Patch antennas

The incorporation of lossy and frequency-dependent materials in the production of modern devices, such as patch antennas, waveguides, or integrated circuits, has become a topic of intensive studies due to several attractive properties. Toward this direction, Yee s algorithm has already received the suitable modifications to cope with lossy [1-4] and dispersive configurations [5-19]. Given the competence of higher order schemes in material simulation, a possible... 

The first applications involve two broadband dual-polarized patch antennas. Figure 8.4(a) describes the former structure fed by a capacitatively coupled and an H slot-coupled feed. 

FIGURE 8.4 (a) Geometry of a dual-polarized circular patch antenna and (b) its return loss for port 2... 

K.-L. Wong and T.-W. Chiou, Broad-band dual-polarized patch antennas fed by ca-pacitatively coupled feed and slot-coupled feed, IEEE Trans. Antennas Propagat., vol. 50, pp. 346-351, Mar. 2002.doi 10.1109/8.999625... 

In this test five IEEE802.1 Ig Cisco Aironet 1,200 Access Points, with 6.5 dBi patch antennas, were used. These are the same Access Points and antennas used in our University in the eduroam wireless network. In these tests the APsnot under service. 

Nevertheless, it is not uncommon to encounter presentations that completely ignore the effect of the antenna loads. One paper in particular stands out in my recollection. There the author claimed to have calculated the RCS of a patch antenna. His model was comprised of merely a single patch suspended somewhere in a dielectric slab over an infinite groundplane. No lead-in wire and obviously no loads. When 1 pointed the deficiency out to him he merely shrugged his shoulders and said, OK, but this is so hard to do ( ). (Concerning hard to do, see Appendix D.)... 

Top view of 3D woven E-textile antenna is shown in Eigure 9.6. Conductive patch of stainless steel and U-shaped slot are shown at the top. The challenge inherent to many advanced communication and navigation application is achieving wideband operation from a single antenna. One such antenna architecture that is capable of achieving the types of bandwidth required is the slotted patch antenna. This antenna used a thick substrate ( 1.5 cm) and the U-shaped slot to increase the bandwidth. 

Suitable topologies for the realization of wearable textile antennas exhibit a low profile and compact dimensions. Those features are particularly convenient for on-body placement and seamless integration into garments. For this reason, the majority of existing textile antennas are microstrip or patch antennas. 

Microstrip antennas, often referred to as patch antennas, are very well known and have received remarkable attention during the last four decades, even though the first idea dates back to the 1950s [5]. The success of microstrip and patch antennas is mainly... 

Basically, textile antennas can be subdivided into two categories, those having a ground plane (such as patch antennas) and those without (such as UWB dipoles). In the first case, the effect on performance is very small, since the ground plane acts as an electric shield between the radiating elements of the antenna and the human body. 

In 2008, using the same protective foam as a substrate, Vallozzi et al. [11] proposed a 2.45 GHz patch antenna with dual polarization, allowing to implement polarization diversity using a single, compact, wearable antenna. The antenna, shown in Fig. 26.7, employs a simple nearly square topology with a small slot in the center and with two coaxial feeds positioned symmetrically on the two patch diagonals. This allows the... 

Figure 26.6 Schematic of the tmncated-comer rectangular patch antenna.

Figure 26.7 Realized prototype of dual polarized patch antenna on foam substrate.

In another recent publication by Mishra et al. [32], a wearable dual-band patch antenna with circular polarization is presented, constructed using conductive metalized nylon fabric (ZeU) for patch and ground plane, and a denim substrate. Its circular polarization outperforms linear polarization as it maximizes transmit/receive power, owing to its orientation independence. The topology consists of a modified rectangular slot patch antenna, with a particular L-shaped topology for the feed, with a surrounding... 

The first one is a four-element patch antenna array for off-body communication in the 60 GHz band. The antenna radiating elements were fabricated by laser cutting a 0.07-mm-thick flexible copper foil, deployed on a cotton substrate with a Shieldlt ground plane. Antenna performance was experimentally tested in free space and in... 

L. Vallozzi, H. Rogier, C. Hertleer, Dual polarized textile patch antenna for integration into protective garments, IEEE Antenn. Wireless Propag. Lett. 7 (2008) 440—443. 

F. Boeykens, L. Vallozzi, H. Rogier, Cylindrical bending of deformable textile rectangular patch antennas, Int. J. Antenn. Propag. (2012) 11. 

K. Koski, E. Lohan, L. Sydanheimo, L. Ukkonen, Y. Rahmat-Samii, Electro-textile UHE RFID patch antennas for positioning and localization applications, in IEEE RFID Technology and Applications Conference (RFID-TA), September 2014. 

S. Chen, T. Kaufmann, C. Fumeaux, Wearable textile microstrip patch antenna for multiple ISM band communications, in 2013 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2013. 

Kiely, E. Washington, G. and Bernhard, J. Design and development of smart microstrip patch antennas. Smart Mater. Struct., 7 (1998), pp. 792-800... 

Shakhtour, H., Heberling, D., Breckenfelder, C., 2013. Fiber-reinforced polymer based patch antenna for automotive and avionic applications. In 35th ESA Antenna Workshop on Antenna and Free Space RF Measurements, 10-13 September 2013. ESTC, Noordwijk, The Netherlands. 

Several RF devices were fabricated (see Figure 10.6) using the above process. They include a 50-microstrip line, a patch antenna, a 4-by-l antenna array with feed network, and a spiral antenna. We note that all these structures remained intact after repetitive flexing and stretching. 

Figure 10.6 Various fabricated RF patterns using textiles on PDMS substrate textile transmission Une, patch antennas, and spiral antenna.

To demonstrate the RF performance of textile antennas, sample patch antennas are fabricated for experimental verification on both planar and curved surfaces (Wang et al., 2012b). Measurements showed that the RF performance of the E-fiber patch antennas on polymer substrate is as good as that of their copper counterparts. 

Figure 10.17 Textile patch antenna and its RF performances (a) on a planar surface and (b) mounted on a cylindrical surface.

Vallozzi, L., Rogier, H., Hertleer, C., 2009. A textile patch antenna with dual polarization for rescue workers garments. In Presented at European Conference on Antennas Propagation, Berlin, Germany. 

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