Reconfigurable antenna

Reconfigurable antenna using a pixel architecture capable of reconfiguring dynamically its frequency of operation, radiation pattern and polarization.^[1]

A reconfigurable antenna is an antenna capable of modifying dynamically its frequency and radiation properties in a controlled and reversible manner.^[2] In order to provide a dynamical response, reconfigurable antennas integrate an inner mechanism (such as RF switches, varactors, mechanical actuators or tunable materials) that enable the intentional redistribution of the RF currents over the antenna surface and produce reversible modifications over its properties. Reconfigurable antennas differ from smart antennas because the reconfiguration mechanism lies inside the antenna rather than in an external beamforming network. The reconfiguration capability of reconfigurable antennas is used to maximize the antenna performance in a changing scenario or to satisfy changing operating requirements.

Types of antenna reconfiguration

Reconfigurable antennas can be classified according to the antenna parameter that is dynamically adjusted, typically the frequency of operation, radiation pattern or polarization.^[3]

Frequency reconfiguration

Frequency reconfigurable antennas can adjust dynamically their frequency of operation. They are particularly useful in situations where several communications systems converge because the multiple antennas required can be replaced by a single reconfigurable antenna. Frequency reconfiguration is generally achieved by modifying physically or electrically the antenna dimensions using RF-switches,^[4] impedance loading^[5] or tunable materials.^[6]

Radiation pattern reconfiguration

Radiation pattern reconfigurability is based on the intentional modification of the spherical distribution of radiation pattern. Beam steering is the most extended application and consists in steering the direction of maximum radiation to maximize the antenna gain in a link with mobile devices. Pattern reconfigurable antennas are usually designed using movable/rotatable structures^[7][8] or including switchable and reactively-loaded parasitic elements.^[9][10][11]

Polarization reconfiguration

Polarization reconfigurable antennas are capable of switching between different polarization modes. The capability of switching between horizontal, vertical and circular polarizations can be used to reduce polarization mismatch losses in portable devices. Polarization reconfigurability can be provided by changing the balance between the different modes of a multimode structure.^[12]

Compound reconfiguration

Compound reconfiguration is the capability of simultaneously tuning several antenna parameters, for instance frequency and radiation pattern. The most common application of compound reconfiguration is the combination of frequency agility and beam-scanning to provide improved spectral efficiencies. Compound reconfigurability is achieved by combining in the same structure different single-parameter reconfiguration techniques^[13][14] or by reshaping dynamically a pixel surface.^[1][15]

See also

• Antennas
• RF MEMS
• Beam steering
• Smart antenna

References

1. Rodrigo, D.; Cetiner, B.A.; Jofre, L. (2014). "Frequency, Radiation Pattern and Polarization Reconfigurable Antenna Using a Parasitic Pixel Layer". IEEE Trans. Antennas Propag. 62 (6). doi:10.1109/TAP.2014.2314464.
2. J.T. Bernhard. (2007). Reconfigurable Antennas. Morgan & Claypool Publishers. doi:10.2200/S00067ED1V01Y200707ANT004.
3. G.H. Huff and J.T. Bernhard. (2008). "Reconfigurable Antennas". In C.A. Balanis. Modern Antenna Handbook. John Wiley & Sons.
4. Panagamuwa, C.J.; Chauraya, A.; Vardaxoglou, J.C. (2006). "Frequency and beam reconfigurable antenna using photoconducting switches". IEEE Trans. Antennas Propag. 54 (2). doi:10.1109/TAP.2005.863393.
5. Erdil, E; Topalli, K; Unlu, M; Civi, O; Akin, T (2007). "Frequency tunable microstrip patch antenna using RF MEMS technology". IEEE Trans. Antennas Propag. 55 (4). doi:10.1109/TAP.2007.893426.
6. Liu, L.; Langley, R. (2008). "Liquid crystal tunable microstrip patch antenna". Electronics Letters. 44 (20). doi:10.1049/el:20081995.
7. Chiao, J.C.; Fu, Y.; Chio, I.M.; DeLisio, M.; Li, L.Y. (1999). "MEMS reconfigurable vee antenna". IEEE MTT-S International Microwave Symposium. 4. doi:10.1109/MWSYM.1999.780242.
8. Rodrigo, D.; Jofre, L.; Cetiner, B.A. (2012). "Circular Beam-Steering Reconfigurable Antenna With Liquid Metal Parasitics". IEEE Trans. Antennas Propag. 60 (4). doi:10.1109/TAP.2012.2186235.
9. Aboufoul, T.; Parini, C.; Chen, X.; Alomainy, A. (2013). "Pattern-Reconfigurable Planar Circular Ultra-Wideband Monopole Antenna". IEEE Trans. Antennas Propag. 61 (10). doi:10.1109/TAP.2013.2274262.
10. Harrington, R.F. (1978). "Reactively controlled directive arrays". IEEE Trans. Antennas Propag. 26 (3). doi:10.1109/TAP.1978.1141852.
11. Hum, S.V.; Perruisseau-Carrier, J. (2014). "Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review". IEEE Trans. Antennas Propag. 62 (1). doi:10.1109/TAP.2013.2287296.
12. Simons, R.N.; Donghoon, C.; Katehi, L.P.B. (2002). "Polarization reconfigurable patch antenna using microelectromechanical systems (MEMS) actuators". IEEE Antennas Propag. Soc. Int.Symp. 2. doi:10.1109/APS.2002.1016015.
13. X.S., Yang; Wang, B.Z.; Wu, W.; Xiao, S. (2007). "Yagi Patch Antenna With Dual-Band and Pattern Reconfigurable Characteristics". IEEE Antennas Wireless Propag. Lett. 6. doi:10.1109/LAWP.2007.895292.
14. Aboufoul, T.; Chen, X.; Parini, C.; Alomainy, A. (2014). "Multiple-parameter reconfiguration in a single planar ultra-wideband antenna for advanced wireless communication systems". IET Microwaves, Antennas & Propagation. 8 (11). doi:10.1049/iet-map.2013.0690.
15. Pringle, L.N.; et al. (2004). "A reconfigurable aperture antenna based on switched links between electrically small metallic patches". IEEE Trans. Antennas and Propag. 52 (6). doi:10.1109/TAP.2004.825648.