Re: Semi-buried transmission line

  In addition to what others have written regarding the book by King and his
  colleagues, there is another good by Galejs, " Antennas in Inhomogeneous
  Media ".

  One important point:

  Gerry Burke, Ed Miller and their other colleagues worked on this famous
  problem. In fact, there is an IEEE T-AP 1984 paper by Burke and Miller
  that is titled " Modeling of Antennas Near a Lossy Interface ". You may
  take a look at it. (Of course both the authors are on the NEC-list and
  they can provide more information.)

  Ed Miller also wrote several papers in Canadian Journal of Physics on
  this problem in 1970's.

  The problem here is similar (or maybe identical) to what is known as
  Sommerfeld type. The principal difficulty is in evaluating these
  integrals particularly near the interface, where there is oscillatory
  divergence. Generally semi-analytic techniques are employed and I guess
  NEC-3,4 definitely has all the capabilities to solve such problems.

  It is just interesting to observe that similar situation arises in the
  full-wave solution of microstrip antennas.

 =================================================================
  Deb Chatterjee

  Graduate Research Assistant
  Radar Systems and Remote Sensing Laboratory
  Department of Electrical Engineering and Computer Science
  Room 322, Nichols Hall
  2291 Irving Hill Road
  Lawrence, KS 66045-2969

  tel: (913)864-7742
  fax: (913)864-7789
  e-mail: dchatterjee_at_kuhub.cc.ukans.edu

On Wed, 3 Jan 1996 w7el_at_teleport.com wrote:

> I've been modeling a Beverage antenna with NEC-4 and it shows the current
> falling off more slowly than actual antenna measurements indicate. As an
> experiment, I then added a buried wire under the antenna, making a
> resistively-terminated transmission line in which one conductor is buried in
> the
> ground and the other suspended an equal distance above it. (The result was
> similar to the original Beverage.)
>
> It seems that the case of a transmission line half buried in a lossy
> half-space
> might be something which has been studied analytically. It would be
> interesting
> to compare the results of an analytical study with those given by NEC-4. Does
> anyone know of any papers on this topic?
>
> Thanks,
>
> Roy Lewallen
Received on Fri Jan 05 1996 - 16:54:00 EST