Study of Antenna Miniaturization and Feeding Techniques
STUDY OF ANTENNA MINIATURIZATION AND FEEDING TECHNIQUES
Divya Sharma, Manvi Chandra, Rishi Pahwa, Vishal Madan Abstract:These days, size reduction & bandwidth enhancement are becoming major design considerations for practical applications of antennas. For this reason, studies to achieve compact & broadband operations of microstrip antennas have greatly increased. Much significant progress in the design of compact microstrip antennas with broadband, dual-frequency, dual polarized, circularly polarized, & gain enhanced operations have been reported over the past several years. Extensive research has also been going on to find the best feeding techniques for these antennas. This report aims to study and analyze these antenna miniaturization & feeding techniques. Theory:The most popular technique in reducing the size of a printed antenna is to use a high dielectric constant material for its substrate. In doing so, the guided-wavelength underneath the patch is reduced &, hence the resonating patch size is also reduced.[1] To further reduce the size, slots can be introduced onto the resonating patch. In doing so, the current on the patch or the field underneath the patch will resonate from one edge of the patch & take longer path around the slots to reach the opposite edge. This longer path, in essence, reduces the resonant frequency or the physical size of the antenna.[2] The third technique is to fold the complete single layer patch antenna to form a two-layer structure & hence reduce the planar dimension by half.The various feeding techniques which offer an improved performance for the microstrip patch antenna include (but are not limited to) inset-feed, transformer coupled-feed, inset space-feed, probe-feed, aperture-coupled feed and proximity-coupled feed. [3]Table :Substrate Thichness – 0.05mm Dielectric Constant | Directivity(Db) | Bandwidth | Efficiency | 1.07 | 9.5 | 11.76 | 94% | 2.55 | 7.6 | 8.2 | 91% | 10.2 | 6.7 | 3.4 |
Divya Sharma, Manvi Chandra, Rishi Pahwa, Vishal Madan Abstract:These days, size reduction & bandwidth enhancement are becoming major design considerations for practical applications of antennas. For this reason, studies to achieve compact & broadband operations of microstrip antennas have greatly increased. Much significant progress in the design of compact microstrip antennas with broadband, dual-frequency, dual polarized, circularly polarized, & gain enhanced operations have been reported over the past several years. Extensive research has also been going on to find the best feeding techniques for these antennas. This report aims to study and analyze these antenna miniaturization & feeding techniques. Theory:The most popular technique in reducing the size of a printed antenna is to use a high dielectric constant material for its substrate. In doing so, the guided-wavelength underneath the patch is reduced &, hence the resonating patch size is also reduced.[1] To further reduce the size, slots can be introduced onto the resonating patch. In doing so, the current on the patch or the field underneath the patch will resonate from one edge of the patch & take longer path around the slots to reach the opposite edge. This longer path, in essence, reduces the resonant frequency or the physical size of the antenna.[2] The third technique is to fold the complete single layer patch antenna to form a two-layer structure & hence reduce the planar dimension by half.The various feeding techniques which offer an improved performance for the microstrip patch antenna include (but are not limited to) inset-feed, transformer coupled-feed, inset space-feed, probe-feed, aperture-coupled feed and proximity-coupled feed. [3]Table :Substrate Thichness – 0.05mm Dielectric Constant | Directivity(Db) | Bandwidth | Efficiency | 1.07 | 9.5 | 11.76 | 94% | 2.55 | 7.6 | 8.2 | 91% | 10.2 | 6.7 | 3.4 |
References: [1] R. Garg, P. Bhartia, I. Bahl, A. Ittipiboon, “Microstrip Antenna Design Handbook”, ARTECH HOUSE, Boston 2001.[2] C. A. Balanis, “Antenna Theory, Analysis and Design”, JOHN WILEY & SONS, INC, New York 1997.[3] W. L. Stutzman , G. A. Thiele, “Antenna Theory and Design” , John Wiley &Sons,2nd Edition ,New York, 1998. | Date of submission: 19/11/2012 Guide’s sign: