma match.
  • Far-Field Fallacy Members Only
    QEX December 1987, pp. 10-11
    Put simply, the performance of a DX antenna needs to be measured under DX conditions.
  • Why We Stack ‘Em! Covering All the Angles Members Only
    A Presentation to The Yankee Clipper Contest Club, Feb. 1, 2003, Milford, CT, by Dean Straw, N6BV, Senior Assistant Technical Editor, ARRL

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