Re: NEC-LIST:nec2 newbie question: Biconical antenna

Stefan:

Biconical antennas are widely used in doing EMC and field strength
measurements. However, they are typically only used between 30 MHz and up to
80 MHz or so. Above 80 MHz and up to 1 GHz., a log periodic antenna is
commonly used. Above 1 GHz a horn antenna is used. The gain of a horn can be
calculated from dimensions with some accuracy.

I am not saying that you cannot use a biconical at 1800 MHz., but I am saying
that the construction would have to be very carefully done. I am not sure what
type of balun would be suitable at 1800 MHz. And getting one to function well
at both 900 and 1800 MHz may be difficult.

You may want to consider a horn antenna. Of course, it depends on what you are
trying to do.

Regards,

Jacob Z. Schanker, P.E.
65 Crandon Way
Rochester, NY 14618

Tel: 585 442 3909
Fax: 585 442 2182
j.schanker_at_ieee.org

  ----- Original Message -----
  From: Stefan Frank
  To: nec-list
  Sent: Wednesday, October 16, 2002 5:05 PM
  Subject: NEC-LIST:nec2 newbie question: Biconical antenna

  Hello list,

  I'm a student in electrical engineering and I try to create a
  biconical antenna for measurements at 900MHz and 1800MHz (GSM cell
  phones). I haven't found much information about biconicals (only in
  Kraus' book and an old article in the Microwave Journal from 1979
  about wire biconicals plus some web pages), so I'm not sure if I'm on
  the right way.
  The antenna should be connected to a spectrum analyzer via BNC or
  N-Connector (50 ohms).

  Criticism, hints, corrections are really appreciated :-)

  Thanks a lot,
  Stefan

  CM Biconical antenna
  CM Cone angle 30 deg.
  CE
  GW 1 14 0 0 0 .02381 0 .04125 .002
  GW 2 7 .02381 0 .04125 0 0 .04125 .002
  GR 1 8
  GM 0 0 0. 0. 0. 0. 0. .003
  GM 0 1 180. 0. 0. 0. 0. 0.
  GW 61 3 0 0 -.003 0 0 .003 .002
  GE 0
  EX 0 61 2 0 1.
  FR 0 36 0 0 500. 50.0
  RP 0 73 73 1001 -90. 0 5. 5. 10000.
  XQ
  EN
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