In this presentation slide, you can discover about Model, Design and Application of Bi-conical Antenna

1. Biconical Antenna
Antenna and Propagation
By :

2. WHY BICONNICAL ANTENNA ?
• Since 2002, the Federal Communication Commission (FCC)
regulated the frequency band from 3.1-10.6 GHz for low-
powered ultra-wideband (UWB) wireless communication [1].
• UWB's combination of larger spectrum, lower power and
pulsed data improves speed and reduces interference with
other wireless spectra.
• Based on the Regulation for UWB communications, one of the
most crucial components is the antenna.
• Biconical antenna configuration is one of many configurations
[2]-[4] that can be used to achieve broadband characteristics.

3. DESIGN OF BICONNICAL ANTENNA
The configuration of a biconical
antenna fed by coaxial cable is shown
in Fig. 1.
The one length is l, cone top radius is
𝑙 · sin(𝛼/2) , cone bottom radius is the
radius of the coaxial cable, flare angle
between the two cones is Ψ .
The upper and lower cones are
symmetrical.
The cones are excited symmetrically at
the apices with the feed gap g.

4. INPUT IMPEDANCE
The input impedance of the antenna with conical length / and
cone angle as given by Papas and King [5] is
𝑍𝑖𝑛 = 𝑍0
1−𝛽/𝛿
1+𝛽/𝛿
where 𝑍0 = 60𝑙𝑛 × 𝑐𝑜𝑡
∝
4
𝛽
𝛿
= 𝑒−2𝑗𝑘𝑙
1 + 𝑗
60
𝑍0
𝑛=1
∞ 2𝑛 + 1
𝑛 𝑛 + 1
𝑃𝑛 cos
∝
2
2
𝜉 𝑛(𝑘𝑙)
−1 + 𝑗
60
𝑍0
𝑛=1
∞ 2𝑛 + 1
𝑛 𝑛 + 1
𝑃𝑛 cos
∝
2
2
𝜉 𝑛(𝑘𝑙)
And 𝜉 𝑛 𝑘𝑙 =
ℎ 𝑛
2
(𝑘𝑙)
ℎ 𝑛−1
2
𝑘𝑙 −
𝑛
𝑘𝑙
ℎ 𝑛
2
(𝑘𝑙)

5. INPUT IMPEDANCE
Where :
𝑘 =
2𝜋
𝜆
, 𝜆 : wavelength in free-space,
𝑍0 : Characteristic impedance of the antenna,
𝑃𝑛 : Legendre polynomial of order n, (4)
𝜉 𝑛(𝑘𝑙) : complex auxiliary function of the real variable kl,
ℎ 𝑛
2
: spherical Hankel function of the 2nd kind,
𝛽
𝛿
: ratio of reflected and outwardly propagating TEM
wave in antenna region.

6. RADIATION PATTERN
𝑅 𝜃 =
𝐸 𝜃(𝑟, 𝜃)
𝐸 𝜃(𝑟, 90 𝜊)
=
𝑛=1
∞
𝑃
𝑛 cos
𝛼
2 𝑃 𝑛
1(cos 𝜃)
ℎ 𝑛−1
2
(𝑘𝑙−
𝑛
𝑘𝑙
)ℎ 𝑛
2
(𝑘𝑙)
2𝑛+1
𝑛(𝑛+1)
𝑗2
𝑛=1
∞
𝑃
𝑛 cos
𝛼
2 𝑃 𝑛
1(0)
ℎ 𝑛−1
2
(𝑘𝑙−
𝑛
𝑘𝑙
)ℎ 𝑛
2
(𝑘𝑙)
2𝑛+1
𝑛(𝑛+1)
𝑗2
where 𝑃𝑛
1cos(𝜃) =
−𝑑𝑃 𝑛(𝑐𝑜𝑠 𝜃)
𝑑𝜃
and the
summation is over odd integral.
The antenna was
considered to be an
isolated source in free-
space with azimuthally
independent radiation
in the H-plane. The E-
plane far-field radiation
pattern normalized to
the field at broadside
(𝜃 = 90 𝜊) has been
analyzed by Papas and
King [6], is

7. RADIATION CHARACTERISTICS
1) Azimuth radiation patterns:
from the antenna configuration (Fig. 1)
exhibiting rotational symmetry (around z-axis),
hence the radiation characteristic would also be
symmetrical (omni-directional) in the azimuth
(H-) plane (Fig. 13) [8]-[10].

