What is a discone antenna?
A discone antenna consists of a horizontal disk fed by the coax center conductor, mounted above the apex of a cone connected to the shield. Introduced by Armig Kandoian in 1946, it provides vertically polarized, omnidirectional radiation and an acceptable match over a wide frequency range, often several octaves above a lower cutoff where the cone slant length is about λ/4.[1][2]
How is a discone dimensioned?
Common design rules put the cone slant length near a quarter wavelength at the lowest frequency, the total cone apex angle around 60°, and the disk diameter around 0.7 of the cone’s base diameter, with a small disk–cone gap. Dimensions are then refined by simulation or measurement.[2][3]
What are its strengths and weaknesses?
Strengths: broad impedance bandwidth, omnidirectional pattern, simple coax feed. Weaknesses: modest gain (roughly that of a dipole), elevation pattern that tilts and develops lobes at the upper end of the band, and size at low frequencies.[2]
Where are discones used?
Wideband scanning receivers, spectrum monitoring, EMC site surveys and aircraft (as blade and biconical derivatives).[3]
Frequently asked questions
Can a discone transmit?
Yes, within its matched band, subject to regulations.
Is a discone the same as a biconical?
Related: a biconical uses two cones; a discone replaces one cone with a disk.
Why does the pattern tilt at high frequency?
The cone becomes many wavelengths long, changing the current distribution.
See also
References
Online sources accessed October 21, 2026; printed works cited by edition. See all sources.
- “Three New Antenna Types and Their Applications”. A. G. Kandoian, Proceedings of the IRE, vol. 34, no. 2. February 1946.
- “Antennas for All Applications, 3rd ed.”. J. D. Kraus and R. J. Marhefka, McGraw-Hill. 2002.
- “Antenna Engineering Handbook, 4th ed.”. J. L. Volakis (ed.), McGraw-Hill. 2007.