Embedded Files
Background:
Despite the small distance between its ears, a female Ormia ochracea has a remarkable ability to locate male field crickets . Experimental research in [1] explains that this ability arises from the mechanical coupling between the Ormia's ears (Fig. 1) modeled as a system consisting of spring and dashpots. For more details please click here.
Figure1: Top: front view of the female Ormia’s ear after the head was removed. Bottom: mechanical model [1].
Our Research:
We proposed a beampattern design approach to achieve high performance with small-aperture arrays inspired by the Ormia’s coupled ears [2], [3]
- Solved the second order differential equations governing the Ormia’s ear response.
- Designed the biologically inspired coupling (BIC) by converting the ear response to fit the desired radio frequencies.
- Applied the BIC to the array factor of a uniform linear array.
- Included the effect of the undesired electromagnetic coupling among the antennas due to their proximity, in the array factor.
- Proposed an algorithm to optimally choose the BIC for maximum radiation performance.
The improvement in the half-power beamwidth, sidelobe suppression and directivity of the radiation pattern proves that the BIC improves the radiation performance of the antenna array.
Figure 2: Power patterns of the uniform ordinary end-fire arrays using standard (blue) and BIC (green) for (a) d=0.1λ , (b) d=0.25λ interelement spacings. Bottom halves of the figures present the half-power beamwidth
Figure 3: Power patterns of the binomial ordinary end-fire arrays using standard (blue) and BIC (green) for (a) d=0.1λ , (b) d=0.25λ interelement spacings. Bottom halves of the figures present the half-power beamwidth
References:
[1] R. N. Miles, D. Robert, and R. R. Hoy, "Mechanically coupled ears for directional hearing in the parasitoid fly Ormia ochracea," J. Acoust. Soc. Am., vol. 98, no. 6, pp. 3059-3070, 1995
[2] M. Akcakaya and A. Nehorai, "Biologically Inspired Coupled Antenna Beampattern Design" Bioinspiration and Biomimetics, .5, no.4, p.046003, 2010.
[3] M. Akcakaya and A. Nehorai, "Biologically inspired coupled beampattern design" Proc. IEEE 5th Int. Waveform Diversity and Design Conf., Niagara Falls, Canada, Aug. 8-13 2010, pp. 48-52.
Google Sites
Report abuse