A Unidirectional, Printed Antenna With High Interport Isolation Over Wider Bandwidth for 2.4 GHz Full Duplex Applications

Antenna/Propagation Domain Self-Interference Cancellation (SIC) for In-Band Full-Duplex Wireless Communication Systems

“…In [17,[49][50][51][52], by employing power dividers [53] with 180° phase shift or hybrid couplers in the feed networks, the SI is further attenuated because they create two coupling paths with out-of-phase signals that cancel with each other to some extent. As shown in Figure 8, two patch antennas with orthogonal polarizations are designed in [54], i.e., one is fed unbalanced and the other is fed differentially with a 3 dB coupler, leading to an ultra-high SIC of 80 dB in the AP domain. To provide an intuitive understanding of the capability of this method, Table 1 summarizes some state-of-the-art IBFD antennas based on polarization orthogonality.…”

Design Optimization of Feeding Networks with a Special Size for Self-Interference Cancellation

“…In addition to using self-interference cancellation (SIC) techniques at the analog and digital stages [3][4][5][6], high isolation at the antenna stage is essential to avoid deterioration of the signal-to-noise ratio (SNR). In general, at least 80 dB isolation should be achieved at the antenna stage [7]. And higher isolation is of benefit to decrease the complexity and requirements of analog and digital stages.…”