Advanced Antenna Miniaturization Techniques for Low-Power, Broadband and Diversity Wireless Systems.

Small Antennas;Radiation Efficiency;Polarization Purity;Bandwidth;Radiation Pattern;Antenna Diversity;Electrical Engineering;Engineering;Electrical Engineering

Oh, JungsuekMichielssen, Eric ;

University of Michigan

关键词: Small Antennas;    Radiation Efficiency;    Polarization Purity;    Bandwidth;    Radiation Pattern;    Antenna Diversity;    Electrical Engineering;    Engineering;    Electrical Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/95991/jungsuek_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Nowadays miniaturized low-power electronics and wireless devices are ubiquitous in everyday life. However, there is still significant interest to further reduce size, lower the power and improve data rate required by such systems. For such goals, antennas still constitute a major bottleneck in terms of size, efficiency, polarization and radiation pattern. Also for many near ground applications, low profile small antennas with vertical polarization are needed to achieve much lower propagation path loss.Conventional approaches to reduce the height of monopole antennas cause significant drop in efficiency and polarization purity. Two novel miniaturization techniques are presented for different levels of size reduction (λ/300 < h < λ/45 where h is antenna height). For h ≈ λ/45, a novel inductively coupled capacitively loaded antenna topology is presented, which enables up to 9dB higher gain than the conventional inverted-F antenna with a small ground plane. For extremely short monopole antennas with h ≈ λ/300, an in-phase two-element monopole antenna topology is demonstrated, which exhibits 16.5 dB higher gain than the conventional inverted-F antenna having the same dimensions. Also, radiation pattern deformation caused by low profile configurations on a small ground plane is addressed and, to solve this problem, novel designs using vertically and horizontally balanced architectures are introduced. For GPS or mobile platforms where the aforementioned miniaturized antennas with vertical polarization cannot provide reliable communication connectivity, a new miniaturization technique is presented to reduce the size of circularly polarized (CP) patch antennas. 75% size reduction is achieved compared to a conventional CP patch antenna and it is 25% smaller than the smallest CP patch antenna reported in the literature. Lastly, a novel approach to combine the miniaturized monopole and patch antenna elements into a compact common aperture diversity antenna is presented for MIMO applications. This achieves a compact size of 0.27λ X 0.27λ X 0.09λ and low envelop correlation (<-30dB) between radiation patterns of two antenna elements composing the diversity antenna.