Abstract: A smart antenna system includes: an antenna array including a plurality of antenna elements, and at least one calibration element; a plurality of transceiver units each having a port coupled with an associated one of the antenna elements, a receive port, and a transmit port; a transceiver calibration unit including a port coupled with the calibration element via a coaxial cable, a receive port, and a transmit port; and signal processing means communicatively coupled with each of the receive ports and the transmit ports of each of the transceiver units, and coupled with the calibration receive port and the calibration transmit port of the calibration unit. A transmitter calibration path associated with each antenna element extends from the transmit port of the associated transceiver unit to the associated antenna element, from the associated antenna element to the calibration element, and from the calibration element to the receive port of the calibration unit.

Abstract: A time division duplex switching circuit provides for selectively coupling signals between an antenna and a front stage transceiver circuit. The switching circuit is operative in a transmit mode and in a receive mode, and includes: a transmitter amplifier having an input and an output; a receiver amplifier having an input and an output; a first circulator including a first port coupled for communication with the front stage transceiver, a second port selectively coupled with the output of the receiver amplifier via a first switching, and a third port selectively coupled with the input of the transmitter amplifier via a second switching; and a second circulator including a first port coupled for communication via the antenna, a second port coupled with the input of the receiver amplifier, and a third port coupled with the output of the transmitter amplifier.