8. RADIATION CHARACTERISTICS
2) Elevation radiation patterns:
From the simulation results ( by 2011 International Symposium on Intelligent
Signal Processing and Communication Systems (ISPACS) ) at different flare
angles Ψ (100°, 80°, 60°, 40°, and 20°), for the fixed cone length l equals
one wavelength of the center frequency (𝜆 𝑓−𝑐𝑒𝑛 ,𝑓 − 𝑐𝑒𝑛 = 7 GHz), feed gap
g 0.5 mm, brass conductivity σ 2.57 x 107 S/m, and at minimum frequency
2 GHz; it was noticed (Fig. 2) that the (E-plane) radiation patterns were
bidirectional towards the broadside direction. The beam width became
wider with respect to the narrower flare angle of the antenna.

9. RADIATION CHARACTERISTICS
Radiation Pattern when value of minimum frequency range (f=2GHz)
applied to Biconical antenna Design :

10. RADIATION CHARACTERISTICS
Radiation Pattern when center value of frequency range (f=7GHz)
applied to Biconical antenna Design :

11. RADIATION CHARACTERISTICS
Radiation Pattern when Maximum value of frequency range (f=7GHz)
applied to Biconical antenna Design :

12. RADIATION CHARACTERISTICS
Comparation of
Radiation Pattern
at different
cone length

13. RETURN LOSS

14. RETURN LOSS

15. RETURN LOSS

16. GAIN

17. PHYSICAL DESIGN OF BICONNICAL ANTENNA

18. REFERENCES
[1] First Report and Order in the Matter of Revision of Part 15 of the Commission's Rules Regarding Ultra-Wideband
Transmission Systems, Released by Federal Communications Commission ET-Docket, pp_ 98-153, 2nd Apr. 2002_
[2] C. Yu, W_ Hong, L. Chiu, G_ Zhai C. Yu, W. Qin, and Z. Kuai, "Ultrawideband printed Log-Periodic dipole antenna
with multiple notched bands," IEEE Trans. Antennas Propagat, vol. 59, pp. 725-732, Mar. 2001.
[3] P_ Jirasakulporn and P. Akkaraekthalin, "A conpact ultra-wideband rectanllli lar slot antanna tuned with T -shape fractal
stub," Electrical Engineering Conference-32, vol. 2, pp. 785-788, Oct 2009_ Prachinburi. Thailand_
[4] H. Schantz, The Art and Science of Ultrawideband Antennas, Artech House Publishers, 2005_
[5] C. H. Papas and R. W_ P_ King, "Input impedance of wide angle conical antennas fed by a coaxial line," Proc_ IRE, vol. 37,
pp_ 1269-1271, Nov_
1949.
[6] C. H. Papas, and R. W. P_ King, "Radiation from wide-angle conical antennas fed by a coaxial line," Proc. IRE , vol. 39,
pp.49-51, Jan. 1951.
[7] CST Microwave Studio, User's Manual, 2011.
[8] S_ S. Sandler and R. W_ P. King, "Compact conical antenna for wideband coverage," IEEE Trans Antennas Propagat, vol.
42, no 3, pp. 436-439, Mar_ 1994_
[9] S_ N_ Samadder and E. L. Mokole, "Biconical antenna with unequal cone angles," IEEE Trans_ Antennas Propagat, vol.
46, no 2, pp_ 181-192, Feb_ 1998_
[10] C. Ghosh and T. K. Sarkar, "Design of a wide-angle biconical antenna for wideband communications," Progress in
Electromagnetics Research B, vol. 16, pp_ 229-245, 2009_
[11] H. T_ Friis, "A note on a simple transmission fonnula," Proc_ IRE, vol. 34, no 5, pp_ 254-256, May 1946_