Design and Application of Biconical Antenna

Design and Application of Biconical Antenna

• 1.
  Biconical Antenna Antenna andPropagation 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 BICONNICALANTENNA 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 inputimpedance 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) Azimuthradiation 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) Elevationradiation 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 Patternwhen value of minimum frequency range (f=2GHz) applied to Biconical antenna Design :
• 10.
  RADIATION CHARACTERISTICS Radiation Patternwhen center value of frequency range (f=7GHz) applied to Biconical antenna Design :
• 11.
  RADIATION CHARACTERISTICS Radiation Patternwhen Maximum value of frequency range (f=7GHz) applied to Biconical antenna Design :
• 12.
  RADIATION CHARACTERISTICS Comparation of RadiationPattern at different cone length
• 13.
  RETURN LOSS
• 14.
  RETURN LOSS
• 15.
  RETURN LOSS
• 16.
  GAIN
• 17.
  PHYSICAL DESIGN OFBICONNICAL ANTENNA
• 18.
  REFERENCES [1] First Reportand 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_