An Omnidirectional and Low-VSWR Ultra Wideband Antenna for a Frequency Band of 6 to 40 GHz

  • Akihide Maeda
  • Takehiko Kobayashi

We have proposed an omnidirectional-in-azimuth, low voltage-standingwave-ratio (VSWR), and easy-to-construct antenna for ultra-wideband (UWB) systems. Omnidirectional and low-VSWR requirements are essential for applications such as UWB channel sounding. The proposed antenna consists of a circular ground plane and a teardrop that is defined as a combination of a finite cone and a sphere inscribed inside the cone at the cone’s base. This antenna can be considered either as a rounded finite monocone antenna or as a simplified volcano smoke antenna. Assuming 50-Ω excitation, the optimum half-cone angle is 48°which gives the lowest maximum VSWR. Following a prototype in the frequency band of 3 to 20 GHz, we constructed the 6 -40 GHz version. The teardrop was 12.5 mm high (the quarter wavelength at 6 GHz) and ground plane was 50 mm in diameter (significantly larger than any quarter wavelength in the designated bandwidth for 6 -40 GHz). The teardrop is connected to the inner conductor of the coaxial cable that penetrates the ground plane. The tip of the inner conductor of a K connector was inserted into the apex of the teardrop.


Ground Plane Group Delay Vector Network Analyzer Quarter Wavelength Absolute Gain 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    K. Haneda, J. Takada, and T. Kobayashi, A parametric UWB propagation channel estimation and its performance validation in an anechoic chamber, IEEE Trans. Microwave Theory and Tech., 54(4) pp.1802-1811, (2006).CrossRefGoogle Scholar
  2. 2.
    J. D. Kraus, Antennas, 2nd ed. (McGraw-Hill, New York, 1988) pp.340-358 and 692-694.Google Scholar
  3. 3.
    H. Schantz, The Art and an Sience of Ultrawideband Antennas, (Artech House, Boston, 2005).Google Scholar
  4. 4.
    T. Taniguchi, and T. Kobayashi, An Omnidirectional and low-VSWR antenna for ultra-wideband wireless systems, Proc. of 2002 IEEE Radio and Wireless Conf. (RAWCON 2002), pp.145-148, (2002).Google Scholar
  5. 5.
    T. Taniguchi, A. Maeda, and T. Kobayashi, Development of An omnidirectional and low-VSWR Ultra wideband antenna, Int. Journal on Wireless and Optical Comms., to be published.Google Scholar
  6. 6.
    T. Taniguchi, and T. Kobayashi, An omnidirectional and low-VSWR antenna for the FCC-approved UWB frequency band, Proc. of IEEE Int. Antennas and Propag. Symp. Digest, 3, pp.460-463, (2003).Google Scholar
  7. 7.
    A. C. Newell, C. F. Stubenrauch, and R. C. Baird, Calibration of microwave antenna gain standards, Proc. IEEE, 74, pp.129-132, (1986).CrossRefGoogle Scholar
  8. 8.
    K. Haneda, J. Takada, and T. Kobayashi, Double directional ultra wideband channel characterization in a line-of-sight home environment, IEICE Trans. Fundamentals, E88-A(9) pp.2264-2271, (2005).CrossRefGoogle Scholar
  9. 9.
    A. Maeda, and T. Kobayashi, A performance comparison of various ultra wideband antennas using the 3-antenna method, Proc. of 2004 Antenna Applications Symp., (2004).Google Scholar
  10. 10.
    T. Barts, et al., Maxwell’s grid equations, Frequenz, 44(1), pp.9-16, (1990).Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Akihide Maeda
    • 1
  • Takehiko Kobayashi
    • 1
  1. 1.Wireless System LaboratoryTokyo Denki UniversityChiyoda-kuJapan

Personalised recommendations