Textile antennas radiation patterns

For textile antennas without a ground plane, the presence of the human body produces substantial effects on the antenna performance because it acts as an absorber for the radiated field and represents an additional loading. This mainly alters the antenna input impedance and efficiency. Radiation patterns also change with respect to the free-space situation the human body acts as a lossy reflector, making the radiation pattern more directional in the off-body direction. An example of such a behavior, on a wearable antenna without ground plane, is shown in Fig. 26.5, where the on-body and free-space horizontal pattern of a wearable UWB monopole antenna on a polyi-mide substrate (realized by the EM group of Ghent University), are compared. 

Figure 10 0 Wearable textile antenna sewn on a cotton shirt, and measured radiation patterns of the textile and copper antennas at 600 MHz for different on-body locations (Wang et al.,...

Figure 10.22 (a) Embroidered multiband textile antenna using E-fibers, and measured and simulated RF performance of the textile antenna in free space (b) Sll, (c) realized gain, and (d) radiation patterns. 

Figure 10.23 Measured and simulated radiation pattern of the multiband textile antenna in free space.

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