Design of Helical Antennas for Full-duplex Communication Systems

With the continuing progress of RF technologies and capabilities, multifunction is a key paradigm allowing for efficient use of space and low-cost systems. A critical factor to fully take advantage of multifunction is the use of true full-duplex simultaneous transmit and receive (STAR) without any traditional forms of multiplexing (spatial, time, frequency, polarization). An important consideration for true STAR systems is the first layer of transmit (Tx) and receive (Rx) isolation provided by the antenna front-end. These front-ends can be realized in bistatic configurations where the physical separation and/or high-impedance surfaces separating the Tx and Rx antennas provide the necessary isolation [1] ; a more desirable configuration, however, is the so-called quasi-monostatic configuration where the Tx and Rx antennas share the same footprint.