A miniaturized annular ring slot antenna is presented. The antenna consists of an annular ring slot structure and a novel folded matching structure. The annular ring slot structure is printed on a substrate and shorted concentrically with a set of conductive vias. The additional matching structure is a ring cavity attached to the back of the annular ring slot structure. Firstly, the diameter of the proposed antenna is reduced by using the folded matching structure comparing with traditional annular ring slot antennas. Secondly, the impedance matching of the proposed antenna is achieved by optimizing the size of the matching structure. A prototype of the proposed antenna with a height of 3.048 mm (0.03λ) and a radius of 47.2 mm (0.4λ) is designed, fabricated and measured. The antenna resonates at 2.67 GHz and has a monopole-like radiation pattern, which shows that the antenna is suitable for the applications of taking off, landing, and long distance communications for a small or mini UAV.
2. Sun, B. H., Y.-F. Wei, S. G. Zhou, and Q. Z. Liu, "Low-profile and horizontally-polarised antenna for UAV applications," Electron. Lett., Vol. 45, 1106-1107, 2009.
doi:10.1049/el.2009.2218
3. Jacobs, I. S., C. P. Bean, D. M. Kokotoff, R. B. Waterhouse, and J. T. Aberle, "An annular ring coupled to a shorted patch," IEEE Trans. Antenna Propag., Vol. 45, 913-920, May 1997.
4. Sharawi, M. S., M. Ibrahim, S. Dief, and D. N. Aloi, "A planar printed antenna array embedded in the wing structure of a UAV for communication link enhancement," Progress In Electromagnetic Research, Vol. 138, 697-715, 2013.
doi:10.2528/PIER13021808
5. Sharawi, M. S., D. N. Aloi, and O. A. Rawashdeh, "Design and implementation of embedded printed antenna arrays in small UAV wing structures," IEEE Transactions on Antennas and Propagation, Vol. 58, No. 8, 2531-2538, Aug. 2010.
doi:10.1109/TAP.2010.2050440
6. Balanis, C. A., Antenna Theory: Analysis and Design, Wiley, New York, 1997.
7. Hong, W. and K. Sarabandi, "Low-profile, multi-element, miniaturized monopole antenna," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 1, Jan. 2009.
doi:10.1109/TAP.2008.2009731
8. Johnson, R. C. and H. Jasik, Antenna Engineering Handbook, McGraw-Hill, New York, 1984.
9. Nikolic, N., J. S. Kot, and T. S. Bird, "Theoretical and experimental study of a cavity backed annular-slot antenna," IEEE Proc. — Microw. Antenna Propag., Vol. 144, No. 5, Oct. 1997.
10. Galejs, J. and T. W. Thompson, "Admittance of a cavity-backed annular slot antenna," IRE Tran. Antennas Propagat., Vol. IO, 671478, Nov. 1962.
11. Patrovsky, A. and R. Sekora, "Structural integration of a thin conformal annular slot antenna for UAV applications," Loughborough Antenna & Propagation Conference, 229-232, 2010.
12. Weiner, M. M., Monopole Antennas, CRC Press, 2003.
doi:10.1201/9780203912676
Submit
