Integrated active antenna with full duplex operation

This paper discusses the design and implementation of a novel two-element active transmit-receive array using dual linear polarization and sequential rotation. Each element includes an integrated oscillator and amplifier mounted on orthogonal edges of a square patch, such that the transmit and receive paths are isolated and polarization duplexed. The array gives in excess of 45-dB transmit-receive isolation with an output power of 5.4 dBm and a receive gain of 8.2 dB at 4.05 GHz. Link budget calculations are used to show expected system performances. These active antennas have potential uses in both short-range communication and radar systems.