Frequency, Radiation Pattern and Polarization Reconfigurable Antenna Using a Parasitic Pixel Layer
This communication presents a reconfigurable antenna capable of independently reconfiguring the operating frequency, radiation pattern and polarization. A switched grid of small metallic patches, known as pixel surface, is used as a parasitic layer to provide reconfiguration capabilities to existing antennas acting as driven element. The parasitic pixel layer presents advantages such as low profile, integrability and cost-effective fabrication. A fully operational prototype has been designed, fabricated and its compound reconfiguration capabilities have been characterized. The prototype combines a patch antenna and a parasitic pixel surface consisting of 6 x 6 pixels, with an overall size of 0.6 lambda x 0.6 lambda and 60 PIN-diode switches. The antenna simultaneously tunes its operation frequency over a 25% frequency range, steers the radiation beam over +/- 30 degrees in E and H-planes, and switches between four different polarizations ((x) over cap, (y) over cap, LHCP, RHCP). The average antenna gain among the different parameter combinations is 4 dB, reaching 6-7 dB for the most advantageous combinations. The distance between the driven and the parasitic layers determines the tradeoff between frequency tuning range (12% to 25%) and radiation efficiency (45% to 55%).