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This is a great summary. I too have struggled to get decent information on the web about antenna theory and design. As it turned out, I was searching wrong :-)

This is a great summary. I too have struggled to get decent information on the web about antenna theory and design. As it turned out, I was searching wrong :-) The keyword is 'electrodynamics' and the canonical text is "Classic Electrodynamics" by Jackson. I am told that if you can understand the contents of this book, antennas are pretty straight forward. I started in on it, got whacked upside the brain a number of times, then backed off to "Introduction to Electrodynamics" by Griffth which is the undergraduate version and does a bit more math review, which was essential in my case. My plan is that once I am through that I'll go back and re-start Jackson. The fun bit here is that if you look for computer code to simulate this stuff you will run into a lot of Fortan code. So if you ever wanted to learn Fortran this will give you some code to puzzle over.

dbcurtis 8y ago
> you will run into a lot of Fortan code. By which you probably refer to the NEC2 code base. NEC2 is public domain, so that is what most hackers use. The native UI is column-senstive punch cards. Blessedly, there are people that have put more modern front-ends on the NEC2 back-end. NEC2 is OK-ish, as long as you avoid the well-known bugs. NEC4 fixes some of the bugs, but falls under ITAR, so requires a license and can't be exported (last I knew, anyway). There are also multi-kilo-dollar-per-seat antenna modeling packages available commercially. NEC2 is pretty old, and an interesting story I heard about the validation of the model was that the DOD, having helicopters handy, stuffed a helicopter full of instruments and flew it around an antenna range to capture ground-truth data for antennas that had been built from models. Last week I was talking with my friend N6BT, who has been in the antenna business for decades. For 3 or so years he has had a quad-rotor that he flies around with a signal generator, and uses the GPS time from the quad-rotor to correlate GPS time-stamped data from his ground-based spectrum analyzer to collect actuals. He is finding MANY discrepancies (primarily at low angles) between NEC4 and actual, due to the sketchy ground models.
- ChuckMcM 8y ago
  That has been my experience as well, at work we have a multi-kilobuck simulation package but we still put the antenna on our range to test it. The range consists of basically a robot arm that can hold the antenna under test (AUT) in any orientation, a transceiver/spectrum analyzer that can move forward or back to get into the near, Fresnel, and far ranges, and a transceiver/spectrum analyzer that is connected to the AUT. Comparing simulations to actual always yields some interesting nuggets of information.
  - dbcurtis 8y ago
    > The range consists of basically a robot arm that can hold the antenna under test (AUT) in any orientation, Which works better at 2.4GHz than at 2.4MHz :)
    - ChuckMcM 8y ago
      Absolutely, that LF and even the HF stuff needs a really really big range :-)
Junk_Collector 8y ago
Jackson is really good. There are actually a lot of other good books in that general category depending on exactly what you are looking for. Cheng's "Field and Wave ELectromagnetics" is an excellent undergrad book to start to learn then you have Harrington's "Time Harmonic Electromagnetic Fields" and Stratton's "Electromagnetic Theory" which are both really fundamental and thorough and more high end you have Collins' "Foundation of Microwave Engineering" and "Field Theory of guided waves" A bit more practical if you like smith charts you've and matching networks you've got Pozar's "Microwave Engineering" and for Antenna theory you've got Stutzman and Thiele's "Antenna Theory and Design" or Kraus' "Anetnnas" Balanis' book is good but a lot of the material in in comes from these books + Jackson and I think it makes a much better reference than a learning text.
stallmanifold 8y ago
For the purposes of learning antenna theory at the level of Balanis's 'Antenna Theory', I think Jackson is severely overkill. It's also written for physicists rather than engineers, so the emphasis is different. On the other hand, Jackson's problems are quite excellent. There's all kinds of interesting stuff in there that is hard to find in most other places (plasma physics and MHD come to mind). Something like Griffiths or Cheng will be just right. I studied Computer Engineering in undergrad, and worked through several books on electrodynamics at the time (and did several courses in EM), including Jackson. I didn't study RF, but my classmates in RF were all using Balanis for their RF and Antenna design courses, which clearly comes before the level of EM where most people are working (suffering?) through Jackson, or Balanis's 'Advanced Engineering Electromagnetics'.

dbcurtis 8y ago

> you will run into a lot of Fortan code. By which you probably refer to the NEC2 code base. NEC2 is public domain, so that is what most hackers use. The native UI is column-senstive punch cards. Blessedly, there are people that have put more modern front-ends on the NEC2 back-end. NEC2 is OK-ish, as long as you avoid the well-known bugs. NEC4 fixes some of the bugs, but falls under ITAR, so requires a license and can't be exported (last I knew, anyway). There are also multi-kilo-dollar-per-seat antenna modeling packages available commercially. NEC2 is pretty old, and an interesting story I heard about the validation of the model was that the DOD, having helicopters handy, stuffed a helicopter full of instruments and flew it around an antenna range to capture ground-truth data for antennas that had been built from models. Last week I was talking with my friend N6BT, who has been in the antenna business for decades. For 3 or so years he has had a quad-rotor that he flies around with a signal generator, and uses the GPS time from the quad-rotor to correlate GPS time-stamped data from his ground-based spectrum analyzer to collect actuals. He is finding MANY discrepancies (primarily at low angles) between NEC4 and actual, due to the sketchy ground models.

ChuckMcM 8y ago
That has been my experience as well, at work we have a multi-kilobuck simulation package but we still put the antenna on our range to test it. The range consists of basically a robot arm that can hold the antenna under test (AUT) in any orientation, a transceiver/spectrum analyzer that can move forward or back to get into the near, Fresnel, and far ranges, and a transceiver/spectrum analyzer that is connected to the AUT. Comparing simulations to actual always yields some interesting nuggets of information.
- dbcurtis 8y ago
  > The range consists of basically a robot arm that can hold the antenna under test (AUT) in any orientation, Which works better at 2.4GHz than at 2.4MHz :)
  - ChuckMcM 8y ago
    Absolutely, that LF and even the HF stuff needs a really really big range :-)

Junk_Collector 8y ago

Jackson is really good. There are actually a lot of other good books in that general category depending on exactly what you are looking for. Cheng's "Field and Wave ELectromagnetics" is an excellent undergrad book to start to learn then you have Harrington's "Time Harmonic Electromagnetic Fields" and Stratton's "Electromagnetic Theory" which are both really fundamental and thorough and more high end you have Collins' "Foundation of Microwave Engineering" and "Field Theory of guided waves" A bit more practical if you like smith charts you've and matching networks you've got Pozar's "Microwave Engineering" and for Antenna theory you've got Stutzman and Thiele's "Antenna Theory and Design" or Kraus' "Anetnnas" Balanis' book is good but a lot of the material in in comes from these books + Jackson and I think it makes a much better reference than a learning text.

stallmanifold 8y ago

For the purposes of learning antenna theory at the level of Balanis's 'Antenna Theory', I think Jackson is severely overkill. It's also written for physicists rather than engineers, so the emphasis is different. On the other hand, Jackson's problems are quite excellent. There's all kinds of interesting stuff in there that is hard to find in most other places (plasma physics and MHD come to mind). Something like Griffiths or Cheng will be just right. I studied Computer Engineering in undergrad, and worked through several books on electrodynamics at the time (and did several courses in EM), including Jackson. I didn't study RF, but my classmates in RF were all using Balanis for their RF and Antenna design courses, which clearly comes before the level of EM where most people are working (suffering?) through Jackson, or Balanis's 'Advanced Engineering Electromagnetics'.