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Indian Journal of Radio & Space Physics (IJRSP) >
IJRSP Vol.40 [2011] >
IJRSP Vol.40(3) [June 2011] >
| Title: | Frequency switching of electrically small patch antenna using metamaterial loading |
| Authors: | Joshi, J G
Pattnaik, Shyam S
Devi, S
Lohokare, M R |
| Keywords: | Electrically small antenna (ESA)
Planar metamaterial
Negative permeability metamaterial
Spilt ring resonator (SRR)
Frequency switchable metamaterial loaded small antenna |
| Issue Date: | Jun-2011 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 84.40.Ba |
| Abstract: | A frequency switchable
planar metamaterial loaded electrically small microstrip patch antenna, capable
of resonating at different frequencies by varying the loading distance, has
been presented in this paper. The rectangular microstrip patch antenna is
loaded with planar metamaterial square spilt ring resonators (SRRs) in three
different configurations at a distance of 0.25, 0.50 and 0.75 mm, respectively to
get the switchable resonant frequency performance. The square SRRs reveals
negative permeability ( ) presenting the single negative metamaterial (SNG)
characteristics. The unloaded rectangular microstrip patch antenna resonates at
23 GHz. In loading condition at different distances, the rectangular microstrip
patch antenna resonates at 9.61, 9.51 and 9.41 GHz, respectively. Using Chu
limit, size of the antenna, that is ka, reaches 0.766, 0.775 and 0.787
in respective configurations, thus, satisfies the condition ka <1 for
electrically small antenna. The resonant frequency of rectangular microstrip
patch antenna decreases with respect to the loading distance due to magnetic
coupling. As the loading distance gets reduced, the mutual inductance increases
resulting in enhancement of the bandwidth of the antenna. In these three
loading conditions, the radiation quality factor (Qrad) is
larger than the minimum Q that is Qchu. The
directivity is more than
7.50 dBi in the presented configurations of electrically small rectangular
microstrip patch antenna. |
| Page(s): | 159-165 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.40(3) [June 2011]
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