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BiCone Antenna

Nov 3rd 2017, 09:27

WB2LYL

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Hi All,

A BiCone Antenna is essentially a dipole antenna that has a very broad frequency bandwidth. The impedance of the BiCone Antenna is determined by the angle between the radiating elements.

Technical descriptions of the BiCone Antenna state:
"The biconical antenna has a broad bandwidth because it is an example of a travelling wave structure; the analysis for a theoretical infinite antenna resembles that of a transmission line. For an infinite antenna, the characteristic impedance at the point of connection is a function of the cone angle only and is independent of the frequency."

Can someone help me understand what a traveling wave structure is?

Thanks,
Wayne - WB2LYL
Nov 4th 2017, 15:46

W1VT

Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
A more practical way of creating a traveling wave structure is to terminate the ends of the antenna in resistors and adjust the values of the resistors so that there is no power reflected back toward the source. Such an antenna can be very broadband.

The most common example is a terminated Beverage antenna.

Zack Lau W1VT
ARRL Senior Lab Engineer
Nov 4th 2017, 18:50

WB2LYL

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Zack,
Thanks for your help. Can you further describe how a "traveling wave structure" achieves a broad operating bandwidth? Your help is appreciated.

Wayne
WB2LYL
Nov 4th 2017, 21:36

W1VT

Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
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JAN 1982 - QST (PG. 11)
Classic Beverage Antenna, Revisited, The
Author: Beverage, Harold, W2BML
http://p1k.arrl.org/pubs_archive/75182
Nov 5th 2017, 10:16

WB2LYL

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Thanks again. I will read the paper/article carefully.

Best Regards, 73
Wayne
WB2LYL
Nov 5th 2017, 20:41

W1VT

Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Some people have a better understanding if they can see what happens in real life. Experimenting with a time domain reflectometer may allow to to better visualize some aspects of antennas and transmission lines.

Zack W1VT
ARRL Senior Lab Engineer

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