Implementation and experimental verification of a millimeter wave smart antenna system

By introducing a wide unlicensed frequency spectrum in the millimeter wave band, FCC has opened an avenue for the communication systems with data rates in Gb/s range. This band presents an unprecedented 2 GHz unlicensed band available throughout the world. On the other hand, developing communication systems operating at these frequencies involves challenges such as high path loss, high antenna directivity, human shadowing, and unavailability of high-gain circuit elements. Use of very high gain antennas is required to overcome the extensive path loss as the output power is limited by the circuit technology. Smart antennas provide very high gain and narrow beams by employing multiple antennas and adaptively focusing the energy in the desired direction. In this paper we present a 2-channel smart-antenna system operating at millimeter wave band which can be used with an antenna switching system to improve the signal power performance and to eliminate the transmitter receiver alignment problem.